ARTICULATIO HUMERI 



9 1 



of the coracoid process. Through this aperture an exten- 

 sive protrusion of the synovial membrane takes place in 

 the form of a bursa mucosa, which, from its position under 

 the upper part of the subscapularis muscle, receives the name 

 of the bursa subscapularis. It is important to note the position 

 and character of this opening, seeing that in some cases the 

 head of the bone may be driven through it in dislocation of 

 the joint. The second aperture is smaller and more distinctly 

 defined. It is placed between the two tubercles of the 



Coraco-acromial 

 ligament 



Coracoid process 



Acromion process 



Coraco-humeral 

 ligament 



Communication 

 between joint- 

 cavity and sub- 

 scapular bursa 



Capsule of joint : 



FIG. 39. Shoulder-joint as seen from the front. 



humerus, at the proximal part of the sulcus intertubercularis, 

 and it is through this that the long tendinous head of the 

 biceps brachii gains admission to the interior of the capsule. 

 The synovial membrane also protrudes from this opening, 

 and lines the sulcus intertubercularis as low as the in- 

 sertion of the pectoralis major. It is not often that the third 

 opening is seen. It is situated, when present, on the lateral 

 or posterior aspect of the capsule, and allows a pocket of 

 synovial membrane to bulge out in the form of a bursa under 

 the infraspinatus muscle. 



At certain points the capsule of the shoulder-joint is 



