It is found in the thumb, the thorax, the middle ear, and the heel.

In a saddle joint, one bone surface is concave while another is convex.

Saddle joints are said to be biaxial,[5] allowing movement in the sagittal and frontal planes.

[2] The term "saddle" arises because the concave-convex bone interaction is compared to a horse rider riding a horse, with both bone surfaces being saddle-shaped.

[1][2] This article incorporates text in the public domain from page 286 of the 20th edition of Gray's Anatomy (1918)