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.[1]
| Ball and socket joint | |
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| 1: Ball and socket joint; 2: Condyloid joint (Ellipsoid); 3: Saddle joint; 4 Hinge joint; 5: Pivot joint; | |
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| Capsule of shoulder-joint (distended). Anterior aspect. |
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.[2]
Other images
Hip
Shoulder
References
- ↑ "Ball-and-socket joint". Encyclopædia Britannica. Encyclopædia Britannica Online.
- ↑ "Synovial Joints - Ball and Socket Joints". University of Michigan. Archived from the original on 10 March 2011. Retrieved 10 March 2011.