Movement asymmetries in high-performing riding horses

Introducing sensitive mechanical tools to determine gait asymmetries in horses has brought a much-needed objective look at lameness assessment. The sensitivity of these tools has increased a problem that has always existed in horse movement assessment: is the asymmetry I am observing mechanical or pain-related? This study takes the first step at exploring this problem but does not answer it. 70% of the horses in this study had asymmetries though were reported to be not lame by the riders. The follow-up needs to be a thorough exam to try and differentiate mechanical vs painful causes of asymmetry.
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<b>Prevalence of movement asymmetries in high-performing riding horses perceived as free from lameness and riders’ perception of horse sidedness</b>

PLoS One. 2024 Jul 30;19(7):e0308061. doi: 10.1371/journal.pone.0308061. eCollection 2024.
Authors
Ebba Zetterberg 1 , Emma Persson-Sjodin 1 , Johan Lundblad 1 , Elin Hernlund 1 , Marie Rhodin 1
Affiliation

1 Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden.

PMID: 39078818
DOI: 10.1371/journal.pone.0308061

Abstract

A high proportion of horses in training, perceived as free from lameness by their owner, exhibit vertical movement asymmetries. These types of asymmetries are sensitive measures of lameness, but their specificity as indicators of orthopaedic pathology or locomotor function remains unclear. Equine athletes performing at a high level could be assumed to exhibit a higher degree of movement symmetry compared with the general horse population, but this has not been confirmed. This study investigated the prevalence of movement asymmetries in horses performing at a high level in three equestrian disciplines; show jumping, dressage and eventing, as well as the association between riders’ perception of horse sidedness and said movement asymmetries. Using an inertial measurement unit-based system (Equinosis), gait analysis was performed on 123 high-performing horses. The mean difference between the two vertical minimum and between the two maximum values of each stride was recorded for the head (HDmin, HDmax) and pelvis (PDmin, PDmax). The horses were defined as asymmetric if one or multiple asymmetry parameters exceeded an absolute trial mean of: >6mm for HDmin or HDmax, and >3mm for PDmin or PDmax, with standard deviation less than the respective mean value. Based on the results, 70% of the horses were classified as asymmetric, which is similar to previous findings for young riding horses and horses competing at a lower level. More than one-third of these high-performing horses had asymmetry values of similar magnitude to those seen in clinically lame horses. No clear associations were observed between rider-perceived sidedness and the vertical movement asymmetry values, indicating that the perceived unevenness between sides is not a determinant of vertical movement asymmetry. Longitudinal studies on movement asymmetries in relation to training intensity and full clinical examinations with local or systemic analgesic testing are desired as further research to determine whether these movement asymmetries indicate a welfare problem.

Copyright: © 2024 Zetterberg et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.