Track Surface Identification Using an Instrumented Horseshoes

Abstract

IntroductionTrack conditions in Thoroughbred racing significantly impact performance and injury. However, surface effects on limb biomechanics at racing speeds are poorly understood.MethodsA racing shoe was modified to contain inertial transducers and a strain gauge to provide motion kinematics and a measure of hoof/surface interaction load. A two‐phase non‐linear surface reaction model was defined to represent the hoof deceleration phase, and the hoof penetration phase where the surface reaction force was represented by a quartic stiffness profile and a fixed damping term. Model parameters were determined using an “output error” iteration method for 25 strides at medium gallop. Parameters were compared using a standard t‐test.ResultsThe sand track had a significantly greater (P<0.0001) maximum penetration of 61 ± 10 mm (mean ± SD), than the grass track (41 ± 0.5 mm). Both stiffness parameters were significantly different between the two tracks (P<0.0001), but damping parameters did not differ significantly. Hoof impact at high speed involved decelerations of over 100 ‘g’ occurring within milliseconds.ConclusionsThis study demonstrated that a surface reaction model using data acquired from an instrumented horseshoe, distinguished between surface reaction profiles of a sand track and a grass track, as a step towards improving track rating methods. A further challenge will be to develop independent checks on instrument calibrations.Ethical Animal ResearchThe study was approved by the University of Melbourne Animal Ethics Committee. Sources of funding: This study was funded by the Rural Industries Research and Development Corporation under project PRJ‐006479, and by a University of Melbourne Research Collaboration Grant. Competing interests: Colin Martin is the Director of SPERERO Pty. Ltd. a consulting and innovations company.