Objectively measured movement asymmetry in yearling Standardbred trotters

Abstract

Background Lameness evaluation of Standardbred trotters can be challenging due to discrepancies in observed movement asymmetry between in‐hand and track exercise, and between different trotting speeds. There are few studies on objective measurement of movement in Standardbreds, and little knowledge regarding biological variation and clinical significance of measured movement asymmetry in this breed. Objectives To quantify the prevalence and magnitude of objectively measured movement asymmetry in young Standardbred trotters, and identify associations with trainer, sex, height, track type and in‐hand measurement prior to or after track trials. Study design Cross‐sectional, observational study. Methods A total of 114 Standardbred yearlings were evaluated with a wireless inertial sensor system during trot in‐hand and when driven on a track. After exclusions relating to lameness or technical difficulties, 103 horses were included in the study; 77 were evaluated in‐hand and on the track, 24 only in‐hand and 2 only on the track. Results Front and/or hindlimb parameters were above asymmetry thresholds previously established for other breeds during in‐hand trials for 94 (93%) horses and during track trials for 74 (94%) horses. Most horses showed mild asymmetry. A minority of horses (20%) switched side of the asymmetry for one or more parameters between in‐hand and track trials. Mixed model analyses revealed no significant effects of trial mode (in‐hand or track trial, in‐hand trial pre‐ or post‐track trial, straight or oval track), trainer or horse height. Females had a significant but small reduction in asymmetry in one front limb parameter (HDmax) compared with males (1.7 mm, 95% CI 0.18‐3.28, P = .03). Main limitations High data variability, reflected in large trial standard deviations, relating mainly to a lack of horse compliance. Conclusions A high proportion of Standardbred yearlings showed movement asymmetries. There was no group‐level effect between in‐hand and track trials, however, considerable individual variation was observed.

Locomotion asymmetry in young Standardbred trotters in training and links to future racing career

“…The results showed that VS for both front and hind limbs recorded in trot in hand did not differ from VS during driving on the track. This is also in accordance with findings by Kallerud et al (2020). Observations made during trot in hand can therefore be considered useful.…”

Effect of Needle and Extracorporeal Shockwave Stimulation of Acupuncture Points on Equine Chronic Multilimb Lameness Using a Single-Formula Approach

“…Others have questioned the role of breed and indeed Standardbred race horses showing particular interstride variability of gait parameters. 27 Considering that interstride CV did not differ between observations, it is plausible that the horses' temperament rather than biological variability of chronic conditions was responsible for the encountered data spread. Consequently, conditioning Standardbred race horses which may be unfamiliar to trotting in hand to experimental procedures may have improved data quality and ultimately aided the detection of treatment effects.…”

Rein tension in harness trotters during on-track exercise

“…It would have been valuable to measure the horses' movements during the exercise tests as well to investigate immediate associations between rein tension and asymmetry on a stride-by-stride basis. Recently published data showed that asymmetries recorded in-hand and when Standardbred yearlings were driven on the track did not differ significantly ( 31 ). Moreover, results from Starke et al ( 33 ) revealed no significant changes in asymmetry based on speed of trotting horses in hand on a straight line.…”