The effect of perineural anaesthesia and handler position on limb loading and hoof balance of the vertical ground reaction force in sound horses.

Abstract

The effects of handler position and perineural anaesthesia in sound horses need investigation to facilitate interpretation of pressure plate analysis in lame horses. To evaluate the effect of handler position and perineural anaesthesia on limb loading and particularly hoof balance in sound horses. Nonrandomised crossover study. Six sound horses were walked and trotted over a pressure plate, with the handler on the left and subsequently on the right side, and finally after a bilateral low palmar digital nerve block. One week later this procedure was repeated before and after a bilateral abaxial sesamoidean nerve block. Peak vertical force, vertical impulse and stance time of 5 hoof prints of both forelimbs were obtained (126Hz), and toe-heel and mediolateral hoof balance curves of the vertical force were plotted throughout stance. Limb-loading and timing data and hoof balance data (beginning, middle and end of the stance phase) were statistically compared (handler left compared with right; before compared with after low palmar digital nerve block and abaxial sesamoidean nerve block; baseline at first measurement session compared with second). There were no significant effects of handler position and perineural anaesthesia on peak vertical force, vertical impulse and stance time. Hoof balance curves were not affected by handler position or perineural anaesthesia. The limb loading data and hoof balance curves were comparable for each horse over the one-week interval. Handler position and perineural anaesthesia do not have an effect on limb loading and toe-heel and mediolateral hoof balance in sound horses, which is of fundamental importance before embarking on pressure plate analysis for lameness diagnosis.