THE MUSCLES AND FASCIA OF THE SHOULDER 



441 



loulder-joint, and is inserted into the highest of the three impressions on the 

 greater tubercle of the humerus; the tendon is intimately adherent to the capsule 

 of the shoulder-joint. 



Infraspinatous Fascia (fascia infraspinata) . The infraspinatous fascia is a dense 

 fibrous membrane, covering the Infraspinatous muscle and fixed to the circum f er- 

 ence of the infraspinatous fossa; it affords attachment, by its deep surface, to some 

 fibers of that muscle. It is intimately attached to the deltoid fascia along the over- 

 lapping border of the Deltoideus. 



FIG. 412. Muscles on the dorsum of the scapula, and the Triceps brachii. 



The Infraspinatus (Fig. 412) 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. 



The Teres minor (Fig. 412) is a narrow, elongated muscle, which arises from 

 the dorsal surface of the axillary border of the scapula for the upper two-thirds of 

 its extent, and from two aponeurotic laminse, one of which separates it from the 

 Infraspinatus, the other from the Teres major. Its fibers run obliquely upward 

 and lateralward ; the upper ones end in a tendon which is inserted into the lowest 

 of the three impressions on the greater tubercle of the humerus; the lowest fibers 

 are inserted directly into the humerus immediately below this impression. The 



