The hock is one of the most hard working, complex and flexible joints in the horse's body. Made up of multiple joints and individual bones all held in place by numerous ligaments and joint capsules, it works as a hinge joint moving by flexion and extension through one plane only. The upper joint between the tibia and talus is highly mobile while the lower tarsal joints are comparatively immobile The hock is subject to significant concussive, weight-bearing, shock-absorbing, loading and rotationa