Shoulder and Arm Bones and Joints The shoulder comprises three bones (the clavicle, scapula, and humerus) and three joints (the glenohumeral, the acromioclavicular [AC], and the scapulothoracic) (Fig. 1). Figure 1 The bones of the shoulder: the clavicle, humerus, and scapula. The clavicle articulates with the scapula at the acromioclavicular joint. The humerus articulates with the scapula at the glenohumeral joint. The glenohumeral joint is the primary articulation of the shoulder, the point where the head of the humerus meets the glenoid. The AC and scapulothoracic joints attach the trunk to the scapula, with the arm appended to it. The...
