Some principles of ligament function, with examples from the tarsal joints of the sheep (Ovis aries)



The effects of ligaments, in limiting or controlling movement, depend on the positions of their attachments relative to the axes of joints. Such effects are explored in a theoretical section, which considers ligaments that cross a single, congruent hinge joint; ligaments that cross two congruent hinge joints; and non-congruent hinge joints controlled by crossed ligaments. The principles derived in the theoretical section are used to explain the complex mechanism of the sheep tarsal joints.