Ball and socket joint

A ball and socket joint (enarthrosis, spheroidal joint) is a joint in which the ball-shaped surface of a bone fits into the cup-like indentation of another bone. This type of joint allows the bone to move in a 360° angle—with more freedom than other joints.

Examples
Examples of this type of joint occur:
in the hip, where the rounded head of the femur (ball) rests in the cup-like acetabulum (socket) of the pelvis.
in the glenohumeral joint of the shoulder, where the rounded head of the humerus (ball) rests in the cup-like glenoid fossa (socket) of the shoulder blade.

Other images

References

Category:Joints