Objective Assessment of Gait Asymmetry in Polo Ponies

Abstract

AimsPolo ponies have demanding athletic careers and are likely to display a degree of movement asymmetry due to subclinical lameness. Due to training and management practices in polo, the prevalence of lameness may be underestimated. Subjective assessment of lameness has been proven to be unreliable and a growing body of evidence supports the use of trunk mounted inertial sensors as a practical field method of objective gait analysis. We set out to test the hypothesis that all polo ponies display some degree of movement asymmetry. It is likely that some of these asymmetries will be severe enough to be classified as lameness. In horses with asymmetry we hypothesise that left forelimb lameness will predominate.MethodsForty polo ponies were equipped with trunk mounted inertial sensors and trotted along a hard, straight surface. Data were analysed according to published protocols and standard objective symmetry indices were derived and compared with published thresholds.ResultsAll 40 horses displayed asymmetrical movement. Twenty‐one (52.5%) were left forelimb asymmetric, and 19 (47.5%) were right forelimb asymmetric. Eighteen of these asymmetric horses had asymmetry values consistent with lameness. Twelve horses were identified as left forelimb lame and 6 horses identified as right forelimb lame. There was an equal division between right and left hindlimb asymmetry. Nine horses had values exceeding the lameness thresholds; 6 were right hind lame and 4 were left hind lame.ConclusionsPolo ponies display asymmetry and some asymmetries are consistent with lameness. There appears to be a bias in left forelimb lameness in this population.Practical significanceThese findings may highlight underlying orthopaedic pathology that may be discipline specific or be a reflection of entrained or inherent laterality/handedness.Ethical animal researchAll procedures were performed with approval of the Royal Veterinary College Ethics Committee. Informed consent was obtained from all owners of the horses used in this study. Approval ref no. 2012/P337. Sources of funding: None. Competing interests: None.