Dynamic evaluation of toe-heel and medio-lateral load distribution and hoof landing patterns in sound, unshod Standardbred horses with toed-in, toed-out and normal hoof conformation.

This study investigated how different hoof shapes (normal, toed-in, toed-out) in unshod Standardbred horses affect the distribution of weight and landing patterns during movement. The researchers discovered that variations in hoof shape do not significantly influence weight distribution or landing patterns, which were primarily characterized by a flat landing. They also noted differences between Standardbred horses and Warmbloods, highlighting the necessity for breed-specific data.

Objective and Methodology

• The research aimed to examine the dynamic load distribution and hoof landing patterns in healthy Standardbred horses with different hoof shapes: normal, toed-in, and toed-out. Understanding these dynamics is critical in the field of equine orthopedics for injury prevention and treatment.
• Twenty-four sound, unshod Standardbreds were walked and trotted over a pressure plate, which recorded peak vertical force (PVF), vertical impulse (VI), stance time (ST) of both forelimbs, mid-lateral and toe-heel load distribution, and hoof landing patterns.
• The researchers used asymmetry indices to compare the readings between both forelimbs and linear mixed models and Chi-square analysis for statistical evaluation.

Findings

• The study found no significant differences in PVF, VI and ST asymmetry among the normal, toed-in, and toed-out horses—both at walk and trot paces. This suggests that hoof shape does not significantly influence these measurements.
• In general, a flat landing was observed more frequently, irrespective of the hoof shape. The researchers found that 39.6% of horses used a flat landing at a walk, and 70.8% used a similar technique when trotting.
• Toed-out horses displayed slightly higher loading in the medial zone at the end of the stance phase at walk than normal horses; this was the only significant difference in load distribution linked with hoof shape.

Conclusion

• The study found that flat landing is more prevalent in Standardbred horses than previously reported in Warmbloods. This difference suggests that there could be breed-specific factors affecting hoof landing patterns and load distribution, emphasizing the need for breed-specific clinical data.
• The researchers concluded that mild deformities in hoof shape do not necessarily influence the distribution of load or landing patterns, countering what may be a common assumption in equine orthopedics.