Ball and Socket Joint

A ball and socket joint is an articulation between the rounded head of one bone (ball) and the concavity of another (socket). It is a type of synovial joint. This type of joint is multiaxial: it permits flexion/extension, abduction/adduction, and rotation. The only two ball and socket joints of the body are the hips and the shoulder (glenohumeral). The shallow socket of the glenoid cavity permits a more extensive range of motion in the shoulder; the deeper socket of the acetabulum and the supporting ligaments of the hip constrain the movement of the femur.