Measuring hoof slip of the leading limb on jump landing over two different equine arena surfaces

Abstract

The amount of hoof slip at the moment of impact can cause musculoskeletal injuries to the horse. Risk of injury is influenced by surface properties, however there is limited understanding of the effect on hoof slip during jump landing. The objectives of this study were to compare hoof slip on two different surfaces and investigate relationships between hoof slip and surface properties. A contact mat and hoof reference marker were designed and validated, the former to indicate the moment of impact and the latter to provide a visible reference marker on the lateral hoof wall. The leading right forelimb of six horses was recorded during jump landing on two different surfaces. Five trials, plus one where the forelimb landed on a contact mat were recorded at 500 Hz using a calibrated high speed camera positioned perpendicular to landing. Surface traction, hardness and penetration were measured between horses. Horizontal displacement of the hoof reference marker was plotted and smoothed with a Butterworth filter at 25 Hz cut off. Hoof slip was measured from impact to mid-stance. Data were analysed using ANOVA and Pearson correlations. A significant difference in hoof slip (10% wax=4.9 ± 2.1 cm and, 3% wax=7.4 ± 3.6 cm) was found between the two surfaces (P<0.01). In addition, hoof slip was correlated with all surface measurements (hardness, traction and penetrability) on the 10% wax surface, but none on the 3% wax surface. Wax content appears to influence hoof slip during jump landing as greater hoof slip was measured on a 3% wax surface and variability on this surface was greater for the group. The results suggest that wax content influenced surface properties and on the 3% wax surface the greater variability in hardness and traction influenced the consistency with which the horses jumped upon it.