SHOULDER

the region where the arm joins the trunk. The articulation of the humerus or arm-bone with the scapula or shoulder-blade is an example of an enarthrodial or ball-and-socket joint. The scapula (q.v.) is a flat triangular bone with a depre ion called the glanoid cavity into whicn the head of the humerus fits. The shallowre of the cavity allows great mobility of the shoulder-joint, but renders it liable to dislocation. A certain amount of protection is afforded by the glanoid ligament which forms a sort of lip about the cavity, increasing its depth, and the acromion, a proce of the scapula which forms a protective arch overhanging the 8. socket. 1707), Eng. admiral; fought in battles of Bantry Bay, 1689, Virgo, 1702, Malaga, 1704; his ship, the A ociation, struck a rock near Scilly Isles and all hands were lost.