The Muscular Muscle

Tough muscle , m. Supraspinatus, trihedral, completely fills the supraspinous fossa, starting from its walls. Muscle bundles, converging into a narrower part of the muscle, are sent to the outside, pass under the acromion and attach to the large tubercle of the humerus. The terminal tendon of the supraspinatus fuses with the posterior surface of the capsule of the shoulder joint and, with its contraction, repels it, preventing infringement of the latter.

Function: withdraws the shoulder.

Innervation: n. Suprascapularis (CV-CVI).

Blood supply: aa. Suprascapularis, circumflexa scapulae.