In vivo measurement of bone strain in the horse.

Strain gauges were successfully bonded in vivo to the cranial, caudal, medial, and lateral aspects of the equine radium and tibia and to the dorsal, palmar, or plantar, medial, the lateral aspects of the metacarpus and metatarsus--all in the mid-diaphyseal region. Various activities were investigated, including walking, trotting or pacing, and standing up from anesthesia. The strain patterns showed that each stride produced a characteristic deformation cycle. The strains were measured and the axial loads were calculated as the horse performed certain activities. The tension band side of each bone was predicted from the results. The tension band sides of the metacarpus and metatarsus were the dorsomedial and dorsolateral aspects; for the radius and tibia, the tension band sides were the cranial and craniolateral aspects, respectively.