Name

# Subscapularis

Pronunciation

(sub-skap-u-LAR E-us)

Origin/Proximal Attachment

Subscapular fossa on the anterior surface of the scapula

Insertion/Distal Attachment

Lesser tubercle of the humerus, capsule of the shoulder joint (lower part)

Action/Relevance

Internally rotates the armStabilizes the glenohumeral joint

Innervation

Upper & lower subscapular nerves (C5, 6)

Notes

The Subscapularis is a large triangular muscle which fills the subscapular fossa, and arises from its medial two-thirds and from the lower two-thirds of the groove on the axillary border of the bone. Some fibers arise from tendinous laminæ which intersect the muscle and are attached to ridges on the bone; others from an aponeurosis, which separates the muscle from the Teres major and the long head of the Triceps brachii. The fibers pass lateralward, and, gradually converging, end in a tendon which is inserted into the lesser tubercle of the humerus and the front of the capsule of the shoulder-joint. The tendon of the muscle is separated from the neck of the scapula by a large bursa, which communicates with the cavity of the shoulder-joint through an aperture in the capsule.