2_>2 THE AirricrLATJOXS 



reach the I'lavicle. The mijirasrapiddr arter;/ pasties over it, and the .wpni.scapular 

 nerve Ixmeath it. Internally, some fibres of the omo-hyoid muscle arisi; from it. 



The inferior transverse or spino-glenoid ligament (tig. 228) reaches from 

 the external border of the si)ine of the scapula to the margin of the glenoid cavity, 



Fui. 22:5. — PosTKKioR View of the Shoulder-joint, showing also the Ackomio- 



CLAVICLLAK JolXT AND THE SPECIAL LiGAMEXTS OF THE SCAPl'LA. 



Transverse ligament 



Conoid ligament 



Acromio-clavicular - 

 ligament 



Tendon of infra- 

 spinatus and teres /^ 



Inferior transverse 

 or spino-glenoid 

 ligament 

 Capsule of shouldei- 



and so forms a foramen imder which the suprascapular vessels and nerve gain the 

 infraspinous fossa. It is usually a weak membranous structure with Init few liga- 

 mentous fibres. 



3. THE SHOULDER-JOINT 

 Class. — Dpirtlrrosls. Subdivision. — Enarthrodla. 



The shoulder is one of the most perfect, and most movable of joints, the large 

 ujjper end of the humerus playing upon the shallow glenoid cavity. Like the hip, 

 it is a ball-and-socket joint. It is retained in position much less by ligaments than 

 by muscles and the effects of atmospheric pressure; and, owing to the looseness of 

 its ca])sule, as well as to all the other conditions of its construction and position, 

 it is exceedingly liable to be displaced; on the other hand, it is sheltered from 

 violence by the two projecting ])rocesses — the acromion and coracoid. 



The jigauients of the shoulder-joint are: — 



C'ai)sular. 



( ileno-humeral. 



Coraco-humeral. 

 Cxlenoid. 



The capsular ligament (figs. 222, 223 and 224) is a loose sac, insufficient in 

 itself to maintain the bones in contact. It consists of fairly distinct but not coarse 

 til)res, closely woven together, and directed, some straight, others oblic^uely, })etween 

 the two bones, a few circular ones being interwoven amongst them. At the scapula, 



