| Pivot joint | |
|---|---|
| 1: Ball and socket joint; 2: Condyloid joint (Ellipsoid); 3: Saddle joint; 4 [[]]; 5: Pivot joint; | |
| Latin | articulatio trochoidea |
| Gray's | subject #70 285 |
A Pivot joint (trochoid joint, rotary joint, Lateral Ginglymus) is a type of diarthrosis, or synovial joint. In pivot joints, the axis of a convex articular surface is parallel with the longitudinal axis of the bone.
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Pivot joints allow for rotation, which can be external (for example when rotating an arm outward), or internal (as in rotating an arm inward). When rotating the forearm, these movements are typically called pronation and supination. In the standard anatomical position, the forearms are supinated, which means that the palms are facing forward, and the thumbs are pointing away from the body. In contrast, a forearm in pronation would have the palm facing backward and the thumb would be closer to the body, pointing medially.
Examples of a pivot joint include:
Note that spherical joints (ball and socket joints), such as the hip joint, also permit rotation (among all other possible motions), and should thus not be confused with pivot joints, where rotation is the only possible movement.
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.
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