Fig 1.0 â The articulating surfaces of the shoulder joint. The shoulder joint is formed by the articulation of the head of the humerus with the glenoid cavity (or fossa) of the scapula. This gives rise to the alternate name for the shoulder joint â the glenohumeral joint.ig 1.0 â The articulating surfaces of the shoulder joint. The shoulder joint is formed by the articulation of the head of the humerus with the glenoid cavity (or fossa) of the scapula. This gives rise to the alternate name for the shoulder joint â the glenohumeral joint.