Measurement of vertical forces and temporal components of the strides of horses using instrumented shoes

Abstract

Summary Instrumented shoes were used to measure the vertical forces exerted by horses moving at a variety of gaits. Two types of shoes were used; one contained a single transducer positioned over the center of the frog and the second contained transducers located at the toe and both sides of the heel. Horses were shod with these instrumented shoes and walked and trotted over a force plate. Forces were simultaneously recorded from the transducers in the shoes and from the force plate. Comparisons were made between the amount and duration of the forces exerted on the transducers and the vertical and horizontal forces recorded from the force plate. Forces recorded from the single transducer shoes showed strong correlations with the forces recorded from the force plate for horses moving at the walk; however, at the trot only moderate correlations occurred between these forces. At both the walk and trot, forces recorded from each side of the heel and the total forces occurring on all three transducers from the front hooves of horses shod with three transducer shoes showed strong correlations to the vertical forces recorded from the force plate. Vertical forces were also recorded from the instrumented shoes as horses walked, trotted and galloped on a track straightaway. Forces recorded from normal horses shod with single transducer shoes on all four feet were greater on the forelimbs than the rear limbs at the walk and trot. At the gallop, forces were highest on the lead front followed by the nonlead front, lead rear and nonlead rearlimb, respectively. Forces recorded from a three transducer shoe on the right front hoof of a horse walking, trotting and galloping in a right lead were highest on the medial side of the heel and occurred during the middle of the support period. Peak forces on the toe occurred at or near the time of heel lift. The results of these studies indicate that these instrumented shoes have advantages over the methods previously used to measure locomotor forces. These instrumented shoes can be used to simultaneously record the temporal components and the amount and distribution of vertical forces exerted during consecutive strides of horses moving at a variety of gaits.