Raising heels of hind hooves changes the equine coffin, fetlock and hock joint angle: a kinematic evaluation on the treadmill at walk and trot

Abstract

Raised heels are commonly recommended for various equine orthopaedic conditions. However, the simultaneous effect of raised heels on the different joint angles of the equine hindlimb throughout the motion cycle has not been previously evaluated. To document the simultaneous effect of raised heels on the joint angles of the equine hindlimb coffin, fetlock and hock joints. Eight sound, adult, Warmblood horses were evaluated barefoot and with a heel wedge of 8 or 16 degrees, walking and trotting on a horizontal treadmill. Markers placed on the dorsal and cranial aspect of the hindlimb were traced using a 3D high speed video system and joint angles calculated. The effects of raising the hindlimb heels by 8 or 16 degrees on the angles of the hindlimb during the stance phase are a reduction of the plantar combined coffin joint and pastern joint angle, a reduction of maximum extension in the fetlock joint, and an increase in maximum hock flexion. The relation between angles did not change significantly during the course of the stance phase in the three measurement situations, with only small differences in time of occurrence of each joint angle maxima and minima. Raising the heels of hind hooves increases flexion of the coffin and hock joints during the stance phases of walk and trot, and a doubling of the angle of the raised heels also doubles the effect on the joint angles investigated. Raised heels reduce the maximum extension of the fetlock joint during the the stance phase at walk and trot. This study provides evidence for the therapeutic use of raised shoes with heels in horses with pain on maximum hock extension, e.g. spavin.