The hip joint connects the torso and the legs; it consists of the socket in the pelvic bone and the head of the femur. The parts of the joint are covered with a cartilaginous lubricated layer to minimize friction between the moving surfaces. The rim of the socket (acetabulum) is enclosed by the labrum, a fibrocartilaginous sealing ring. The synovial membrane excretes a liquid that nurtures the cartilage; the function of the cartilage is largely comparable to that of a shock absorber. The hip joint is enclosed by a strong capsule; ligaments between the bones stabilize the joint, while tendons and muscles make it move. Its design as a ball-and-socket joint ensures maximum mobility.
Anatomical image of the hip joint