SHOULDER

1

SHOULDER FLEXION TO 90° DEGREES

Tested muscles:

1. Deltoid (anterior fibers):

- Origin: Anterior border and superior surface of the lateral 1/3 of the clavicle.

- Insertion: Deltoid tuberosity of humerus.

- Nerve supply: Axillary nerve (C5, C6).

- Actions:

a) Flexes and medially rotates the shoulder joint.

b) Acts as stabilizer when abduction of shoulder is performed by the deltoid middle

fibers.

2. Coracobrachialis:

- Origin: Apex of coracoids process of scapula.

- Insertion: Antero-medial surface of middle of shaft of humerus, opposite to the

deltoid tuberosity.

- Nerve supply: Musculocutaneous nerve (C6, C7).

- Actions: Flexes and adducts the shoulder joint.

Accessory muscles:

1. Pectoralis major (Clavicular fibers).

2. Biceps brachii.

Range of motion:

2

The range of motion tested here is from 0° to 90°. This range of motion may

be limited by:

- Ankylosis of the shoulder joint.

Test procedures:

* Grade 3 “Fair strength”:

- Patient starting position: Sitting with elbow slightly flexed.

- Therapist position and grasps: Therapist stands behind the patient near the affected

shoulder. One hand is placed over the shoulder to fix the scapula.

- Command: “Pull your arm up in front of you, while your palm toward the floor (to

90°), relax”.

* Grades 4 and 5: “Good and Normal strength”:

- Patient starting position: Same as for “Grade 3”.

- Therapist position and grasps: Same as for “Grade 3”, plus the distal hand gives

resistance above the elbow joint.

- Resistance:

a) Grade 4: Moderate leading resistance is given directly opposite to the line of

motion.

b) Grade 5: Maximum resistance is given as for “Grade 4”, plus a “Hold” position is

kept at the end of the range of motion.

- Command: Same as for “Grade 3”, plus “Hold” at the end of the range of motion

when testing for “Grade 5”.

NOTES:

a) The patient is asked to keep his forearm in pronation to prevent lateral rotation with

substitution by biceps brachii, when testing the shoulder flexor muscles with the

elbow in extension.

b) Isolation of coracobrochialis: To isolate the coracobrochialis, the motion must be

performed with the elbow in complete flexion and forearm supinated. The flexion of

the shoulder then will be performed with a slight lateral rotation.

c) Assistance from the biceps in shoulder flexion is decreased in this position because

the complete elbow flexion and forearms supination place the muscle in too-short a

position to be effective in shoulder flexion.

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* Grade 2 “Poor strength”:

- Patient starting position: Side lying with affected arm (over) supported on a smooth

board or by therapist; and elbow slightly flexed.

- Therapist position and grasps: Therapist stands behind the patient’s affected

shoulder and the proximal hand is placed over the shoulder to stabilize the scapula.

The distal hand stabilizes the board or supports the patient’s arm.

- Command: “Pull your arm in front of you (to 90°), relax”.

* Grade 1 and 0 “Trace and Zero strength”:

- Patient starting position: Same as for “Grade 2” or supine lying.

- Therapist position and grasps: Same as for “Grade 2” and the muscle contraction is

palpated by the proximal hand on the anterior of the shoulder joint. If the supine lying

position is used, the therapist fixes the scapula with one hand and palpates muscle

contraction with the other hand.

Effect of weakness of shoulder flexors:

a) Weakness of shoulder flexors decreases the strength of shoulder flexion.

b) In addition, weakness of coracobrachialis muscle will impair function, particularly

in movements which involve shoulder with complete elbow flexion and supination

(e.g. combing the hair).

4

MUSCLE TESTING FOR FLEXION TO 90 DEGREES

Grade “3”

Fair Strength

Grade “4, 5”

Good and Normal

Strength

Grade “2”

5

Poor Strength

Grade “1, 0”

Trace and Zero

Strength

6

SHOULDER EXTENSION

Tested muscles:

1. Latissimus dorsi:

- Origins:

a) Spinous processes of last six thoracic vertebrae.

b) Last three or four ribs.

c) Through the thoraco-lumbar fascia from the lumbar and sacral vertebrae.

d) Posterior 1/3 of external lip of iliac crest.

e) A slip from the inferior angle of the scapula.

- Insertion: Inter-tubercular groove of humerus.

- Nerve supply: Thoraco-dorsal nerve (C6, C7, C8).

- Actions:

a) With the origin fixed, it medially rotates, adducts and extends the shoulder joint.

b) By continued action, it depresses the shoulder girdle and assists in lateral flexion of

the trunk.

c) With the insertion fixed, it assists in tilting the pelvis anteriorly and laterally.

d) Acting bilaterally, this muscle assists in hyper-extending the spine and anteriorly

tilting the pelvis, or in flexing the spine depending upon its relation to the axes of

motion.

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e) This muscle is extremely important in relation to movements such as climbing,

walking with crutches or hoisting the body up on parallel bars, in which the muscle

acts to lift the body toward the arm.

f) Forceful arm movements in swimming, rowing and chopping are largely dependent

on the strength of this muscle. All shoulder adductors and medial rotators act in these

strong movements but the latissimus dorsi is probably of major importance.

g) May act as an accessory muscle of respiration.

2. Teres major:

- Origin: Dorsal surfaces of inferior angle and lower third of lateral border of scapula.

- Insertion: Crest of lesser tubercle of humerus.

- Nerve supply: Lower subscapular nerve (C5, C6, C7).

- Actions: Medially rotates, adducts and extends the shoulder joints.

3. Deltoid (Posterior fibers):

- Origin: Inferior lip of posterior border of spine scapula.

- Insertion: Deltoid tuberosity of humerus.

- Nerve supply: Axillary nerve (C5, C6).

- Actions:

a) Extends and laterally rotates the shoulder joint.

b) Acts as stabilizer when the medial fibers of deltoid are performing abduction of the

shoulder.

Accessory muscles:

1. Triceps (long head).

2. Teres minor.

Range of motion:

The range of motion of shoulder extension beyond the midline is 0° to 50°.

This range of motion may be limited by:

- Tension of shoulder flexor muscles.

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Test procedures

* Grade 3 “Fair strength”:

- Patient starting position: Prone lying with arm along body side.

- Therapist position and grasps: Therapist stands beside the table and fixes the

scapula with his proximal hand placed over the shoulder.

- Command: “Pull your arm up with palm up, relax”.

* Grades 4 and 5 “Good and Normal strength”:

- Patient starting position: Same as for “Grade 3”.

- Therapist position and grasps: Same as for “Grade 3”, plus apply resistance with the

distal hand above the elbow joint.

- Resistance:

a) Grade 4: Moderate leading resistance directly opposing the line of motion.

b) Grade 5: Maximum resistance throughout the range of motion, plus a “Hold”

position is kept at the end of range.

- Command: Same as for “Grade 3”, plus “Hold” at the end of the range of motion

when testing for “Grade 5”.

* Grade 2 “Poor strength”:

- Patient starting position: Side lying with affected arm over and resting on a smooth

board or supported by therapist; and the forearm in pronation.

- Therapist position and grasps: Therapist stands in front of the patient. The proximal

hand is placed over the shoulder to stabilize the scapula.

- Command: “Pull your arm backward, relax”.

* Grade 1 and 0 “Trace and Zero strength”:

- Patient starting position: Same as for “Grade 2” or prone lying.

- Therapist position and grasps: Same as for “Grade 2”, plus the distal hand palpates

fibers of teres major on lower part of axillary border of scapula; and fibers of

latissimus dorsi slightly below.

NOTE: Motion should take place primarily at gleno-humeral joint. Patient should not

be allowed to tip the scapula forward, in an effort to complete range of motion.

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Effects of weakness:

a) Latissimus dorsi: Weakness interferes with many activities, which involve mainly

adduction toward the body or the body toward the arm. The strength of shoulder

extension and lateral trunk flexion is diminished.

b) Teres major: Weakness diminishes the strength of medial rotation and extension of

humerus.

c) Deltoid (posterior fibers): Weakness diminishes the strength of extension of

humerus.

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MUSCLE TESTING FOR SHOULDER EXTENSION

Grade “3”

Fair Strength

Grade “4, 5”

Good and Normal

Strength

Grade “2”

Poor Strength

Grade “1, 0”

Trace and Zero

Strength

11

SHOULDER ABDUCTION TO 90°

Tested muscles:

1. Deltoid “Middle fibers”:

- Origin: Lateral margin and superior surface of acromion.

- Insertion: Deltoid tuberosity of humerus.

- Nerve supply: Axillary nerve (C5, C6).

- Action: Abducts the shoulder joint.

2. Supraspinatus:

- Origin: Medial two thirds of supraspinatus fossa of scapula.

- Insertions:

a) Superior facet of greater tubercle of humerus.

b) Shoulder joint capsule.

- Nerve supply: Supra-scapular nerve (C4, C5, C6).

- Actions:

a) Abducts the shoulder joint.

b) Stabilizes the head of humerus in the glenoid cavity during the movements of this

Accessory muscle:

- Deltoid “anterior and posterior fibers” as stabilizers.

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Range of motion:

The range of motion tested is from 0° to 90°. This range may be limited by:

- Ankylosis of the shoulder joint.

Test procedures:

* Grade 3 “Fair strength”:

- Patient starting position: Sitting over the edge of table, arm at side in mid-position

between medial and lateral rotation and the elbow flexed a few degrees.

- Therapist position and grasps: Therapist stands behind the patient. Proximal hand is

placed on shoulder to stabilize scapula.

- Command: “With palm down, raise your arm up and out (to 90°), relax”.

NOTE: Action should be done without lateral rotation at shoulder joint to prevents

substitution by biceps brachii.

* Grades 4 and 5 “Good and Normal strength”:

- Patient starting position: Same as for “Grade 3”.

- Therapist position and grasps: Same as for “Grade 3”, distal hand is placed

proximal to elbow joint to give resistance.

- Resistance:

a) Grade 4: Moderate leading resistance is given in a form of pressing down, directly

opposing line of raising the arm up to 90 degrees.

b) Grade 5: Maximum resistance throughout the range of motion, plus a “Hold”

position is kept at the end of the range.

- Command: Same as for “Grade 3”, plus “Hold” at the end of the range when testing

for “Grade 5”.

* Grade 2 “Poor strength”:

- Patient starting position: Supine lying, arm beside the body in mid position between

medial and lateral rotation.

- Therapist position and grasps: Therapist stands beside the table, proximal hand

placed on the shoulder to stabilize the scapula.

- Command: “With palm down, pull your arm out (to 90°), relax”.

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* Grade 1 and 0 “Trace and Zero strength”:

- Patient starting position: Same as for “Grade 2”

- Therapist position and grasps: Same as for “Grade 2”; distal hand grasping the

forearm to give sense of motion to the patient. Proximal hand palpates middle fibers

of deltoid on lateral surface of upper third of arm.

- Command: “Try to pull your arm out (to 90°), relax”.

Effects of weakness:

a) Deltoid middle fibers:

- Weakness results in inability to lift the arm in abduction against gravity.

- In the presence of paralysis of the entire deltoid and supraspinatus, the humerus

tends to subluxate downward if the arm remains.

- Unsupported in a hanging position, the capsule of the shoulder joint permits almost

an inch of separation of the head of the humerus from the glenoid cavity.

- In case of axillary nerve involvement, in which the deltoid is weak while the

supraspinatus is not affected, these above described effects on the shoulder joint are

not as marked but tend to progress if the deltoid strength does not return.

b) Supraspinatus:

Weakness or rupture of supraspinatus tendon decreases the shoulder joint

stability, allowing the head of humerus to alter its relationship with the glenoid cavity.

14

MUSCLE TESTING FOR SHOULDER ABDUCTION TO 90°

Grade “3”

Fair Strength

Grade “4, 5”

Good and Normal

Strength

Grade “2”

Poor Strength

Grade “1, 0”

15

Trace and Zero

Strength

Note:

Note:

16

SHOULDER ADDUCTOR MUSCLES

Tested muscles:

1. Latissimus dorsi:

- Refer to “Shoulder extensor muscles” for its anatomical description.

2. Teres major:

- Refer to “Shoulder extensor muscles” for its anatomical description.

3. Pectoralis major:

- Origins:

a) Anterior surface of sterna half of clavicle.

b) Anterior surface of sternum.

c) Cartilages of first six or seven ribs.

d) Oponeurosis of the obliquus externus abdominis.

- Insertion: Lateral lip of inter-tubercular groove of humerus.

- Nerve supply:

a) Upper fibers: Lateral pectoral nerve (C5, C6, C7).

b) Lower fibers: Lateral and medial pectoral nerves (C6, C7, C8, T1).

- Actions:

a) Upper fibers: Flex the shoulder joint and horizontally adduct the humerus toward

the opposite shoulder.

b) Lower fibers:

- Depress the shoulder girdle by virtue of attachment on the humerus.

- Horizontally adduct the humerus toward the opposite iliac crest.

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Accessory muscle:

- Subscapularis

Range of motion:

Pure adduction of the shoulder joint is from 90° of abduction to 0° position.

Test procedures:

- The testing of adductor muscles to evaluate their strength is described in the

laboratories on shoulder extensor muscles and medial rotator muscles as most of them

have the triple function.

- The pectoralis major muscle test is described in the laboratory on horizontal

adduction.

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SHOULDER HORIZONTAL ABDUCTION

Tested muscles:

1. Deltoid muscle (Posterior fibers):

- Refer to laboratory on “Shoulder extensor muscles” for its anatomical description.

Range of motion:

The range of motion of horizontal abduction is of approximately 135°. This

range of motion may be limited by:

a) Tension of anterior fibers of capsule of gleno-humeral joint.

b) Tension of pectoralis major and deltoid anterior fibers.

Test procedures:

* Grade 3 “Fair strength”:

- Patient starting position: Prone lying, shoulder abducted to 90 degrees. Upper arm

is resting on table and forearm hanging over the edge.

- Therapist position and grasps: Therapist stands beside the table. Proximal hand is

placed on the shoulder, while distal hand on lateral border of scapula to stabilize it.

- Command: “Pull your upper arm up, relax”.

* Grade 4 and 5 “Good and Normal strength”:

- Patient starting position: Same as for “Grade 3”.

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- Therapist position and grasps: Same as for “Grade 3” but distal hand is placed

proximal to elbow joint to give resistance.

- Resistance:

a) Grade 4: Moderate leading resistance is given in a form of pressing the upper arm

directly opposing line of raising the upper arm up.

b) Grade 5: Maximum resistance is applied throughout the range of motion, plus a

“hold” position is kept at the end of the range.

- Command: Same as for “Grade 3”, plus “hold” at the end of the range when testing

for “Grade 5”.

* Grade 2 “Poor strength”:

- Patient starting position: Sitting on a stool, arm supported or resting on a table in a

position of 90° of flexion.

- Therapist position and grasps: Therapist stands behind the patient. Proximal hand is

placed on the shoulder, while the distal one is placed on the lateral border of scapula

to stabilize it.

- Command: “Move your arm backward, relax”.

* Grade 1 and 0 “Trace and Zero strength”

- Patient starting position: Same as for “Grade 2”.

- Therapist position and grasps: Therapist stands in front of the patient. The distal

hand palpates the fibers of posterior portion of deltoid on posterior aspect of shoulder

joint.

- Command: “Try to move your arm backward, relax”.

Effect of weakness:

Weakness of deltoid posterior fibers will result in inability to perform

horizontal abduction of the shoulder against gravity.

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MUSCLE TESTING FOR SHOULDER HORIZONTAL ABDUCTION

Grade “3”

Fair Strength

Grade “4, 5”

Good and Normal

Strength

Grade “2”

Poor Strength

21

Grade “1, 0”

Trace and Zero

Strength

22

SHOULDER HORIZONTAL ADDUCTION

Tested muscle:

* Pectoralis major:

Refer to laboratory on “Shoulder adductor muscles” for its anatomical description.

Accessory muscle:

- Deltoid “Anterior Fibers”.

Range of motion:

The range of motion of horizontal adduction of the shoulder is approximately

135°. This range of motion may be limited by:

a) Tension of shoulder extensor muscle.

b) Contact of arm with the chest.

Test procedures:

* Grade 3 “Fair strength”:

- Patient starting position: Back lying, arm abducted to 90°.

- Therapist position and grasps: Therapist stands near the edge of the table. The

proximal hand is placed under the shoulder at the scapula.

- Command: “Raise your arm up to vertical position, relax”.

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* Grades 4 and 5 “Good and Normal strength”:

- Patient starting position: Same as for “Grade 3”.

- Therapist position and grasps: Same as for “Grade 3” but the distal hand grasps the

upper arm proximal to elbow joint to give resistance.

- Resistance:

a) Grade 4: Moderate loading resistance is given in a form of pressing down the upper

arm, directly opposing line of rising.

b) Grade 5: Maximal resistance is given throughout the range of motion, plus a “hold”

position kept at the end of the range.

- Command: Same as for “Grade 3”, plus “hold” at the end of the range when testing

for “Grade 5”

* Grade 2 “Poor strength”:

- Patient starting position: Sitting on a stool, arm resting on the table in a position of

abduction to 90°.

- Therapist position and grasps: Therapist stands behind the patient. The proximal

hand is placed on the shoulder to stabilize the trunk.

- Command: “Pull your arm forward, relax”.

* Grades 1 and 0 “Trace and Zero strength”:

- Patient starting position: Same as for “Grade 2”.

- Therapist position and grasps: Same as for “Grade 2”, the distal hand palpates

tendon of pectoralis major near insertion on anterior aspect of upper arm. Muscle

fibers of both sternal and clavicular portions may be observed and palpated on upper

anterior aspect of thorax.

- Command: “Try to move your arm forward, relax”.

NOTE: Sternal and clavicular portions of pectoralis major may be isolated to some

degree:

b) In “Normal and Good grades”, test resistance is given in a direction opposite

to the line of pull of the muscle fibers:

Sternal or lower portion: upward and outward.

Clavicular of upper portion: downward and outward.

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b) In “Fair grade” test, the arm is placed above 90 of abduction for testing the lower

portion and below 90° of abduction for testing the upper portion. The patient is then

asked to pull his arm to the vertical position for each direction of muscle fibers being

tested.

Effects of weakness:

a) Upper fibers:

- Weakness of these fibers decreases the ability to draw the arm in horizontal

adduction across the chest, making it difficult to touch the hand to the opposite

shoulder.

- It also decreases strength of shoulder flexion and medial rotation.

b) Lower fibers:

- Weakness of these fibers decreases the strength of medial rotation of the shoulder

and adduction obliquely toward the opposite hip.

- There is a loss of continuity of muscle action from the pectoralis major to the

external oblique and internal oblique on the opposite side. This leads to difficult

chopping or striking movements.

- From a supine position, if the subject arm is placed diagonally overhead, he will

find it difficult to lift the arm from the table.

- He will also have difficulty holding any large of heavy object on both hands at or

near waist level.

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MUSCLE TESTING FOR SHOULDER HORIZONTAL ADDUCTION

Grade “3”

Fair Strength

Grade “4, 5”

Good and Normal

Strength

Grade “2”

26

Poor Strength

Grade “1, 0”

Trace and Zero

Strength

27

SHOULDER EXTERNAL ROTATION

Tested muscles:

1. Infraspinatus:

- Origin: Medial 2/3 of infraspinous fossa of scapula.

- Insertions:

a) Middle facet of greater tubercle of humerus.

b) Shoulder joint capsule.

- Nerve supply: Supra-scapular nerve (C4, C5, C6).

- Actions:

a) Laterally rotates the shoulder joint.

b) Stabilizes head of humerus in the glenoid cavity during movements of this joint.

2. Teres minor:

- Origin: Upper 2/3, dorsal surface of lateral border of scapula.

- Insertions:

a) Lowest facet of greater tubercle of humerus.

b) Shoulder joint capsule.

- Nerve supply: Axillary nerve (C5, C6).

- Actions:

a) Laterally rotates the shoulder joint.

b) Stabilizes head of humerus in the glenoid cavity during movements of this joint.

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Accessory muscle:

- Deltoid (posterior fibers).

-

Range of motion:

The range of motion of shoulder lateral rotation is approximately of 90°. This

range of motion may be limited by:

a) Tension of superior portion of capsular ligament coraco-humeral ligament.

b) Tension of medial rotator muscles of the shoulder.

Test procedures:

* Grade 3 “Fair strength”:

- Patient starting position: Prone lying, shoulder abducted to 90°, upper arm

supported on table and forearm hanging vertically over edge.

- Therapist position and grasps: Therapist stands beside table at the level of the

patient’s waist. The proximal hand and forearm is placed over the shoulder and

scapula to stabilize it. The distal hand is placed over the arm above the elbow to

prevent abduction to occur during the test.

- Command: “Pull your hand up and toward your head, relax”.

* Grades 4 and 5 “Good and Normal strength”:

- Patient starting position: Same as for “Grade 3”.

- Therapist position and grasps: Same as for “Grade 3” but the distal hand is placed

over the patient’s wrist to give resistance.

- Resistance:

a) Grade 4: Moderate leading resistance is given in a form of pressing down directly

opposite to the line of motion.

b) Grade 5: Maximal resistance is given throughout the range of motion, plus a “hold”

position is kept at the end of the range.

- Command: Same as for “Grade 3”, plus “hold” at the end of the range of motion

when testing for “Grade 5”.

* Grade 2 “Poor strength”:

29

- Patient starting position: Prone lying with the entire affected arm over the edge of

the table in medially rotated position. (Palm in the direction of the foot of the table).

- Therapist position and grasps: Same as for the other grades but his two hands are

placed one over and one under the shoulder joint to stabilize the scapula.

- Command: “Turn your whole arm so that your palms, while the inside of your elbow

is facing you, relax”.

* Grades 1 and 0 “Trace and Zero strength”:

- Patient starting position: Same as for “Grade 2”.

- Therapist position and grasps: Same as for “Grade 2” but one hand is palpating the

muscle contraction of teres minor on the axillary border of scapula and infraspinatus

over the body of scapula below the spine of scapula.

- Command: Same as for “Grade 2”.

Effect of weakness of shoulder lateral rotators:

- In case of weakness of these muscles, the humerus assumes a position of medial

rotation. Lateral rotation in anti-gravity positions is difficult or impossible.

NOTE:

- Though for grading a weak lateral rotator group against gravity, the prone position

may be used; the supine position is preferred to eliminate the necessity of maximal

trapezius fixation and decrease the assistance from deltoid posterior.

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MUSCLE TESTING FOR SHOULDER EXTERNAL ROTATION

Grade “3”

Fair Strength

Grade “4, 5”

Good and Normal

Strength

Grade “2”

Poor Strength

31

Grade ”1, 0”

Trace and Zero

Strength

32

SHOULDER INTERNAL ROTATION

Tested muscles:

1. Subscapularis.

2. Pectoralis major.

3. Latissimus dorsi.

4. Teres major.

Accessory muscles:

- Deltoid (anterior fibers).

Range of motion:

The range of motion of shoulder medial rotation is of approximately 90°. This

range of motion may be limited by:

a) Tension of superior portion of capsular ligament.

b) Tension of lateral rotator muscles of the shoulder.

Test procedures:

a. Grade 3 “Fair strength”:

- Patient starting position: Prone lying with affected shoulder abducted to 90°, upper

arm supported on the table and forearm hanging vertically over the edge of the table.

- Therapist position and grasps: Therapist stands beside the table. The proximal hand

and forearm is placed on shoulder and scapula to stabilize it but allowing freedom for

the shoulder rotation.

- Command: “Pull your hand back and up, keeping your upper arm on table, relax”.

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Please refer to laboratories on “Shoulder extensors and adductor muscles” for the anatomical description of these muscles.

* Grades 4 and 5 “Good and Normal strength”:

- Patient starting position: Same as for “Grade 3”.

- Therapist position and grasps: Same as for “Grade 3”, plus the distal hand is placed

at the patient’s wrist level to give resistance.

- Resistance:

a) Grade 4: Moderate leading resistance in a form pressing down is given directly

opposing the line of motion.

b) Grade 5: Maximum resistance is applied throughout the full range of motion, plus a

“hold” position is kept at the end of the range.

- Command: Same as for “Grade 3”, plus “hold” at the end of the range of motion

when testing for “Grade 5”.

* Grade 2 “Poor strength”:

- Patient starting position: Prone lying with entire arm hanging over the edge of table

in lateral rotation (palm and interior of elbow facing the patient).

- Therapist position and grasps: Same as for “Grade 3”.

- Command: “Turn your whole arm in, so that your palm and the interior of your

elbow face me, relax”.

* Grade 1 and 0 “Trace and Zero strength”:

- Patient starting position: Same as for “Grade 2”.

- Therapist position and grasps: Same as for “Grades 2 and 3”, plus the distal hand

palpates muscle contraction of:

a) Subscapularis (deep in axilla near insertion).

b) Latissimus dorsi is described in the laboratory on “Shoulder extension muscles”.

c) Pectoralis major palpation is described in the laboratory on “Shoulder horizontal

adduction”.

- Command: Same as for “Grade 2”.

Effect of weakness:

In as much as the medial rotator muscles are also the strong shoulder adductor

muscles, the ability to perform both medial rotation and adduction is decreased by the

weakness of these muscles.

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MUSCLE TESTING FOR SHOULDER INTERNAL ROTATION

Grade “3”

Fair Strength

Grade “4, 5”

Good and Normal

Strength

Grade “2”

Poor Strength

35

Grade “1, 0”

Trace and Zero

Strength

36