The shoulder is the only
joint in the body that can accomplish a 360 degree rotation, although this
level of mobility translates into a lesser degree of stability than other
joints. The primary function of the shoulder is to support, or anchor,
the different positions of the hand and arm.
The bony structures of the
shoulder include the scapula, humerus, and clavicle, which together create
two separate joints -- the glenohumeral joint and the acromioclavicular
joint. Some of the muscles and tendons that support the shoulder joint
are referred to as the rotator cuff.
