Rupture of the distal sesamoidean ligaments of a horse: Vertical forces and temporal components of the strides before, during and after injury

Abstract

Summary The temporal components and vertical forces of the strides before, during and following rupture of the distal sesamoidean ligaments of the right forelimb were recorded from instrumented shoes. The right front hoof was shod with an instrumented shoe containing transducers located at the toe and both sides of the heel. The left front hoof was shod with a shoe containing a single transducer positioned over the center of the frog. The Thoroughbred mare had galloped through a track straightaway and entered the turn when the injury occurred. The horse had changed from a right to left lead five strides before the breakdown. In the three strides prior to the injury, no abnormalities, such as stumbling, were observed. During the stride in which the breakdown occurred, the right front hoof landed first on the lateral side of the heel rather than on the medial side as in the preceding strides. The forces on both sides of the heel initially increased in a normal pattern and at the time of peak force, rupture of the distal sesamoidean ligaments apparently occurred. Following the injury, marked changes were observed in the force-time curves which included a pronounced impact force on the toe and very low peak forces on all transducers.