Determination of hoof mass and centre of mass from morphological measurements.

Determination of net joint moments and powers requires accurate measurements of mass and centre of mass (COM) for the limb segments. The objective of this research was to develop regression equations for calculating mass and COM of the hoof segment that are applicable over a wide range of hoof morphologies. Ninety-one hooves (mean +/- s.d. 0.99 +/- 0.50 kg) were weighed and the 3-dimensional COM determined using a mass balance technique. Ten morphological variables were measured and used as independent variables in linear regressions with dependent variables of mass and centre of mass. The regression equation for mass was dependent upon coronet circumference, lateral height, solar length, solar width, heel height, toe height and base circumference (r2 = 0.978). Mediolateral COM was dependent only on solar length (r2 = 0.874). Dorsopalmar COM depended only upon solar length (r2 = 0.792) and vertical COM was defined only by lateral height (r2 = 0.377). Midlateral COM, measured at the midhoof wall along the tubules, was found to depend on coronet circumference, lateral height, toe length and toe height (r2 = 0.414). The large sample size and the inclusion of a variety of hoof masses and morphologies allow these results to be generalised to a wide range of the equine population. It was concluded that the mass and COM of the hoof segment can be estimated to a high degree of accuracy based on easily obtained morphological measurements.