Horizontal moment around the hoof’s centre of pressure during walking in a straight line.

The research investigates the twisting moments (forces) around the center of pressure of a horse’s hoof during walking. It measured these forces on both the forelimbs and hindlimbs of nine Thoroughbred horses to determine symmetry or asymmetry of the forces. The research showed observable differences across forelimbs in some horses, indicating potential bilateral variations in future studies.

Research Methodology

• The research examined nine healthy Thoroughbred horses, all around 53 years of age, and each with an average weight of 502 kg.
• The horses were made to walk in a straight line over force measuring equipment known as a Kistler force platform, which recorded the forces of the horse’s hoofs.
• Data was collected from five separate trials for each of the forelimbs and hindlimbs of the horses.
• The researchers calculated the moment around the hoof’s center of pressure, derived from the horizontal forces in the transverse (left-to-right) and cranio-caudal (front-to-back) directions.

Research Findings

• The calculated twisting forces around the hoof’s center of pressure varied between different horses but were consistent within individual horses’ limbs.
• Hindlimbs generally showed an identical or biphasic moment pattern, with the highest twisting forces observed in the first half of their stance (while bearing weight).
• For each horse, peak moments were internal (facing towards the center of the horse’s body) under both hindlimbs.
• In contrast, in the forelimbs of 7 out of 9 horses, an asymmetric pattern was found, with the left forelimb typically exerting an internal moment, while the right forelimb exerted an external moment.
• The other two horses exerted internal moments in both forelimbs.

Conclusions

• The researchers concluded that in 7 out of 9 horses, the forelimbs exhibited asymmetrical horizontal moments around the hoof’s center of pressure.
• The hindlimbs, in contrast, exhibited mechanical symmetry during their stance, exerting an internal moment during retraction (pulling back).
• This study suggests that joint motions in horses’ forelimbs are likely to be asymmetrical, and future research into equine locomotion should consider possible bilateral variations (differences between the left and right side).