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

The research study investigates the impact of elevated heels on the joint angles of a horse’s hindlimb, particularly noting the effects on the coffin, fetlock, and hock joints. The results demonstrate that raising the heels increases the flexion of the coffin and hock joints while decreasing the maximum extension of the fetlock joint during both walking and trotting.

Research Objective and Methods

• The primary objective of this study was to examine the simultaneous impact of raising the heels of a horse’s hindlimb on the joint angles of the coffin, fetlock, and hock during their motion cycle.
• The experiment was conducted using eight healthy adult Warmblood horses, who were evaluated both barefoot and with an 8 or 16 degrees heel wedge while walking and trotting on a flat treadmill.
• Markers were placed on the dorsal and cranial aspects of the horses’ hindlimbs and their movements were recorded using a 3D high-speed video system.
• The joint angles were then calculated based on the video recordings.

Research Findings

• The data shows that raising the heel height of a horse’s hindlimb by 8 or 16 degrees during the stance phase reduced the combined plantar coffin joint and pastern joint angle. In other words, this lifting resulted in more flexion or bending of these joints.
• At the same time, an increase in the heel height led to a reduction of maximum extension in the fetlock joint. This suggests a decreased stretch in the fetlock joint when the heels were elevated.
• The maximum hock flexion, alternatively, increased with greater heel height. Meaning, the hock joint bent further upon lifting the horse’s heel.
• Despite these alterations, the relationship between each joint’s angles remained largely consistent during the course of the stance phase under all three measurement settings; any changes were merely slight variances in when the joints reached their maximum and minimum angles.

Conclusions and Therapeutic Implications

• The study concluded that increasing the heel height has a proportional effect on the joint angles of a horse’s hindlimb. A higher heel led to increased flexion in the coffin and hock joints and reduced maximum extension in the fetlock joint during the walk and trot stance phase.
• From a therapeutic perspective, the study suggests that horses suffering from pain on maximum hock extension, for example, due to spavin, might benefit from wearing raised heel shoes. Consequently, this research could inform treatment strategies for various equine orthopedic ailments.