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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.
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
Range of motion:
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.
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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.
* 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).
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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
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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
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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.
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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”
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Trace and Zero
Strength
Note:
Note:
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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
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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”.
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* Grade 2 “Poor strength”:
- 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.
Please refer to laboratories on “Shoulder
extensors and adductor muscles” for the
anatomical description of these muscles.
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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* 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