Dance Anatomy & Kinesiology

392

Muscle Proximal attachment(s) Distal attachment(s) Primary action(s)

Rotator cuff muscles

Supraspinatus

(soo-prah-spi-NAH-tus)

Inner portion of supra-

spinous fossa of scapula

Top of greater tubercle of

humerus

Shoulder abduction

Stabilization of shoulder

Infraspinatus

(in-frah-spi-NAH-tus)

Medial portion of

infraspinous fossa of

scapula

Middle of greater tubercle

of humerus

Shoulder external rotation

Stabilization of shoulder

Shoulder horizontal abduction

Component of SIT force couple

Teres minor

(TE-reez MY-nor)

Dorsal aspect of lateral

border of scapula

Lower greater tubercle and

adjacent shaft of humerus

Same as infraspinatus

Subscapularis

(sub-scap-u-LAR-is)

Costal surface of scapula

(subscapular fossa)

Lesser tubercle of

humerus

Shoulder internal rotation

Stabilization of shoulder

Component of SIT force couple

Other glenohumeral muscles

Pectoralis major

(pek-to-RA-lis MAY-jer)

Inner two-thirds of anterior

aspect of clavicle

Sternum

Costal cartilage of ribs

1 or 2 to 6 or 7 near

sternum

Intertubercular groove of

humerus extending down

from tubercles about 3

inches (7.6 centimeters)

Clavicular:

Shoulder flexion

Shoulder abduction above 90°

Assists with shoulder adduction

(lower ranges)

Sternal:

Shoulder extension

Shoulder adduction

Both:

Shoulder horizontal adduction

Shoulder internal rotation

Deltoid

(DEL-toid)

Outer anterior aspect of

clavicle

Acromion of scapula

Lower border of spine of

scapula

Deltoid tuberosity of

humerus

Anterior:

Shoulder flexion

Shoulder horizontal adduction

Assists with shoulder internal rotation

Middle:

Shoulder abduction

Shoulder horizontal abduction

Posterior:

Shoulder extension

Shoulder horizontal abduction

Assists with shoulder external rotation

Coracobrachialis

(kor-ah-ko-bra-kee-AL-is)

Coracoid process of

scapula

Anteromedial aspect of

middle of humerus

Shoulder flexion

Shoulder adduction

Shoulder horizontal adduction

Latissimus dorsi

(lah-TIS-i-mus DOR-see)

T6-L5 spinous processes

Sacrum

Crest of ilium

Posterior aspect of lower

3 ribs

Lower intertubercular

groove of humerus

parallel to attachment of

pectoralis major

Shoulder extension

Shoulder adduction

Shoulder horizontal abduction

Shoulder internal rotation

Depression of humerus

Teres major

(TE-reez MAY-jer)

Inferior angle of scapula Medial lip of

intertubercular groove

Shoulder extension

Shoulder adduction

Shoulder horizontal abduction

Shoulder internal rotation

(Depression of humerus)

TABLE 7.2 Summary of Attachments and Primary Actions of the Muscles of the Shoulder Complex (continued)