Human Anatomy - Kotsan I. Ya. 2009

General overview of muscles responsible for movements of individual body parts
Movements of the upper limb
Shoulder movements at the shoulder joint

The Muscles of the shoulder girdle surround the shoulder joint and, along with certain shoulder muscles, facilitate the movement of the humerus around three mutually perpendicular axes: the frontal, sagittal, and vertical.

Flexion of the arm is performed by the flexor muscles that cross the frontal axis of the shoulder joint and are located anterior to it:

1) the deltoid Muscle (anterior part);

2) the coracobrachialis muscle;

3) the biceps brachii muscle;

4) the pectoralis major muscle (belonging to the trunk muscles).

Extension of the arm is performed by the muscles that cross the frontal axis of the shoulder joint and are located posterior to it:

1) the deltoid muscle (posterior part);

2) the infraspinatus muscle;

3) the teres minor muscle;

4) the teres major muscle;

5) the triceps brachii muscle (long HEAD);

6) the latissimus dorsi muscle.

Abduction of the arm relative to the sagittal axis of the shoulder joint is performed by the shoulder girdle muscles that cross this axis and are located lateral to it:

1) the deltoid muscle;

2) the supraspinatus muscle.

Adduction of the arm. There are no dedicated muscles crossing the sagittal axis of the shoulder joint and positioned medially to it; therefore, adduction of the arm occurs According to the parallelogram of forces rule through the simultaneous contraction of muscles located anterior (pectoralis major) and posterior (latissimus dorsi and teres major) to the shoulder joint. These muscles are assisted by:

1) the infraspinatus muscle;

2) the teres minor muscle;

3) the subscapularis muscle;

4) the long head of the triceps brachii muscle;

5) the coracobrachialis muscle.

Pronation of the arm (medial rotation) is performed by muscles that cross the vertical axis of the shoulder joint and attach anterior to it:

1) the subscapularis muscle;

2) the pectoralis major muscle;

3) deltoid muscle (anterior part);

4) latissimus dorsi muscle;

5) teres major muscle.

Supination of the arm (lateral rotation) is performed by muscles that cross the vertical axis of the shoulder joint and are located posterior to it:

1) infraspinatus muscle;

2) teres minor muscle;

3) deltoid muscle (posterior part).