The Infraspinatus muscle is a lateral rotator of the glenohumeral joint and adductor of the arm.

It attaches medially to the infraspinous fossa of the scapula and laterally to the greater tubercle of the humerus.

The Infraspinatus is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa; it arises by fleshy fibers from its medial two-thirds, and by tendinous fibers from the ridges on its surface; it also arises from the infraspinatous fascia which covers it, and separates it from the Teretes major and minor.

The fibers converge to a tendon, which glides over the lateral border of the spine of the scapula, and, passing across the posterior part of the capsule of the shoulder-joint, is inserted into the middle impression on the greater tubercle of the humerus.

The tendon of this muscle is sometimes separated from the capsule of the shoulder-joint by a bursa, which may communicate with the joint cavity.

External links

Muscles of the upper limb

Musculus infraspinatus | Muscle infra-épineux | Otot infraspinatus | Musculus infraspinatus | Mięsień podgrzebieniowy | Infraspinatus