Example of Pivot Joint

Also known as a trochoid joint or rotary joint. Medical term used to describe 'ball and socket joints'. The reference relates to a bone freely rotating, or pivoting, around another bone. Use of the term is generic, referring to a principle of anatomical construction. In practice, these joints are very different in terms of function and structure, and the term is used to describe this specific common characteristic. The degree of rotation varies, from partial to complete.

Examples of Pivot Joints:

The elbow, or ulna of the lower arm.
The shoulder where the upper arm bone connects to the socket joint.
https://en.wikipedia.org/wiki/Pivot_joint

Image Example of Pivot Joint:

1: Ball and socket joint; 2: Condyloid joint (Ellipsoid); 3: Saddle joint; 4 Hinge joint; 5: Pivot joint;