The Effect of Perineural Anesthesia and Handler Position on Limb Loading and Hoof Balance of the Vertical Ground Reaction Force in Sound Horses

Abstract

IntroductionTo facilitate interpretation of limb loading and hoof balance obtained by pressure plate analysis in lame horses, the effects of handler position and perineural anesthesia in sound horses need investigation.MethodsSix sound Warmblood horses were walked and trotted over a pressure plate, with the handler at the left and subsequently the right side, and before and after a bilateral palmar digital nerve block. One week later, this procedure was repeated before and after a bilateral abaxial sesamoid nerve block. Peak vertical force (PVF), vertical impulse (VI) and stance time (ST) of 5 hoof prints of both forelimbs were obtained (126 Hz). Asymmetry ratios were calculated.Toe‐heel and medio‐lateral hoof balance curves of the vertical force were calculated. Mixed model ANOVA was used for statistical analysis of asymmetry ratios (α = 0.05). Hoof balance curves were assessed qualitatively.ResultsThere were no significant effects of handler position and perineural anesthesia on PVF and VI; small but significant effects of perineural anesthesia on ST at walk were associated with variability in horses′ speed between sessions at walk (P = 0.046); no significant differences at trot. Hoof balance curves were not affected by handler position or perineural anesthesia, and were highly repeatable within each individual horse.ConclusionsThe lack of any effect of handler position or perineural anaesthesia on limb loading and toe‐heel and medial‐lateral hoof balance in sound horses makes it probable that significant aberrations found using pressure plate analysis are related to abnormalities and hence may be relevant in lameness diagnosis.Ethical Animal ResearchThe study was approved by the ethical committee of the Faculty of Veterinary Medicine of Ghent University (n° 2012/151). Sources of funding: Ghent University. Competing interests: none.