138 



SHOULDER JOINT. 



The transverse or coracoid ligament is a narrow but strong fasciculus 



which crosses the notch in the upper border of the scapula, from the 



base of the coracoid process, and converts it 



Fig. 65.* into a foramen. The supra- scapular nerve 



passes through this foramen. 



4. Slioulder Joint. The scapulo-humeral 

 articulation is an enarthrosis, or ball and socket 

 joint its ligaments are, the 



Capsular, 



Coraco-humeral, 



Glenoid. 



The capsular ligament completely encircles 

 the articulating head of the scapula and the 

 head of the hurnerus, and is attached to the 

 neck of each bone. It is thick above, where 

 resistance is most required, and is strength- 

 ened by the tendons of the supra- spinatus, 

 infra-spinatus, teres minor, and subscapularis 

 muscles : below it is thin and loose. The 

 capsule is incomplete at the point of contact 

 with the tendons, so that they obtain upon 

 their inner surface a covering of synovial mem- 

 brane. 



The coraco-humeral ligament is a broad 

 band which descends obliquely outwards from 

 the border of the coracoid process to the greater 

 tuberosity of the humerus, and serves to strength- 

 en the superior and anterior part of the capsu- 

 lar ligament. 



The glenoid ligament is the prismoid band of 

 fibro-cartilage, which is attached around the 

 margin of the glenoid cavity for the purposes 



of protecting its edges, and deepening its cavity. It divides supe- 

 riorly into two slips which are continuous with the long tendon of the 

 biceps ; hence the ligament is frequently described as being formed 

 by the splitting of that tendon. The cavity of the articulation is 

 traversed by the long tendon of the biceps, which is enclosed in a 

 sheath of synovial membrane in its passage through the joint. 



The synovial membrane of the shoulder joint is very extensive ; it 

 communicates anteriorly through an opening in the capsular ligament 

 with a large bursal sac, which lines the under surface of the tendon of 

 the subscapularis muscle. Superiorly, it frequently communicates 

 through another opening in the capsular ligament with a bursal sac 



* An internal view of the ligaments of the elbow joint. 1. The anterior 

 ligament. 2. The internal lateral ligament. 3. The orbicular ligament. 4. 

 The oblique ligament. 5. The interosseous ligament. 6. The internal con- 

 dyle of the humerus, which conceals the posterior ligament. 



