Shoulder

The scapula and clavicle comprise the shoulder linking the forelimb to the axial skeleton at the sternoclavicular joint. Because primates use their forelimbs in diverse ways, their shoulder complex is characterized by the need for mobility. The scapula's position within layers of muscle permits relatively free motion on the ribcage, and augments the mobility displayed by the shoulder joint itself. Morphological differences in the components of the shoulder complex among primates can be related to whether that mobility needs to be restricted to maintain stability, or enhanced to confer a wider range of motion.