saddle joint

saddle joint: carpometacarpal joint

A saddle joint: the carpometacarpal joint.

A saddle joint is a type of synovial joint in which the articular surfaces are reciprocally concavoconvex and resemble a saddle on a horse's back. Saddle joints permit flexion, extension, abduction, adduction, and rotation. The best example of this type of joint is the carpometacarpal joint of the thumb.