This joint (fig. 312) is composed of six bones, viz., the calcis, astragalus, cuboid, cuneiform magnum, cuneiform medium, and cuneiform parvum.

The Calcis is situated at the posterior and outer part of the hock, of which it forms the "point", and gives attachment to the tendons of important muscles as well as to powerful ligaments. It articulates in front with the astragalus and below with the cuboid bone and the cuneiform magnum, on which it rests.