In humans, the only true anatomical joints between the shoulder girdle and the axial skeleton (the spine) are the sternoclavicular joints (collar bone onto your sternum) on each side. No anatomical joint exists between each scapula and the rib cage; instead the muscular connection or physiological joint between the two permits great mobility of the shoulder girdle because the upper limb is not usually involved in weight bearing, its stability has been sacrificed in exchange f