





Introduction to Physical Therapy and Patient Skills?

CHAPTER 12: Manual Muscle Testing



CHAPTER OBJECTIVES
At the completion of this chapter, the reader will be able to:
1. Understand the importance of manual muscle testing
2. Perform a gross muscle screening of a patient's strength
3. Perform specific manual muscle tests to the shoulder
4. Perform specific manual muscle tests to the elbow
5. Perform specific manual muscle tests to the wrist and forearm
6. Perform specific manual muscle tests to the hand
7. Perform specific manual muscle tests to the hip
8. Perform specific manual muscle tests to the knee
9. Perform specific manual muscle tests to the leg and foot
10. Perform specific manual muscle tests of the trunk
11. Describe the strengths and weaknesses of the various grading systems used with manual muscle testing.
12. Interpret the different results that can be obtained from a manual muscle test.
OVERVIEW

Northeastern University
Access Provided by:



Movement occurs through the interaction between the nervous and musculoskeletal systems. The nervous system provides cognition, perception, and sensory integration and is primarily involved in the control of movement, while the musculoskeletal system provides the power for movement. A basic overview of the neurologic structures is provided in Chapter 4. This chapter provides an overview of the anatomy and physiology of the musculoskeletal system and then describes how the muscular system can be assessed.
GROSS MUSCLE SCREENING
Muscle testing requires that the patient be able to voluntarily control the tension developed in the muscles. A patient with a disorder of the central nervous system who demonstrates spasticity is not an appropriate candidate for muscle testing.
A gross muscle screening is performed on a patient when a quick assessment of the patient's general level of muscle strength is required. If any weakness is found during the gross muscle screening test, a specific muscle test is then performed. It is important to remember that the gross muscle screening does not detail the determination of strength; it only provides the clinician with information as to whether a region of the body is either normal or weak. An example when a gross muscle screening would be used is when the clinician is preparing the patient to get out of a wheelchair and to ambulate using a standard walker the clinician needs to determine whether the patient has sufficient strength to weight bear through the lower extremities and to weight bear through the upper extremities. Regardless of the type of muscle testing used, the procedure is innately subjective and



Downloaded 2024 3 16 1:39 P Your IP is 155.33.135.27 CHAPTER 12: Manual Muscle Testing,
 2024 McGraw Hill. All Rights Reserved. Terms of Use   Privacy Policy   Notice   Accessibility


Page 1 / 164



depends on the subject's ability to exert a maximal contraction. This ability can be negatively affected by such factors as pain, poor comprehension, motivation, cooperation, fatigue, and fear.
The gross muscle testing procedures for each of the main regions of the body are described in Table 12 1. As mentioned, one of the more common gross muscle testing procedures is the one performed by the clinician before gait training with an assisted device when the clinician is not sure of the patient's capabilities. In this scenario, the clinician must efficiently assess the strength of the major muscle groups that are used when using an assistive device. The muscle groups tested include the shoulder abductors (Figure 12 1), the shoulder flexors (Figure 12 2), the shoulder extensors (Figure 12 3), the elbow flexors (Figure 12 4), the elbow extensors (Figure 12 5), the wrist extensors (Figure 12 6), the wrist flexors (Figure 12 7), the hip flexors (Figure 12 8), the knee extensors (Figure 12 9), the knee flexors and hip extensors (the hamstrings) (Figure 12 10), the hip abductors (Figure 12 11), the ankle dorsiflexors (Figure 12 12), and the ankle plantarflexors (Figure 12 13).
TABLE 12 1
Gross Muscle Screening


Patient Position 
Tested Muscle Group 

Procedure 


Supine
Hip flexors
The patient is instructed to raise both legs off the supporting surface simultaneously while keeping both legs straight. The position is held for 10 seconds. The hip flexors can also be tested in the sitting position.



Hip abductors
The patient is instructed to abduct the legs to each side, then to hold the position while the clinician attempts to bring the legs together.



Hip adductors
The patient is instructed to keep the legs together while the clinician attempts to separate the legs.



Hip extensors
The patient is instructed to flex the hips and the knees, keeping the soles of the feet on the supporting surface, and to raise the pelvis from the supporting surface. This position is held for 10 seconds.



Shoulder flexors and scapular upward rotators
The patient is instructed to flex the shoulder to 90  with the elbow straight and to hold the position while the clinician attempts to push the arms into extension.



Shoulder extensors and scapula downward rotators
The patient is instructed to flex the shoulder to 90  with the elbow straight and to hold the position while the clinician attempts to push the arms into flexion.



Shoulder horizontal abductors
The patient is instructed to flex the shoulder to 90  with the elbow straight and to hold the position while the clinician attempts to push the arms together into horizontal adduction



Shoulder adductors
The patient is instructed to bring the hands together in front of the chest, keeping the elbow straight, and to hold this position. The clinician attempts to separate the arms into horizontal abduction.



Neck and trunk flexors
The patient is instructed to hold both arms straight in front of the body and then to raise the head and shoulders off the supporting surface, and to hold this position.


Supine or sitting
Shoulder abductors
The patient is instructed to abduct the shoulder to the side up to shoulder level with the elbows straight. The clinician attempts to push the arms down to the patient's sides into shoulder adduction.



Shoulder adductors
The patient is instructed to abduct the shoulder to the side up to shoulder level with the elbows straight. The clinician attempts to push the arms over the patient's head into shoulder abduction.







Downloaded 2024 3 16 1:39 P Your IP is 155.33.135.27 CHAPTER 12: Manual Muscle Testing,
 2024 McGraw Hill. All Rights Reserved. Terms of Use   Privacy Policy   Notice   Accessibility


Page 2 / 164





Shoulder internal rotators
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The clinician attempts to push the arms outward into external rotation of the shoulder.





Shoulder external rotators
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The clinician attempts to push the arms inward into internal rotation of the shoulder.





Elbow flexors
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The clinician attempts to push the forearms toward the supporting surface into elbow extension.





Elbow extensors
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The clinician attempts to push the forearms toward the shoulders into elbow flexion.





Forearm supinators
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The clinician attempts to turn the palms toward the body into pronation.





Forearm pronators
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The clinician attempts to turn the palms away from the body into supination.





Wrist flexors
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The clinician attempts to push the palms upward into wrist extension.





Wrist extensors
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The clinician attempts to push the hand downward into wrist flexion.





Finger flexors
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The clinician places his or her index and middle fingers into the patient's hand and the patient is asked to squeeze the fingers. The clinician then attempts to pull the fingers out.





Finger extensors
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The patient is asked to straighten the fingers, and then the clinician attempts to push the fingers into flexion.





Anterior interossei
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The patient is asked to adduct the fingers, and then the clinician attempts to pull the fingers into abduction.





Posterior interossei
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The patient is asked to abduct the fingers, and then the clinician attempts to push the fingers into adduction.





Opponens pollicis
The patient is instructed to hold the arms at the sides, flex the elbows to approximately 90 , and place the forearms in neutral. The clinician places his or her index finger between the patient's thumb and each finger one at a time while asking the patient to pinch the finger.




Sitting
Latissimus dorsi and triceps
The patient is instructed to place both hands on the supporting surface next to the hips, keeping the elbows straight and the shoulder shrugged. The patient is then asked to depress the scapular by lifting the buttocks off the supporting surface.





Upper trapezius and levator scapulae
The patient is instructed to shrug the shoulders toward the ears and to hold the position. The clinician attempts to push the shoulders down into depression.











Downloaded 2024 3 16 1:39 P Your IP is 155.33.135.27 CHAPTER 12: Manual Muscle Testing,
 2024 McGraw Hill. All Rights Reserved. Terms of Use   Privacy Policy   Notice   Accessibility


Page 3 / 164




Internal rotators of the hip and evertors of the feet
The patient is instructed to evert the foot and to hold the position while the clinician pushes on the lateral border of each foot, into inversion and external rotation of the hip.



External rotators of the hip and invertors of the feet
The patient is instructed to invert the foot and to hold the position while the clinician pushes on the medial border of each foot, into eversion and internal rotation of the hip.


Prone
Rhomboids, middle trapezius, and posterior deltoid
The patient is instructed to flex the elbows level with the shoulders, pinch or adduct the scapulae together, and raise the arms from the supporting surface. The clinician attempts to push the arms downward.



Elbow and shoulder extensors
The patient is instructed to raise the arm off the supporting surface while keeping the arms at the sides and the elbows straight. The clinician attempts to push the arms downward.



Extensors of the hips, back, neck, and shoulders
The patient is instructed to keep the arms at the sides and to raise the head and shoulders and arms and legs off the supporting surface simultaneously by arching the back. The position is held for 10 seconds.


Prone or sitting
Hamstrings
The patient is instructed to flex the knees to about 90 . The clinician attempts to pull the knees into extension.



Quadriceps
The patient is instructed to flex the knees to about 90 . The clinician attempts to push the knees into flexion.


Standing
Gastrocnemius/soleus
The patient is instructed to stand on one leg with one finger on the supporting surface for balance. The patient is then asked to rise up on tiptoes and to repeat 10 times. The other leg is then tested.



Dorsiflexors
The patient is instructed to walk on the heel for 10 steps.



Hip and knee extensors
The patient is instructed to do five partial deep knee bends.





FIGURE  12 1


Gross muscle testing of the shoulder abductors




FIGURE  12 2

Gross muscle testing of the shoulder flexors


FIGURE  12 3


Gross muscle testing of the shoulder extensors


FIGURE  12 4


Gross muscle testing of the elbow flexors




FIGURE  12 5


Gross muscle testing of the elbow extensors




FIGURE  12 6

Gross muscle testing of the wrist extensors


FIGURE  12 7


Gross muscle testing of the wrist flexors




FIGURE  12 8


Gross muscle testing of the hip flexors




FIGURE  12 9

Gross muscle testing of the knee extensors


FIGURE  12 10


Gross muscle testing of the knee flexors and hip extensors


FIGURE  12 11


Gross muscle testing of the hip abductors




FIGURE  12 12


Gross muscle testing of the ankle dorsiflexors


FIGURE  12 13


Gross muscle testing of the ankle plantarflexors




SPECIFIC MUSCLE TESTING
Specific muscle testing, also called manual muscle testing (MMT) is a procedure for the evaluation of the voluntary function and strength of individual muscles and muscle groups based on effective performance of limb movement in relation to the forces of gravity and manual resistance.

MMT is typically used when the gross muscle screening shows specific muscle weakness. From a physiologic viewpoint, MMT measures the ability of the musculotendinous units to act across a bone joint lever arm system to actively generate motion, or passively resist movement against gravity and variable resistance.1
The results from MMT can be influenced by a number of factors:
 The length of the muscle at the time of the contraction. The amount of tension a muscle produces depends on its length as it contracts. Each muscle has its own optimal length to produce optimal tension for some muscles the lengthened position is more favorable than the shortened position. Generally speaking, as a muscle continues to lengthen, it eventually reaches a point of passive insufficiency, where it is not capable of generating its maximum force output (see active and passive insufficiency in Chapter 4).
 Whether the muscle acts on one joint or multiple joints. As a one joint muscle shortens, or as the distal and proximal attachments of a two joint muscle approach each other during a concentric contraction, the tension diminishes.
 The type of muscle contraction. Physiologically, a muscle is capable of generating its greatest tension during an eccentric contraction, less tension when contracting isometrically, and even less tension when contracting concentrically.2
 The speed of contraction. The faster a muscle produces a concentric contraction, the less ability the muscle has to generate tension as velocity increases, tension decreases.
 The length of the moment arm. As a muscle moves through its range of motion, the torque generated varies with the length of the moment arm (distance from the axis of rotation see Chapter 4). For example, as the elbow moves from full extension into flexion, the moment arm increases, reaching its maximum at approximately 90  of flexion, and then decreases throughout the remainder of the range of motion.
 Whether the muscle is working against gravity or with gravity. The force of gravity has the greatest leverage and therefore is able to produce the greatest toll on the body segment when the segment is horizontal.
To assess strength, strength values using MMT have traditionally been used between similar muscle groups on opposite extremities, or antagonistic ratios. This information is then used to determine whether a patient is fully rehabilitated. An agonist muscle contracts to produce the desired movement. From a rehabilitation viewpoint, knowledge of a specific muscle's synergists and antagonists is very important:
 Synergist. Synergist muscles are muscle groups that work together with the agonist to produce a desired movement.3 In essence, a synergist muscle can be viewed as a muscle's helper muscle, as the force generated by the synergists works in the same direction. Synergist muscles may need to be strengthened so that they can assist the agonist muscle.
 Antagonists. The antagonist muscle can oppose the desired movement. Antagonists allow movement by relaxing and lengthening in a gradual manner to ensure that the desired motion occurs, and that it does so in a coordinated and controlled fashion. Care must be taken to ensure that the antagonist muscles are not adaptively shortened and to monitor whether the antagonist muscles are not overpowering the agonist muscle.
To assist the clinician, for each of the specific muscle tests, the synergists and antagonist are provided.



To accurately perform a specific muscle test, the clinician must have knowledge of the following:
 The origin and insertion of the muscle being tested.
 The function of the muscle being tested. Muscles rarely perform one single action; instead they form groups of actions that overlap with the functions of other muscles. For that reason, if a component of a muscle's function is lost, other muscles that have duplicate functions can compensate for that loss.
 How to eliminate substitute or trick motions. This is best accomplished by using standardized testing positions. Where appropriate, these motions are included in each of the test procedures so that the clinician is aware of what to avoid.
 How to skillfully apply resistance. Pressure should be applied slowly, very gently, and gradually before progressing to the maximum resistance tolerable.
 The standard positions for each muscle test based on the effects of gravity. Typically the patient is positioned in either an antigravity or a gravity  eliminated position (see later).
 The standard methods of grading muscle strength. A number of grading methods have been described (see later).
It should be noted that there is considerable variability in the amount of resistance that normal muscles can hold against. The application of resistance throughout the arc of motion (referred to as a make test or active resistance test) in addition to resistance applied at only one point in the arc of motion (referred to as a break test) can help in judging the strength of a muscle.4
The main purposes of specific muscle testing are as follows:
 To help determine a diagnosis. For example, specific muscle testing can aid in precisely localizing a lesion in the peripheral nervous system.  To establish a baseline for muscle reeducation and exercise.
 To determine a patient's need for supportive apparatus (orthosis, assistive device of ambulation, or splints).  To help determine a patient's progress.
Several scales have been devised to assess muscle strength, including numerical, descriptive, and fractional (Table 12 2). The patient is positioned in an antigravity position for grades 3 to 5 and in a gravity eliminated position for grades 0 to 2. If the muscle strength is less than grade 3, then the methods advocated in muscle testing manuals must be used.4 For the testing methods and positions described in this chapter, it is assumed that the patient has a grade of 3 to 5. Alternative, gravity eliminated/minimized positions will also be provided.



TABLE 12 2
Manual Muscle Grading

Numerical
Descriptive
Fractional
Description
10
Normal
5/5
Ability to complete test movement and/or hold test position against gravity and maximum (strong) pressure
9
Good +
4+/5
Ability to complete test movement and/or hold test position against gravity and slightly less than maximum (moderate to strong) pressure
8
Good
4/5
Ability to complete test movement and/or hold test position against gravity and moderate pressure
7
Good ?
4?/5
Ability to complete test movement and/or hold test position against gravity and slightly less than moderate (slight to moderate) pressure
6
Fair +
3+/5
Ability to complete test movement and/or hold test position against gravity and minimal (slight) pressure
5
Fair
3/5
Ability to complete test movement and/or hold test position against gravity but cannot hold if even slight pressure is applied
4
Fair ?
3?/5
Ability to complete at least 1/2 of test movement against gravity. Cannot complete full test movement against gravity. NOTE: Kendall and colleaguesa refer to this as a very gradual release from antigravity test
position
3
Poor +
2+/5
Ability to initiate test movement against gravity, but completes less than 1/2 of test movement range OR Ability to complete test movement in a gravity lessened position against resistance throughout the range OR Ability to complete test movement and hold test position in a gravity lessened position against pressure
2
Poor
2/5
Ability to complete test movement in gravity lessened position with friction reduced. No movement against gravity
1
Poor ?
2?/5
Ability to initiate or complete partial test movement in a gravity lessened position with friction reduced; unable to complete full range of test movement.
T
Trace
1/5
Feeble but palpable muscle contraction or prominent tendon during muscle contraction with no visible motion of the part
0
Zero
0/5
No palpable muscle contraction


aData from Kendall FP, McCreary EK, Provance PG: Muscles: Testing and Function. Baltimore, Williams & Wilkins, 1993.
A number of problems exist with the grading systems. The grading systems for MMT produce ordinal data with unequal rankings between grades. For example, a muscle grade of 4 is not equivalent to 75% of the strength represented by a grade 5; it is a natural grade determined by the effect of gravity, manual resistance, the patient's age, and so forth. In general, the grades 5 (normal) and 4 (good) typically encompass a large range of a muscle's strength although a score of 5 does not mean that the muscle is normal in every circumstance (e.g., when at the onset of fatigue or in a state of exhaustion) whereas the grades of 3 (fair), 2 (poor), and 1 (trace) include a much narrower range.4 As a result, scores of 4 or 5 require some subjectivity, which can increase the variability between testers, whereas the precise definitions for 0 to 3 scores produce little tester to tester variability. Some of the confusion arises from the descriptions of maximal, moderate, and minimal, or considerable, which removes much of the




objectivity from the tests. It has been advocated by some to add + or ? to the scales. The   is used to describe that the test range is not complete but the motion is over one half the standard test range of motion (e.g., a grade of 2  with a patient who achieves more than one half of the standard range, with gravity eliminated). The + is used to describe the test range that is less than one half of the test range (e.g., a grade of 2+ with a patient who achieves less than one half of the standard range, in the anti gravity position).


To be a valid test, strength testing must elicit a maximum contraction of the muscle being tested. The following strategies ensure that this occurs:
1. Comparing the passive range of motion to the active range of motion. To achieve a grade of 3 to 5, the muscle must move through the entire available range. One of the most common mistakes is to overgrade or undergrade a muscle by assessing a muscle in a patient who is unable to achieve the full available range of motion.
2. Placing the joint which the muscle to be tested crosses in, or close to, its open packed position. This strategy helps protect the joint from excessive compressive forces, and the surrounding inert structures from excessive tension. The body area or segment to be evaluated is exposed, and the subject is properly draped. It is important to remember that the position used is dependent on the overall condition and comfort of the patient.
3. Placing the muscle to be tested in a shortened position. This puts the muscle in an ineffective physiologic position and has the effect of increasing motor neuron activity. Three basic factors must be considered with specific muscle testing: (1) the weight of the limb or distal segment with a minimal effect of gravity on the moving segment; (2) the weight of the limb plus the effects of gravity on the limb or segment; and (3) the weight of the limb or segment plus the effects of gravity plus manual resistance.
4. Using standardized positions. If the muscle to be tested is not isolated, the clinician is merely testing a muscle group rather than an individual muscle. Initially, the standardized gravity minimized positions may be necessary to avoid the effect of the weight of the moving body segment on the force measurement. For example, to test the strength of the hip abductors, the patient is positioned in supine so that the muscle action pulls in a horizontal plane relative to the ground.4
5. Stabilizing the appropriate parts of the body. When performing a specific muscle test, emphasis is placed on correct stabilization of the body part on which the muscle originates in addition to careful avoidance of substitution by other muscle groups to enhance accuracy. Substitutions by other muscle groups during testing indicate the presence of weakness. It does not, however, tell the clinician the cause of the weakness.
6. Apply force at the appropriate location. The force is typically applied distally on the segment to where the muscle insertion occurs, except when a longer lever is needed. The application of force is usually made at the end of range with one joint muscles and at midrange with two joint muscles. Resistance is always applied at right angles to the long axis of the segment. The force is applied by the clinician in a direction opposite to the torque (the rotary force around an axis, which is a combination of the force along the longitudinal axis of the segment on which the muscle attaches and another force that is at right angles to the axis of motion) exerted by the muscle being tested.
7. Give consideration to the patient's age, size, strength, occupation, and neuromuscular condition. It is important to remember that the standardized



positions are applicable to the adult population and may need to be adjusted for the aged or younger subjects. In addition, the clinician should know his or her own limitations.
8. For grades 3 to 5, ask the patient to perform an eccentric muscle contraction. This can be accomplished by using the command "Don't let me move you." Because the tension at each cross bridge and the number of active cross bridges are greater during an eccentric contraction, the maximum eccentric muscle tension developed is greater with an eccentric contraction than with a concentric one.
9. Breaking the contraction. It is important to break the patient's muscle contraction, in order to ensure that the patient is making a maximal effort and that the full power of the muscle is being tested. Although force values determined with make and break tests are highly correlated, break tests usually result in greater force values than make tests,8,9 so they should not be used interchangeably.
10. Holding the contraction for at least 5 seconds. Weakness resulting from nerve palsy has a distinct fatigability. The muscle demonstrates poor endurance, because usually it is only able to sustain a maximum muscle contraction for about 2 to 3 seconds before complete failure occurs. This strategy is based on the theories behind muscle recruitment, wherein a normal muscle, while performing a maximum contraction, uses only a portion of its motor units, keeping the remainder in reserve to help maintain the contraction. A palsied muscle, with its fewer functioning motor units, has very few, if any, motor units in reserve. If a muscle appears to be weaker than normal, further investigation is required, as follows:
a. The test is repeated three times. Muscle weakness resulting from disuse will be consistently weak and should not become weaker with several repeated contractions.
b. Another muscle that shares the same innervation is tested. Knowledge of both spinal and peripheral nerve innervation will aid the clinician in determining which muscle to select.
11. Comparing findings with uninvolved side. One study found no statistically significant difference in force between the dominant and nondominant lower extremities, but did find the difference between the dominant and nondominant upper extremities.10 Sapega11 states that a difference in muscle force between sides of greater than 20% probably indicates abnormality, whereas a difference of 10% to 20% possibly indicates abnormality.
As always, these tests cannot be evaluated in isolation but have to be integrated into a total clinical profile before drawing any conclusion about the patient's condition. Many factors can influence the results from MMT, including:
 Age
 Type of contraction (isometric, concentric, or eccentric)  Muscle size
 Speed of contraction  Training effect
 Joint position  Fatigue
 Nutrition status
 Level of motivation  Pain
 Body type
 Limb dominance




Although the grading of muscle strength has its role in the clinic, and the ability to isolate the various muscles is very important in determining the source of nerve palsy, specific grading of individual muscles does not give the clinician much information on the ability of the structure to perform functional tasks. In addition, measurements of isometric muscle force are specific to a point or small range in the joint range excursion and thus cannot be used to predict dynamic force capabilities.15, 16 and 17
More recently, the use of quantitative muscle testing (QMT) has been recommended to assess strength, as it produces interval data that describe force production. QMT methods include:
 The use of handheld dynamometers. Although more costly and time consuming than manual muscle testing, handheld dynamometry can be used to improve objectivity and sensitivity. Patients are typically asked to push against the dynamometer in a maximal isometric contraction (make test), or hold a position until the clinician overpowers the muscle producing an eccentric contraction (break tests).4 Normative force values for particular muscle groups by patient age and gender have been reported, with some authors including regression equations that take into account body weight and height.18

 The use of an isokinetic dynamometer. This is a stationary, electromechanical device that controls the velocity of the moving body segment by resisting and measuring the patient's effort so that the body segment cannot accelerate beyond a preset angular velocity.4 Isokinetic dynamometers measure torque and range of motion as a function of time and can provide an analysis of the ratio between the eccentric contraction and concentric contraction of a muscle at various positions and speeds.24 This ratio is aptly named the eccentric/concentric ratio.25 The ratio is calculated by dividing the eccentric strength value by the concentric strength value. Various authors26,27 have demonstrated that the upper limit of this ratio is 2.0 and that lower ratios indicate pathology.25,28 Alternatively, the same recommendations for manual muscle testing advocated by Sapega11 can be used: a difference in muscle force between sides of greater than 20% probably indicates abnormality, whereas a difference of 10% to 20% possibly indicates abnormality. To ensure the validity of isokinetic dynamometry measurements, calibration of equipment is necessary and should be performed each day of testing, at the same speed and damp setting to be used during the testing.29
One of the major criticisms of muscle testing is the overestimation of strength when a muscle is weak as identified by QMT, compared to the same muscle being graded as normal by MMT, such that a theoretical percentage score based on MMT is likely to grossly overestimate the strength of a patient.7
Studies that compare the reliability of MMT and QMT often come to the conclusion that MMT may be consistent and reliable, but it is unable to detect subtle differences in strength.30,31 Thus, although MMT results are more consistent, the variation produced by QMT can appreciate differences in strength undetectable in MMT.7 For example, Beasley2 showed that 50% of the knee extensor strength needed to be lost before MMT was able to identify weakness.




MUSCLE TESTING OF THE SHOULDER COMPLEX
A number of significant muscles control motion at the shoulder and provide dynamic stabilization. Rarely does a single muscle act in isolation at the shoulder. For simplicity, the muscles acting at the shoulder may be described in terms of their functional roles: scapular pivoters, humeral propellers, humeral positioners, and shoulder protectors (Table 12 3).32
TABLE 12 3
Muscles of the Shoulder Complex 

Scapular pivoters
Trapezius
Serratus anterior
Levator scapulae
Rhomboid major
Rhomboid minor
Humeral propellers
Latissimus dorsi
Teres major
Pectoralis major
Pectoralis minor
Humeral positioners
Deltoid
Shoulder protectors
Rotator cuff (supraspinatus, infraspinatus, teres minor, and subscapularis)
Long head of the biceps brachii



Scapular Pivoters



The scapular pivoters comprise the trapezius, serratus anterior, levator scapulae, rhomboid major, and rhomboid minor.32 As a group, these muscles are involved with motions at the scapulothoracic articulation, and their proper function is vital to the normal biomechanics of the whole shoulder complex. The scapular muscles can contract isometrically, concentrically, or eccentrically, depending on the desired movement and whether the movement involves acceleration or deceleration. To varying degrees, the serratus anterior and all parts of the trapezius cooperate during the upward rotation of the scapula.
Trapezius 

The trapezius muscle (Figure 12 14) originates from the medial third of the superior nuchal line, the external occipital protuberance, the ligamentum nuchae, the apices of the seventh cervical vertebra, all the thoracic spinous processes, and the supraspinous ligaments of the cervical and thoracic vertebrae. This muscle traditionally is divided into middle, upper, and lower parts (see Figure 12 14), according to anatomy and function.
 The upper fibers descend to attach to the lateral third of the posterior border of the clavicle.
 The middle fibers of the trapezius run horizontally to the medial acromial margin and superior lip of the spine of the scapula.
 The inferior fibers ascend to attach to an aponeurosis gliding over a smooth triangular surface at the medial end of the spine of the scapula to a tubercle at the scapular lateral apex.

FIGURE  12 14


Trapezius muscle and its relationship to some of the other scapular pivoters

The nerve supply to the trapezius is from the spinal accessory (cranial nerve [CN] XI) and from the anterior ramus of C2 4.
Upper Trapezius

The upper portion of the trapezius originates from the external occipital protuberance, medial one third of the superior nuchal line, the ligamentum nuchae, and the spinous process of the seventh cervical vertebra (see Figure 12 14). It inserts on the lateral one third of the clavicle and acromion processes of the scapula. It has been suggested that the upper fibers of this muscle have a different motor supply than the middle and lower



portions.33,34 Recent clinical and anatomic evidence seems to suggest that the spinal accessory nerve (CN XI) provides the most important and consistent motor supply to all portions of the trapezius muscle, and that although the C2 4 branches of the cervical plexus are present, no particular elements of innervation within the trapezius have been determined.35
One of the functions of the upper trapezius is to produce shoulder girdle elevation on a fixed cervical spine. For the trapezius to perform its actions, the cervical spine must be stabilized by the anterior neck flexors to prevent simultaneous occipital extension from occurring. Failure to prevent this occipital extension would allow the head to translate anteriorly, resulting in a decrease in the length, and therefore the efficiency, of the trapezius,36 and an increase in the cervical lordosis. The synergists for the upper trapezius include the rhomboid major and minor, the middle trapezius, the levator scapulae, and the serratus anterior. The antagonists for the upper trapezius include the lower trapezius, pectoralis minor, subclavius, pectoralis major (sternal portion), serratus anterior, and latissimus dorsi. Weakness of the upper trapezius results in a decrease in the ability to approximate the acromial end of the scapula and the occiput, difficulty raising the head from a prone position, and difficulty with abduction and flexion of the humerus above shoulder level.37 Adaptive shortening of the muscle results in elevation of the shoulder girdle. Unilateral contracture of this muscle is frequently seen in torticollis cases. This muscle is a common location for trigger points.

To specifically test this muscle, the patient is seated with the arm relaxed at the sides. The patient is asked to raise the shoulder as high as possible, and to extend and rotate the occiput toward the elevated shoulder (Figure 12 15). The clinician stabilizes the top of the shoulders with one hand, and applies resistance against the head in the direction of cervical flexion anterolaterally (see Figure 12 15). The command given to the patient is "Don't let me separate your head and shoulder." Substitution or trick motions can include abduction and upward rotation of the scapula (serratus anterior), elevation and downward rotation of the scapula (rhomboid major and minor), anterior tilting of the scapula (pectoralis minor), and elevation of the first and second ribs (scalenus muscle group). The gravity minimized/eliminated position for this muscle is with the patient positioned in supine or prone with the upper limb and shoulder supported.

FIGURE  12 15


Test position for the upper portion of the trapezius




Middle Trapezius

The middle portion of the trapezius originates from the spinous processes of the first through fifth thoracic vertebrae and inserts on the medial margin of the acromion and the superior lip of the spine of the scapula (see Figure 12 14) forming the cervicothoracic part of the muscle. Working alone, this muscle produces scapular adduction (retraction). The synergists for the middle trapezius include the rhomboid major and minor, the upper and lower trapezius, the levator scapulae, and the serratus anterior (depending on its action). The antagonists for the middle trapezius include the lower trapezius (depending on its action), serratus anterior, pectoralis minor, and pectoralis major (sternal portion).
To specifically test this muscle, the patient is positioned in prone with the shoulder abducted to 90 , the elbow extended, and the upper extremity externally rotated so that the thumb points toward the ceiling (Figure 12 16). The clinician applies pressure against the forearm in a downward direction toward the table. The command given to the patient is "Don't let me push your arm down while keeping your elbow straight and your thumb pointing upward." Substitution or trick motions can include trunk rotation, horizontal abduction of the shoulder (posterior deltoid) elevation and downward rotation of the scapula (rhomboid major and minor), depression and downward rotation of the scapula (lower trapezius), synergistic contraction of the upper and lower fibers of the trapezius muscle, and synergistic contraction of the lower trapezius and the rhomboids. The gravity  minimized/eliminated position for this muscle is with the patient positioned in sitting with the upper limb supported on a friction free surface in a position of 90  of abduction and 90  of elbow flexion.

FIGURE  12 16


Test position for the middle trapezius




Lower Trapezius

The lower fibers of this muscle originate from the spinous processes of the 6th through 12th thoracic vertebrae (see Figure 12 14) and insert at the tubercle of the apex of the spine of the scapula. Working alone, the lower trapezius muscle stabilizes the scapula against lateral displacement (abduction) produced by the serratus anterior and to stabilize the scapula against scapular elevation produced by the levator scapulae. The synergists for the lower trapezius include the rhomboid major and minor, the middle and upper trapezius, the pectoralis minor, and the latissimus dorsi. The antagonists for the lower trapezius include the upper trapezius, levator scapulae, rhomboid major and minor, and serratus anterior.
To specifically test this muscle, the patient is positioned in prone with the arm placed diagonally overhead, and the shoulder is externally rotated (Figure 12 17). The clinician applies pressure against the forearm downward toward the table. The command given to the patient is "Don't let me push your arm down while keeping your arm diagonally upward and your thumb facing upward." Substitution or trick motions can include assistance from the posterior deltoid, latissimus dorsi, or pectoralis major. The gravity minimized/eliminated position for this muscle is with the patient positioned in prone with the arms by the sides and the upper extremity supported by the clinician. The patient is asked to depress and adduct the scapula through full range of motion.

FIGURE  12 17


Test position for the lower trapezius


Serratus Anterior

The muscular digitations of the serratus anterior (Figure 12 18) originate from the upper 8 to 10 ribs and fascia over the intercostals. The muscle is composed of three functional components39,40:



 The upper component originates from the first and second ribs and inserts on the superior angle of the scapula.
 The middle component arises from the second, third, and fourth ribs and inserts along the anterior aspect of the medial scapular border.
 The lower component is the largest and most powerful, originating from the fifth through ninth ribs. It runs anterior to the scapula and inserts on the medial border of the scapula.

FIGURE  12 18


Serratus anterior muscle

The serratus anterior is activated with all shoulder movements, but especially during shoulder flexion and abduction.40 Working in synergy with the upper and lower trapezius, as part of a force couple, the main function of the serratus anterior is to protract and upwardly rotate the scapula,41,42 while providing a strong, mobile base of support to position the glenoid optimally for maximum efficiency of the upper extremity.43 Its lower fibers draw the lower angle of the scapula forward to rotate the scapula upward while maintaining the scapula on the thorax during arm elevation.44 This moves the coracoacromial arch out of the path of the advancing greater tuberosity and opposes the excessive elevation of the scapula by the levator scapulae and trapezius muscles.45 Without upward rotation and protraction of the scapula by the serratus anterior, full glenohumeral (G H) elevation is not possible. In fact, in patients with complete paralysis of the serratus anterior, Gregg and colleagues43 reported that abduction is limited to 110 .
Dysfunction of serratus anterior muscle causes winging of the scapula as the patient attempts to elevate the arm.46,47 Scapulothoracic dysfunction can also contribute to G H instability, as the normal stable base of the scapula is destabilized during abduction or flexion.47, 48 and 49
The serratus anterior muscle is innervated by the long thoracic nerve (C5 7). The synergists for the serratus anterior include the upper and lower trapezius, pectoralis minor, latissimus dorsi, and subclavius. The antagonists for the serratus anterior include the middle trapezius, levator scapulae, and rhomboids.




To specifically test this muscle, the patient is positioned in supine, standing, or sitting.
 Supine: the patient is asked to flex the shoulder to 90  with slight abduction and with the elbow in extension. From this position, the patient moves the arm upward toward the ceiling by abducting the scapula. The clinician applies resistance by grasping around the forearm and elbow and applying a downward and inward pressure toward the table (Figure 12 19). The command given to the patient is "Try to lift your arm higher by moving your shoulder forward while I push down on it."
 Standing: the patient places a hand against the wall with the shoulder in forward flexion to 80  to 90  and the elbows locked in extension. While monitoring the inferior angle of the scapula for any winging, the command given to the patient is "Push against the wall."
 Sitting: this test focuses on the upward rotation action of the serratus in the abducted position. The patient is asked to move the humerus into approximately 120  to 130  of flexion. Using one hand, the clinician wraps the thumb and index finger around the inferior aspect of the scapula and the other hand is placed on the anterior aspect of the arm (Figure 12 20). The command given to the patient is "Keep your arm still while I try and push it down," as the clinician pushes downwardly on the arm while applying a resistive force with the other hand into internal rotation of the inferior angle of the scapula.

FIGURE  12 19


Test position for the serratus anterior patient supine


FIGURE  12 20




Test position for the serratus anterior patient sitting

Substitution or trick motions typically occur in sitting and can include flexion of the vertebrae or rotation of the vertebrae.
The gravity minimized/eliminated position for this muscle is with the patient positioned in sitting with the upper limb resting on a table, with the shoulder positioned in 90  of flexion, and the elbow extended.
Levator Scapulae

The levator scapulae muscle (see Figure 12 14) originates by tendinous strips from the transverse processes of the atlas, axis, and C3 and C4 vertebrae and descends diagonally to insert on the medial superior angle of the scapula.
The levator scapulae can act on either the cervical spine or the scapula. If it acts on the cervical spine, it can produce extension, side bending, and rotation of the cervical spine to the same side.50 When acting on the scapula during upper extremity flexion or abduction, the levator scapula muscle acts as an antagonist to the lower trapezius muscle and provides eccentric control of scapular upward rotation in the higher ranges of motion.51
Both the trapezius and levator scapulae muscles are activated with increased upper extremity loads.36,40,52
The levator scapulae muscle is innervated by the posterior (dorsal) scapular nerve (C3 5). The synergists for the levator scapulae include all portions of the trapezius and the rhomboid major and minor. The antagonists for the levator scapulae include the lower trapezius, pectoralis minor, pectoralis major (lower portion), subclavius, serratus anterior, and latissimus dorsi.
To specifically test this muscle, the patient is positioned in sitting with the arms relaxed at the sides. The patient is asked to raise the shoulder as high as possible while the clinician generates resistance downward on top of the shoulder (see Figure 12 15). The command given to the patient is "Don't let me push your shoulder down." It is worth remembering that it is difficult to differentiate the strength of the levator scapulae from that of the upper trapezius. For this reason, the levator scapulae strength is often assessed together with the rhomboids, or with the upper trapezius.
Rhomboid Major and Minor



The rhomboid muscles help control scapular positioning, particularly with horizontal flexion and extension of the shoulder complex.51 Based on anatomy and function, the rhomboids are divided into a major and a minor muscle.
 The rhomboid major muscle (see Figure 12 14) originates from the second to fifth thoracic spinous processes and the overlying supraspinous ligaments. The fibers descend to insert on the medial scapular border between the root of the scapular spine and the inferior angle of the scapula.
 The rhomboid minor muscle (see Figure 12 14) originates from the lower ligamentum nuchae and the seventh cervical and first thoracic spinous processes and attaches to the medial border of the scapula at the root of the spine of the scapula.
The rhomboid muscles are innervated by the posterior (dorsal) scapular nerve (C4 5). Working together, the rhomboid muscles adduct and elevate the scapula and downwardly rotate the scapula. The rhomboid major muscle helps stabilize the scapula against the rib cage. The synergists for the rhomboids include all portions of the trapezius muscle and the levator scapulae. The antagonists for the rhomboids include the lower trapezius, pectoralis major and minor, serratus anterior, and latissimus dorsi.
To specifically test this muscle, the patient is positioned in prone with the head turned toward the tested side, the elbow flexed, and the ipsilateral humerus abducted, slightly extended, and externally rotated (Figure 12 21a). The clinician applies pressure with one hand against the patient's arm in the direction of abducting the scapula and externally rotating the inferior angle, while the other hand is placed against the patient's shoulder in the direction of depression (see Figure 12 21a). The command given to the patient is "Don't let me push your arm down." Substitution or trick motions can include assistance from the wrist extensors, middle trapezius, posterior deltoid, latissimus dorsi, teres major, and levator scapulae. An alternative test can be performed with the patient positioned in prone with the upper extremity positioned in 90  of abduction and internally rotated so that the thumb is pointing down (Figure 12 21b). The patient is asked to raise the arm toward the ceiling and to hold the position while the clinician applies a downward force to the patient's forearm. The gravity minimized/eliminated position for this muscle is with the patient positioned in sitting with the hand resting on the lumbar spine.

FIGURE  12 21a


Test position for the rhomboids (and levator scapulae)


FIGURE  12 21b


Alternate test position for the rhomboids



Humeral Propellers
The total muscle mass of the shoulder's internal rotators (subscapularis, anterior deltoid, pectoralis major, latissimus dorsi, and teres major) is much greater than that of the external rotators (infraspinatus, teres minor, and posterior deltoid).38 This fact explains why the shoulder internal rotators produce about 1.75 times greater isometric torque than the external rotators.53 Peak torques of the internal rotators also exceed the external rotators when measured isokinetically, under both concentric and eccentric conditions.38,54
Latissimus Dorsi

The latissimus dorsi muscle (Figure 12 22) originates from the spinous processes of the last six thoracic vertebrae, the lower three or four ribs, the lumbar and sacral spinous processes through the thoracolumbar fascia, the posterior third of the external lip of the iliac crest, and a slip from the inferior scapular angle. The scapular slip allows the latissimus dorsi to act at the scapulothoracic articulation. The latissimus dorsi inserts on the intertubercular sulcus of the humerus. The latissimus dorsi functions as an extensor, adductor, and powerful internal rotator of the shoulder, and also assists in scapular depression, retraction, and downward rotation.55 It is innervated by the thoracodorsal nerve (C6 8). The synergists for the latissimus dorsi include the teres major, anterior and posterior deltoid, triceps brachii, erector spinae, subscapularis, and pectoralis major. The antagonists for the latissimus dorsi include the middle trapezius, supraspinatus, infraspinatus, teres minor, anterior and posterior deltoid, coracobrachialis, biceps brachii, and pectoralis major (clavicular portion).

FIGURE  12 22


Latissimus dorsi and teres major muscles their relation to each other and to the rhomboids and levator scapulae



To specifically test this muscle, the patient is positioned in prone with the shoulder internally rotated and adducted and the palm facing upward (Figure 12 23). The patient is asked to extend the shoulder while keeping the elbow straight. The command given to the patient is "While keeping your palm facing the ceiling, don't let me push your arm down." The clinician stabilizes the thorax, and resistance is given proximal to the elbow joint using a force that is a combination of shoulder abduction and minimal flexion (see Figure 12 23). Substitution or trick motions can include scapular adduction with no shoulder motion, anterior tipping and abduction of the scapula, assistance from the teres major, posterior deltoid, or pectoralis major (sternal head). The gravity minimized/eliminated position for this muscle is with the patient positioned in sidelying, with the upper limb supported in 90  of shoulder flexion and internal rotation, and with the elbow flexed.
FIGURE  12 23


Test position for the latissimus dorsi stabilization of the thorax not shown




Teres Major

The teres major (see Figure 12 22) originates from the inferior third of the lateral border of the scapula and just superior to the inferior angle. The teres major tendon inserts on the medial lip of the intertubercular groove of the humerus. The teres major functions to complement the actions of the latissimus dorsi in that it extends, adducts, and internally rotates the G H joint. It is innervated by the lower subscapular nerve (C5, C6). The synergists for the teres major include the latissimus dorsi, anterior and posterior deltoid, triceps brachii (long head), pectoralis major, and subscapularis. The antagonists for the teres major are numerous and include the middle deltoid, supraspinatus, infraspinatus, teres minor, coracobrachialis, biceps brachii, anterior and posterior deltoid, and pectoralis major (clavicular portion).
To specifically test this muscle, the patient is positioned in prone with the upper extremity extended, abducted, and medially rotated and with the back of the hand resting on the small of the back. The clinician places a hand against the arm proximal to the elbow (Figure 12 24), and the command given to the patient is "Keeping your hand against your back, don't let me move your arm toward the table," while the clinician generates a force into flexion and abduction of the upper extremity. Substitution or trick motions can include scapular adduction without shoulder motion, external rotation of the glenohumeral joint, and assistance from the latissimus dorsi, pectoralis major, and teres minor. In general, the teres major muscle is not tested in a gravity eliminated position, because it will only contract against resistance.
FIGURE  12 24


Test position for the teres major


Pectoralis Major

The pectoralis major (Figure 12 25) originates from the sternal half of the clavicle, half of the anterior surface of the sternum to the level of the sixth



or seventh costal cartilage, the sternal end of the sixth rib, and the aponeurosis of the obliquus externus abdominis. The fibers of the pectoralis major converge to form a tendon that inserts on the lateral lip of the intertubercular sulcus of the humerus. Although this muscle does not insert on the scapula, it does act on the scapulothoracic articulation through its insertion on the humerus. The function of the pectoralis muscle depends on which fibers are activated:
 Upper fibers (clavicular head) internal rotation, horizontal adduction, flexion, abduction (once the humerus is abducted 90 , the upper fibers assist in further abduction), and adduction (with the humerus below 90  of abduction) of the G H joint
 Lower fibers (sternal head) internal rotation, horizontal adduction, extension, and adduction of the G H joint

FIGURE  12 25


Pectoralis major muscle

From a functional perspective, this muscle is important with crutch walking or ambulation within the parallel bars. The pectoralis major is innervated by the medial (lower fibers) and lateral (upper fibers) pectoral nerves (C8 T1 and C5 7, respectively). The synergists for the clavicular portion include the sternal portion of the pectoralis major, subscapularis, latissimus dorsi, teres major, anterior and middle deltoid, coracobrachialis, pectoralis minor, serratus anterior, and biceps brachii. The antagonists for the clavicular portion include the latissimus dorsi, teres major, middle and posterior deltoid, infraspinatus, triceps brachii (long head), teres minor, and supraspinatus. The synergists for the sternal portion include the clavicular portion of the pectoralis major, posterior deltoid, latissimus dorsi, teres major, triceps brachii (long head), and pectoralis minor. The antagonists for the sternal portion include the supraspinatus, deltoid, trapezius, serratus anterior, levator scapulae, and rhomboids.




To specifically test this muscle, the patient is positioned in supine. The patient's arm position depends on which portion of the muscle is being tested:
 Clavicular portion (upper fibers): the patient arm is positioned in 60  to 90  of shoulder abduction and the elbow is slightly flexed. The patient is then asked to horizontally adduct the shoulder as the clinician applies resistance at the forearm (or proximal to the elbow if the elbow flexors are weak) in a downward and outward direction (Figure 12 26). The coracobrachialis, a synergist of the upper fibers, can also be assessed (Figure 12 26a).
 Sternal portion (lower fibers): the patient arm is positioned in 120  of shoulder abduction with the elbow slightly flexed. The patient is asked to move the arm down and in across the body as the clinician applies resistance at the elbow in an up and outward direction (Figure 12 27).
Substitution or trick motions can include trunk rotation and assistance from the anterior deltoid, coracobrachialis, and biceps brachii. The gravity  minimized/eliminated position for this muscle is with the patient positioned in sitting with the shoulder positioned in neutral rotation and in 90  of abduction, the elbow flexed to 90 , and the upper limb supported.

FIGURE  12 26


Test position for the pectoralis major upper fibers


FIGURE  12 26a


Test position for the coracobrachialis




FIGURE  12 27


Test position for the pectoralis major lower fibers


Pectoralis Minor

The pectoralis minor (Figure 12 28) originates from the outer surface of the upper margins of the third to fifth ribs near their cartilage. The fibers of the pectoralis minor ascend laterally, converging to a tendon that inserts on the coracoid process of the scapula.

FIGURE  12 28


Pectoralis minor muscle



Working alone, this muscle depresses the shoulder, downwardly rotates the scapula, and protracts the scapula. This muscle can also assist with elevation of the ribs during forced inspiration. The pectoralis minor muscle is innervated by the medial pectoral nerve (C6 8). The pectoralis minor is prone to adaptive shortening, particularly if the patient commonly adopts a rounded shoulder posture, which in turn can result in impingement on the cords of the brachial plexus or the axillary vessels. The synergists to this muscle include the pectoralis major, lower trapezius, serratus anterior, latissimus dorsi, levator scapulae, rhomboid major and minor, and middle trapezius. The antagonists of this muscle are the trapezius, levator scapulae, latissimus dorsi, serratus anterior, and the rhomboid major and minor.
To specifically test this muscle, the patient is positioned in supine with the arms at the sides and the patient is asked to lift the shoulder girdle from the table (without using force from the elbow or hand) and to hold the position while the clinician applies resistance against the anterior aspect of the shoulder (Figure 12 29) in a downward direction toward the table. Substitution or trick motions can include flexion of the wrist or fingers, which can give the appearance of anterior tipping of the scapula. The gravity minimized/eliminated position for this muscle is with the patient positioned in sitting with the hand resting on the small of the back.

FIGURE  12 29


Test position for pectoralis minor

Humeral Positioners

Deltoid

The deltoid muscle originates from the lateral third of the clavicle, the superior surface of the acromion, and the spine of the scapula (Figure 12 30). It



inserts into the deltoid tuberosity of the humerus. The deltoid can be described as three separate muscles anterior, middle, and posterior all of which function as humeral positioners, positioning the humerus in space.32
FIGURE  12 30


Deltoid muscle

Working alone, the three separate muscles of the deltoid can produce shoulder horizontal adduction, shoulder flexion, internal rotation of the shoulder, and shoulder scaption (arm elevated in the plane of the scapula). Working in a combined fashion, the deltoid can produce shoulder abduction. The deltoid muscle is innervated by the axillary nerve (C5 6). The synergists and antagonists of this muscle depend on which of the three portions is being used:
 Anterior deltoid (see Figure 12 30). The synergists include the middle and posterior deltoid, subscapularis, biceps brachii, pectoralis major, coracobrachialis, and supraspinatus. The antagonists include the triceps brachii (long head), posterior deltoid, latissimus dorsi, teres major, infraspinatus, and teres minor.
 Middle deltoid (see Figure 12 30). The synergists are the supraspinatus, posterior deltoid, and anterior deltoid. The antagonists are latissimus dorsi, teres major, coracobrachialis, and triceps brachii (long head).
 Posterior deltoid (see Figure 12 30). The synergists are the teres minor, latissimus dorsi, teres major, triceps brachii (long head), and infraspinatus.
To specifically test this muscle, the patient's arm position used depends on which portion of the muscle is being tested:
 Anterior deltoid. The patient is positioned in sitting or supine with the shoulder abducted in minimal flexion and external rotation. The command given to the patient is "Place your arm diagonally outward from your body and hold it against my resistance." While stabilizing the patient's shoulder with one hand, the clinician uses the other hand to apply resistance to the anterior and medial aspect of the arm proximal to the elbow in



the direction of abduction and minimal extension (Figure 12 31). Substitution or trick motions can include elevating the shoulder and leaning backward; assistance from the biceps brachii, coracobrachialis, or pectoralis major (clavicular head); or moving the scapula. The gravity  minimized/eliminated position for this muscle is with the patient positioned in sidelying with the upper extremity supported and the shoulder positioned in neutral, and the elbow flexed.
 Middle deltoid. The patient is positioned in sitting with the arm abducted to 90  and the elbow flexed to approximately 90 . The patient is asked to hold this position while the clinician applies resistance just proximal to the elbow in a downward direction (Figure 12 32). Substitution or trick motions can include trunk flexion to the opposite side, or assistance from the biceps brachii, supraspinatus, or serratus anterior. The gravity  minimized/eliminated position for this muscle is with the patient positioned in supine with the upper extremity supported and the elbow flexed to 90 .
 Posterior deltoid. The patient positioned in sitting with the shoulder abducted to approximately 90  and positioned in minimal shoulder extension and internal rotation. The patient is asked to push the arms back toward the clinician as the clinician uses one hand to stabilize the shoulder and the other hand to apply resistance to the posterolateral aspect of the arm, proximal to the elbow, in the direction of shoulder abduction and slight flexion (Figure 12 33). Substitution or trick motions can include assistance from the long head of the triceps or adduction of the scapula without horizontally abducting the shoulder. The gravity minimized/eliminated position for this muscle is with the patient positioned in sitting with the upper extremity supported on a table, and the shoulder and elbow flexed to 90 .

FIGURE  12 31


Test position for the anterior deltoid


FIGURE  12 32


Test position for the middle deltoid




FIGURE  12 33


Test position for the posterior deltoid

Shoulder Protectors

Rotator Cuff

The rotator cuff (RC) muscles consist of the supraspinatus, infraspinatus, teres minor, and the subscapularis:
 Supraspinatus (Figure 12 34). The supraspinatus muscle originates above the spine of the scapula, in the supraspinatus fossa, and inserts on



the greater tuberosity of the humerus. Working alone, the supraspinatus abducts, or elevates, the G H joint.
 Infraspinatus (Figure 12 35). The infraspinatus muscle originates below the spine of the scapula, in the infraspinatus fossa, and inserts on the posterior aspect of the greater tuberosity of the humerus. Working alone, the infraspinatus externally rotates the G H joint.
 Teres minor (see Figure 12 35). The teres minor muscle originates on the lateral scapula border and inserts on the inferior aspect of the greater tuberosity of the humerus. Working alone, the teres minor muscle externally rotates the G H joint.
 Subscapularis (Figure 12 36). The subscapularis muscle originates on the anterior surface of the scapula, sitting directly over the ribs, and inserts on the lesser tuberosity of the humerus. Working alone, the subscapularis is an internal rotator of the shoulder. It also depresses the head of the humerus, allowing it to move freely in the G H joint during elevation of the arm. Internal rotation of the shoulder dominates over external rotation secondary to the greater muscle mass of the subscapularis.

FIGURE  12 34


Supraspinatus muscle


FIGURE  12 35


Infraspinatus and teres minor muscles




FIGURE  12 36


Subscapularis muscle

The RC muscles are referred to as the protectors of the shoulder because, in addition to working individually to move the humerus, they have an important role in the function of the shoulder and serve the following roles32:
 Assist in the rotation of the shoulder and arm. At the G H joint, elevation through abduction of the arm requires that the greater tuberosity of the humerus pass under the coracoacromial arch. For this to occur, the humerus must externally rotate, and the acromion must elevate.56 External rotation of the humerus is produced actively by a contraction of the infraspinatus and teres minor, and by a twisting of the joint capsule. A force couple exists in the transverse plane between the subscapularis anteriorly and the infraspinatus and teres minor posteriorly in which co  contraction of the infraspinatus, teres minor, and subscapularis muscles both depresses and compresses the humeral head during overhead movements.




In the frontal plane, there is another force couple between the deltoid and the inferior rotator cuff muscles (infraspinatus, subscapularis, and teres minor). With the arm fully adducted, contraction of the deltoid produces a vertical force in a superior direction, resulting in an upward translation of the humeral head relative to the glenoid. Co contraction of the inferior rotator cuff muscles produces both a compressive force and a downward translation of the humerus that counterbalances the force of the deltoid, thereby stabilizing the humeral head.
Electromyography (EMG) studies have shown that during casual elevation of the arm in normal shoulders, the deltoid and the rotator cuff act continuously throughout the motion of abduction, each reaching a peak of activity between 120  and 140  of abduction.57,58 However, during more rapid and precise movements such as those involved with throwing, a more selective pattern emerges with specific periods of great intensity.59 Weakening of the rotator cuff appears to allow the deltoid to elevate the proximal part of the humerus in the absence of an adequate depressor effect from the rotator cuff. A decrease in the subacromial space is created, and impingement of the rotator cuff on the anterior aspect of the acromion occurs.60,61
 Reinforce the G H capsule. The rotator cuff muscles, together with the glenohumeral ligament (and the long head of the biceps often referred to as the fifth rotator cuff muscle), enhance stability. For example, firing of the rotator cuff muscles increases the tension of the middle G H ligament when the arm is abducted to 45  and externally rotated.62
 Control much of the active arthrokinematics of the G H joint. Contraction of the horizontally oriented supraspinatus produces a compression force directly into the glenoid fossa.60 This compression force holds the humeral head securely in the glenoid cavity during its superior roll, which provides stability to the joint, and also maintains a mechanically efficient fulcrum for elevation of the arm.60 In the shoulder's midrange position, when all of the passive restraints are lax, joint stability is achieved almost entirely by the rotator cuff. In addition, as previously mentioned, without adequate supraspinatus force, the near vertical line of force of a contracting deltoid tends to jam or impinge the humeral head superiorly against the coracoacromial arch.38
The synergists and antagonists of the rotator cuff muscles depend on the individual muscles of the group:
 Teres minor. The synergists are the infraspinatus and the posterior deltoid. The antagonists are the anterior deltoid, subscapularis, pectoralis major, latissimus dorsi, and teres major.
 Subscapularis. The synergists are the pectoralis major, anterior deltoid, teres major, and latissimus dorsi. The antagonists are the infraspinatus, posterior deltoid, and teres minor.
Supraspinatus. The synergist is the middle deltoid. The antagonists are the teres major, latissimus dorsi, and pectoralis major.
Infraspinatus. The synergists are the teres minor and posterior deltoid. The antagonists are the subscapularis, pectoralis major, latissimus dorsi, anterior deltoid, and teres major.
Each of the muscles of the rotator cuff can be specifically tested, with the patient setup dependent on which muscle is being tested:
Teres minor. The patient is positioned in prone with the shoulder abducted to 90  and the arm supported by the table so that the forearm is permitted to move freely (Figure 12 37). The patient is asked to externally rotate the shoulder so that the forearm moves toward the ceiling. The patient is asked to hold this position while the clinician applies resistance at the patient's wrist in a downward direction with one hand, while using the other hand to support the patient's elbow (see Figure 12 37). The teres minor can also be tested with the patient in supine with the humerus in external rotation and the elbow held at a right angle. Using one hand, the clinician stabilizes the upper arm, while using the other arm



to apply pressure in the direction of internal rotation of the humerus (Figure 12 38).
 Subscapularis. The patient is positioned in prone with the shoulder abducted to 90  and the upper arm resting on the table so that the forearm is permitted to move freely (Figure 12 39). The patient is asked to internally rotate the shoulder so that the forearm moves toward the ceiling. The patient is asked to hold the position while the clinician applies resistance at the wrist in a downward direction with one hand, while using the other hand to support the patient's arm (see Figure 12 39). The subscapularis can also be tested with the patient in supine with the upper arm at the side and the elbow held at a right angle (Figure 12 40). Using one hand to stabilize the patient's upper arm, the clinician uses the other hand to apply force against the inner aspect of the patient's wrist and forearm in a direction of external rotation. Substitution or trick motions can include scapular abduction, pronation of the forearm, and assistance from the pectoralis major, teres major, and latissimus dorsi. The gravity  minimized/eliminated position for this muscle is with the patient positioned in prone with the shoulder flexed over the edge of the table.
 Supraspinatus. The patient is positioned in sitting with the arm by the side and the head rotated ipsilaterally and extended. Using one hand, the clinician palpates the supraspinatus; the other hand applies resistance at the elbow into shoulder adduction while the patient is asked to raise the arm up into shoulder abduction. This is a difficult muscle to isolate as it works in conjunction with the middle deltoid.
 Infraspinatus. The patient is positioned in prone with the shoulder abducted to 90  and the arm supported by the table so that the forearm is permitted to move freely (see Figure 12 37). The patient is asked to externally rotate the shoulder so that the forearm moves toward the ceiling and to hold that position. Using one hand, the clinician stabilizes the patient's elbow while using the other hand to apply resistance in a downward direction at the patient's wrist (see Figure 12 37). The infraspinatus can also be tested with the patient in supine with the humerus in external rotation and the elbow held at a right angle. Using one hand, the clinician stabilizes the upper arm, while using the other arm to apply pressure in the direction of internal rotation of the humerus (see Figure 12 38).

FIGURE  12 37


Test position for the shoulder external rotators teres minor and infraspinatus patient prone


FIGURE  12 38


Test position for the shoulder external rotators teres minor and infraspinatus patient supine




FIGURE  12 39


Test position for the shoulder internal rotators subscapularis


FIGURE  12 40




Long Head of the Biceps Brachii

The biceps brachii muscle is a large fusiform muscle in the anterior compartment of the upper extremity, which has two tendinous origins from the scapula (Figure 12 40a). The medial head and long head of the biceps (LHB) normally originate from the coracoid process and supraglenoid tubercle of the scapula, respectively. However, researchers have noted that the origin of the biceps tendon varies, not only in the type of insertion (single, bifurcated, or trifurcated), but also in the specific anatomic location where it inserts.63,64 The proximal LHB tendon receives some arterial supply from labral branches of the suprascapular artery.65 As it leaves its origin, the LHB tendon is surrounded by a synovial sheath, which ends at the distal end of the bicipital groove, making the tendon an intra articular but extrasynovial structure.63 As the LHB tendon moves between the greater and lesser tuberosities, it is stabilized in position by the tendoligamentous sling made up of the coracohumeral ligament, superior G H ligament, and fibers from the supraspinatus and subscapularis.63,66 Once in the bicipital groove, the LHB tendon passes under the transverse humeral ligament, which bridges the groove.67 After coursing through the groove, the two heads join to form the biceps muscle belly at the level of the deltoid insertion.68 The medial tendon is interarticular, lying inside the G H capsule.69, 70 and 71 This tendon is not as common a source of shoulder pain as the long tendon, and it rarely ruptures.69, 70 and 71

FIGURE  12 40a

Biceps brachii and brachialis muscles



The function of the biceps as a forearm supinator and secondarily as an elbow flexor is well known (see Muscle Testing of the Elbow).72 At the shoulder joint, however, the function of the LHB tendon is less clear, with most references regarding it as a weak flexor of the shoulder.73 Cadaveric studies have suggested that the LHB tendon functions as a humeral head depressor (in full external rotation), an anterior stabilizer, a posterior stabilizer, a limiter of external rotation, a lifter of the glenoid labrum, and a humeral head compressor of the shoulder.74, 75, 76 and 77 The muscle has also been described as having important role in decelerating the rapidly moving arm during activities such as forceful overhand throwing.63 In the anatomic position, the biceps has no ability to elevate the humerus. If the arm is rotated 90  externally, the tendon of the long head aligns with the muscle belly to form a straight line across the humeral head. As the biceps contracts in this position, the humeral head rotates beneath the tendon, resisting external rotation of the humeral head and increasing the anterior stability of the G H joint.78, 79 and 80 Contraction of the long head of the biceps when the arm is abducted and externally rotated fixes the humeral head snugly against the glenoid cavity, as the resultant force passes obliquely through the center of rotation of the humeral head and at right angles to the glenoid.78 The humeral head is prevented from moving upward by the hoodlike action of the biceps tendon, which exerts a downward force and assists the depressor function of the cuff.81, 82 and 83 Interestingly, the biceps tendon was found to be wider in cuff deficient shoulders in one study.84
The biceps brachii muscle is innervated by the musculocutaneous nerve.

The strength of the LHB is assessed in combination with the short head of the biceps (see Elbow Flexors later).
MUSCLE TESTING OF THE ELBOW
A summary of the muscles of the elbow is outlined in Table 12 4.
TABLE 12 4
Muscles of the Elbow, Forearm, Wrist, and Hand: Their Actions, Nerve Supply, and Nerve Root Derivation



Muscles 

Nerve Supply 
Nerve Root Derivation 

Action 


Triceps
Radial
C7 C8
Elbow extension












Anconeus
Radial
C7 C8, (T1)





Brachialis
Musculocutaneous
C5 C6, (C7)
Elbow flexion




Biceps brachii
Musculocutaneous
C5 C6





Brachioradialis
Radial
C5 C6, (C7)





Biceps brachii
Musculocutaneous
C5 C6
Supination of the forearm




Supinator
Posterior interosseous (radial)
C5 C6





Pronator quadratus
Anterior interosseous (median)
C8, T1
Pronation of the forearm




Pronator teres
Median
C6 C7





Flexor carpi radialis
Median
C6 C7





Extensor carpi radialis longus
Radial
C6 C7
Extension of the wrist




Extensor carpi radialis brevis
Posterior interosseous (radial)
C7 C8





Extensor carpi ulnaris
Posterior interosseous (radial)
C7 C8





Flexor carpi radialis
Median
C6 C7
Flexion of the wrist




Flexor carpi ulnaris
Ulnar
C7 C8





Flexor carpi ulnaris
Ulnar
C7 C8
Ulnar deviation of the wrist




Extensor carpi ulnaris
Posterior interosseous (radial)
C7 C8





Flexor carpi radialis
Median
C6 C7
Radial deviation of the wrist




Extensor carpi radialis longus
Radial
C6 C7





Abductor pollicis longus
Posterior interosseous (radial)
C7 C8





Extensor pollicis brevis
Posterior interosseous (radial)
C7 C8





Extensor digitorum communis
Posterior interosseous (radial)
C7 C8
Extension of the fingers












Downloaded 2024 3 16 1:39 P Your IP is 155.33.135.27 CHAPTER 12: Manual Muscle Testing,
 2024 McGraw Hill. All Rights Reserved. Terms of Use   Privacy Policy   Notice   Accessibility


Page 43 / 164



Extensor indicis
Posterior interosseous (radial)
C7 C8



Extensor digiti minimi
Posterior interosseous (radial)
C7 C8



Flexor digitorum profundus
Lateral: Anterior interosseous (median)
C8, T1
Flexion of the fingers (lateral aspect flexes the 2nd and 3rd digits; medial aspect flexes the 4th and 5th digits




Medial: Ulnar
C8, T1



Flexor digitorum superficialis
Median
C7 C8, T1
Flexion of the fingers



Elbow Flexors
Anatomic, biomechanic, and electromyographic analyses have demonstrated that the prime movers of elbow flexion are the biceps, brachialis, and brachioradialis (see Table 12 4).85 The pronator teres, flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), and extensor carpi radialis longus (ECRL) muscles are considered to be weak flexors of the elbow.86 Most elbow flexors, and essentially all the major supinator and pronator muscles, have their distal attachments on the radius.87 Contraction of these muscles, therefore, pulls the radius proximally against the humeroradial joint.88,89 The combined efforts of all the elbow flexors can create large amounts of elbow flexion torque. The interosseous membrane transfers a component of this muscle force to the radius and to the ulna, thereby dissipating some of the force.87 The reverse action of the elbow flexors can be used in a closed chain perspective (see Chapter 4) by bringing the upper arm closer to the forearm, such as when performing a pull up.90
Biceps Brachii

The biceps is a two headed muscle that spans two joints. The short head of the biceps arises from the tip of the coracoid process of the scapula, whereas the long head arises from the supraglenoid tuberosity of the scapula (see Figure 12 40a). The biceps has two insertions: the radial tuberosity and by the lacertus fibrosus (see Figure 12 40a).
At the elbow, the biceps is the dominant flexor, but its secondary function is supination of the forearm.91 The supination action of the biceps increases the more the elbow is flexed and is maximal at 90 . It diminishes again when the elbow is fully flexed. No,92 or limited,93 biceps muscle activity has been demonstrated during elbow flexion, with the forearm pronated.86 The biceps, via its long head, also functions as a shoulder flexor (see Muscles of the Shoulder earlier).
The biceps brachii muscle is innervated by the musculocutaneous nerve.
The synergists of this muscle include the brachialis and brachioradialis, supinator, anterior deltoid, coracobrachialis, pectoralis major (clavicular portion), FCR, FCU, pronator teres, and extensor carpi radialis longus and brevis. The antagonists include the triceps brachii and anconeus, pronator teres, pronator quadratus, posterior deltoid, and latissimus dorsi.
To specifically test this muscle the patient is positioned in sitting with the elbow flexed to approximately 90  and the forearm in supination. Using one hand to stabilize the patient's shoulder, the clinician uses the other hand to apply resistance over the anterior aspect of the patient's forearm while asking the patient to hold the position of elbow flexion against the resistance (Figure 12 41). As with all of the elbow flexors, the gravity  minimized/eliminated position is with the patient positioned in sitting with the arm supported on a table at 90  of abduction, the shoulder in neutral rotation, and the elbow extended. Substitution or trick motions when testing any of the elbow flexors can include shoulder extension and assistance from the pronator teres or the wrist and finger extensors and flexors.

FIGURE  12 41



Test position for the biceps brachii


Brachialis 

The brachialis (see Figure 12 41) originates from the lower two thirds of the anterior surface of the humerus and inserts on the ulnar tuberosity and the coronoid process. The brachialis is the workhorse of the elbow and functions to bend the elbow regardless of the degree of pronation and supination of the forearm,93 It is the most powerful flexor of the elbow when the forearm is pronated.94
The brachialis muscle is innervated by the musculocutaneous and radial nerves.
The synergists of the brachialis include the biceps brachii, brachioradialis, extensor carpi radialis longus and brevis, pronator teres, FCR, and FCU. The antagonists of this muscle include the triceps brachii and anconeus.
To specifically test this muscle the patient is positioned in sitting or supine with the elbow flexed and the forearm pronated (Figure 12 42). Using one hand to stabilize the patient's elbow, the clinician places the other hand over the posterior surface of the patient's forearm proximal to the wrist and applies a force in the direction of elbow extension while asking the patient to try and prevent the motion (see Figure 12 42).

FIGURE  12 42


Test position for the brachialis


Brachioradialis 



The brachioradialis (Figure 12 43) arises from the proximal two thirds of the lateral supracondylar ridge of the humerus and the lateral intermuscular septum. It travels down the forearm and inserts on the lateral border of the styloid process on the distal aspect of the radius.
FIGURE  12 43


Brachioradialis muscle

The brachioradialis appears to have a number of functions, two of which occur with rapid movements of elbow flexion. Initially it functions as a shunt muscle, overcoming centrifugal forces acting on the elbow, and then by adding power to increase the speed of flexion.91
The brachioradialis also functions to bring a pronated or supinated forearm back into the neutral position of pronation and supination. In the neutral or pronated position, the muscle acts as a flexor of the elbow, an action that diminishes when the forearm is held in supination.93,95
The brachioradialis muscle is innervated by the radial nerve. The synergists of the brachioradialis include the biceps brachii, brachialis, supinator, pronator teres, pronator quadratus, FCR, FCU, palmaris longus, and flexor digitorum superficialis. The antagonists include the triceps brachii and anconeus, extensor carpi radialis longus and brevis, extensor carpi ulnaris, and extensor digitorum communis.
To specifically test this muscle, the patient is positioned in sitting or supine with the elbow flexed and the forearm placed in a neutral position half way between supination and pronation (Figure 12 44). Using one hand to stabilize the patient's elbow, the clinician places the other hand proximal to the patient's wrist and applies a force into elbow extension while asking the patient to resist the movement.

FIGURE  12 44


Test position for the brachioradialis




Pronator Teres

The pronator teres (Figure 12 45) has two heads of origin: a humeral head and an ulnar head. The humeral head arises from the medial epicondylar ridge of the humerus and common flexor tendon, whereas the ulnar head arises from the medial aspect of the coronoid process of the ulna. The pronator teres inserts on the anterolateral surface of the midpoint of the radius. The muscle functions predominantly to pronate the forearm, but can also assist with elbow flexion.94, 95 and 96

FIGURE  12 45


Pronator teres muscle

The pronator teres is innervated by the median nerve.
The synergists of this muscle include the biceps brachii, brachioradialis, brachialis, FCR, FCU, palmaris longus, flexor digitorum superficialis, and the pronator quadratus. The antagonists of this muscle include the triceps brachii and anconeus, biceps brachii, brachioradialis, and supinator.
To specifically test this muscle, the patient is positioned in sitting or supine with the elbow flexed to approximately 60  and the forearm fully pronated (Figure 12 46). Using one hand, the clinician stabilizes the patient's elbow against the patient's thorax while placing the other hand proximal to the patient's wrist (see Figure 12 46). The patient is asked to maintain the position while the clinician generates a force into forearm supination.
Substitution or trick motions can include trunk flexion to the contralateral side, and abduction and internal rotation of the shoulder. The gravity  minimized/eliminated position for this muscle is with the patient positioned in sitting with the shoulder supported on a table at 90  of flexion, the elbow flexed to 90 , and the forearm perpendicular to the table.




FIGURE  12 46


Test position for the pronator teres


Extensor Carpi Radialis Longus

The ECRL arises from a point superior to the lateral epicondyle of the humerus on the lower third of the supracondylar ridge, just distal to the brachioradialis. It travels down the forearm to insert on the posterior surface of the base of the second metacarpal (Figure 12 47). The muscle functions as a weak flexor of the elbow, as well as providing wrist extension and radial deviation.

FIGURE  12 47


Extensor carpi radialis longus and brevis

The ECRL is innervated by the radial nerve. The synergists of this muscle include the extensor carpi ulnaris, FCR, extensor digitorum communis, extensor indicis, extensor pollicis longus, extensor pollicis brevis, and abductor pollicis longus. The antagonists of this muscle include the extensor carpi ulnaris, FCU, FCR, palmaris longus, flexor digitorum profundus, flexor digitorum superficialis, and flexor pollicis longus.
To specifically test this muscle the patient is positioned in sitting or supine with the elbow extended and the forearm just short of full pronation. Using one hand, the clinician supports the patient's forearm and the patient is asked to extend the wrist in a radial direction (Figure 12 48). Using the other hand, the clinician applies pressure on the posterior aspect of the patient's hand along the second through fourth metacarpal bones in an ulnar direction while asking the patient to prevent the movement (Figure 12 48).

FIGURE  12 48


Test position for the extensor carpi radialis longus and brevis




Flexor Carpi Radialis

The FCR (Figure 12 49) arises from the common flexor tendon on the medial epicondyle of the humerus and inserts on the base of the second and third metacarpal bones. The FCR functions to flex the elbow and wrist but also assists in pronation and radial deviation of the wrist.

FIGURE  12 49


Flexor carpi radialis muscle and the palmaris longus (cut)

The FCR is innervated by the median nerve. The synergists of this muscle include the FCU, palmaris longus, flexor digitorum profundus, flexor digitorum superficialis, flexor pollicis longus, extensor carpi radialis longus and brevis, extensor pollicis brevis, and abductor pollicis longus. The antagonists of this muscle include the FCU, extensor carpi ulnaris, flexor pollicis longus, extensor carpi radialis longus and brevis, extensor digitorum communis, extensor indicis, and extensor pollicis longus.
To specifically test this muscle the patient is positioned in sitting or supine, with the wrist flexed and ulnarly deviated and the forearm in supination. Using one hand, the clinician supports the patient forearm, while using the index and middle finger of the other hand to apply pressure on the thenar eminence in an ulnar and extension direction (Figure 12 50). The patient is asked to prevent this motion.

FIGURE  12 50


Test position for the flexor carpi radialis




Flexor Carpi Ulnaris

The FCU (Figure 12 51) arises from two heads. The humeral head arises from the medial humeral epicondyle as part of the common flexor tendon, while the ulnar head arises from the proximal portion of the subcutaneous border of the ulna. The FCU inserts directly onto the pisiform, the hamate via the pisohamate ligament, and onto the anterior surface of the base of the fifth metacarpal, via the pisometacarpal ligament. The FCU functions to assist with elbow flexion in addition to flexion and ulnar deviation of the wrist.
FIGURE  12 51


Flexor carpi ulnaris muscle

The FCU is innervated by the ulnar nerve. The synergists of this muscle include the FCR, palmaris longus, flexor digitorum profundus, flexor digitorum superficialis, flexor pollicis longus, extensor carpi ulnaris, biceps brachii, brachialis, pronator teres, brachioradialis, and extensor carpi radialis longus and brevis. The antagonists of this muscle include the triceps brachii and anconeus, extensor carpi radialis longus and brevis, extensor carpi ulnaris, extensor digitorum communis, extensor indicis, extensor digiti minimi, extensor pollicis longus, extensor pollicis brevis, FCR, and abductor pollicis longus.
To specifically test this muscle, the patient is positioned in supine or sitting with the forearms supported, the wrist flexed, and the fingers relaxed. The patient is asked to flex and ulnarly deviate the wrist. While stabilizing the wrist with one hand, the clinician generates a radial and extension force with the other on the medial aspect of the patient's hand (Figure 12 52).

FIGURE  12 52


Test position for the flexor carpi ulnaris



Forearm Pronators

Pronator Teres

See earlier discussion.

Pronator Quadratus 


The fibers of the pronator quadratus run perpendicular to the direction of the arm, running from the most distal quarter of the anterior ulna to the distal quarter of the anterior radius (Figure 12 53). It is the only muscle that attaches only to the ulna at one end and the radius at the other end.

FIGURE  12 53


Pronator quadratus muscle

The pronator quadratus, which is the main pronator of the hand, is innervated by the anterior interosseous branch of the median nerve. The synergists for this muscle include the pronator teres, brachioradialis, and FCR. The antagonists include the biceps brachii, brachioradialis, and supinator.
To specifically test this muscle the patient is positioned in sitting or supine with the elbow completely flexed and the forearm pronated. Using one hand to stabilize the patient's elbow, the clinician places the other hand proximal to the patient's wrist and applies a force into supination while asking the patient to prevent the movement (Figure 12 54).

FIGURE  12 54



Test position for the pronator quadratus


Flexor Carpi Radialis

See earlier discussion.
Forearm Supinators

Biceps

See earlier discussion. It is important to remember that the effectiveness of the biceps as a supinator is greatest when the elbow is flexed to 90 , placing the biceps tendon at a 90  angle to the radius. In contrast, with the elbow flexed only 30 , much of the rotational efficiency of the biceps is lost.90
Supinator 

The supinator (Figure 12 55) originates from the lateral epicondyle of the humerus, the lateral collateral ligament (LCL), the annular ligament, the supinator crest, and the ulnar fossa. It inserts on the superior third of the anterior and lateral surface of the radius. The supinator muscle is a relentless forearm supinator, similar to the brachialis during elbow flexion. The supinator functions to supinate the forearm in any elbow position, whereas the previously mentioned ECRL and brevis work as supinators during fast movements, and against resistance.

FIGURE  12 55


Supinator muscle



The nervous system usually recruits the supinator muscle for low power tasks that require a supination motion only, while the biceps remains relatively inactive a fine example of the law of parsimony.87

The supinator is innervated by the radial nerve.
The synergists for the supinator include the biceps brachii, and the brachioradialis. The antagonists include the pronator teres, pronator quadratus, brachioradialis, and FCR.
To specifically test this muscle the patient is positioned in standing or sitting. The patient's arm can be positioned in one of two ways:  The shoulder flexed to 90 , the elbow fully flexed, and the forearm fully supinated (Figure 12 56).
 The shoulder and elbow extended behind the patient and the forearm supinated (Figure 12 57).
Using one hand to stabilize the patient's upper arm at the elbow, the clinician places the other hand just proximal to the patient's wrist and applies a force into pronation while asking the patient to prevent the motion.

FIGURE  12 56


Test position for the supinator




FIGURE  12 57


Alternate test position for the supinator


Elbow Extensors
There are two muscles that extend the elbow: the triceps and the anconeus (see Table 12 4).
Triceps Brachii

The triceps brachii (Figure 12 58) has three heads of origin. The long head arises from the infraglenoid tuberosity of the scapula, the lateral head from the posterior and lateral surface of the humerus, and the medial head from the lower posterior surface of the humerus. The muscle inserts on the superoposterior surface of the olecranon and deep fascia of the forearm. The triceps has its maximal force in movements that combine both elbow
 extension and shoulder extension. Like the biceps, it is a two joint muscle. The medial head of the triceps is the workhorse of elbow extension, with the 



lateral and long heads recruited during heavier loads.75 During strong contractions of the triceps for example, a push up, which involves a combination of elbow extension and shoulder flexion as the triceps strongly contracts to extend the elbow, the shoulder simultaneously flexes by action of the anterior deltoid, which overpowers the shoulder extension torque of the long head of the triceps.90

FIGURE  12 58


Triceps brachii and anconeus


Anconeus

The anconeus arises from the lateral epicondyle of the humerus and inserts on the lateral aspect of the olecranon and posterior surface of the ulna (see Figure 12 58). The exact function of the anconeus in humans has yet to be determined, although it appears as a fourth head of the elbow extension mechanism, similar to the quadriceps of the knee.87 It has been suggested that in addition to assisting with elbow extension, the anconeus functions to stabilize the ulnar head in all positions (except radial deviation) and to pull the subanconeus bursa and the joint capsule out of the way during extension, thus avoiding impingement.96,99 The anconeus has also been found to stabilize the elbow during forearm pronation and supination.93




The triceps brachii and anconeus are innervated by the radial nerve.
The synergists of the triceps brachii and anconeus include the latissimus dorsi, teres major, and posterior deltoid. The antagonists include the biceps brachii, brachioradialis, brachialis, FCR, FCU, pronator teres, and the extensor carpi radialis longus and brevis.
To specifically test the triceps brachii and anconeus, three different positions can be used:
 Patient prone. The patient abducts the shoulder to 90 , extends the elbow fully, and then unlocks it slightly (Figure 12 59).
 Patient supine. The patient abducts the shoulder to 90 , extends the elbow fully, and then unlocks it slightly (Figure 12 60).
 Patient sitting. The patient abducts the shoulder to 160 180 , extends the elbow fully, and then unlocks it slightly (Figure 12 61). This position is the one used most commonly.

FIGURE  12 59


Test position for the triceps brachii patient prone


FIGURE  12 60


Test position for the triceps brachii patient supine




FIGURE  12 61


Test position for the triceps brachii patient sitting

With each of the foregoing positions, the clinician uses one hand to stabilize the upper arm and places the other hand proximal to the patient's wrist. The patient is asked to hold the arm position while the clinician applies a force into elbow flexion.
Substitution or trick motions can include flexion of the shoulder. The gravity minimized/eliminated position for this muscle is with the patient positioned in sitting with the shoulder supported in 90  of abduction and internal rotation and with the elbow flexed and the forearm in neutral.
 MUSCLE TESTING OF THE WRIST AND FOREARM	




The muscles of the forearm are contained within three major fascial compartments, the anterior forearm, the posterior forearm, and the compartment referred to as the mobile wad (Table 12 5), all of which can be described as the 18 extrinsic muscles that originate in the forearm and insert within the hand.101 The flexors, which are located in the anterior compartment, flex the wrist and digits, whereas the extensors, located in the posterior compartment, extend the wrist and the digits.
TABLE 12 5
Muscle Compartments of the Forearm 

Compartment 
Principal Muscles
Anterior
Pronator teres Flexor carpi radialis Palmaris longus
Flexor digitorum superficialis Flexor digitorum profundus Flexor pollicis longus
Flexor carpi ulnaris Pronator quadratus
Posterior
Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor digitorum communis Extensor digitorum proprius Extensor digiti quinti
Extensor carpi ulnaris
Mobile wad
Brachioradialis
Extensor carpi radialis longus Extensor carpi radialis brevis


The extrinsic group, whose muscle bellies lie proximal to the wrist, join with the intrinsic muscles located entirely within the hand. This design provides for a large number of muscles to act on the hand without excessive bulkiness. The extrinsic tendons enhance wrist stability by balancing flexor and extensor forces and compressing the carpals.
The amount of tendon excursion determines the available range of motion at a joint. To calculate the amount of tendon excursion needed to produce a certain number of degrees of joint motion involves an appreciation of geometry. A circle's radius equals approximately 1 radian (57.29 ). The mathematical radius, which is equivalent to the moment arm, represents the amount of tendon excursion required to move the joint through 1 radian.102 For example, if a joint's moment arm is 10 mm, the tendon must glide 10 mm to move the joint 60  (approximately 1 radian) or 5 mm to move the joint 30  (  radian).103
Anterior Compartment of the Forearm
Superficial Muscles

Pronator Teres

See earlier discussion.



Flexor Carpi Radialis (FCR)

See earlier discussion.
Palmaris Longus

The inconsistent palmaris longus (see Figure 12 49) arises from the medial humeral epicondyle as part of the common flexor tendon and inserts on the transverse carpal ligament and palmar aponeurosis. The function of the palmaris longus is to flex the wrist, and it may play a role in thumb abduction in some people.104
The palmaris longus is innervated by the median nerve. The synergists of this muscle include the FCR, FCU, flexor digitorum profundus, flexor digitorum superficialis, and flexor pollicis longus. The antagonists of this muscle include the extensor carpi ulnaris, extensor carpi radialis longus and brevis, extensor digitorum communis, extensor pollicis longus, and extensor indicis.
To specifically test this muscle, the patient is positioned in sitting or supine with the forearm supinated and is asked to flex the wrist and cup the palm (Figure 12 62). While supporting the patient's forearm with one hand, the clinician uses the other hand to apply an uncupping and wrist extension force to the thenar and hypothenar eminences of the patient's hand (see Figure 12 62).

FIGURE  12 62


Test position for the palmaris longus


Flexor Carpi Ulnaris (FCU)

See earlier discussion.
Intermediate Muscle

Flexor Digitorum Superficialis (FDS)



The FDS has a three headed origin (Figure 12 63). The humeral head arises from the medial humeral epicondyle as part of the common flexor tendon. The ulnar head arises from the coronoid process of the ulna. The radial head arises from the oblique line of the radius. The FDS inserts on the middle phalanx of the medial four digits via a split, "sling" tendon. The FDS serves to flex the proximal and middle interphalangeal joints of the medial four digits and assist with elbow flexion and wrist flexion. The FDS possesses tendons that are capable of relatively independent action at each finger.

FIGURE  12 63


Flexor digitorum superficialis muscle

The FDS is innervated by the median nerve. The synergists of this muscle include the flexor digitorum profundus, FCR, FCU, palmaris longus, lumbricals, interossei, abductor digiti minimi, flexor digiti minimi, and opponens digiti minimi. The antagonists to this muscle include the extensor carpi radialis longus and brevis, extensor carpi ulnaris, extensor digitorum communis, extensor indicis, lumbricals, and interossei.
To specifically test this muscle the patient is positioned in sitting or supine with the forearm supported in supination and the metacarpophalangeal (MCP) joint stabilized by the clinician. The patient is asked to bend the middle phalanx of the finger (Figure 12 64) while the patient maintains the three fingers not being tested into extension and prevents the wrist from excessive flexing (see Figure 12 64). The clinician tests each finger individually by applying an extension force to the anterior aspect of the middle phalanx while asking the patient to prevent the movement.

FIGURE  12 64


Test position for the flexor digitorum superficialis


Deep Muscles

Flexor Pollicis Longus (FPL)

The FPL has its origin on the anterior surface of the radius, medial border of the coronoid process of the ulna, and the adjacent interosseous
 membrane. It inserts on the distal phalanx of the thumb (Figure 12 65). The FPL functions to flex the thumb.	




FIGURE  12 65


Flexor pollicis longus muscle

The FPL is innervated by the anterior interosseous branch of the median nerve. The synergists of this muscle include the FCR, FCU, palmaris longus, flexor digitorum profundus, FDS, flexor pollicis brevis, abductor pollicis brevis, and adductor pollicis. The antagonists to this muscle include the extensor carpi radialis longus and brevis, extensor carpi ulnaris, extensor digitorum communis, extensor indicis, extensor pollicis longus, extensor pollicis brevis, abductor pollicis brevis, and abductor pollicis longus.
To specifically test this muscle, the patient is positioned in sitting or supine with the hand resting on a surface and the forearm in supination. Using one hand, the clinician stabilizes the MCP joint of the thumb into extension (Figure 12 66) and uses the other hand to generate an extension force to the anterior aspect of the distal phalanx of the thumb (see Figure 12 66).

FIGURE  12 66


Test position for flexor pollicis longus


Flexor Digitorum Profundus (FDP)



The FDP arises from the medial and anterior surfaces of the proximal ulna, the adjacent interosseous membrane, and the deep fascia of the forearm (Figure 12 67). The FDP inserts on the base of the distal phalanges of the medial four digits. The FDP functions to flex the distal interphalangeal (DIP) joints, after the FDS flexes the second phalanges, and assists with flexion of the wrist. The tendons of the FDS and FDP are held against the phalanges by a fibrous sheath. At strategic locations along the sheath, five dense annular pulleys (designated A1, A2, A3, A4, and A5) and three thinner cruciform pulleys (designated C1, C2, and C3) prevent the tendons from bowstringing.105
FIGURE  12 67


Flexor digitorum profundus muscle


The FDP has a dual nerve supply: the medial two heads are supplied by the ulnar nerve, whereas the lateral two heads are supplied by the anterior interosseous branch of the median nerve. The synergists of this muscle include the FCR, FCU, palmaris longus, FDS, FPL, lumbricals, interossei, abductor digiti minimi, flexor digiti minimi, and opponens digiti minimi. The antagonists of this muscle include the extensor carpi radialis longus and brevis, extensor carpi ulnaris, extensor digitorum communis, extensor indicis, extensor pollicis longus, lumbricals, and interossei.
To specifically test this muscle, the patient is positioned in sitting or supine with the wrist in a neutral position or slightly extended. Using one hand, the clinician stabilizes the proximal and middle phalanges of the finger to be tested. The patient is asked to flex the DIP joint of the finger while the clinician applies an extension force to the anterior aspect of the DIP (Figure 12 68).

FIGURE  12 68


Test position for flexor digitorum profundus muscle




Pronator Quadratus 

See earlier discussion.
Posterior Compartment of the Forearm
Superficial Muscles

Extensor Carpi Radialis Longus (ECRL)

See earlier discussion.
Extensor Carpi Radialis Brevis (ECRB)

The ECRB arises from the common extensor tendon on the lateral epicondyle of the humerus, and from the radial collateral ligament (see Figure 12  47). It inserts on the posterior surface of the base of the third metacarpal bone. The muscle stretches across the radial head during pronation, resulting in increased tensile stress when the forearm is pronated, the wrist is flexed, and the elbow is extended. The more medial location of the ECRB compared to the ECRL makes it the primary wrist extensor, but it has also a slight action of radial deviation.

The ECRB receives its nerve supply from the posterior interosseous branch of the radial nerve. The synergists and antagonists of this muscle are similar to those of the ECRL except for those that cross the elbow.
To specifically test this muscle, the patient is positioned in sitting or supine with the elbow fully flexed (to place the ECRL in a position of mechanical insufficiency), and the forearm just short of full pronation supported by the examiner or the table (Figure 12 69). The patient is asked to extend the wrist in a radial direction and to hold that position while the clinician applies pressure on the posterior aspect of the hand along the second and third metacarpal bones.

FIGURE  12 69



Test position for the extensor carpi radialis brevis


Extensor Digitorum Communis (EDC)

The EDC, which consists of the extensor indices, extensor digiti minimi, and extensor digitorum, arises from the lateral humeral epicondyle, part of the common extensor tendon and inserts on the lateral and posterior aspect of the medial four digits (Figure 12 70). The EDC functions to extend the medial four digits.

FIGURE  12 70


Extensor digitorum communis muscle



The EDC is innervated by the posterior interosseous branch of the radial nerve. The synergists of this muscle include the extensor carpi radialis longus and brevis, extensor carpi ulnaris, extensor indicis, extensor pollicis longus, lumbricals, and interossei. The antagonist of this muscle include the FCR, FCU, palmaris longus, FDP, FDS, flexor pollicis longus, lumbricals, interossei, abductor digiti minimi, flexor digiti minimi, and opponens digiti minimi.
To specifically test this muscle the patient is positioned supine or sitting with the forearm pronated, the wrist positioned in neutral halfway between flexion and extension and the MCP and proximal interphalangeal (PIP) joints slightly flexed. The patient is asked to extend the MCP of the finger to be tested and to hold that position. The clinician uses one hand to stabilize the wrist and, using two fingers of the other hand, applies pressure against the posterior surfaces of the patient's proximal phalanges (Figure 12 71).

FIGURE  12 71


Test position for the extensor digitorum communis




Extensor Digiti Minimi (EDM)

The EDM arises from a muscular slip from the ulnar aspect of the extensor digitorum muscle and inserts on the proximal phalanx of the fifth digit. The EDM extends the MCP of the fifth digit and, in conjun ction with the lumbricals and interossei, extends the interphalangeal joints of the fifth digit. The EDM also assists in abduction of the fifth digit.

The EDM is innervated by the posterior interosseous branch of the radial nerve.
To specifically test this muscle the patient is positioned supine or sitting with the forearm pronated, the wrist positioned in neutral halfway between flexion and extension and the MCP and PIP joints slightly flexed. The patient is asked to extend the MCP of the fifth digit and to hold that position. The clinician uses one hand to stabilize the wrist and, using two fingers of the other hand, applies pressure against the posterior surface of the patient's proximal phalange.
Extensor Carpi Ulnaris (ECU). The ECU arises from the common extensor tendon on the lateral epicondyle of the humerus and the posterior border of the ulna (Figure 12 72). It inserts on the medial side of the base of the fifth metacarpal bone. The ECU is an extensor of the wrist in supination, and primarily causes ulnar deviation of the wrist in pronation, working in synergy with the FCU to prevent radial deviation during pronation.109
FIGURE  12 72


Extensor carpi ulnaris muscle





The ECU is innervated by the posterior interosseous branch of the radial nerve. The synergists for this muscle include the FCU, FPL, extensor carpi radialis longus and brevis, EDC, extensor indicis, and extensor pollicis longus. The antagonist of this muscle include the FCR, extensor carpi radialis longus and brevis, extensor pollicis brevis, abductor pollicis longus, FCU, palmaris longus, FDP, FDS, and FPL.
To specifically test this muscle, the patient is positioned sitting or supine with the forearm positioned in complete pronation. The patient is asked to extend the wrist in an ulnar direction and to hold this position. Using one hand to stabilize the patient's forearm, the clinician uses the other hand to apply pressure to the posterior aspect of the patient's hand along the fifth metacarpal bone in a radial direction (Figure 12 73).

FIGURE  12 73


Test position for the extensor carpi ulnaris



Deep Muscles

Abductor Pollicis Longus (APL)

The APL arises from the dorsal surface of the proximal portion of the radius, ulna, and interosseous membrane and inserts on the ventral surface of the base of the first metacarpal (Figure 12 74). The APL functions in abduction, extension, and external rotation of the first metacarpal.

FIGURE  12 74


Abductor pollicis longus muscle



The APL is innervated by the posterior interosseous branch of the radial nerve. The synergists of this muscle include the FCR, extensor carpi radialis longus and brevis, abductor pollicis brevis, and extensor pollicis brevis. The antagonists of this muscle include the FCU, extensor carpi ulnaris, FPL, flexor pollicis brevis, and adductor pollicis.
To specifically test this muscle, the patient is positioned sitting or supine. The patient is asked to abduct and slightly extend the thumb and to hold that position. Using one hand, the clinician stabilizes the patient's hand and uses the other hand to apply an adduction and flexion force against the lateral aspect of the distal first metacarpal (Figure 12 75).

FIGURE  12 75


Test position for the abductor pollicis longus




Extensor Pollicis Brevis (EPB)

The EPB arises from the posterior surface of the radius and interosseous membrane, just distal to the origin of the APL. It inserts on the posterior surface of the proximal phalanx of the thumb via the extensor expansion (Figure 12 76). The EPB functions in extension of the proximal phalanx of the thumb.

FIGURE  12 76


Extensor pollicis brevis muscle



The EPB is innervated by the posterior interosseous branch of the radial nerve. The synergists of this muscle include the FCR, extensor carpi radialis longus and brevis, abductor pollicis longus, and abductor pollicis brevis. The antagonists of this muscle include the FCU, extensor carpi ulnaris, flexor pollicis longus, flexor pollicis brevis, and adductor pollicis.
To specifically test this muscle, the patient is positioned sitting or supine with the MCP joint of the thumb extended. Using one hand, the clinician stabilizes the patient's hand, while using a finger from the other hand to apply a flexion force against the proximal phalanx of the thumb (Figure 12  7 7).

FIGURE  12 77


Test position for the extensor pollicis brevis




Extensor Pollicis Longus (EPL)

The EPL arises from the posterior surface of the midportion of the ulna and intero sseous membrane. It inserts on the posterior surface of the distal phalanx of the thumb via the extensor expansion (Figure 12 78). The EPL functions in extension of the distal phalanx of the thumb and is thus involved in extension of the middle phalanx and the MCP joint of the thumb.

FIGURE  12 78


Extensor pollicis longus muscle



The EPL is innervated by the posterior interosseous branch of the radial nerve. The synergists of this muscle include the abductor pollicis brevis, flexor pollicis brevis, adductor pollicis, extensor carpi radialis longus and brevis, extensor carpi ulnaris, extensor digitorum communis, extensor indicis, and first anterior interosseous. The antagonists of this muscle include the flexor pollicis longus, flexor pollicis brevis, abductor pollicis brevis, FCR, FCU, palmaris longus, FDP, and FDS.
To specifically test this muscle, the patient is positioned in sitting or supine with the thumb extended. The clinician uses one hand to stabilize the patient's hand and uses the other to apply a flexion force to the distal phalanx of the posterior surface of the patient's thumb (Figure 12 79).

FIGURE  12 79


Test position for the extensor pollicis longus




Extensor Indicis (EI)

The EI arises from the posterior surface of the ulna, distal to the other deep muscles, and inserts on the extensor expansion of the index finger. The EI is involved in extension of the proximal phalanx of the index finger.
The EI is innervated by the posterior interosseous branch of the radial nerve. The synergists of this muscle include the extensor carpi radialis longus and brevis, extensor carpi ulnaris, EDC, EPL, lumbricals, and interossei. The antagonists of this muscle include the FCR, FCU, palmaris longus, FDP, FDS, FPL, lumbricals, and interossei.
To specifically test this muscle, the patient is positioned in sitting or supine and is asked to extend the index finger. The clinician uses one hand to stabilize the patient's hand and uses the other hand to generate a flexion force to the posterior aspect of the proximal phalanx of the index finger (see Figure 12 71).
MUSCLE TESTING OF THE HAND
The muscles of the hand are those that originate and insert within the hand and are responsible for the fine finger movements.
Short Muscles of the Thumb

Abductor Pollicis Brevis (APB)

The APB arises from the flexor retinaculum and the trapezium bone and inserts on the radial aspect of the proximal phalanx of the thumb (Figure 12  8 0). The APB functions to abduct the first metacarpal and proximal phalanx of the thumb.

FIGURE  12 80


Abductor pollicis brevis muscle



The APB is innervated by the median nerve. The synergists of this muscle include the abductor pollicis longus, flexor pollicis longus, and flexor pollicis brevis. The antagonists of this muscle include the abductor pollicis and extensor pollicis longus.
To specifically test this muscle, the patient is positioned in sitting or supine and is asked to abduct the thumb. Using one hand, the clinician stabilizes the patient's wrist and hand and uses the other hand to generate a downward force against the proximal phalanx of the patient's thumb (Figure 12  8 1).

FIGURE  12 81


Test position for the abductor pollicis brevis




Flexor Pollicis Brevis (FPB)

The FPB arises from two heads. The superficial head arises from the flexor retinaculum and the trapezium bone, whereas the deep head arises from the floor of the carpal canal (Figure 12 82). The FPB inserts on the base of the proximal phalanx of the thumb. The FPB functions to flex the proximal phalanx of the thumb.

FIGURE  12 82


Flexor pollicis brevis muscle

The FPB has dual innervation the superficial head receives its innervation from the median nerve, whereas the deep head is innervated by the ulnar nerve. The synergists to this muscle include the flexor pollicis longus, abductor pollicis brevis, and adductor pollicis. The antagonists of this muscle include the extensor pollicis longus and extensor pollicis brevis.
To specifically test this muscle, the patient is positioned in sitting or supine and is asked to flex the thumb. Using one hand, the clinician stabilizes the



patient's wrist and hand and uses the other hand to apply an extension force to the anterior surface of the proximal phalanx of the patient's thumb (Figure 12 83).
FIGURE  12 83


Test position for the flexor pollicis brevis


Opponens Pollicis (OP)

The OP arises from the flexor retinaculum and the trapezium bone and inserts along the radial surface of the first metacarpal (Figure 12 84). The OP functions to flex, rotate, and slightly abduct the first metacarpal across the palm to allow for opposition to each of the other digits.

FIGURE  12 84


Opponens pollicis muscle



The OP is innervated by the median nerve. The synergists of this muscle include the flexor pollicis brevis and adductor pollicis. The antagonists include the extensor pollicis longus and extensor pollicis brevis.
To specifically test this muscle, the patient is positioned in sitting or supine and is asked to touch his or her thumb to the little finger (a combination of flexion, abduction, and slight internal rotation). The clinician uses one hand to stabilize the patient's wrist and hand, and the other hand to generate pressure to the metacarpal bone of the thumb in an adduction and external rotation and extension direction (Figure 12 85).

FIGURE  12 85


Test position for the opponens pollicis




Adductor Pollicis (AP)

The AP arises from two heads. The transverse head originates from the ventral surface of the shaft of the third metacarpal, whereas the oblique head originates from the trapezium, trapezoid, and capitate bones (Figure 12 86) and the base of the second and third metacarpal bone. The AP inserts on the ulnar side of the base of the proximal phalanx of the thumb. The AP functions to adduct the carpometacarpal joint and adducts and assists in flexion of the MCP joints and opposition of the thumb. The AP may also assist in extending the interphalangeal joint.

FIGURE  12 86


Adductor pollicis

The AP is innervated by the deep branch of the ulnar nerve. The synergists of this muscle include the extensor pollicis longus, flexor pollicis longus, flexor pollicis brevis, opponens pollicis, and first anterior interossei. The antagonists include the abductor pollicis brevis, abductor pollicis longus, flexor pollicis longus, and extensor pollicis brevis.



To specifically test this muscle, the patient is positioned in sitting or supine and is asked to move the thumb toward the palm. Using one hand, the clinician stabilizes the patient's wrist and hand, while using the other to apply an abduction force to the inner aspect of the thumb (Figure 12 87).

FIGURE  12 87


Test position for the adductor pollicis


Short Muscles of the Fifth Digit

Abductor Digiti Minimi (ADM)

The ADM arises from the pisiform bone and the tendon of the flexor carpi ulnaris. It inserts on the ulnar aspect of the base of the proximal phalanx of the fifth digit, together with the flexor digiti minimi brevis (Figure 12 88). The ADM functions to abduct the fifth digit.

FIGURE  12 88


Abductor digiti minimi muscle



The ADM is innervated by the deep branch of the ulnar nerve. The synergists for this muscle include the interossei, FDP, FDS, and fourth lumbrical. The antagonists to this muscle include the anterior interossei, extensor digitorum communis, and extensor digiti minimi.
To specifically test this muscle, the patient is positioned sitting or supine and is asked to abduct the little finger. The clinician uses one hand to stabilize the patient's wrist and hand, and the other to apply an adduction force against the ulnar aspect of the middle phalanx of the patient's fifth digit (Figure 12 89).

FIGURE  12 89


Test position for the abductor digiti minimi


Flexor Digiti Minimi (FDM)

The FDM originates from the flexor retinaculum and the hook of the hamate bone (Figure 12 90). It inserts on the ulnar aspect of the base of the proximal phalanx of the fifth digit, together with the abductor digiti minimi. The FDM functions to flex the proximal phalanx of the fifth digit.




FIGURE  12 90


Flexor digiti minimi muscle

The FDM is innervated by the deep branch of the ulnar nerve. The synergists for this muscle include the opponents digiti minimi, lumbricals 3 and 4, interossei, flexor digitorum profundus, and flexor digitorum superficialis. The antagonists include the extensor digitorum communis and extensor digiti minimi.
To specifically test this muscle, the patient is positioned sitting or supine and is asked to flex the little finger at the MCP joint while maintaining the interphalangeal joint in extension. Using one hand, the clinician stabilizes the patient's hand, while using the other to apply an extension force against the flexed proximal phalanx of the patient's fifth digit (Figure 12 91).

FIGURE  12 91


Test position for the flexor digiti minimi


Opponens Digiti Minimi (ODM)



The ODM arises from the flexor retinaculum and the hook of the hamate bone and inserts on the ulnar border of the shaft of the fifth metacarpal bone (Figure 12 92). The ODM functions to provide a small amount of flexion and external rotation of the fifth digit.

FIGURE  12 92

Opponens digiti minimi muscle

The ODM is innervated by the deep branch of the ulnar nerve. The synergists of this muscle include the flexor digiti minimi, abductor digiti minimi, fourth lumbricals, third and fourth anterior interossei, flexor digitorum superficialis, and flexor digitorum profundus. The antagonists include the extensor digitorum communis, extensor digiti minimi, and abductor digiti minimi.
To specifically test this muscle, the patient is positioned in sitting or supine and is asked to try to cup the fifth metacarpal toward the thumb. Using one hand, the clinician stabilizes the patient's hand, while using the index finger of the other hand to push against the first metacarpal of the fifth digit and apply a downward force (Figure 12 93).

FIGURE  12 93


Test position for the opponens digit minimi



Interosseous Muscles of the Hand
The interossei muscles of the hand are divided by anatomy and function into anterior (palmar) and posterior (dorsal) interossei.
Anterior Interossei

The three anterior (palmar) interossei have a variety of origins and insertions (Figure 12 94). The first interosseus originates from the ulnar surface of the second metacarpal bone and inserts on the ulnar side of the proximal phalanx of the second digit. The second palmar interosseus arises from the radial side of the fourth metacarpal bone and inserts into the radial side of the proximal phalanx of the fourth digit. The third palmar interosseus originates from the radial side of the fifth metacarpal bone and inserts into the radial side of the proximal phalanx of the fifth digit. Each of the anterior interossei functions to adduct the digit to which it is attached toward the middle digit. The anterior interossei also function to extend the distal and then the middle phalanges.

FIGURE  12 94


Lumbricals, anterior and posterior interossei



The anterior interossei are innervated by the deep branch of the ulnar nerve. The synergists to the anterior interossei include the posterior interossei, lumbricals, flexor digitorum profundus and superficialis, extensor indicis, extensor digitorum communis, extensor digiti minimi, abductor digiti minimi, flexor digiti minimi, opponens digiti minimi, and adductor pollicis. The antagonists to the anterior interossei include the posterior interossei, extensor digitorum communis, extensor indicis, extensor digiti minimi, abductor digiti minimi, flexor digitorum profundus and superficialis, and lumbricals.
To specifically test this muscle group, the patient is positioned sitting or supine with the digits not being tested stabilized, and the finger being tested brought toward midline. One by one, the clinician applies pressure in an abduction direction against the appropriate phalanx of the thumb, index, ring, and little finger (Figure 12 95).

FIGURE  12 95


Test position for the anterior interossei


Posterior Interossei

 The four posterior (dorsal) interossei have a varied origin and insertion similar to those of their anterior counterparts (see Figure 12 94). The posterior 



interossei originate via two heads from adjacent sides of the metacarpal bones. The first posterior interosseus muscle inserts into the radial side of the proximal phalanx of the second digit. The second inserts into the radial side of the proximal phalanx of the third digit. The third inserts into the ulnar side of the proximal phalanx of the third digit, and the fourth inserts into the ulnar side of the proximal phalanx of the fourth digit. The posterior interossei abduct the index, middle, and ring fingers from the midline of the hand.
The posterior interossei receive their innervation from the deep branch of the ulnar nerve.
To specifically test this muscle group, the patient is positioned sitting or supine with the digits not being tested stabilized, and the finger being tested moved away from midline. One by one, the clinician applies pressure in the direction of adduction against the appropriate phalanx of the thumb, index, ring, and little finger (Figure 12 96).

FIGURE  12 96


Test position for the posterior interossei

Lumbricals
The lumbrical muscles are usually four small intrinsic muscles of the hand that originate from the FDP tendons and insert into the dorsal hood apparatus (see Figure 12 94). Occasionally, more than four lumbricals are found in one hand.111
During contraction, the lumbricals pull the FDP tendons distally, thus possessing the unique ability to relax their own antagonist.112 They function to perform the motion of interphalangeal joint extension with the MCP joint held in extension and can assist in MCP flexion.109
The lumbrical muscles also serve an important role in the proprioception of the hand, providing feedback about the position and movement of the hand and finger joints.112

The lumbricals have dual innervation. Lumbricals I and II are innervated typically by the median nerve, whereas the third and fourth lumbricals are innervated by the ulnar nerve. The synergists for the lumbricals include the posterior interossei, flexor digitorum profundus and superficialis, abductor digiti minimi, flexor digiti minimi, opponens digiti minimi, extensor digitorum communis, extensor indices, and anterior interossei. The




antagonists include the extensor digitorum communis, extensor indices, anterior interossei, and flexor digitorum profundus and superficialis.
To specifically test this muscle group, the patient is positioned in sitting or supine and is asked to place the hand into an intrinsic plus position (Figure 12 97) and to hold a piece of paper. Using one hand, the clinician tries to pull a sheet of paper from the patient's grasp. Pressure is thus applied in two distinct phases:
1. A flexion force is applied to the posterior surfaces of the distal and middle phalanges.
2. An extension force is applied to the anterior surfaces of the proximal phalanges.

FIGURE  12 97


Test position for the lumbricals


MUSCLE TESTING OF THE HIP
The hip joint is surrounded by a large number of muscles that accelerate, decelerate, and stabilize the hip joint. Indeed, 21 muscles cross the hip, providing both triplanar movement and stability between the femur and acetabulum.113 Consequently, abnormal performance of the hip muscles may alter the distribution of forces across the joint articular surfaces, potentially causing, or at least predisposing, degenerative changes in the articular cartilage, bone, and surrounding connective tissues.113

The hip muscles and their respective actions are outlined in Tables 12 6 and 12 7.
TABLE 12 6
Origin, Insertion, and Innervation of Muscles Acting across the Hip Joint


Muscle 
Origin
Insertion 
Innervation 












Adductor brevis
External aspect of the body and inferior ramus of the pubis.
The line from the greater trochanter of the
Obturator






linea aspera of the femur
nerve




Adductor longus
In angle between pubic crest and symphysis.
The middle third of the linea aspera of the
Obturator






femur
nerve




Adductor magnus
Inferior ramus of pubis, ramus of ischium, and the inferolateral
To the linea aspera and adductor tubercle of
Obturator





aspect of the ischial tuberosity.
the femur
nerve and







tibial portion







of the sciatic







nerve




Biceps femoris
Long head arises from the sacrotuberous ligament and
On the lateral aspect of the head of the fibula,
Tibial portion





posterior aspect of the ischial tuberosity. Short head does not
the lateral condyle of the tibial tuberosity,
of the sciatic





act across the hip.
the lateral collateral ligament, and the deep
nerve, S1






fascia of the leg





Gemelli (superior
Superior posterior (dorsal) surface of the spine of the ischium
Superior  and inferior medial surface of the
Sacral plexus




and inferior)
and inferior upper part of the tuberosity of the ischium.
greater trochanter





Gluteus maximus
Posterior gluteal line of the ilium, iliac crest, aponeurosis of the
Iliotibial tract of the fasciae latae and gluteal
Inferior gluteal





erector spinae, posterior (dorsal) surface of the lower part of
tuberosity of the femur
nerve





the sacrum, side of the coccyx, sacrotuberous ligament, and







intermuscular fascia.






Gluteus medius
Outer surface of the ilium between the iliac crest and the
Lateral surface of the greater trochanter
Superior





posterior gluteal line, anterior gluteal line, and fascia.

gluteal nerve




Gluteus minimus
Outer surface of the ilium between the anterior and inferior
On the anterior surface of the greater
Superior





gluteal lines, and the margin of the greater sciatic notch.
trochanter
gluteal nerve




Gracilis
The body and inferior ramus of the pubis.
The superior medial surface of the proximal
Obturator






tibia, just proximal to the tendon of the
nerve






semitendinosus





Iliacus
Superior two thirds of the iliac fossa and upper surface of the
Fibers converge with tendon of the psoas
Femoral





lateral part of the sacrum.
major to lesser trochanter.
nerve.




Obturator externus
Rami of the pubis, ramus of the ischium, and medial two thirds
Trochanteric fossa of the femur.
Obturator





of the outer surface of the obturator membrane.

nerve.




Obturator internus
Internal surface of the anterolateral wall of the pelvis and
Medial surface of the greater trochanter.
Sacral plexus.





obturator membrane.






Pectineus
Pectineal line.
Along a line extending from the lesser
Femoral or






trochanter to the linea aspera.
obturator or







accessory







obturator







nerves.




Piriformis
Pelvic surface of the sacrum, gluteal surface of the ilium,
Upper border of the greater trochanter of
Sacral plexus.




Downloaded 2024 3 16 1:39 P Your IP is 155.33.135.27 CHAPTER 12: Manual Muscle Testing,
 2024 McGraw Hill. All Rights Reserved. Terms of Use   Privacy Policy   Notice   Accessibility


Page 88 / 164












































TABLE 12 7
Hip Actions and Muscles If in Anatomic Position

Northeastern University
Access Provided by:
































Downloaded 2024 3 16 1:39 P Your IP is 155.33.135.27 CHAPTER 12: Manual Muscle Testing,
 2024 McGraw Hill. All Rights Reserved. Terms of Use   Privacy Policy   Notice   Accessibility


Page 89 / 164




Hip Action
Prime Movers 
Assistant Movers 
Flexors
Iliopsoas Sartorius
Tensor fasciae latae Rectus femoris Pectineus
Adductor longus
Adductor brevis Gracilis
Gluteus minimus (anterior fibers)
Extensors
Gluteus maximus Semitendinosus Semimembranosus Biceps femoris (long head)
Adductor magnus (posterior head)
Gluteus medius (middle and posterior fibers) Adductor magnus (anterior head)
Abductors
Gluteus medius (all fibers) Gluteus minimus (all fibers) Tensor fasciae latae
Sartorius Rectus femoris Piriformis
Adductors
Adductor magnus (anterior and posterior heads) Adductor longus
Adductor brevis Gracilis Pectineus
Biceps femoris (long head)
Gluteus maximus (posterior fibers) Quadratus lumborum
Obturator externus
External rotators
Gluteus maximus Gemellus inferior Gemellus superior Obturator internus Quadratus femoris
Piriformis (at less than 60  hip flexion)
Gluteus medius (posterior fibers) Gluteus minimus (posterior fibers Biceps femoris (long head) Sartorius
Obturator externus
Internal rotators
No prime movers
Semitendinosus Semimembranosus Gracilis
Piriformis (at 90  hip flexion) Gluteus medius (anterior fibers) Adductor longus
Adductor brevis Pectineus
Adductor magnus (posterior head) Gluteus minimus (anterior fibers) Tensor fasciae latae


Data from Anderson LC: The anatomy and biomechanics of the hip joint. J Back Musculoskeletal Rehabil 4:145 153, 1994; and Neumann DA: Kinesiology of the hip: a focus on muscular actions. J Orthop Sports Phys Ther 40:82 94, 2010.

 Iliopsoas	
Downloaded 2024 3 16 1:39 P Your IP is 155.33.135.27

CHAPTER 12: Manual Muscle Testing,
 2024 McGraw Hill. All Rights Reserved. Terms of Use   Privacy Policy   Notice   Accessibility

Page 90 / 164




The iliopsoas muscle, formed by the iliacus and psoas major muscles (Figure 12 98), is the most powerful of the hip flexors. This muscle also functions as a weak adductor and external rotator of the hip. The iliopsoas attaches to the hip joint capsule, thereby affording it some support. Because the muscle spans both the axial and appendicular components of the skeleton, it also functions as a trunk flexor and affords an important element of vertical stability to the lumbar spine, especially when the hip is in full extension and passive tension is greatest in the muscle.113,115 Theoretically, a sufficiently strong and isolated bilateral contraction of any hip flexor muscle will rotate the femur toward the pelvis, the pelvis (and possibly the trunk) toward the femur, or both actions simultaneously.113 The synergists of this muscle include the sartorius, pectineus, tensor fasciae latae, adductor brevis and longus, adductor magnus (anterior portion), gluteus minimus, rectus femoris, gluteus medius, gluteus maximus, piriformis, biceps femoris (long head), and gracilis. The antagonists of this muscle include the erector spinae, gluteus maximus, adductor magnus (posterior portion), gluteus medius, hamstrings, gluteus minimus, tensor fasciae latae, and sartorius.

FIGURE  12 98


Iliopsoas muscle

To specifically test this muscle, the patient is positioned in supine or sitting:
 Supine. The patient's lower extremity is positioned in knee extension, slight hip abduction, and flexion of the hip (Figure 12 99).
 Sitting. With the knee flexed, the patient flexes the hip (Figure 12 100).

FIGURE  12 99



Test position for iliopsoas patient supine


FIGURE  12 100


Test position for iliopsoas patient sitting



With both positions, the clinician applies pressure on the distal femur in the direction of hip extension and abduction while the patient attempts to prevent the motion. Caution should be taken to ensure that the patient does not externally rotate the femur, as this will cause the hip adductors to contract. Substitution or trick motions can include hip abduction and external rotation, hip abduction and internal rotation, or assistance from the rectus femoris. The gravity minimized/eliminated position for this muscle is with the patient positioned in sidelying with the extremity supported on a friction free surface and the hip positioned in neutral rotation with the knee flexed to 90 .
Gluteus Maximus

The gluteus maximus (Figure 12 101) is the largest and most important hip extensor and external rotator of the hip. The muscle consists of a larger superficial and a deep portion. The inferior gluteal nerve, which innervates the muscle, is located on the deep portion.

FIGURE  12 101


Gluteus maximus muscle

The gluteus maximus is usually active only when the hip is in flexion, such as during stair climbing or cycling, or when extension of the hip is resisted.116



The synergists for this muscle include the adductor magnus, gluteus medius, hamstrings, gluteus minimus, tensor fasciae latae, piriformis, sartorius, iliopsoas, adductor brevis and longus, pectineus, and gracilis. The antagonists of this muscle include the iliopsoas; pectineus; tensor fasciae latae; adductor magnus, brevis, and longus; gluteus medius and minimus; sartorius; rectus femoris; gracilis; and piriformis.
To specifically test this muscle, the patient is positioned in prone with the knee flexed to at least 90  (to eliminate hamstring activation) and the hip extended (Figure 12 102). The clinician applies a force over the distal femur in a direction of hip flexion while the patient attempts to prevent the motion. Substitution or trick motions can include assistance from the hamstrings or an increase in the lumbar lordosis. The gravity  minimized/eliminated position for this muscle is with the patient positioned in sidelying with the extremity supported, the hip flexed to 90 , and the knee flexed.

FIGURE  12 102


Test position for gluteus maximus


Gluteus Medius

The gluteus medius (Figure 12 103) is critical for balancing the pelvis in the frontal plane during one leg stance,117 which accounts for approximately 60% of the gait cycle.118 During one leg stance, approximately 3 times the body weight is transmitted to the hip joint with two thirds of that being generated by the hip abductor mechanism.118 In addition to its role as a stabilizer, the gluteus medius also functions as a decelerator of hip adduction.
FIGURE  12 103


Gluteus medius muscle



Because of its shape, the gluteus medius is known as the deltoid of the hip. The muscle can be divided into two functional parts: an anterior portion and a posterior portion. The anterior portion works to flex, abduct, and internally rotate the hip. The posterior portion extends and externally rotates the hip. On the deep surface of this muscle is located the superior gluteal nerve and the superior and inferior gluteal vessels. The synergists of this muscle include the gluteus maximus and minimus, tensor fasciae latae, sartorius, iliopsoas, rectus femoris, pectineus, adductor longus and brevis, adductor magnus, gracilis, hamstrings, and piriformis. The antagonists of the muscle include the tensor fasciae latae, sartorius, iliopsoas, rectus femoris, pectineus, adductor longus and brevis, adductor magnus, gracilis, hamstrings, gluteus maximus, piriformis, and gluteus minimus.
To specifically test this muscle the patient is positioned in sidelying with the tested leg uppermost. The patient hip is positioned in abduction, slight extension, and external rotation (Figure 12 104). While stabilizing the pelvis with one hand, the clinician applies a force of abduction and minimal flexion to the hip while the patient attempts to prevent the motion. Substitution or trick motions can include assistance from the quadratus lumborum and the lateral abdominals, which can tilt the pelvis laterally, giving the appearance of abduction; assistance from the gluteus maximus (superior fibers); or allowing the patient to roll slightly toward the supine position, which places the tensor fasciae latae in a more favorable position for hip abduction. The gravity minimized/eliminated position for this muscle is with the patient positioned in supine with the extremity on a friction free surface.

FIGURE  12 104


Test position for gluteus medius




Gluteus Minimus

The gluteus minimus (Figure 12 105) is a rather thin muscle situated between the gluteus medius muscle and the external surface of the ilium. The muscle is the major internal rotator of the femur. It receives assistance from the tensor fasciae latae, semitendinosus, semimembranosus, and gluteus medius.116 The gluteus minimus also abducts the thigh, as well as helping the gluteus medius with pelvic support. The synergists of this muscle include the gluteus medius, tensor fasciae latae, sartorius, iliopsoas, rectus femoris, pectineus, adductor longus and brevis, adductor magnus (anterior portion), gracilis, hamstrings, gluteus maximus, and piriformis. The antagonists of this muscle include the adductor longus and brevis, adductor magnus, gracilis, sartorius, iliopsoas, hamstrings, gluteus maximus, piriformis, pectineus, and gluteus medius.

FIGURE  12 105


Gluteus minimus muscle



To specifically test this muscle, the patient is positioned in sidelying with the tested side uppermost. The patient is asked to abduct the hip while avoiding any rotation, flexion, or extension of the hip (Figure 12 106). While stabilizing the pelvis with one hand, the clinician applies an adduction and minimal extension force to the hip while the patient attempts to prevent the motion from occurring.
FIGURE  12 106


Test position for gluteus minimus




Tensor Fasciae Latae (TFL)

The TFL (Figure 12 107) envelops the muscles of the thigh and seldom works alone. In addition to counteracting the backward pull of the gluteus maximus on the iliotibial band (ITB), the TFL also flexes, abducts, and externally rotates the hip. The trochanteric bursa is found deep to this muscle, as it passes over the greater trochanter, and is a common source of lateral thigh pain.119 The attachment of the TFL via the ITB to the anterolateral tibia provides a flexion moment in knee flexion and an extension moment in knee extension.79 The synergists of this muscle include the iliopsoas, sartorius, pectineus, gluteus medius and minimus, gracilis, adductor longus and brevis, adductor magnus (anterior portion), gluteus maximus, piriformis, rectus femoris, and hamstrings. The antagonists of this muscle include the hamstrings, gluteus medius, adductor magnus, adductor longus and brevis, pectineus, gracilis, gluteus maximus, piriformis, sartorius, iliopsoas, and piriformis.

FIGURE  12 107


Tensor fasciae latae muscle



To specifically test this muscle, the patient is positioned in supine with the knee extended. The patient is asked to abduct, flex, and internally rotate the hip and to hold the position (Figure 12 108) while the clinician applies resistance in a direction of hip extension and hip abduction (the rotational component is not resisted) on the distal tibia. Substitution or trick motions can include assistance from the hip flexors. The gravity  minimized/eliminated position for this muscle is with the patient positioned in long sitting with the hips supported on the table, flexed to 45  and in neutral rotation, and the upper extremities supporting the trunk.
FIGURE  12 108


Test position for tensor fasciae latae





Rectus Femoris

The rectus femoris muscle (Figure 12 109), one of the four quadriceps muscles, is a two joint muscle that arises from two tendons: one, the anterior or straight, from the anterior inferior iliac spine; the other, the posterior or reflected, from a groove above the brim of the acetabulum. The rectus femoris combines movements of flexion at the hip and extension at the knee. It functions more effectively as a hip flexor when the knee is flexed, such as when a person kicks a ball.116 The specific test for this muscle is described in the section Muscle Testing of the Knee.

FIGURE  12 109


Quadriceps femoris muscle




Hip External Rotators

The hip external rotators (Figure 12 110) include the piriformis, quadratus femoris, obturator internus, obturator externus, gemellus superior, and gemellus inferior.
 Piriformis. The piriformis (see Figure 12 110) is the most superior of the external rotators of the hip. The piriformis is an external rotator of the hip at less than 60  of hip flexion. At 90  of hip flexion, the piriformis reverses its muscle action, becoming an internal rotator and abductor of the hip.124 The piriformis, with its close association with the sciatic nerve, can be a common source of buttock and leg pain.125, 126, 127 and 128
 Quadratus femoris. The quadratus femoris muscle (see Figure 12 110) is a flat, quadrilateral muscle, located between the inferior gemellus and the superior aspect of the adductor magnus.
 Obturator internus. The obturator internus (see Figure 12 110) is normally an external rotator of the hip and an internal rotator of the ilium but becomes an abductor of the hip at 90  of hip flexion.129
 Obturator externus. The obturator externus (see Figure 12 110), named for its location external to the pelvis, is an adductor and external rotator of the hip.130
 Superior and inferior gemelli muscles. These muscles (see Figure 12 110) are considered accessories to the obturator internus tendon. The superior gemellus is the smaller of the two.130
FIGURE  12 110


External rotators of the hip




The external rotators of the hip are tested as a group. The patient is positioned in sitting with the thigh supported on the table and the lower leg over the end of the table. The patient rotates the hip externally such that the foot moves toward the contralateral side (Figure 12 111). Using one hand, the clinician stabilizes the patient's thigh while with the other hand generating a force of internal rotation of the hip by applying pressure to the inner aspect of the leg (see Figure 12 111).

FIGURE  12 111


Test position for external rotators of the hip





Hip Internal Rotators

The internal rotators of the hip consist of the tensor fasciae latae, gluteus minimus, and gluteus medius (anterior fibers). These muscles are tested as a group. The patient is positioned in sitting with the thigh supported on the table and the lower leg over the end of the table. The patient rotates the hip internally such that the foot moves away from the contralateral side. Using one hand, the clinician stabilizes the patient's thigh while with the other hand generating a force of external rotation of the hip by applying pressure to the outer aspect of the leg (Figure 12 112).

FIGURE  12 112


Test position for internal rotators of the hip




Hip Adductors

The adductors of the hip are found on the medial aspect of the joint (Figure 12 113). The main action of this muscle group is to adduct the thigh in the open kinetic chain and stabilize the lower extremity to perturbation in the closed kinetic chain. Each individual muscle can also provide assistance in hip flexion and rotation.133
 Adductor magnus. The adductor magnus (see Figure 12 113) is the most powerful adductor, and it is active to varying degrees in all hip motions except abduction. The posterior portion of the adductor magnus is sometimes considered functionally as a hamstring because of its anatomic alignment. Because of its size, the adductor magnus is less likely to be injured than the other hip adductors.134
 Adductor longus. During resisted adduction, the adductor longus (see Figure 12 113) is the most prominent muscle of the adductors and forms the medial border of the femoral triangle. The adductor longus also assists with external rotation, in extension, and internal rotation in other positions. The adductor longus is the most commonly strained adductor muscle.135
 Gracilis. The gracilis (see Figure 12 113) is the most superficial and medial of the hip adductor muscles. It is also the longest. The gracilis functions to adduct and flex the thigh and flex and internally rotate the leg.
 Pectineus. The pectineus (see Figure 12 113) is an adductor, flexor, and internal rotator of the hip. Like the iliopsoas, the pectineus attaches to and supports the joint capsule of the hip.

FIGURE  12 113


Hip adductor muscles



The other adductors of the hip include the adductor brevis and obturator externus muscles.
The hip adductors are tested as a group. The patient is positioned in sidelying with the tested side closest to the table. The clinician supports the uppermost leg in hip abduction, and the patient is asked to adduct the lower leg off the table (Figure 12 114) while the clinician applies a downward force. The gravity minimized/eliminated position for this muscle group is with the patient positioned in supine.

FIGURE  12 114


Test position for hip adductor muscle group


Sartorius 

The sartorius muscle (see Figure 12 115) is the longest muscle in the body. The sartorius is responsible for flexion, abduction, and external rotation of the hip, and some degree of knee flexion.136 Given its numerous actions, this muscle has numerous synergists and antagonists.
FIGURE  12 115


Sartorius muscle



To specifically test this muscle, the patient is positioned in supine. The patient is asked to externally rotate, abduct, and flex the hip while also flexing the knee. The clinician places one hand on the outer aspect of the patient's knee and uses the other hand to cup the patient's ankle. The patient is asked to prevent any motion as the clinician applies an extension, internal rotation, and adduction force to the hip, while also applying an extension force to the knee (Figure 12 116).
FIGURE  12 116


Test position for sartorius


Hamstrings

The hamstrings muscle group consists of the biceps femoris, the semimembranosus, and the semitendinosus.
 Biceps femoris. The long head of the biceps femoris (Figure 12 117) is the only portion that acts on the hip. It is active during conditions that require lesser amounts of force, such as decelerating the limb at the end of the swing phase and during forceful hip extension.137 As a whole, the biceps femoris extends the hip, flexes the knee, and externally rotates the tibia. The biceps femoris (53%) is the most commonly strained muscle



of the hamstring complex.
 Semimembranosus. The semimembranosus (Figure 12 118), the most medial of the hamstrings, assists with hip extension, knee flexion, and internal rotation of the tibia.
 Semitendinosus. The semitendinosus (see Figure 12 118) has the longest tendinous insertion of the hamstrings. It assists with hip extension, knee flexion, and internal rotation of the tibia.

FIGURE  12 117


Biceps femoris muscle


FIGURE  12 118


Semitendinosus and semimembranosus muscles

All three muscles of the hamstring complex (except for the short head of the biceps) work with the posterior adductor magnus and the gluteus maximus to extend the hip. In addition to the actions just listed, the hamstrings also weakly adduct the hip. When the hamstrings contract as a unit, their forces are exerted at the hip and knee joints simultaneously; functionally, however, they can actively mobilize only one of the two joints at the same time. Compared to walking and jogging, running is a stressful activity for the hamstrings and increases the high demands on their tendon attachments, especially during eccentric contractions. During running, the hamstrings have three main functions:
1. They decelerate knee extension at the end of the forward swing phase of the gait cycle. Through an eccentric contraction, the hamstrings decelerate the forward momentum (i.e., leg swing) at approximately 30  short of full knee extension. This action helps provide dynamic stabilization to the weight bearing knee.
2. At foot strike, the hamstrings elongate to facilitate hip extension through an eccentric contraction, thus further stabilizing the leg for weight bearing.
3. The hamstrings assist the gastrocnemius in paradoxically extending the knee during the takeoff phase of the running cycle.



The specific tests for these muscles are described in the section Muscle Testing of the Knee.
MUSCLE TESTING OF THE KNEE
The major muscles that act on the knee joint complex are the quadriceps, the hamstrings (semimembranosus, semitendinosus, and biceps femoris), the gastrocnemius, the popliteus, and the hip adductors.
Quadriceps

The quadriceps muscles can act to extend the knee when the foot is off the ground, although more commonly, they work as decelerators, preventing the knee from buckling when the foot strikes the ground.123,138 The four muscles that make up the quadriceps are the rectus femoris, the vastus intermedius, the vastus lateralis (VL), and the vastus medialis (see Figure 12 109). The quadriceps tendon represents the convergence of all four muscle tendon units, and it inserts at the anterior aspect of the superior pole of the patella. The quadriceps muscle group is innervated by the femoral nerve.
 Rectus femoris. The rectus femoris (see Figure 12 109) is the only quadriceps muscle that crosses the hip joint. It originates at the anterior inferior iliac spine. The other quadriceps muscles originate on the femoral shaft. This gives the hip joint considerable importance with respect to the knee extensor mechanism in the examination and intervention.123 The line of pull of the rectus femoris, with respect to the patella, is at angle of about 5  with the femoral shaft.123
 Vastus intermedius. The vastus intermedius (see Figure 12 109) has its origin on the proximal part of the femur, and its line of action is directly in line with the femur.
 Vastus lateralis. The VL (see Figure 12 109) is composed of two functional parts: the VL and the vastus lateralis obliquus (VLO).138 The VL has a line of pull of about 12 15  to the long axis of the femur in the frontal plane, whereas the VLO has a pull of 38 48 .123
 Vastus medialis. The vastus medialis (see Figure 12 109) is composed of two functional parts that are anatomically distinct138: the vastus medialis obliquus (VMO) and the vastus medialis proper, or longus (VML).139
 Vastus medialis obliquus. The VMO (see Figure 12 109) arises from the adductor magnus tendon.140 The insertion site of the normal VMO is the medial border of the patella, approximately one third to one half of the way down from the proximal pole. If the VMO remains proximal to the proximal pole of the patella and does not reach the patella, there is an increased potential for patellar malalignment.141
The vector of the VMO is medially directed, and it forms an angle of 50  to 55  with the mechanical axis of the leg.138,140,142,143 The VMO is least active in the fully extended position144, 145 and 146 and plays little role in extending the knee, acting instead to realign the patella medially during the extension maneuver. It is active in this function throughout the whole range of extension.
According to Fox,147 the vastus medialis is the weakest of the quadriceps group and appears to be the first muscle of the quadriceps group to atrophy and the last to rehabilitate.148 The normal VMO/VL ratio of EMG activity in standing knee extension from 30  to 0  is 1:1,149 but in patients who have patellofemoral pain, the activity in the VMO decreases significantly; instead of being tonically active, it becomes phasic in action.150 The presence of swelling also inhibits the VMO, and it requires almost half of the volume of effusion to inhibit the VMO as it does to inhibit the rectus femoris and VL muscles.151
The VMO is frequently innervated independently from the rest of the quadriceps by a separate branch from the femoral nerve.138
 Vastus medialis longus. The VML originates from the medial aspect of the upper femur and inserts anteriorly into the quadriceps tendon, giving it a line of action of approximately 15  to 17  off the long axis of the femur in the frontal plane.123
Because the quadriceps group is aligned anatomically with the shaft of the femur and not with the mechanical axis of the lower extremity, any quadriceps muscle contraction (regardless of knee flexion angle) results in compressive forces acting on the patellofemoral joint.152 The quadriceps



group is particularly important when climbing stairs, walking up inclines, or standing from a seated position.
The synergists of this muscle group include the gluteus maximus, tensor fasciae latae, iliopsoas, pectineus, gluteus minimus, gluteus medius, sartorius, adductor brevis and longus, and adductor magnus (anterior portion). The antagonists of this muscle group include the hamstrings, gracilis, sartorius, popliteus, gastrocnemius, tensor fasciae latae, gluteus maximus, adductor magnus (posterior portion), piriformis, and gluteus medius.
To specifically test this muscle group, the patient is positioned sitting at the edge of the table with the thigh supported and the leg hanging over the edge (Figure 12 119). The patient is asked to lean backward to relax the hamstrings and then to straighten the knee to just short of full extension. Using one hand, the clinician stabilizes the patient's thigh and places the other hand over the anterior surface of the distal leg just proximal to the ankle. The clinician applies a force into knee flexion with the hand just proximal to the ankle while asking the patient to resist the movement.

FIGURE  12 119


Test position for the quadriceps femoris group


Hamstrings

As previously mentioned, the hamstrings primarily function to extend the hip and to flex the knee.
 Semimembranosus. At the knee, this muscle inserts on the posterior medial aspect of the medial condyle of the tibia and has an important expansion that reinforces the posteromedial corner of the knee capsule (see Figure 12 118). During knee flexion, the semimembranosus pulls the meniscus posteriorly and internally rotates the tibia on the femur.
 Semitendinosus. Passing over the MCL, the semitendinosus (see Figure 12 118) inserts into the medial surface of the tibia and deep fascia of the lower leg, distal to the attachment of the gracilis, and posterior to the attachment of the sartorius. These three structures are collectively called the pes anserinus ("goose's foot") at this point.
 Biceps femoris. The biceps femoris (see Figure 12 117) inserts on the lateral condyle of the tibia and the head of the fibula. The superficial layer of the common tendon has been identified as the major force creating external tibial rotation and controlling internal rotation of the femur.153 The pull of the biceps on the tibia retracts the joint capsule and pulls the iliotibial tract posteriorly, keeping it taut throughout flexion.
The hamstrings are specifically tested based on their anatomy the semimembranosus and semitendinosus are tested together, and the biceps femoris is tested separately. The gravity minimized/eliminated position for this muscle group is with the patient positioned in sidelying with the tested leg on a friction free surface.
 To specifically test the semimembranosus and semitendinosus, the patient is positioned in prone with the knee flexed to approximate 45  and the tibia internally rotated so that the toes are pointing inward (Figure 12 120). Using one hand to stabilize the patient's thigh, the clinician places the other hand just proximal to the ankle on the posterior aspect of the patient's leg and applies a force into knee extension while asking the



patient to prevent the motion (see Figure 12 120).
 To specifically test the biceps femoris, the patient is positioned in prone with the knee flexed to approximately 45  and the tibia in slight external rotation so that the toes are pointing outward (Figure 12 121). Using one hand to stabilize the patient's thigh, the clinician places the other hand just proximal to the ankle on the posterior aspect of the patient's leg and applies a force into knee extension while asking the patient to prevent the motion (see Figure 12 121).

FIGURE  12 120


Test position for the biceps femoris


FIGURE  12 121


Test position for the semitendinosus and semimembranosus


Gastrocnemius

The gastrocnemius originates from above the knee by two heads, each head connected to a femoral condyle and to the joint capsule (Figure 12 122). Approximately halfway down the leg, the gastrocnemius muscles blend to form an aponeurosis. As the aponeurosis progressively contracts, it accepts the tendon of the soleus, a flat broad muscle deep to the gastrocnemius. The aponeurosis and the soleus tendon end in a flat tendon, called the Achilles tendon, which attaches to the posterior aspect of the calcaneus. The two heads of the gastrocnemius and the soleus are collectively known as the triceps surae.



FIGURE  12 122

Gastrocnemius and plantaris muscles

At the knee, the gastrocnemius functions to flex or extend the knee, depending on whether the lower extremity is weight bearing or not. Kendall and colleagues154 have proposed that a weakness of the gastrocnemius may cause knee hyperextension.
In addition, it has been proposed that the gastrocnemius acts as an antagonist of the anterior cruciate ligament, exerting an anteriorly directed pull on the tibia throughout the range of knee flexion extension motion, particularly when the knee is near extension.155,156
The specific test for this muscle is described in the Muscles of the Leg and Foot section later.
Popliteus

The popliteus (Figure 12 123) originates from the lateral femoral condyle near the LCL. The muscle has several attachments, including the lateral aspect of the lateral femoral condyle, the posterior medial aspect of the head of the fibula, and the posterior horn of the lateral meniscus.157 The larger base of this triangular muscle inserts obliquely into the posterosuperior part of the tibia above the soleal line. The muscle has several important functions, including the reinforcement of the posterior third of the lateral capsular ligament158 and the unlocking of the knee during flexion from terminal knee extension during gait. It performs this latter task by internally rotating the tibia on the femur, preventing impingement of the posterior horn of the lateral meniscus by drawing it posteriorly, and, with the posterior cruciate ligament, preventing a posterior glide of the tibia.158, 159, 160 and 161 Because knee joint injury frequently involves some component of transverse plane rotation and the popliteus muscle has been described as an important, primary, dynamic, transverse plane, rotatory knee joint stabilizer, an understanding of its function in relation to other posterolateral knee joint structures is important.162 Attached to the popliteus tendon is the popliteofibular ligament, which forms a strong attachment between the popliteal tendon and the fibula. This ligament adds to posterolateral stability.163, 164, 165 and 166
FIGURE  12 123


Popliteus muscle





The popliteus muscle is innervated by the tibial nerve. The synergists of this muscle include the hamstrings, gracilis, sartorius, gastrocnemius, and tensor fasciae latae. The antagonists of this muscle include the biceps femoris and the quadriceps.
To specifically test this muscle, the patient is positioned in sitting with the knee flexed to 90 . The patient is asked to internally rotate the tibia (Figure 12 124). There is no resistance applied for this test the test is used to determine whether the muscle is active and capable of internally rotating the tibia.

FIGURE  12 124


Testing the function of the popliteus




Tensor Fasciae Latae

In addition to its actions at the hip, the tensor fasciae latae (TFL) is also a weak extensor of the knee, but only when the knee is already extended. The specific test for this muscle is described in the Muscles of the Hip section.
MUSCLE TESTING OF THE LEG AND FOOT
Extrinsic Muscles of the Leg and Foot
The extrinsic muscles of the foot (Table 12 8) can be divided into anterior, posterior superficial, posterior deep, and lateral compartments.



TABLE 12 8
Extrinsic Muscle Attachments and Innervation

Muscle 
Proximal 
Distal 
Innervation 
Gastrocnemius
Medial and lateral condyle of femur
Posterior surface of calcaneus through Achilles tendon
Tibial S2 (S1)
Plantaris
Lateral supracondylar line of femur
Posterior surface of calcaneus through Achilles tendon
Tibial S2 (S1)
Soleus
Head of fibula, proximal third of shaft, soleal line, and midshaft of posterior tibia
Posterior surface of calcaneus through Achilles tendon
Tibial S2 (S1)
Tibialis anterior
Distal to lateral tibial condyle, proximal half of lateral tibial shaft, and interosseous membrane
First cuneiform bone, medial and plantar surfaces, and base of first metatarsal
Deep peroneal L4 (L5)
Tibialis posterior
Posterior surface of tibia, proximal two thirds posterior of fibula, and interosseous membrane
Tuberosity of navicular bone and tendinous expansion to other tarsals and metatarsals
Tibial L4 and L5
Fibularis (peroneus) longus
Lateral condyle of tibia, head and proximal two thirds of fibula
Base of first metatarsal and first cuneiform, lateral side
Superficial peroneal L5 and S1 (S2)
Fibularis (peroneus) brevis
Distal two thirds of lateral fibular shaft
Tuberosity of fifth metatarsal
Superficial peroneal L5 and S1 (S2)
Fibularis (peroneus) tertius
Lateral slip from extensor digitorum longus
Tuberosity of fifth metatarsal
Deep peroneal L5 and S1
Flexor hallucis longus
Posterior distal two thirds fibula
Base of distal phalanx of great toe
Tibial S2 (S3)
Flexor digitorum longus
Middle three fifths of posterior tibia
Base of distal phalanx of lateral four toes
Tibial S2 (S3)
Extensor hallucis longus
Middle half of anterior shaft of fibula
Base of distal phalanx of great toe
Deep peroneal L5 and S1
Extensor digitorum longus
Lateral condyle of tibia, proximal anterior surface of shaft of fibula
One tendon to each lateral four toes, to middle phalanx, and extending to distal phalanges
Deep peroneal L5 and S1



Anterior Compartment

 This compartment contains the dorsiflexors (extensors) of the foot. These include the tibialis anterior, extensor digitorum longus, extensor hallucis	
Downloaded 2024 3 16 1:39 P Your IP is 155.33.135.27

CHAPTER 12: Manual Muscle Testing,
 2024 McGraw Hill. All Rights Reserved. Terms of Use   Privacy Policy   Notice   Accessibility

Page 114 / 164



longus, and fibularis (peroneus) tertius.
Tibialis Anterior

The tibialis anterior originates from the upper two thirds of the lateral surface of the tibia, interosseous membrane, and deep fascia and inserts into the medial and plantar surface of the medial cuneiform and base of the first metatarsal bone of the foot (Figure 12 125). The tibialis anterior muscle, which is the first large tendon palpated anterior to the medial malleolus, produces the motion of dorsiflexion and inversion.

FIGURE  12 125


Tibialis anterior muscle

The tibialis anterior is innervated by the deep fibular (peroneal) nerve. The synergists of this muscle include the extensor digitorum longus, extensor hallucis longus, fibularis tertius, tibialis posterior, flexor digitorum longus, flexor hallucis longus, gastrocnemius, and soleus. The antagonists for this muscle include the tibialis posterior, fibularis longus and brevis, gastrocnemius, soleus, flexor digitorum longus, flexor hallucis longus, fibularis tertius, and extensor digitorum longus.
To specifically test this muscle, the patient is positioned in supine or sitting, and the patient's foot is positioned in dorsiflexion and inversion, with the great toe pointing downward (to minimize activation of the extensor hallucis longus). The knee must remain flexed during the test to allow complete dorsiflexion. Using one hand, the leg is stabilized by the clinician, while resistance is applied to the medial posterior aspect of the forefoot in an inferior/lateral direction into plantarflexion and eversion (Figure 12 126).
FIGURE  12 126



Testing position for tibialis anterior


Extensor Digitorum Longus

The extensor digitorum longus (EDL) arises from the lateral condyle of the tibia, the proximal three fourths of the anterior surface of the body of the fibula, the proximal portion of the interosseous membrane, the deep fascia, and the adjacent intermuscular septa (Figure 12 127). The muscle divides into four slips that insert into the middle and distal phalanges of the lateral four toes. The EDL functions to produce ankle dorsiflexion, foot eversion, and extension of the metatarsophalangeal (MTP), proximal, and DIP joints of the lateral four toes.

FIGURE  12 127


Extensor digitorum longus and brevis muscles



The EDL is innervated by the deep fibular (peroneal) nerve. The synergists of this muscle include the extensor digitorum brevis, extensor hallucis longus, tibialis anterior, fibularis tertius, and fibularis longus and brevis. The antagonists of this muscle include the flexor digitorum longus, lumbricals, anterior interossei, posterior interossei, tibialis posterior, flexor digitorum brevis, gastrocnemius, soleus, flexor hallucis longus, fibularis longus and brevis, tibialis anterior, and extensor hallucis longus.
To specifically test this muscle, the patient is positioned sitting or supine, and the patient is asked to extend the toes. Using one hand to stabilize the



metatarsals and keeping the foot in slight plantarflexion, the clinician uses the other hand to apply force against the proximal phalanges of toes 2 through 5 in the direction of toe flexion (Figure 12 128).
FIGURE  12 128


Test position for extensor digitorum longus


Extensor Hallucis Longus (EHL)

The EHL arises from the anterior middle third of the surface of the fibula and interosseous membrane. As the muscle fibers descend, they become a tendon that inserts on the base of the distal phalanx of the great toe (Figure 12 129). The EHL functions to extend the great toe and dorsiflex the foot, and it assists with foot inversion.

FIGURE  12 129


Extensor hallucis longus muscles



The EHL is innervated by the deep fibular (peroneal) nerve. The synergists of this muscle include the extensor digitorum brevis, tibialis anterior, extensor digitorum longus, and fibularis tertius. The antagonists of this muscle include the flexor hallucis longus, gastrocnemius, soleus, tibialis posterior, flexor digitorum longus, flexor hallucis longus, fibularis longus and brevis, and abductor hallucis.
To specifically test this muscle, the patient is positioned in supine or sitting and the ankle is positioned in a neutral position. The patient is asked to extend the MTP and interphalangeal joints of the great toe and to hold a position while the clinician applies pressure on the distal phalanx in a plantarflexion direction (Figure 12 130).

FIGURE  12 130


Test position for the extensor hallucis longus




Fibularis (Peroneus) Tertius

The fibularis tertius arises from the lower third of the anterior surface of the fibula, the lower part of the interosseous membrane, and the adjacent intermuscular septum (see Figure 12 127). Working alone, the muscle functions to provide ankle dorsiflexion and foot eversion.
The fibularis tertius is innervated by the deep fibular (peroneal) nerve. The synergists for this muscle include the extensor digitorum longus, extensor hallucis longus, tibialis anterior, and fibularis longus and brevis. The antagonist of this muscle include the flexor digitorum longus, tibialis posterior, gastrocnemius, soleus, flexor hallucis longus, fibularis longus and brevis, tibialis anterior, and extensor hallucis longus.
To specifically test this muscle, the patient is positioned sitting or supine, and the patient is asked to dorsiflex and then evert the foot (Figure 12 131). While using one hand to stabilize the patient's lower leg, the clinician uses the other hand to apply pressure along the dorsal and lateral aspects of the foot into a plantarflexion and inversion direction while asking the patient to prevent the motion.

FIGURE  12 131


Test position for the peroneus tertius



Posterior Superficial Compartment

This compartment, located posterior to the interosseous membrane, contains the calf muscles that plantarflex the foot. These include the gastrocnemius, soleus (Figure 12 132), and plantaris muscles (see Figure 12 122).

FIGURE  12 132


Soleus muscle




Gastrocnemius

The two heads of the gastrocnemius arise from the posterior aspects of the distal femur (see Figure 12 122).168 As the two muscles descend, they form the Achilles tendon along with the soleus muscle. The Achilles tendon courses distally to attach about three quarters of an inch below the superior portion of the os calcis, on the medial aspect of the calcaneus. The medial head of the gastrocnemius is by far the largest component and, according to electromyographic studies, is the most active of the two during running.169,170

The gastrocnemius functions to provide ankle plantarflexion, knee flexion, and mild ankle inversion.
The gastrocnemius is innervated by the tibial nerve. The synergists of this muscle include the flexor digitorum longus, tibialis posterior, flexes hallucis longus, fibularis longus and brevis, soleus, hamstrings, gracilis, sartorius, tensor fasciae latae, popliteus, tibialis anterior, and extensor hallucis longus. The antagonists of this muscle include the extensor digitorum longus, extensor hallucis longus, tibialis anterior, fibularis tertius, quadriceps, and peroneus longus and brevis.




To specifically test the gastrocnemius, the patient is positioned in standing on one leg holding onto something for balance. Keeping the knee straight, the patient is asked to raise up on the toes (Figure 12 133). For a normal grading, the patient should be able to repeat this 10 times.

FIGURE  12 133


Test position for the gastrocnemius


Soleus

The soleus muscle arises from the posterior proximal one third of the fibula and the middle third of the tibia (see Figure 12 132). It conjoins with the gastrocnemius tendon to form the Achilles tendon. The soleus muscle, which is innervated by the tibial nerve, produces ankle plantarflexion. The synergists of this muscle include the flexor digitorum longus, tibialis posterior, flexor hallucis longus, fibularis longus and brevis, gastrocnemius, tibialis anterior, and extensor hallucis longus. The antagonists of this muscle include the extensor digitorum longus, extensor hallucis longus, tibialis anterior, fibularis tertius, and fibularis longus and brevis.
To specifically test this muscle, the patient is positioned in prone with the knee flexed to 90 . Using one hand, the clinician stabilizes the distal leg of the patient by holding the proximal ankle. The patient is asked to plantarflex the ankle without inversion or eversion of the foot, and the clinician applies a dorsiflexion force to the posterior calcaneus (Figure 12 134).

FIGURE  12 134


 Test position for the soleus	





Plantaris

The plantaris muscle originates from the distal portion of the lateral supracondylar line of the femur, the adjacent part of the popliteal surface, and the oblique popliteal ligament (see Figure 12 122). Its tendon inserts on the posterior calcaneus. The plantaris muscle, which has its own tendon and contributes no fibers to the Achilles tendon, works with the gastrocnemius to plantarflex the ankle and assists in flexion of the knee joint.175 The plantaris muscle is tested using the specific test of the gastrocnemius.
Posterior Deep Compartment

This compartment contains the flexors of the foot. These muscles course behind the medial malleolus. They include the posterior tibialis, flexor digitorum longus, and flexor hallucis longus.
Tibialis Posterior

The tibialis posterior arises from the majority of the interosseous membrane, lateral portion of the posterior aspect of the tibia, proximal two thirds of the medial surface of the fibula, the adjacent intermuscular septa, and deep fascia (Figure 12 135). Its extensive insertions include the tuberosity of the navicular bone, by fibrous expansions to the sustentaculum tali, three cuneiforms, the cuboid, and bases of the second, third, and fourth metatarsal bones. The primary function of the tibialis posterior muscle is to invert and plantarflex the foot. It also provides support to the medial longitudinal arch.176 The tibialis posterior is innervated by the tibial nerve. The synergists of this muscle include the flexor digitorum longus, flexor hallucis longus, fibularis longus and brevis, gastrocnemius, soleus, tibialis anterior, and extensor hallucis longus. The antagonists of this muscle include the fibularis longus and brevis, fibularis tertius, extensor digitorum longus, extensor hallucis longus, and tibialis anterior.

FIGURE  12 135


Tibialis posterior muscle



To specifically test this muscle, the patient is positioned supine or sitting with the foot and ankle plantarflexed and inverted. The patient is asked to sustain this position throughout the test. Using one hand, the clinician stabilizes the proximal to the patient's ankle, while using the other hand to apply an eversion and dorsiflexion force to the patient's foot and ankle (Figure 12 136).
FIGURE  12 136


Test position for the tibialis posterior


Flexor Digitorum Longus (FDL)

The FDL originates from the posterior aspect of the tibia and inserts on the distal phalanges of toes 2 to 5 (Figure 12 137). The FDL functions to flex the phalanges of the lateral four toes and assists with plantarflexion of the foot. The FDL is innervated by the tibial nerve. The synergists of this muscle include the lumbricals, anterior interossei, posterior interossei, tibialis posterior, flexor hallucis longus, fibularis longus and brevis, gastrocnemius, soleus, tibialis anterior, and extensor hallucis longus. The antagonists of this muscle include the extensor digitorum longus, extensor hallucis longus, extensor digitorum brevis, tibialis anterior, fibularis tertius, and fibularis longus and brevis.

FIGURE  12 137


Flexor digitorum longus



To specifically test this muscle, the patient is positioned supine or sitting. The patient is asked to flex the toes and to sustain the position throughout the test. Using one hand to stabilize the midfoot, the clinician applies an extension force to the toes (Figure 12 138).

FIGURE  12 138


Test position for the flexor digitorum longus


Flexor Hallucis Longus (FHL)

The FHL originates from the distal two thirds of the fibula and inserts on the distal phalanx of the great toe (Figure 12 139). The FHL flexes the great toe and also assists with plantarflexion of the foot. The FHL is innervated by the tibial nerve. The synergists of this muscle include the abductor



hallucis, flexor digitorum longus, tibialis posterior, fibularis longus and brevis, gastrocnemius, soleus, tibialis anterior, and extensor hallucis longus. The antagonists of this muscle include the extensor hallucis longus, extensor digitorum brevis, extensor digitorum longus, tibialis anterior, fibularis tertius, and fibularis longus and brevis.
FIGURE  12 139


Flexor hallucis longus muscle

To specifically test this muscle, the patient is positioned in supine or sitting and is asked to flex the great toe. It is important to note that the patient may have difficulty isolating the motion of this toe from the other toes. Using one hand to stabilize the patient's ankle, the clinician uses the other hand to stabilize the metatarsals while applying an extension force of the great toe (Figure 12 140).

FIGURE  12 140


Test position for the flexor hallucis longus



Lateral Compartment

This compartment contains the fibularis (peroneus) longus and brevis (Figure 12 141). The fibularis (peroneal) tendons lie behind the lateral malleolus in a fibro osseous tunnel formed by a groove in the fibula and the superficial fibular (peroneal) retinaculum.

FIGURE  12 141


Fibularis (peroneus) longus and brevis muscles


Fibularis (Peroneus) Longus and Brevis

The fibularis longus arises from the lateral condyle of the tibia, the proximal two thirds of the fibula, and the adjacent intermuscular septum and inserts at the base of the first metatarsal and the medial cuneiform bone. The fibularis brevis arises from the distal two thirds of the fibula and the adjacent intermuscular septum and inserts on the tuberosity on the base of the fifth metatarsal. The two muscles work in combination to produce ankle plantarflexion, foot eversion, and first metatarsal depression (longus).



Both of the muscles are innervated by the superficial fibular (peroneal) nerve. The synergists to these two muscles include the fibularis tertius, flexor digitorum longus, tibialis posterior, flexor hallucis longus, gastrocnemius, soleus, and extensor digitorum longus. The antagonist of these two muscles include the tibialis anterior, tibialis posterior, flexor digitorum longus, flexor hallucis longus, extensor hallucis longus, extensor digitorum longus, fibularis tertius, gastrocnemius, and soleus.

Both of these muscles are tested together. The patient is positioned in sitting or supine, and is asked to plantarflex and evert the foot (Figure 12 142). Using one hand, the clinician stabilizes the distal leg and, using the other hand, applies a force on the lateral aspect of the foot into inversion and dorsiflexion.

FIGURE  12 142

Test position for the longus and brevis fibularis


Intrinsic Muscles of the Foot

Beneath the plantar aponeurosis plantar fascia are the four muscular layers of the intrinsic muscles of the plantar foot (Table 12 9), as well as the plantar ligaments of the rear  and mid foot. The intrinsic muscles provide support to the foot during propulsion.180
TABLE 12 9
Intrinsic Muscles of the Foot



Muscle 
Proximal 
Distal 
Innervation 


Extensor digitorum brevis
Distal superior surface of calcaneus
Posterior (dorsal) surface of second through fourth toes and base of proximal phalanx
Deep peroneal S1 and S2











Flexor hallucis brevis
Plantar surface of cuboid and third cuneiform bones
Base of proximal phalanx of great toe
Medial plantar S3 (S2)


Flexor digitorum brevis
Tuberosity of calcaneus
One tendon slips into base of middle phalanx of each of the lateral four toes
Medial and lateral plantar S3 (S2)


Extensor hallucis brevis
Distal superior and lateral surfaces of calcaneus
Posterior (dorsal) surface of proximal phalanx
Deep peroneal S1 and S2


Abductor hallucis
Tuberosity of calcaneus and plantar aponeurosis
Base of proximal phalanx and medial side
Medial plantar L5 and


Adductor hallucis
Base of second, third, and fourth metatarsals and deep plantar ligaments
Proximal phalanx of first digit lateral side
Medial and lateral plantar S1 and S2



Lumbricales medial and adjacent sides of flexor digitorum longus tendon to each lateral digit
Medial side of proximal phalanx and extensor hood
Medial and lateral plantar L5, S1, and S2 (L4)


Plantar interossei


First
Base and medial side of third metatarsal
Base of proximal phalanx and extensor hood of third digit



Second
Base and medial side of fourth metatarsal
Base of proximal phalanx and extensor hood of fourth digit
Medial and lateral plantar S1 and S2


Third
Base and medial side of fifth metatarsal
Base of proximal phalanx and extensor hood of fifth digit



Posterior (dorsal) interossei


First
First and second metatarsal bones
Proximal phalanx and extensor hood of second digit medially



Second
Second and third metatarsal bones
Proximal phalanx and extensor hood of second digit laterally
Medial and lateral plantar S1 and S2


Third
Third and fourth metatarsal bones
Proximal phalanx and extensor hood of third digit laterally



Fourth
Fourth and fifth metatarsal bones
Proximal phalanx and extensor hood of fourth digit laterally



Abductor digiti minimi
Lateral side of fifth metatarsal bone
Proximal phalanx of fifth digit
Lateral plantar S1 and S2






The intrinsic muscles of the foot include the following:
 Abductor hallucis. This muscle arises from the medial process of the calcaneal tuberosity and inserts into the medial side of the base of the proximal phalanx of the great toe (Figure 12 143). The muscle, which is innervated by the medial plantar nerve, functions to abduct the great toe and to stabilize the first metatarsal. The synergist of this muscle is the flexor hallucis longus. The antagonists of this muscle are the adductor hallucis, extensor hallucis longus, and extensor digitorum brevis.
To specifically test this muscle, the patient is positioned in supine or sitting. Using one hand, the clinician stabilizes the patient's foot while using the other hand to apply adduction force to the great toe and while asking the patient to prevent the motion (Figure 12 144). It is important to remember that this muscle is difficult for many people to isolate.
 Abductor digiti minimi. This muscle arises from the lateral process of the calcaneal tuberosity as well as the plantar aponeurosis and inserts into the lateral side of the base of the proximal phalanx of the little toe. The muscle functions to assist in flexion of the interphalangeal joint of the fifth digit and to stabilize the forefoot. The synergists of this muscle include the flexor digitorum longus and the fourth lumbrical. The antagonist to this muscle is the fifth anterior interossei.
 Flexor digitorum brevis (Figure 12 145). This muscle arises from the medial process of the calcaneal tuberosity, lateral to the abductor hallucis and deep to the central portion of the plantar fascia, and inserts into the middle phalanx of the lateral four toes. The flexor digitorum brevis flexes the PIP joints and assists in flexion of the MTP joints of the second through fifth digits.
To specifically test this muscle, the patient is positioned in sitting or supine. Using one hand to stabilize the patient's midfoot, the clinician uses the other hand to apply pressure against the plantar surface of the PIP joints of the second through fifth digits (Figure 12 146).
 Flexor digitorum accessorius (quadratus plantae; Figure 12 147). This muscle arises from the calcaneal tuberosity via two heads. The medial head arises from the medial surface of the calcaneus and the medial border of the long plantar ligament, whereas the lateral head arises from the lateral border of the plantar surface of the calcaneus and the lateral border of the long plantar ligament. The muscle terminates in tendinous slips, joining the long flexor tendons to the second, third, fourth, and occasionally fifth toes. This muscle modifies the line of pull of the flexor digitorum longus tendons and assists in flexion of the second through fifth digits. There is no specific test for this muscle.
 Lumbricales. There are four lumbricales (see Figure 12 148), all of which arise from the tendon of the flexor digitorum longus. The first arises from the medial side of the tendon of the second toe, the second from adjacent sides of the tendons for the second and third toes, the third from adjacent sides of the tendons for the third and fourth toes, and the fourth from adjacent sides of tendons for the fourth and fifth toes. They insert with the tendons of the extensor digitorum longus and interossei into the bases of the terminal phalanges of the four lateral toes. The function of the lumbricales is to flex the MTP joint and extend the PIP joint. The first lumbrical is innervated by the medial plantar nerve, whereas lumbricals two through four are innervated by the lateral plantar nerve. The synergist to these muscles is the flexor digitorum longus. The antagonists of this muscle group include the extensor digitorum longus and the extensor digitorum brevis. To specifically test these muscles, the patient is positioned supine or sitting and is asked to flex the MTP joints of the feet. While using one hand to stabilize the patient's foot, the clinician uses the other hand to apply an extension force under the MTP joints of toes 2 through 4 (Figure 12 149).
 Flexor hallucis brevis (Figure 12 150). This muscle arises from the medial part of the plantar surface of the cuboid bone, the adjacent portion of the lateral cuneiform, and the posterior tibialis tendon and inserts on the medial and lateral side of the proximal phalanx of the great toe. This muscle functions to flex the MTP joint of the great toe and is innervated by the tibial nerve.
To specifically test this muscle, the patient is positioned in supine or sitting. Using one hand to stabilize the foot proximal to the MTP joint and maintaining a neutral position of the foot and ankle, the clinician uses the other hand to apply an extension force at the MTP joints of the great toe (Figure 12 151).
 Adductor hallucis (see Figure 12 143). This muscle arises via two heads: an oblique and a transverse head. The oblique head arises from the bases of the second, third, and fourth metatarsal bones and the sheath of the fibularis (peroneus) longus. The transverse head arises from the joint capsules of the second, third, fourth, and fifth MTP heads and the deep transverse metatarsal ligament. The adductor hallucis inserts on the lateral side of the base of the proximal phalanx of the great toe. The adductor hallucis functions to adduct and assists in flexion of the MTP joint of the great toe and is innervated by the tibial nerve. There is no specific test for this muscle.



 Posterior (dorsal) interossei (see Figure 12 148). The four posterior (dorsal) interossei are bipennate, and they arise from adjacent sides of the metatarsal bones. The first inserts into the medial side of the proximal phalanx of the second toe. The second inserts into the lateral side of the proximal phalanx of the second toe. The third inserts into the lateral side of the proximal phalanx of the third toe, and the fourth inserts into the lateral side of the proximal phalanx of the fourth toe. The posterior (dorsal) interossei function to abduct the second, third, and fourth toes around an axis through the second metatarsal ray. The posterior interossei are innervated by the lateral plantar nerve. The synergists of these muscles include the flexor digitorum longus, flexor hallucis longus, and lumbricals 2 through 4. The antagonists of these muscles are the anterior interossei.
 Plantar interossei (see Figure 12 148). The three plantar interossei are unipennate and arise from the bases and medial sides of the third, fourth, and fifth metatarsal bones. They insert into the medial sides of the bases of the proximal phalanges of the third, fourth, and fifth toes. The plantar interossei function to adduct the lateral three toes from the midline and are innervated by the lateral plantar nerve. The synergists of this muscle include the flexor digitorum longus, flexor hallucis longus, and lumbricals 2 through 4. The antagonists of this muscle are the posterior interossei.

FIGURE  12 143


Abductor hallucis and adductor hallucis muscles


FIGURE  12 144


Test position for the abductor hallucis




FIGURE  12 145


Flexor digitorum brevis muscle




FIGURE  12 146


Test position for the flexor digitorum brevis


FIGURE  12 147


Quadratus plantae muscle


FIGURE  12 148


Lumbricales and interossei muscles




FIGURE  12 149


Test position for the lumbricales


FIGURE  12 150


Flexor hallucis brevis muscle




FIGURE  12 151


Test position for the flexor hallucis brevis

To specifically test these muscle groups, the patient is positioned in supine or sitting and is asked to extend the interphalangeal joints of the four lateral toes. The clinician stabilizes the MTP joints and places a finger on the posterior surface of the distal phalanges of each toe in the direction of flexion (Figure 12 152).



FIGURE  12 152


Test position for the interossei muscles


Posterior (Dorsal) Intrinsic Muscles

The posterior (dorsal) intrinsic muscles of the foot are the extensor hallucis brevis (EHB) and extensor digitorum brevis (EDB).
Extensor Hallucis Brevis

The EHB inserts into the base of the proximal phalanx of the great toe. The muscle is innervated by the lateral terminal branch of the deep fibular (peroneal) nerve. The extensor hallucis brevis is tested along with the extensor hallucis longus. Unless innervation to the extensor hallucis longus is absent, a weakness of the extensor digitorum brevis cannot be determined accurately.
Extensor Digitorum Brevis

The EDB originates from the superior lateral aspect of the calcaneus and inserts into the base of the second, third, and fourth proximal phalanges (see Figure 12 127). The EDB functions to extend the MTP joints of toes 1 through 4.
The EDB is innervated by the lateral terminal branch of the deep fibular (peroneal) nerve. The synergists of this muscle include the extensor hallucis longus and the extensor digitorum longus. The antagonist of this muscle include the flexor digitorum longus, flexor hallucis longus, abductor hallucis, lumbricals, anterior interossei, and dorsal interossei.
The EDB is tested together with the extensor digitorum longus (see Figure 12 128).
MUSCLE TESTING OF THE TRUNK
Various manual muscle testing methods have been used to assess adult abdominal strength clinically:
 Kendall and colleagues37 have proposed two different procedures to measure abdominal muscle strength.
1. An assessment of a person's ability to keep the lumbar spine flat against the table while lowering both legs, with knees extended, from an initial position of 90  of hip flexion. The point in the range of motion at which the lumbar spine begins to demonstrate lordosis determines the muscle grade.
2. An assessment of strength based on the ability to flex the vertebral column and come to a sitting position while the legs remain stabilized in extension.



 Daniels and Worthingham181 assign grades of trunk flexor muscle strength by having the person clear the scapulae from the table during trunk flexion. The lower extremities are stabilized in extension during their Normal (Grade 5), Good (Grade 4), and Fair (Grade 3) muscle test positions.
 Harvey and Scott182 used a timed curl down (reverse sit up) test to measure abdominal muscle strength in young women.
The Specific Tests

Neck Flexors

The neck flexors include the following muscles:
 Sternocleidomastoid (SCM). The SCM is the largest muscle in the anterior neck. It is attached inferiorly by two heads, arising from the posterior aspect of the medial third of the clavicle and the manubrium of the sternum. From here, it passes superiorly and posteriorly to attach on the mastoid process of the temporal bone. The motor supply for this muscle is from the accessory nerve (CN XI), whereas the sensory innervation is supplied from the anterior (ventral) rami of C2 and C3.183
 Prevertebral muscles (longus colli, longus capitis, rectus capitis anterior, and rectus capitis lateralis).
 Longus colli. The longus colli consists of a vertical portion that originates from the bodies of the first three thoracic and last three cervical vertebrae, an inferior oblique portion that originates from the bodies of the first three thoracic vertebrae, and the superior oblique portion that originates from anterior tubercles of the transverse processes of C3 5. The various portions of the longus colli insert into the bodies of C2 4, the anterior tubercles of the transverse processes of C5 6, and the anterior tubercle of the atlas. The longus colli is innervated by branches of the anterior primary rami of C2 8.
 Longus capitis. The longus capitis originates from the anterior tubercles of the transverse processes of C3 6 and inserts onto the inferior surface of the basilar part of the occipital bone. The longus capitis is innervated by the muscular branches of C1 4.
 Rectus capitis anterior (RCA). The RCA originates from the lateral mass of the atlas and inserts onto the base of the occipital bone in front of the foramen magnum. The RCA is innervated by the muscular branches of C1 2.
 Rectus capitis lateralis (RCL). The RCL originates from the upper surface of the transverse process of the atlas and inserts onto the inferior surface of the jugular process of the occipital bone. The RCL is innervated by branches of the anterior rami of C1 2.
 Scalenus anterior, medius, and posterior. The scalenes extend obliquely like ladders (scala means ladder in Latin).
 Scalenus anterior. The scalenus anterior runs vertically, behind the SCM on the lateral aspect of the neck. Arising from the anterior tubercles of the C3 6 transverse processes, it travels to the scalene tubercle on the inner border of the first rib. It is supplied by the anterior (ventral) rami of C4, C5, and C6.
 Scalenus medius. The scalenus medius is the largest and longest of the scalenus group, attaching to the transverse processes of all cervical vertebrae except the atlas (although it often attaches to this) and running to the upper border of the first rib. It is innervated by the anterior (ventral) rami of C3 8.
 Scalenus posterior. The scalenus posterior is the smallest and deepest of the scalenus group, running from the posterior tubercles of the C4  6 transverse processes to attach to the outer aspect of the second rib. It is innervated by the anterior (ventral) rami of C5, C6, and C7.
 Suprahyoid. The suprahyoid muscles include digastric, stylohyoid, geniohyoid, and mylohyoid.
 Geniohyoid. The geniohyoid muscle is a narrow muscle situated under the mylohyoid muscle. The muscle functions to elevate the hyoid bone. It is innervated by C1 through CN XII.
 Digastric. As its name suggests, the digastric muscle consists of two bellies. The posterior belly arises from the mastoid notch of the temporal bone, whereas the anterior belly arises from the digastric fossa of the mandible. The posterior belly is innervated by a branch from the facial nerve. The anterior belly is innervated by the inferior alveolar branch of the trigeminal nerve.



 Mylohyoid. This flat, triangular muscle arises from the whole length of the mylohyoid line of the mandible. The posterior fibers pass inferomedially to insert into the body of the hyoid bone. The middle and anterior fibers insert into a median fibrous raphe extending from the symphysis menti to the hyoid bone, where they joint at an angle with the fibers of the opposite muscle. The mylohyoid muscle is innervated by the mylohyoid nerve, a branch of the inferior alveolar nerve, which is a branch of the mandibular nerve, a division of the trigeminal nerve.
 Stylohyoid. The stylohyoid muscle arises from the posterior and lateral surface of the styloid process of the temporal bone, near the base, and, passing inferiorly and anteriorly, inserts into the body of the hyoid bone at its junction with the greater cornu and just superior the omohyoid muscle. It is innervated by the facial nerve (CN VII).
 Infrahyoid. The infrahyoid muscles comprise the sternohyoid, omohyoid, sternothyroid, and thyrohyoid muscles.
 Sternohyoid. The sternohyoid muscle is a straplike muscle that originates from the sternum and inserts on the hyoid bone.
 Omohyoid. The omohyoid muscle, situated lateral to the sternohyoid, consists of two bellies. The superior belly arises from the intermediate tendon and inserts on the hyoid bone, whereas the inferior belly arises from the superior border of the scapular and inserts on the intermediate tendon.
 Sternothyroid. The sternothyroid muscle arises from the sternum and inserts on the thyroid cartilage.
 Thyrohyoid. The thyrohyoid muscle arises from the thyroid cartilage and inserts on the hyoid bone.
These infrahyoid muscles are innervated by fibers from the upper cervical nerves. The nerves to the lower part of these muscles are given off from a loop, the ansa cervicalis.
To specifically test this muscle group, the patient is positioned in supine with the head in the anatomic position. The patient is asked to lift the head of the treatment table while keeping the chin tucked. Grading can be done as follows184:

?10
N
5/5: five repetitions
?5
F
3/5: 3 to 4 repetitions
?2
P
2/5: 1 to 2 repetitions
?0
Zero
0/5: zero repetitions


Neck Extensors

The neck extensors include the following muscles:
Upper trapezius. See Muscle Testing of the Shoulder.
Splenius capitis. The splenius capitis extends upward and laterally, from the posterior (dorsal) edge of the nuchal ligament and the spinous processes of the lower cervical and upper thoracic vertebrae (T4 C7) to the mastoid process of the occipital bone just inferior to the superior nuchal line and deep to the SCM muscle. This muscle is segmentally innervated by the lateral branches of the posterior (dorsal) rami of the spinal nerves.
Splenius cervicis. The splenius cervicis is just inferior and appears continuous with the capitis, extending from the spines of the third to the sixth thoracic vertebrae to the posterior tubercles of the transverse processes of the upper cervical vertebrae. This muscle is segmentally innervated by the lateral branches of the posterior (dorsal) rami of the spinal nerves.
Erector spinae (cervical). The erector spinae complex spans multiple segments, forming a large musculotendinous mass consisting of the



iliocostalis, longissimus, and spinalis muscles. This muscle group is segmentally innervated by the lateral branches of the posterior (dorsal) rami of the spinal nerves.
 Transversospinalis. The transversospinalis muscles are a group of muscles that include the semispinalis, the multifidus, and the rotatores. This muscle group is segmentally innervated by the posterior (dorsal) rami of the spinal nerves.
To specifically test this muscle group, the patient is positioned in prone with the head in the anatomic position. The patient is asked to lift the head of the treatment table and to hold it against gravity. Grading can be done as follows184:

10
N
5/5: 20 seconds
5
F
3/5: 10 to 19 seconds
2
P
2/5: 1 to 9 seconds
0
Zero
0/5: zero seconds.


Anterior Trunk (Upper Abdominal) Flexors

The anterior trunk flexors include the rectus abdominis, transversus abdominis, and internal and external abdominal obliques.
 Rectus abdominis. The rectus abdominis originates from the cartilaginous ends of the fifth through seventh ribs and xiphoid and inserts on the superior aspect of the pubic bone.
 Transversus abdominis. The transverse abdominis muscle originates from the lateral one third of the inguinal ligament, the anterior two thirds of the inner lip of the iliac crest, the lateral raphe of the thoracolumbar fascia, and the internal aspects of the lower six costal cartilages, where it interdigitates with the diaphragm.185 Its upper and middle fibers run transversely around the trunk and blend with the fascial envelope of the rectus abdominis muscle, while the lower fibers blend with the insertion of the internal oblique muscle on the pubic crest.
 Internal oblique. The internal oblique, which forms the middle layer of the lateral abdominal wall, is located between the transversus abdominis and the external oblique muscles.186 It has multiple attachments to the inguinal ligament, lateral raphe, iliac crest, pubic crest, transverse abdominis, and costal cartilages of the seventh through ninth costal cartilages.
External oblique. The external oblique originates from the lateral aspect of the 5th through 12th ribs and through interdigitations with the serratus anterior and latissimus dorsi. The muscle travels obliquely, medially, and inferiorly to insert into the linea alba, inguinal ligament, anterior superior iliac spine, iliac crest, and pubic tubercle. To specifically test this muscle group, the patient is positioned in the supine with the hips and knees flexed, the feet flat on the table, and the shoulder joints flexed to 90 . The patient is asked to assume a sitting position without using the upper extremities. Grading can be done as follows:



10
N
5/5: Able to correctly complete test movement (flex the vertebral column and keep it flexed while entering the hip flexion phase and coming to a sitting position) with the hands clasped behind the head
9
G+
4+/5: Able to correctly complete test movement with hands at shoulders
8
G
4/5: Able to correctly complete test movement with arms crossed at the chest
7
G 
4 /5: Able to correctly complete test movement with arms crossed at the abdomen
6
F+
3+/5: Able to correctly complete test movement with arms extended forward
5
F
3/5: Able to correctly perform posterior pelvic tilt and flex the vertebral column with arms extended forward, but is unable to maintain the trunk flexion when attempting to enter the hip flexion phase of the test movement
4
F 
3 /5: Able to tilt the pelvis posteriorly and keep the pelvis and thorax approximated as the head is raised from the table
2
P
2/5: Same position as 3 /5 grade: able to tilt the pelvis posteriorly but unable to maintain it as head is raised from the table
1
T
1/5: Same position as 3 /5 grade: When patient attempts to depress the chest or tilt the pelvis posteriorly, a contraction can be felt in the anterior abdominal muscles, but there is no approximation of the pelvis and thorax
0
Zero
0/5: No palpable muscle contraction



Lateral Trunk Flexors

The lateral trunk flexors include the erector spinae and the abdominals on the same side as the direction of side flexion. To specifically test this muscle group, the patient is positioned in sidelying with the leg straight and a pillow between the legs. The clinician stabilizes the legs and, while maintaining the upper arm along the side and the other arm across the chest, the patient is asked to lift the body off the floor toward the ceiling. This test can be graded as follows:
 Normal: able to fully lift and bend the back sideways
 Good: able to lift and then the back sideways with the shoulder 4 inches from the floor  Fair: able to lift and bend the back sideways with the shoulder 2 inches from the floor  Poor: unable to lift and bend the back sideways
Anterior Trunk (Lower Abdominals) Flexors. To specifically test this muscle group, the patient is positioned in supine with both of the legs straight and the arms folded across the chest. The patient is asked to raise the legs to a vertical position one at a time while keeping the back flat on the floor and then to slowly lower the legs together to the floor. This test can be graded based on the height at which the patient is unable to maintain the low back flat on the floor, as follows:



10
N
5/5
Able to perform posterior pelvic tilt and hold low back flat on table while lowering the legs to the fully extended position 0  to 15  (table level)
9
G+
4+/5
Able to perform posterior pelvic tilt and hold low back flat on table while lowering the legs to an angle of 15  to 30  with the table
8
G
4/5
Able to perform posterior pelvic tilt and hold low back flat on table while lowering the legs to an angle of 30  to 45  with the table
7
G 
4 /5
Able to perform posterior pelvic tilt and hold low back flat on table while lowering the legs to an angle of 45  to 60  with the table
6
F+
3+/5
Able to perform posterior pelvic tilt and hold low back flat on table while lowering the legs to an angle of 60  to 75  with the table
5
F
3/5
Able to perform posterior pelvic tilt and hold low back flat on table while lowering the legs to an angle of >75  with the table
4
F 
3 /5
and lower: The leg lowering test is not performed

The clinician should note if the patient exhibits any of the following faulty movement patterns:
 Excessive participation of the rectus abdominis throughout leg lowering  Excessive participation of head and neck for stabilization
 Increased intra abdominal pressure to stabilize lumbar spine (holding breath)
Back Extensors

The muscles that provide back extension are numerous and very difficult to isolate. To specifically test this muscle group, the patient is positioned in prone with the hands clasped behind the back. The patient is asked to raise the trunk off the floor. According to Kendall and colleagues,37 back extensor strength is best graded as slight, moderate, or marked, based on the judgment of the examiner. For example:
 Slight: Able to complete test movement with hands behind the head
 Moderate: Able to complete test movement with hands clasped behind the back
Marked: Able to partially complete the test movement to the point where the xiphoid process is raised slightly, with the hands clasped behind the back
McGill and colleagues187,188 have published normative data for the lateral, flexor, and extensor tests for young (mean age 21 years), healthy individuals (Table 12 10).



TABLE 12 10
Endurance Times and Flexion/Extension Ratios for the Flexor Endurance Test, Lateral Endurance Test, and Extensor Endurance Test

Test 
Men (mean age 21 years)
Women (mean age 21 years)
Men (mean age 34 years)
Extension
162 seconds
185 seconds
103
Flexion
136 seconds
134 seconds
66
Right lateral endurance (SB) test
95 seconds
75 seconds
54
Left lateral endurance (SB) test
99 seconds
78 seconds
54
Flexion/extension ratio
0.84
0.72
0.71
RSB/LSB ratio
0.96
0.96
1.05
RSB/extension ratio
0.58
0.40
0.57
LSB/extension ratio
0.61
0.42
0.58


The following tests can be used to assess the strength of the lumbar stabilizers.
Lower Abdominal Hollowing

The abdominal hollowing exercise tests the ability of the multifidus and transverse abdominis to co contract.189,190 These muscles are important for the provision of segmental control to the spine, because they provide an important stiffening effect on the lumbar spine, thereby enhancing dynamic stability.191
The patient is positioned supine. The patient is instructed to contract the deep abdominal muscles and to draw the navel up toward the chest and in toward the spine, so as to hollow the abdomen. When the muscle contracts properly, an increase in tension can be felt at a point 2 cm medial and inferior to the anterior superior iliac spine. If a bulging is felt at this point, the internal oblique is contracting rather than the transverse abdominis.189,190 The multifidus is palpated simultaneously and should be felt to swell at a point just lateral to the spinous process.189,190 The patient's head and upper trunk must remain stable, and he or she is not permitted to flex forward, push through the feet, or tilt the pelvis.
Spine Rotators and Multifidus Test

This test is designed to assess the ability of the spinal rotators and multifidus to stabilize the trunk during dynamic extremity movements.192 The patient is positioned in the quadruped position, with the pelvis positioned in neutral using muscular control. The patient is then asked to perform the following maneuvers: (1) single straight arm and hold, (2) single straight leg lift and hold, and (3) contralateral straight arm and straight leg lift and hold. The scoring for this test is as follows192:



Normal
(5)
=
able to perform contralateral arm and leg lift, both sides, while maintaining neutral pelvis (20  to 30 second hold)
Good
(4)
=
able to maintain neutral pelvis while performing single leg lift, but not able to hold pelvis in neutral when doing contralateral arm and leg lift (15  to 20 second hold)
Fair (3)
=
Able to do single arm lift and maintain neutral pelvis (15  to 20 second hold)
Poor (2)
=
Unable to maintain neutral pelvis while doing single arm lift
Trace
(1)
=
Unable to raise arm or leg off the table to the straight position



Abdominal Endurance Test

This test measures the endurance of the abdominals. The patient is positioned supine, with the hips flexed to approximately 45 , the feet flat on the bed, and the arms by the side. A line is drawn 8 cm (for patients 40 years and older) or 12 cm (for patients younger than 40 years of age) distal to the fingers.193 The patient is asked to tuck in the chin and to curl the trunk and touch the line with the fingers. The patient holds this position for as long as possible. The test is graded as follows154,194:

Normal (5)
=
20  to 30 second hold
Good (4)
=
15  to 20 second hold
Fair (3)
=
10  to 15 second hold
Poor (2)
=
1  to 10 second hold
Trace (1)
=
Unable to raise more than the head off the table


Side Support or Side Bridge Test

The so called side support or side bridge position has been identified as optimizing the challenge to the quadratus lumborum while minimizing the load on the lumbar spine.187 The patient is in the sidelying position, with the knees flexed to 90  and resting the upper body on the elbow. The test can be made more difficult by having the knees extended so that the legs are straight. The patient is asked to lift the pelvis off the table and to straighten the curve of the spine without rolling forward or backward. This position is then held. The test is graded as follows:



Normal (5)
=
Able to lift pelvis off the table and hold spine straight for a 20  to 30 second hold
Good (4)
=
Able to lift pelvis off the table but has difficulty holding spine straight for a 15  to 20 second hold
Fair (3)
=
Able to lift pelvis off the table but has difficulty holding spine straight for a 10  to 15 second hold
Poor (2)
=
Able to lift pelvis off the table but cannot hold spine straight for a 1  to 10 second hold
Trace (1)
=
Unable to lift pelvis off the table



Double Straight Leg Lowering Test

The straight leg lowering test can be used to assess core strength.189,195, 196, 197, 198, 199, 200 and 201 The patient is in the supine hooklying position, with the hips flexed to 90  and with a pressure cuff placed under the lumbar spine at the level of L4 to L5. The cuff is inflated to 40 mm Hg. The clinician raises the patient's legs until the pelvis is seen to posteriorly rotate, and the needle on the pressure monitor begins to move. The patient is asked to perform the lower abdominal hollowing maneuver so as to prevent further pelvic motion, and is then asked to lower the legs toward the bed while maintaining the lower abdominal hollowing. At the point when the cuff pressure is seen to increase or decrease, or when the pelvis anteriorly rotates, the test is over, and the hip angle at which this occurs is measured. This test may also be graded using the following scoring194:

Normal (5)
=
Able to reach 0 to 15  from the table before pelvis tilts
Good (4)
=
Able to reach 16 to 45  from the table before pelvis tilts
Fair (3)
=
Able to reach 46 to 75  from the table before pelvis tilts
Poor (2)
=
Able to reach 75 to 90  from the table before pelvis tilts
Trace (1)
=
Unable to hold pelvis in neutral

A study by Youdas and colleagues201 found that the odds of a patient having chronic low back pain is increased if the score on the leg lowering test for the abdominal muscles exceeds 50  for men and 60  for women. Another study202 found that there is a natural tendency for the pelvis to rotate anteriorly from very early on during this test, and that, as healthy young subjects were unable to prevent the tilting, the preceding scoring system may be questionable.
The Bent Knee Lowering Test

The lower abdominal musculature can be assessed in a similar fashion.195,196,199 The patient is positioned supine with the knees and hips flexed to approximately 90 . A pressure cuff, inflated to 40 mm Hg, is placed under the L4 to L5 segment. The patient is asked to perform the abdominal hollowing maneuver, and then to slowly lower the legs to the bed until the pressure on the monitor is seen to decrease. The hip angle is again measured at the point where there is a change in the pressure cuff reading, or where the anterior tilt of the pelvis occurred.



Normal (5)
=
Able to reach 0 to 15  from the table before pelvis tilts
Good (4)
=
Able to reach 16 to 45  from the table before pelvis tilts
Fair (3)
=
Able to reach 46 to 75  from the table before pelvis tilts
Poor (2)
=
Able to reach 75 to 90  from the table before pelvis tilts
Trace (1)
=
Unable to hold pelvis in neutral



Trunk Raise

The trunk raise test can be used to assess the endurance of the iliocostalis lumborum (erector spinae) and the multifidus.195,199,203,204 The patient is positioned prone, with the hands behind the back, or by the sides. The patient is instructed to extend at the lumbar spine by raising the chest off the bed to approximately 30  (the axilla can be used as the reference for the axis if a goniometer is used) and to hold the position for as long as possible. The clinician times the test195:

Normal (5)
=
20  to 30 second hold
Good (4)
=
15  to 20 second hold
Fair (3)
=
10  to 15 second hold
Poor (2)
=
1  to 10 second hold
Trace (1)
=
Unable to raise more than the head off the table


Lunge 

The patient is asked to perform a lunge. The clinician notes the quality and quantity of the motion, as well as the ability of the patient to sustain the position for 30 seconds.205 Excessive shaking of the legs with this maneuver may indicate weakness of the lumbopelvic stabilizers or poor balance and proprioception.
Muscle Testing the Trunk in the Athletic Population
According to McGill and colleagues,188,189 the torso flexors, extensors, and lateral musculature are involved in spine stability during virtually any task, and therefore the endurance of each of these muscles groups should be measured. The following tests are recommended:
Flexor endurance test. The patient is positioned in sitting with the back supported at an angle of approximately 60  from the floor (Figure 12  153), with both knees and hips flexed to 90  and the arms folded across the chest. The patient's foot can be stabilized manually or by using a belt (see Figure 12 153). Once the patient is ready, the support is removed from the back (Figure 12 154), and the patient attempts to maintain the isometric posture for as long as possible. Failure occurs when the patient is no longer able to maintain the position.
Lateral endurance test. The patient is positioned in the full side bridge position (Figure 12 155). The patient attempts to maintain this position for as long as possible. Failure occurs when the patient loses the straight backed posture and the hip returns to the table. The test is then repeated on the other side.



 Extensor endurance test. The patient is positioned in prone with the lower extremity supported so that the trunk and upper extremities are over the edge of the table (Figure 12 156). The upper extremities are held across the chest. Failure occurs when the upper body drops from the horizontal position.

FIGURE  12 153


Flexor endurance test start position


FIGURE  12 154


Flexor endurance test support removed


FIGURE  12 155


Lateral endurance test




FIGURE  12 156


Extensor endurance test

McGill used these tests on young, healthy individuals (92 men and 137 women with a mean age of 21 years), and with a group of men with a mean age of 34 years with no history of back trouble. The results are depicted in Table 12 10. According to McGill, the interpretation of absolute endurance should be secondary to interpreting the imbalance among the three muscle groups, and the discrepancies outlined in Table 12 11 suggest unbalanced endurance, which increases the potential for injury and should thus be the focus of the intervention.
TABLE 12 11
Asymmetrical Unbalances

Right side bridge/left side bridge endurance
>0.05
Flexion/extension endurance
>1.0
Side bridge (either side)/extension endurance
>0.75
Extensor strength (N. m)/extensor endurance (seconds) strength to endurance ratio
>4.0



 USING SPECIFIC MUSCLE TESTING FOR DIAGNOSIS	




Specific muscle testing can provide the clinician with valuable information in addition to the strength grade of the muscle. Cyriax reasoned that if the clinician isolates and then applies tension to a structure, he or she could make a conclusion as to the integrity of that structure.206 According to Cyriax, pain with a contraction generally indicates an injury to the muscle or a capsular structure.206 This suspicion can be confirmed by combining the findings from the isometric test with the findings of the passive motion and the joint distraction and compression tests (Table 12 12). Pain that occurs consistently with resistance, whatever the length of the muscle, may indicate a tear of the muscle belly. Pain with muscle testing may indicate a muscle injury, a joint injury, or a combination of both. Pain that does not occur during the test, but occurs on the release of the contraction, is thought to have an articular source, produced by the joint glide that occurs following the release of tension.
TABLE 12 12
Differential Diagnosis of Contractile, Inert, and Neural Tissue Injury


Contractile Tissue
Inert Tissue 
Neural Tissue 
Pain
Cramping, dull, and ache
Dull sharp
Burning and lancinating
Paresthesia
No
No
Yes
Duration
Intermittent
Intermittent
Intermittent constant
Dermatomal distribution
No
No
Yes
Peripheral nerve sensory distribution
No
No
Yes (if peripheral nerve involved)
End feel
Muscle spasm
Boggy and hard capsular
Stretch



Cyriax also introduced the concept of tissue reactivity. Tissue reactivity is the manner in which different stresses and movements can alter the clinical signs and symptoms. This knowledge can be used to gauge any subtle changes to the patient's condition.207
Strength testing may also be used to examine the neurologic integrity of muscles. Weakness in muscle testing must be differentiated between weakness throughout the range of motion (pathologic weakness) and weakness that only occurs in certain positions (positional weakness).
Thus, strength testing can provide the clinician with the following findings154:
 A weak and painless contraction may indicate palsy or a complete rupture of the muscle tendon unit. The motor disorder of peripheral neuropathy is first manifested by weakness and diminished or absent tendon reflex.208
 A strong and painless contraction indicates a normal finding.
 A weak and painful contraction: A study by Franklin and colleagues209 indicated that the conditions related to this finding need to be expanded to include not only serious pathology, such as a significant muscle tear or tumor, but relatively minor muscle damage and inflammation such as that induced by eccentric isokinetic exercise.4
	A strong and painful contraction indicates a grade I contractile lesion.	



The degree of certainty regarding the findings just described depends on a combination of the length of the muscle tested and the force applied. To fully test the integrity of the muscle tendon unit, a maximum contraction must be performed in the fully lengthened position of the muscle tendon unit. Although this position fully tests the muscle tendon unit, there are some problems with testing in this manner:
 The joint and its surrounding inert tissues are in a more vulnerable position and could be the source of the pain.
 It is difficult to differentiate among damage to the contractile tissue of varying severity. The degree of significance with the findings in resistive testing depends on the position of the muscle and the force applied (Table 12 13). For example, pain reproduced with a minimal contraction in the rest position for the muscle is more strongly suggestive of a contractile lesion than pain reproduced with a maximal contraction in the lengthened position for the muscle.
 As a muscle lengthens, it reaches a point of passive insufficiency, where it is not capable of generating its maximum force output.
If the same muscle is tested on the opposite side, using the same testing procedure, the concern about the length of the muscle is removed, because the focus of the test is to provide a comparison with same muscle on the opposite side, rather than to assess the absolute force output.
TABLE 12 13
Strength Testing Related to Joint Position and Muscle Length

Muscle Length 
Rationale 
Fully lengthened
Muscle in position of passive insufficiency

Tightens the inert component of the muscle

Tests for muscle tears (tenoperiosteal tears) while using minimal force
Midrange
Muscle in strongest position

Tests overall power of muscle
Fully shortened
Muscle in its weakest position

Used for the detection of palsies, especially if coupled with an eccentric contraction



TABLE 12 14
Comparison of MMT Gradesa






Medical Research Councilb
Worthinghamc
McCrearyd
Explanation




5
Normal (N)
100%
Holds test position against maximal










resistance




4+
Good + (G+)

Holds test position against moderate to strong pressure




4
Good (G)
80%
Holds test position against moderate resistance




4?
Good ? (G?)

Holds test position against slight to moderate pressure




3+
Fair + (F+)

Holds test position against slight resistance




3
Fair (F)
50%
Holds test position against gravity




3?
Fair ? (F?)

Gradual release from test position




2+
Poor + (P+)

Moves through partial ROM against gravity OR
Moves through complete ROM, gravity eliminated, and holds against pressure




2
Poor (P)
20%
Able to move through full ROM, gravity eliminated




2?
Poor ? (P?)

Moves through partial ROM, gravity eliminated




1
Trace (T)
5%
No visible movement; palpable or observable  tendon prominence/flicker contraction



Downloaded 2024 3 16 1:39 P Your IP is 155.33.135.27 CHAPTER 12: Manual Muscle Testing,
 2024 McGraw Hill. All Rights Reserved. Terms of Use   Privacy Policy   Notice   Accessibility


Page 151 / 164



0
0
0%
No palpable or observable muscle contraction


The grades of 0, 1, and 2 are tested in the gravity minimized position (contraction is perpendicular to the gravitational force). All other grades are tested in the antigravity position.
The more functional of the three grading systems because it tests a motion that utilizes all of the agonists and synergists involved in the motion.a
Designed to test a specific muscle rather than the motion. Requires both selective recruitment of a muscle by the patient and a sound knowledge of anatomy and kinesiology on the part of the clinician to determine the correct alignment of the muscle fibers.a




aPalmer ML, Epler M: Principles of examination techniques, in Palmer ML, Epler M (eds): Clinical Assessment Procedures in Physical Therapy. Philadelphia, JB Lippincott, 1990, pp 8 36.
bFrese E, Brown M, Norton B: Clinical reliability of manual muscle testing: middle trapezius and gluteus medius muscles. Phys Ther 67:1072 1076, 1987.

cDaniels K, Worthingham C: Muscle Testing Techniques of Manual Examination (ed 5). Philadelphia, WB Saunders, 1986.

dKendall FP, McCreary EK, Provance PG: Muscles: Testing and Function. Baltimore, Williams & Wilkins, 1993.

REFERENCES

1. American Medical Association: Guides to the Evaluation of Permanent Impairment (ed 5). Chicago, American Medical Association, 2001.

2. Beasley WC: Quantitative muscle testing: principles and applications to research and clinical services. Arch Phys Med Rehabil 42:398 425, 1961. [PubMed: 13688259] 

3. MacConnail MA, Basmajian JV: Muscles and Movements: A Basis for Human Kinesiology. New York, Robert Krieger, 1977.

4. White DJ: Musculoskeletal examination, in O'Sullivan SB, Schmitz TJ (eds): Physical Rehabilitation (ed 5). Philadelphia, FA Davis, 2007, pp 159 192.

5. Florence JM, Pandya S, King WM et al.: Intrarater reliability of manual muscle test (Medical Research Council scale) grades in Duchenne's muscular dystrophy. Phys Ther 72:115 122; discussion 122 126, 1992. [PubMed: 1549632] 

6. Barr AE, Diamond BE, Wade CK et al.: Reliability of testing measures in Duchenne or Becker muscular dystrophy. Arch Phys Med Rehabil 72:315 9, 1991. [PubMed: 2009048] 

7. Nadler SF, Rigolosi L, Kim D et al.: Sensory, motor, and reflex examination, in Malanga GA, Nadler SF (eds): Musculoskeletal Physical Examination  An Evidence Based Approach. Philadelphia, Mosby, 2006, pp 15 32.

8. Bohannon RW: Make tests and break tests of elbow flexor muscle strength. Phys Ther 68:193 194, 1988. [PubMed: 3340656] 

9. Stratford PW, Balsor BE: A comparison of make and break tests using a hand held dynamometer and the Kin Com. J Orthop Sports Phys Ther 19:28 32, 1994.
CrossRef [PubMed: 8156061] 

10. Andrews AW, Thomas MW, Bohannon RW: Normative values for isometric muscle force measurements obtained with hand held dynamometers.




11. Sapega AA: Muscle performance evaluation in orthopedic practice. J Bone Joint Surg 72A:1562 1574, 1990.

12. Iddings DM, Smith LK, Spencer WA: Muscle testing: part 2. Reliability in clinical use. Phys Ther Rev 41:249 256, 1961. [PubMed: 13717380]


13. Silver M, McElroy A, Morrow L et al.: Further standardization of manual muscle test for clinical study: applied in chronic renal disease. Phys Ther 50:1456 1465, 1970. [PubMed: 5472510] 

14. Marx RG, Bombardier C, Wright JG: What we know about the reliability and validity of physical examination tests used to examine the upper extremity. J Hand Surg 24A:185 193, 1999.
CrossRef

15. Astrand PO, Rodahl K: Textbook of Work Physiology. New York, McGraw Hill, 1973.

16. Astrand PO, Rodahl K: The Muscle and Its Contraction: Textbook of Work Physiology. New York, McGraw Hill, 1986.

17. Muller EA: Influences of training and inactivity of muscle strength. Arch Phys Med Rehabil 51:449 462, 1970. [PubMed: 5448109] 

18. Phillips BA, Lo SK, Mastaglia FL: Muscle force measured using "break" testing with a hand held myometer in normal subjects aged 20 to 69 years. Arch Phys Med Rehabil 81:653 661, 2000. [PubMed: 10807107] 

19. Beck M, Giess R, Wurffel W et al.: Comparison of maximal voluntary isometric contraction and Drachman's hand held dynamometry in evaluating patients with amyotrophic lateral sclerosis. Muscle Nerve 22:1265 1270, 1999.
CrossRef [PubMed: 10454724] 

20. Roy MA, Doherty TJ: Reliability of hand held dynamometry in assessment of knee extensor strength after hip fracture. Am J Phys Med Rehabil 83:813 818, 2004.
CrossRef [PubMed: 15502733] 

21. Hutten MM, Hermens HJ: Reliability of lumbar dynamometry measurements in patients with chronic low back pain with test retest measurements on different days. Eur Spine J 6:54 62, 1997.
CrossRef [PubMed: 9093828] 

22. Stokes HM, Landrieu KW, Domangue B et al.: Identification of low effort patients through dynamometry. J Hand Surg 20A:1047 1056, 1995. CrossRef

23. Bohannon RW: Hand held compared with isokinetic dynamometry for measurement of static knee extension torque (parallel reliability of dynamometers). Clin Phys Physiol Meas 11:217 222, 1990.
CrossRef [PubMed: 2245586] 

24. Hartsell HD, Forwell L: Postoperative eccentric and concentric isokinetic strength for the shoulder rotators in the scapular and neutral planes. J Orthop Sports Phys Ther 25:19 25, 1997.
CrossRef [PubMed: 8979172] 

25. Hartsell HD, Spaulding SJ: Eccentric/concentric ratios at selected velocities for the invertor and evertor muscles of the chronically unstable ankle. Br J Sports Med 33:255 258, 1999.




26. Griffin JW: Differences in elbow flexion torque measured concentrically, eccentrically and isometrically. Phys Ther 67:1205 1208, 1987. [PubMed: 3615588] 

27. Hortobagyi T, Katch FI: Eccentric and concentric torque velocity relationships during arm flexion and extension. J Appl Physiol 60:395 401, 1995. CrossRef

28. Trudelle Jackson E, Meske N, Highenboten C et al.: Eccentric/concentric torque deficits in the quadriceps muscle. J Orthop Sports Phys Ther 11:142 145, 1989.
CrossRef [PubMed: 18796919] 

29. Rothstein JM, Lamb RL, Mayhew TP: Clinical uses of isokinetic measurements. Critical issues. Phys Ther 67:1840 1844, 1987. [PubMed: 3685109]


30. Bohannon RW: Manual muscle test scores and dynamometer test scores of knee extension strength. Arch Phys Med Rehabil 67:390 392, 1986. [PubMed: 3718198] 

31. Mulroy SJ, Lassen KD, Chambers SH et al.: The ability of male and female clinicians to effectively test knee extension strength using manual muscle testing. J Orthop Sports Phys Ther 26:192 199, 1997.
CrossRef [PubMed: 9310910] 

32. Jobe FW, Pink M: Classification and treatment of shoulder dysfunction in the overhead athlete. J Orthop Sports Phys Ther 18:427 431, 1993. CrossRef [PubMed: 8364598] 

33. Haymaker W, Woodhall B: Peripheral Nerve Injuries. Principles of Diagnosis. London, WB Saunders, 1953.

34. Brodal A: Neurological Anatomy. London, Oxford University Press, 1981.

35. Mercer S, Campbell AH: Motor innervation of the trapezius. J Man Manip Ther 8:18 20, 2000. CrossRef

36. Ayub E: Posture and the upper quarter, in Donatelli RA (ed): Physical Therapy of the Shoulder (ed 2). New York, Churchill Livingstone, 1991, pp 81  90.

37. Kendall FP, McCreary EK, Provance PG et al.: Muscles: Testing and Function, with Posture and Pain. Baltimore, Williams & Wilkins, 2005.

38. Neumann DA: Shoulder complex, in Neumann DA (ed): Kinesiology of the Musculoskeletal System: Foundations for Physical Rehabilitation. St Louis, Mosby, 2002, pp 91 132.

39. White SM, Witten CM: Long thoracic nerve palsy in a professional ballet dancer. Am J Sports Med 21:626 629, 1993. CrossRef [PubMed: 8396356] 

40. Jobe CM: Gross anatomy of the shoulder, in Rockwood CA, Matsen FA (eds): The Shoulder (ed 2). Philadelphia, WB Saunders, 1998, pp 35 97.

41. Connor PM, Yamaguchi K, Manifold SG et al.: Split pectoralis major transfer for serratus anterior palsy. Clin Orthop 341:134 142, 1997. [PubMed: 9269166] 





43. Gregg JR, Labosky D, Hearty M et al.: Serratus anterior paralysis in the young athlete. J Bone Joint Surg 61A:825 832, 1979.

44. Marks PH, Warner JJP, Irrgang JJ: Rotator cuff disorders of the shoulder. J Hand Ther 7:90 98, 1994. CrossRef [PubMed: 8038882] 

45. Warner JJ, Navarro RA: Serratus anterior dysfunction. Recognition and treatment. Clin Orthop Rel Res 349:139 48, 1998. CrossRef

46. Leffert RD: Neurological problems, in Rockwood CA Jr, Matsen FR III (eds): The Shoulder. Philadelphia, WB Saunders, 1990, pp 750 773.

47. Perry J: Biomechanics of the shoulder, in Rowe CR (ed): The Shoulder. New York, Churchill Livingstone, 1988, pp 1 15.

48. Warner JJP, Micheli LJ, Arslanian LE et al.: Scapulothoracic motion in normal shoulders and shoulders with glenohumeral instability and impingement syndrome. A study using Moire topographic analysis. Clin Orthop 285:191 199, 1992. [PubMed: 1446436] 

49. Post M: Pectoralis major transfer for winging of the scapula. J Shoulder Elbow Surg 4:1 9, 1995. CrossRef [PubMed: 7874558] 

50. Kapandji IA: The Physiology of Joints. New York, Churchill Livingstone, 1974.

51. Dunleavy K: Relationship between the shoulder and the cervicothoracic spine. La Crosse, Wisc, Orthopedic Section, APTA, 2001.
52. Porterfield J, De Rosa C: Mechanical Neck Pain: Perspectives in Functional Anatomy. Philadelphia, WB Saunders, 1995.
53. Murray MP, Gore DR, Gardner GM et al.: Shoulder motion and muscle strength of normal men and women in two age groups. Clin Orthop Rel Res 192:268 273, 1985.
54. Mikesky AE, Edwards JE, Wigglesworth JK et al.: Eccentric and concentric strength of the shoulder and arm musculature in collegiate baseball pitchers. Am J Sports Med 23:638 42, 1995.
CrossRef [PubMed: 8526283]
55. Perry J: Muscle Control of the Shoulder, in Rowe CR (ed): The Shoulder. New York, Churchill Livingstone, 1988, pp 17 34.
56. Culham E, Peat M: Functional anatomy of the shoulder complex. J Orthop Sports Phys Ther 18:342 350, 1993. CrossRef [PubMed: 8348135]
57. Blackburn TA, McLeod WD, White B et al.: EMG analysis of posterior rotator cuff exercises. Athl Training 25:40 45, 1990.
58. Bradley JP, Tibone JE: Electromyographic analysis of muscle action about the shoulder. Clin Sports Med 4:789 805, 1991.
59. Perry J, Glousman RE: Biomechanics of throwing, in Nicholas JA, Hershman EB (eds): The Upper Extremity in Sports Medicine. St Louis, CV Mosby, 1990, pp 727 751.
60. Sharkey NA, Marder RA: The rotator cuff opposes superior translation of the humeral head. Am J Sports Med 23:270 275, 1995. CrossRef [PubMed: 7661251]
61. Sharkey NA, Marder RA, Hanson PB: The role of the rotator cuff in elevation of the arm. Trans Orthop Res Soc 18:137, 1993.



62. Turkel SJ, Panio MW, Marshall JL et al.: Stabilizing mechanisms preventing anterior dislocation of the glenohumeral joint. J Bone Joint Surg [Am] 63:1208 1217, 1981. [PubMed: 7287791] 

63. Chepeha JC: Shoulder trauma and hypomobility, in Magee DJ, Zachazewski JE, Quillen WS (eds): Pathology and Intervention in Musculoskeletal Rehabilitation. St Louis, Saunders, 2009, pp 92 124.

64. Vangsness CT Jr, Jorgenson SS, Watson T et al.: The origin of the long head of the biceps from the scapula and glenoid labrum. An anatomical study of 100 shoulders. 95J Bone Joint Surg [Br] 76:951 4, 1994.

65. Altchek D, Wolf B: Disorders of the biceps tendon, in Krishnan S, Hawkins R, Warren R (eds): The Shoulder and the Overhead Athlete. Philadelphia, PA, Lippincott, Williams & Wilkins, 2004, pp 196 208.

66. Habermeyer P, Magosch P, Pritsch M et al.: Anterosuperior impingement of the shoulder as a result of pulley lesions: a prospective arthroscopic study. J Shoulder Elbow Surg 13:5 12, 2004.
CrossRef [PubMed: 14735066] 

67. Krupp RJ, Kevern MA, Gaines MD et al.: Long head of the biceps tendon pain: differential diagnosis and treatment. J Orthop Sports Phys Ther 39:55 70, 2009.
CrossRef [PubMed: 19194019] 

68. Mathes SJ, Nahai F: Biceps brachii, in Mathes SJ, Nahai F (eds): Clinical Atlas of Muscle and Musculocutaneous Flaps. St Louis, Mosby, 1979, pp 426 432.

69. Matsen FA III, Arntz CT: Subacromial impingement, in Rockwood CA Jr, Matsen FA III (eds): The Shoulder. Philadelphia, WB Saunders, 1990, pp 623 648.

70. Neer CS II: Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report. J Bone Joint Surg [Am] 54:41 50, 1972. [PubMed: 5054450] 

71. Neer C: Impingement lesions. Clin Orthop 173:71 77, 1983.

72. Lucas DB: Biomechanics of the shoulder joint. Arch Surg 107:425 432, 1973. CrossRef [PubMed: 4783038] 

73. Levy AS, Kelly BT, Lintner SA et al.: Function of the long head of the biceps at the shoulder: electromyographic analysis. J Shoulder Elbow Surg 10:250 255, 2001.
CrossRef [PubMed: 11408907] 

74. Andrews JR, Carson WG, McLeod WD: Glenoid labrum tears related to the long head of the biceps. Am J Sports Med 13:337 341, 1985. CrossRef [PubMed: 4051091] 

75. Basmajian JV, Deluca CJ: Muscles Alive: Their Functions Revealed by Electromyography. Baltimore, Williams & Wilkins, 1985.

76. Basmajian JV, Bazant FJ: Factors preventing downward dislocation of the adducted shoulder joint: an electromyographic and morphological study. J Bone Joint Surg 41A:1182 1186, 1959.

77. Itoi E, Kuechle DK, Newman SR et al.: Stabilising function of the biceps in stable and unstable shoulders. J Bone Joint Surg [Am] 75B:546 550, 1993.



78. Rodosky MW, Harner CD, Fu FH: The role of the long head of the biceps muscle and superior glenoid labrum in anterior stability of the shoulder. Am J Sports Med 22:121 130, 1994.
CrossRef [PubMed: 8129095] 

79. Norkin C, Levangie P: Joint Structure and Function: A Comprehensive Analysis. Philadelphia, FA Davis, 1992.

80. Pagnani M, Deng X H, Warren RF et al.: Effect of lesions of the superior portion of the glenoid labrum on glenohumeral translation. J Bone Joint Surg 77A:1002 1010, 1995.

81. Payne LZ, Deng X, Craig EV et al.: The combined dynamic and static contributions to subacromial impingement. Am J Sports Med 25:801 808, 1997.
CrossRef [PubMed: 9397268] 

82. Warner JJP, McMahon PJ: The role of the long head of the biceps brachii in superior stability of the glenohumeral joint. J Bone Joint Surg 77A:366 372, 1995.

83. Kido T, Itoi E, Konno N et al.: The depressor function of biceps on the head of the humerus in shoulders with tears of the rotator cuff. J Bone Joint Surg 82B:416 419, 2000.
CrossRef

84. Itoi E, Hsu HC, Carmichael SW et al.: Morphology of the torn rotator cuff. J Anat 186:429 434, 1995. [PubMed: 7649844] 

85. Jobe FW, Nuber G: Throwing injuries of the elbow. Clin Sports Med 5:621, 1986. [PubMed: 3768968] 

86. Ryan J: Elbow, in Wadsworth C (ed): Current Concepts of Orthopedic Physical Therapy Home Study Course. La Crosse, Wisc, Orthopaedic Section, APTA, 2001.

87. Neumann DA: Elbow and forearm complex, in Neumann DA (ed): Kinesiology of the Musculoskeletal System: Foundations for Physical Rehabilitation. St Louis, Mosby, 2002, pp 133 171.

88. Schuind F, Garcia Elias M, Cooney WP et al.: Flexor tendon forces: In vivo measurements. J Hand Surg 17A:291 298, 1992. CrossRef

89. Schuind FA, Goldschmidt D, Bastin C et al.: A biomechanical study of the ulnar nerve at the elbow. J Hand Surg [Br] 20:623 627, 1995. CrossRef [PubMed: 8543869] 

90. Jackson Manfield P, Neumann DA: Structure and function of the elbow and forearm complex, in Jackson Manfield P, Neumann DA (eds): Essentials of Kinesiology for the Physical Therapist Assistant. St Louis, MO, Mosby Elsevier, 2009, pp 91 122.

91. Pauly JE, Rushing JL, Schering LE: An electromyographic study of some muscles crossing the elbow joint. Anat Rec 1:42, 1967.

92. Basmajian JV, Latif A: Integrated actions and functions of the chief flexors of the elbow: a detailed electromyographic analysis. J Bone Joint Surg 39A:1106 1118, 1957.

93. Funk DA, An KA, Morrey BF et al.: Electromyographic analysis of muscles across the elbow joint. J Orthop Res 5:529 538, 1987. CrossRef [PubMed: 3681527] 

94. Basmajian JV, Deluca CJ: Muscles Alive (ed 5). Baltimore, Williams & Wilkins, 1985, pp 268 269.




95. Thepaut Mathieu C, Maton B: The flexor function of the muscle pronator teres in man: a quantitative electromyographic study. Eur J Appl Physiol 54:116 121, 1985.
CrossRef

96. An KN, Morrey BF: Biomechanics of the elbow, in Morrey BF (ed): The Elbow and Its Disorders (ed 2). Philadelphia, WB Saunders, 1993, pp 53 73.

97. An KN, Hui FC, Morrey BF et al.: Muscles across the elbow joint: a biomechanical analysis. J Biomech 14:659 669, 1981. CrossRef [PubMed: 7334026] 

98. Davidson PA, Pink M, Perry J et al.: Functional anatomy of the flexor pronator muscle group in relation to the medial collateral ligament of the elbow. Am J Sports Med 23:245 250, 1995.
CrossRef [PubMed: 7778713] 

99. Reid DC: Functional Anatomy and Joint Mobilization (ed 2). Edmonton, University of Alberta Press, 1975.

100. Hirasawa Y, Sawamura H, Sakakida K: Entrapment neuropathy due to bilateral epitrochlearis muscles: a case report. J Hand Surg Am 4:181 184, 1979.
CrossRef [PubMed: 422832] 

101. Onieal M E: Common wrist and elbow injuries in primary care. Lippincotts Prim Care Pract 3:441 450, 1999. [PubMed: 10624278] 

102. Brand PW, Hollister AM, Agee JM: Transmission, in Brand PW, Hollister AM (eds): Clinical Mechanics of the Hand. St Louis, Mosby, 1999, pp 61  99.

103. Wadsworth C: Wrist and hand, in Wadsworth C (ed): Current Concepts of Orthopedic Physical Therapy Home Study Course. La Crosse, Wisc, Orthopaedic Section, APTA, 2001.

104. Kaplan EB: Anatomy and kinesiology of the hand, in Flynn JE (ed): Hand Surgery (ed 2). Baltimore, Williams & Wilkins, 1975.

105. Holtzhausen L M, Noakes TD: Elbow, forearm, wrist, and hand injuries among sport rock climbers. Clin J Sports Med 6:196 203, 1996. CrossRef

106. Linburg RM, Conmstock BE: Anomalous tendon slips from the pollicis longus to the flexor digitorum profundus. J Hand Surg 4:79 83, 1979. CrossRef

107. Rennie WRJ, Muller H: Linburg syndrome. Can J Surg 41:306 308, 1998. [PubMed: 9711164] 

108. Brand PW: Clinical Mechanics of the Hand. St Louis, Mosby, 1985.

109. Tubiana R, Thomine J M, Mackin E: Examination of the Hand and Wrist. London, Mosby, 1996.

110. Ketchum LD, Thompson DE: An experimental investigation into the forces internal to the human hand, in Brand PW (ed): Clinical Mechanics of the Hand. St Louis, CV Mosby, 1985.

111. Hollinshead WH: Anatomy for Surgeons (ed 2). New York, Harper & Row, 1969.

112. Wadsworth CT: Anatomy of the Hand and Wrist, Manual Examination and Treatment of the Spine and Extremities. Baltimore, Williams & Wilkins, 1988, pp 128 138.

113. Neumann DA: Kinesiology of the hip: a focus on muscular actions. J Orthop Sports Phys Ther 40:82 94, 2010.




114. Delp SL, Hess WE, Hungerford DS et al.: Variation of rotation moment arms with hip flexion. J Biomech 32:493 501, 1999. CrossRef [PubMed: 10327003] 

115. Yoshio M, Murakami G, Sato T et al.: The function of the psoas major muscle: passive kinetics and morphological studies using donated cadavers. J Orthop Sci 7:199 207, 2002.
CrossRef [PubMed: 11956980] 

116. Hall SJ: The biomechanics of the human lower extremity, in Basic Biomechanics (ed 3). New York, McGraw Hill, 1999, pp 234 281.

117. Janda V: On the concept of postural muscles and posture in man. Aust J Physiother 29:83 84, 1983. CrossRef [PubMed: 25025491] 

118. Fagerson TL: Hip pathologies: diagnosis and intervention, in Magee DJ, Zachazewski JE, Quillen WS (eds): Pathology and Intervention in Musculoskeletal Rehabilitation. St Louis, Saunders, 2009, pp 497 527.

119. Gordon EJ: Trochanteric bursitis and tendinitis. Clin Orthop 20:193 202, 1961. [PubMed: 13707155] 

120. Renne JW: The iliotibial band friction syndrome. J Bone Joint Surg 57:1110 1111, 1975. [PubMed: 1201997] 

121. Evans P: The postural function of the iliotibial tract. Ann R Coll Surg Engl 61:271 280, 1979. [PubMed: 475270] 

122. Pease BJ, Cortese M: Anterior knee pain: differential diagnosis and physical therapy management, Orthopaedic Physical Therapy Home Study Course 92 1. La Crosse, Wisc, Orthopaedic Section, APTA, 1992.

123. Grelsamer RP, McConnell J: Normal and abnormal anatomy of the extensor mechanism, In The Patella: A Team Approach. Austin, Texas, PRO ED, 1998, pp 11 24.

124. Kapandji IA: The Physiology of the Joints, Lower Limb. New York, Churchill Livingstone, 1991.

125. Durrani Z, Winnie AP: Piriformis muscle syndrome: an underdiagnosed cause of sciatica. J Pain Symptom Manage 6:374 379, 1991. CrossRef [PubMed: 1880438] 

126. Julsrud ME: Piriformis syndrome. J Am Podiatr Med Assoc 79:128 131, 1989. CrossRef [PubMed: 2724111] 

127. Pace JB, Nagle D: Piriformis syndrome. West J Med 124:435 439, 1976. [PubMed: 132772] 

128. Steiner C, Staubs C, Ganon M et al.: Piriformis syndrome: pathogenesis, diagnosis, and treatment. J Am Osteopath Assoc 87:318 323, 1987. [PubMed: 3583849] 

129. Harvey G, Bell S: Obturator neuropathy. An anatomic perspective. Clin Orthop Rel Res 363:203 11, 1999. CrossRef

130. Williams PL, Warwick R, Dyson M et al.: Gray's Anatomy (ed 37). London, Churchill Livingstone, 1989.

 131. Dixon MC, Scott RD, Schai PA et al.: A simple capsulorrhaphy in a posterior approach for total hip arthroplasty. J Arthroplasty 19:373 376, 2004.	




132. Mihalko WM, Whiteside LA: Hip mechanics after posterior structure repair in total hip arthroplasty. Clin Orthop Rel Res 420:194 198, 2004. CrossRef

133. Lynch SA, Renstrom PA: Groin injuries in sport: treatment strategies. Sports Med 28:137 144, 1999. CrossRef [PubMed: 10492031] 

134. Holmich P: Adductor related groin pain in athletes. Sports Med Arth Rev 5:285 291, 1998.

135. Hasselman CT, Best TM, Garrett WE: When groin pain signals an adductor strain. Physician Sports Med 23:53 60, 1995.

136. Johnson CE, Basmajian JV, Dasher W: Electromyography of the sartorius muscle. Anat Rec 173:127 130, 1972. CrossRef [PubMed: 5033767] 

137. Anderson MA, Gieck JH, Perrin D et al.: The relationship among isokinetic, isotonic, and isokinetic concentric and eccentric quadriceps and hamstrings force and three components of athletic performance. J Orthop Sports Phys Ther 14:114 120, 1991.
CrossRef [PubMed: 18796821] 

138. Lieb F, Perry J: Quadriceps function. J Bone Joint Surg [Am] 50:1535, 1968. [PubMed: 5722849] 

139. Hallisey MJ, Doherty N, Bennett WF et al.: Anatomy of the junction of the vastus lateralis tendon and the patella. J Bone Joint Surg [Am] 69:545  549, 1987. [PubMed: 3571314] 

140. Bose K, Kanagasuntheram R, Osman MBH: Vastus medialis oblique: an anatomic and physiologic study. Orthopedics 3:880 883, 1980. [PubMed: 24822568] 

141. Grelsamer RP: Patellar Malalignment. J Bone Joint Surg [Am] 82A:1639 1650, 2000.

142. Koskinen SK, Kujala UM: Patellofemoral relationships and distal insertion of the vastus medialis muscle: a magnetic resonance imaging study in nonsymptomatic subjects and in patients with patellar dislocation. Arthroscopy 8:465 468, 1992.
CrossRef [PubMed: 1466706] 

143. Raimondo RA, Ahmad CS, Blankevoort L et al.: Patellar stabilization: a quantitative evaluation of the vastus medialis obliquus muscle. Orthopedics 21:791 795, 1998. [PubMed: 9672916] 

144. Nakamura Y, Ohmichi H, Miyashita M: EMG relationship during maximum voluntary contraction of the quadriceps, IX Congress of the International Society of Biomechanics. Waterloo, Ontario, 1983.

145. Knight KL, Martin JA, Londerdee BR: EMG comparison of quadriceps femoris activity during knee extensions and straight leg raises. Am J Phys Med 58:57 69, 1979. [PubMed: 434132] 

146. Brownstein BA, Lamb RL, Mangine RE: Quadriceps torque and integrated electromyography. J Orthop Sports Phys Ther 6:309 314, 1985. CrossRef [PubMed: 18802296] 

147. Fox TA: Dysplasia of the quadriceps mechanism: hypoplasia of the vastus medialis muscle as related to the hypermobile patella syndrome. Surg Clin North Am 55:199 226, 1975. [PubMed: 1118794] 



148. Tria AJ, Palumbo RC, Alicia JA: Conservative care for patellofemoral pain. Orthop Clin North Am 23:545 554, 1992. [PubMed: 1408039]


149. Reynolds L, Levin TA, Medeiros JM et al.: EMG activity of the vastus medialis oblique and the vastus lateralis in the their role in patellar alignment. Am J Sports Med 62:62 70, 1983.

150. Moller BN, Krebs B, Tideman Dal C et al.: Isometric contractions in the patellofemoral pain syndrome. Arch Orthop Trauma Surg 105:24, 1986. CrossRef [PubMed: 3707304] 

151. Reid DC: Anterior knee pain and the patellofemoral pain syndrome, in Sports Injury Assessment and Rehabilitation. New York, Churchill Livingstone, 1992, pp 345 398.

152. Larson RL, Jones DC: Dislocations and ligamentous injuries of the knee, in Rockwood CA, Green DP (eds): Fractures in Adults (ed 2). Philadelphia, JB Lippincott, 1984, pp 1480 1591.

153. Gill DM, Corbacio EJ, Lauchle LE: Anatomy of the knee, in Engle RP (ed): Knee Ligament Rehabilitation. New York, Churchill Livingstone, 1991, pp 1 15.

154. Kendall FP, McCreary EK, Provance PG: Muscles: Testing and Function. Baltimore, Williams & Wilkins, 1993.

155. O'Connor JJ: Can muscle co contraction protect knee ligaments after injury or repair? J Bone Joint Surg 75 B:41 48, 1993.

156. Fleming BC, Renstrom PA, Goran O et al.: The gastrocnemius muscle is an antagonist of the anterior cruciate ligament. J Orthop Res 19:1178  1184, 2001.
CrossRef [PubMed: 11781021] 

157. Timm KE: Knee, in Richardson JK, Iglarsh ZA (eds): Clinical Orthopaedic Physical Therapy. Philadelphia, WB Saunders, 1994, pp 399 482.

158. Sudasna S, Harnsiriwattanagit K: The ligamentous structures of the posterolateral aspect of the knee. Bull Hosp Joint Dis Orthop Institute 50:35  40, 1990.

159. Brownstein B, Noyes FR, Mangine RE et al.: Anatomy and biomechanics, in Mangine RE (ed): Physical Therapy of the Knee. New York, Churchill Livingstone, 1988, pp 1 30.

160. Magee DJ: Orthopedic Physical Assessment (ed 2). Philadelphia, WB Saunders, 1992.

161. Reid DC: Knee ligament injuries, anatomy, classification, and examination, in Reid DC (ed): Sports Injury Assessment and Rehabilitation. New York, Churchill Livingstone, 1992, pp 437 493.

162. Nyland J, Lachman N, Kocabey Y et al.: Anatomy, function, and rehabilitation of the popliteus musculotendinous complex. J Orthop Sports Phys Ther 35:165 179, 2005.
CrossRef [PubMed: 15839310] 

163. Veltri DM, Deng XH, Torzilli PA et al.: The role of the cruciate and posterolateral ligaments in stability of the knee. A biomechanical study. Am J Sports Med 23:436 443, 1995.
CrossRef [PubMed: 7573653] 

164. Veltri DM, Deng XH, Torzilli PA et al.: The role of the popliteofibular ligament in stability of the human knee. A biomechanical study. Am J Sports Med 24:19 27, 1996.




165. Maynard MJ, Deng XH, Wickiewicz TL et al.: The popliteofibular ligament. Rediscovery of a key element in posterolateral stability. Am J Sports Med 24:311 316, 1996.
CrossRef [PubMed: 8734881] 

166. Veltri DM, Warren RF, Wickiewicz TL et al.: Current status of allographic meniscal transplantation. Clin Orthop 306:155 162, 1994. [PubMed: 8070188] 

167. Last RJ: The popliteus muscle and the lateral meniscus. J Bone Joint Surg 32B:93 99, 1950.

168. Scioli MW: Achilles tendinitis. Orthop Clin North Am 25:177 182, 1994. [PubMed: 8290227] 

169. Soma CA, Mandelbaum BR: Achilles tendon disorders. Clin Sports Med 13:811 23, 1994. [PubMed: 7805108] 

170. Gerdes MH, Brown TW, Bell A et al.: A flap augmentation technique for Achilles tendon repair. Postoperative strength and functional outcome. Clin Orthop 280:241 246, 1992. [PubMed: 1611752] 

171. Reynolds NL, Worrell TW: Chronic Achilles peritendinitis: etiology, pathophysiology, and treatment. J Orthop Sports Phys Ther 13:171 176, 1991. CrossRef [PubMed: 18796841] 

172. Carr AJ, Norris SH: The blood supply of the calcaneal tendon. J Bone Joint Surg 71B:100 101, 1989.

173. Lagergren C, Lindholm A: Vascular distribution in the Achilles tendon: an angiographic and microangiographic study. Acta Chir Scand 116:491  495, 1958.

174. Nelen G, Martens M, Bursens A: Surgical treatment of chronic Achilles tendinitis. Am J Sports Med 17:754 759, 1989. CrossRef [PubMed: 2624286] 

175. Nichols AW: Achilles tendinitis in running athletes. J Am Board Fam Pract 2:196 203, 1989. [PubMed: 2665426] 

176. Conti SF: Posterior tibial tendon problems in athletes. Orthop Clin North Am 25:109 121, 1994. [PubMed: 8290223] 

177. Clarke HD, Kitaoka HB, Ehman RL: Peroneal tendon injuries. Foot Ankle 19:280 288, 1998. CrossRef [PubMed: 9622417] 

178. Brage ME, Hansen ST: Traumatic subluxation/dislocation of the peroneal tendons. Foot Ankle 13:423 431, 1992. CrossRef [PubMed: 1427535] 

179. Thordarson DB, Schotzer H, Chon J et al.: Dynamic support of the human longitudinal arch. Clin Orthop 316:165 172, 1995. [PubMed: 7634700]


180. Mann R, Inman V: Phasic activity of intrinsic muscles of the foot. J Bone Joint Surg 46A:469 480, 1964.

181. Daniels K, Worthingham C: Muscle Testing Techniques of Manual Examination (ed 5). Philadelphia, WB Saunders, 1986.

182. Harvey VP, Scott GD: An investigation of the curl down test as a measure of abdominal strength. Res Q 38:22 27, 1967. [PubMed: 4227078]




183. Fitzgerald MJT, Comerford PT, Tuffery AR: Sources of innervation of the neuromuscular spindles in sternomastoid and trapezius. J Anat 134:471 490, 1982. [PubMed: 6213591] 

184. Palmer ML, Epler M: Clinical Assessment Procedures in Physical Therapy. Philadelphia, JB Lippincott, 1990.

185. Huijbregts PA: Lumbopelvic region: anatomy and biomechanics, in Wadsworth C (ed): Current Concepts of Orthopaedic Physical Therapy Home Study Course. La Crosse, Wisc, Orthopaedic Section, APTA, 2001.

186. Lee DG: The Pelvic Girdle: An Approach to the Examination and Treatment of the Lumbo Pelvic Hip Region (ed 2). Edinburgh, Churchill Livingstone, 1999.

187. McGill SM, Childs A, Liebenson C: Endurance times for low back stabilization exercises: clinical targets for testing and training from a normal database. Arch Phys Med Rehabil 80:941 944, 1999.
CrossRef [PubMed: 10453772] 

188. Green JP, Grenier SG, McGill SM: Low back stiffness is altered with warm up and bench rest: implications for athletes. Med Sci Sports Exerc 34:1076 1081, 2002.
CrossRef [PubMed: 12131244] 

189. Jull G, Richardson CA, Hamilton C et al.: Towards the Validation of a Clinical Test for the Deep Abdominal Muscles in Back Pain Patients, Manipulative Physiotherapists Association of Australia, 1995.

190. Richardson CA, Jull GA, Hodges P et al.: Therapeutic Exercise for Spinal Segmental Stabilization in Low Back Pain. London, Churchill Livingstone, 1999.

191. Aspden RM: Review of the functional anatomy of the spinal ligaments and the lumbar erector spinae muscles. Clin Anat 5:372 387, 1992. CrossRef

192. Magee DJ: Lumbar Spine, in Magee DJ (ed): Orthopedic Physical Assessment (ed 4). Philadelphia, WB Saunders, 2002, pp 467 566.

193. Moreland J, Finch E, Stratford P et al.: Interrater reliability of six tests of trunk muscle function and endurance. J Orthop Sports Phys Ther 26:200 208, 1997.
CrossRef [PubMed: 9310911] 

194. Reese NB: Muscle and Sensory Testing. Philadelphia, WB Saunders, 1999.

195. Ashmen KJ, Swanik CB, Lephart SM: Strength and flexibility characteristics of athletes with chronic low back pain. J Sport Rehabil 5:372 387, 1996.

196. Hodges P, Richardson C, Jull G: Evaluation of the relationship between laboratory and clinical tests of transversus abdominis function. Physiother Res Int 1:30 40, 1996.
CrossRef [PubMed: 9238721] 

197. O'Sullivan P, Twomey L, Allison G: Evaluation of specific stabilizing exercise in the treatment of chronic low back pain with radiologic diagnosis of spondylolysis or spondylolisthesis. Spine 22:2959 2967, 1997.
CrossRef [PubMed: 9431633] 




198. O'Sullivan P, Twomey L, Allison G: Altered patterns of abdominal muscle activation in chronic back pain patients. Aust J Physiother 43:91 98, 1997.
CrossRef [PubMed: 11676676] 

199. Clark MA: Integrated Training for the New Millennium. Thousand Oaks, Calif, National Academy of Sports Medicine, 2001.

200. Clarkson HM: Musculoskeletal Assessment (ed 2). Philadelphia, Lippincott Williams & Wilkins, 2000.

201. Youdas JW, Garrett TR, Egan KS et al.: Lumbar lordosis and pelvic inclination in adults with chronic low back pain. Phys Ther 80:261 275, 2000. [PubMed: 10696153] 

202. Zannotti CM, Bohannon RW, Tiberio D et al.: Kinematics of the double leg lowering test for abdominal muscle strength. J Orthop Sports Phys Ther 32:432 436, 2002.
CrossRef [PubMed: 12322809] 

203. Gracovetsky S, Farfan HF: The optimum spine. Spine 11:543, 1986. CrossRef [PubMed: 3538436] 

204. Gracovetsky S, Farfan HF, Helleur C: The abdominal mechanism. Spine 10:317 324, 1985. CrossRef [PubMed: 2931829] 

205. Hyman J, Liebenson C: Spinal stabilization exercise program, in Liebenson C (ed): Rehabilitation of the Spine: A Practitioner's Manual. Baltimore, Lippincott Williams & Wilkins, 1996, pp 293 317.

206. Cyriax J: Textbook of Orthopaedic Medicine, Diagnosis of Soft Tissue Lesions (ed 8). London, Bailliere Tindall, 1982.

207. Tovin BJ, Greenfield BH: Impairment based diagnosis for the shoulder girdle, in Evaluation and Treatment of the Shoulder: An Integration of the Guide to Physical Therapist Practice. Philadelphia, FA Davis, 2001, pp 55 74.

208. Rowland LP: Diseases of the motor unit, in Kandel ER, Schwartz JH, Jessell TM (eds): Principles of Neural Science (ed 4). New York, McGraw Hill, 2000, pp 695 712.

209. Franklin ME: Assessment of exercise induced minor lesions: the accuracy of Cyriax's diagnosis by selective tissue tension paradigm. J Orthop Sports Phys Ther 24:122, 1996.
CrossRef [PubMed: 8866270] 



































































































































































