Hoof ground interaction: when biomechanical stimuli challenge the tissues of the distal limb.

Expectations of, and demands on, today’s equine athlete require monitoring of its locomotor system to maintain orthopaedic health. In the practical situation, the soundness of the distal limb is one of the most important features in the performance horse and manifested lameness is too often the result of irreparable damage to critical tissues. To understand the delicate balance between soundness and lameness, in-depth knowledge is needed as to which biomechanical signals produced by hoof ground interaction may engender physiological or pathological tissue adaptations. To date, we can measure accurately the biomechanical stimuli in terms of forces, pressures, movements, accelerations and strains in the distal limb at impact, support and break-over. Furthermore, we can see the results of these biomechanical challenges to critical tissues of the distal limb, at a young age as ‘maturation or functional adaptation’ and at an older age often as ‘wear or damage’. The purpose here is to review the recent biomechanical literature to hoof ground interaction and to relate presentday knowledge in this field to potential challenges to distal limb tissues, which may impair the health status of the locomotor system of the horse.