A cross‐sectional survey investigating challenges in lameness identification among equine owners

Background: To improve detection of equine back-related disorders, it is important to establish how movement dynamics in horses' thoracolumbo-sacral spine are normally affected by intrinsic and extrinsic factors.Objective: To quantify how discipline, activity, gait and surface impact rotational upper-body movement in horses from the military and police forces.Study design: Cross-sectional.Methods: 106 owner-sound horses were walked and trotted in-hand in a straight-line at walk and trot over hard and soft surfaces.During exercises, inertial sensors (XSens MTw) were mounted with doublesided tape to the poll, withers, thoracic vertebrae-13 (T13) and 18 (T18), lumbar vertebra-3 (L3), sacrum (between tubera sacrale) and caudal sacrum.Linear mixed models assessed whether horse discipline (load pulling or non-load pulling), activity level (active or retired), gait (walk or trot) or surface (soft or hard) influenced rotational differences among adjacent sensors (significance at p < 0.05).Results: Horses used for pulling loads had significantly reduced axialrotation between withers-T13 and T13-T18, by 2.3-2.6 , and reduced flexion-extension at poll-withers and T13-T18, by 1.3-1.5 (p 0.009).Active horses showed instances of reduced axial-rotation (at T18-L3, L3-sacrum, sacrum-caudal-sacrum, p 0.002, 2.7-3.8 ), flexionextension (T18-L3, L3-sacrum, p 0.006, 0.8-0.9 ) and lateral-bending (withers-T13, sacrum-caudal-sacrum, p 0.002, 1.0-2.0 ), but also had increased axial-rotation at withers-T13 (p = 0.02, 1.7 ) and increased flexion-extension at poll-withers (p < 0.001, 2.7 ). Trotting increased axial-rotation at all sites by 1.9-7.6 (p < 0.001), except poll-withers, but reduced lateral-bending at all sites by 0.4-8.3(p < 0.001), except L3-sacrum.Soft surfaces increased rotational range of movements, by 0.2-2.4 , in the 12/18 significant surface comparisons (p 0.03).Main limitations: Walk and trot speeds varied.Conclusions: These data will help to develop an equine back dynamics reference framework, to which individuals may be compared.Further work will explore these data in the context of horse movement asymmetry, age, stride duration, breed and objective surface properties.