SHOULDER- AND ELBOW-JOINTS 



6l 



ular surfaces: the head of the humerus and the glenoid fossa of the 

 scapula. The fossa is deepened by a rim of fibro-cartilage called 

 the glenoid margin. The capsule is attached to the scapula around 

 the margin of the glenoid fossa, and to the humerus around the 

 anatomic neck. It is so loose that the head of the humerus will 



Conoid ligament 



Superior transverse 



scapular ligament 



Trapezoid ligament 



Coraco-acromial ligament 



Short head of biceps 

 Subscapular tendon 



Capsule of shoulder 



Long tendon of biceps 



FIG. 56. ANTERIOR VIEW OF SHOULDER, SHOWING ALSO CORACO-CLAVICULAR AND 

 CORACO-ACROMIAL LIGAMENTS. (Morris.') 



fall an inch away from the glenoid fossa by its own weight, if the 

 surrounding muscles be removed; it contains a synovial mem- 

 brane which covers the glenoid margin and folds like a sheath 

 around the long tendon of the biceps muscle (Fig. 56). 



Motions. In every possible direction, as flexion, extension, ab- 

 duction, adduction, rotation, and circumduction, with greater free- 

 dom than any other joint of the body, because the socket is so 

 shallow and the capsule is so loose. 



Elbow- joint. A hinge-joint (ginglymus) (Fig. 57). 



Articular surfaces: the trochlea of the humerus in the semilunar 

 notch of the ulna; the capitulum of the humerus in the depressed 

 head of the radius. 



