Shoulder MusclesTaelar Shelton, MS, ATC, AT/L

Rotator Cuff Muscles

•Supraspinatus•Infraspinatus•Teres Minor•Subscapularis

•“SITS” Muscles

Supraspinatus• O: Supraspinous foss• I: greater tubercle• A: Assists in

abduction, stabilizes shoulder, prevents dislocation

Infraspinatus • O: Infraspinous fossa• I: Greater tubercle of

the humerus• A: External rotation of

the humerus

Teres Minor• O: Lateral boder of

dorsal surface of scapula

• I: greater tubercle• A: external rotation of

humerus

Subscapularis• O: subscapular fossa• I: lesser tubercle• A: internal rotation of

humerus

Rhomboids Major• O: Spinous processes

T2-T5• I: inferior, medial

boarder of the scapula• A: Retracts the

scapula

Rhomboids Minor• O: spinous process of

C7-T1• I: Superior, medial

boarder of the scapula• A: Retracts scapula

Serratus Anterior• O: Ribs 1-8• I: Anterior surface of

the vertebral (medial) border of the scapula

• A: Protracts and holds the scapula against the chest wall