Biomechanical and mechanical investigations of the hoof-track interface in racing horses.

The aim of this article is to review current knowledge of kinetic variables of the hoof-track interaction and track properties relevant to the objective of minimizing injuries to horses at racing tracks. In each phase of the stance--primary impact, secondary impact, support, and breakover, the hoof experiences different combinations of force and acceleration. The role of each combination, and of measured track properties, in causing catastrophic and chronic injuries to the limbs of racing horses is unknown. Limited data of this type have been provided in previous epidemiologic studies of risk factors for breakdown. Future epidemiological studies should include characterization of the track surfaces and a more complete description of the kinematics of the hoof and surface. Consideration of an appropriate range of physical properties is necessary in track design, testing, and maintenance.