Kinetics of the Forelimb in Horses Trotting an Uphill and Downhill Slope

Abstract

IntroductionEquine training often includes running on tracks with different uphill (UP) or downhill (DOWN) slopes and examination of lame horses on a slope can be used to investigate the origin of lameness. However little is known about the kinetics of horses in such circumstances. The aim of this study was to quantify and compare ground reaction force, acceleration and sliding of the hoof in the forelimb of horses trotting an uphill and downhill slope.MethodsThe right front hoof of 5 horses was equipped with a dynamometric horseshoe and an accelerometer allowing the measurement of 3D ground reaction force and hoof acceleration and displacement. The horses were trotted in hand (3.5 m/s) on a 7% inclined asphalt area successively uphill and downhill. Data were analysed using an ANOVA, accounting for correlated repeated measurements within each horse (P<0.01).ResultsSpeed was not significantly different between UP and DOWN. The maximal longitudinal breaking force of the hoof, maximal vertical force, vertical impulse and longitudinal sliding of the hoof at impact were significantly increased on DOWN compared to UP (respectively +97.7%, +8.4%, +16.6% and +450%). Stride frequency and longitudinal propulsive force were significantly decreased on DOWN compared to UP (respectively −5.1% and −48.7%).ConclusionsThe results of this study (increased longitudinal breaking force and maximal vertical force on a downward slope) are consistent with previous measurements of superficial digital flexor tendon loading on the same area [1]. Conversely increased propulsive force on an uphill slope needs to be taken into account during rehabilitation of horses with deep digital flexor tendon injuries.Ethical Animal ResearchThe local Animal Care and Ethics Committee advised that no formal approval was required for this study. Sources of funding: Conseil Régional de Basse‐Normandie, the Fonds Unique Interministériel, the French Ministry of Agriculture, the FEDER and the Institut Français du Cheval et de l'Equitation (IFCE). Competing interests: none.