Equine hoof function investigated by pressure transducers inside the hoof and accelerometers mounted on the first phalanx.

The dampening of hoof impact was investigated by measuring the accelerations transmitted through structures of the hoof in horses trotting freely on an asphalt tarmac. The hoof dampened the vibrations transmitted to the first phalanx. Shoeing decreased the viscous dampening and increased the median power frequency and the maximal amplitude of the vibrations transmitted to the first phalanx. The pressure inside the digital cushion of the foreleg was recorded. The pressure dropped during the stance phase, indicating expansion of the hoof. The expansion of the hoof was not produced by frog or sole weight bearing because this would have increased the intra-digital cushion pressure. The pressure theory of hoof function must presumably therefore be rejected. Shoeing the horses augmented the intra-digital cushion pressure drop and probably impaired the movements of the hoof wall.