Ligaments of wrist. Posterior view.
A saddle joint (sellar joint, articulation by reciprocal reception) is a type of synovial joint in which the opposing surfaces are reciprocally concave and convex.
The movements of saddle joints are similar to those of the condyloid joint and include flexion, extension, adduction, abduction, and circumduction but not axial rotation. Saddle joints are said to be biaxial, allowing movement in the sagittal and frontal planes.