ABSTRACT
The upper limb accounts for 5" of the body weight. The movements of the clavicle and scapula, humerus, radius, ulna and wrist have one collective purpose - to put the hand into the desired position for whatever it is required to do. Since the limb is essentially suspended from the trunk of the body mainly by muscles and not by a large joint, it has great freedom of movement. The stability of the shoulder depends on its surrounding muscles and not on its bony structure. As a result, it is the most mobile joint in the body and the most frequently dislocated. The tendon of the long head of biceps runs over the top of the head of the humerus within the joint cavity and passes out of the joint capsule, surrounded by a tubular sleeve of synovial membrane to lie in the intertubercular groove of the humerus.
