Head, withers and pelvic movement asymmetry and their relative timing in trot in racing Thoroughbreds in training

Summary Background Horses show compensatory head movement in hindlimb lameness and compensatory pelvis movement in forelimb lameness but little is known about the relationship of withers movement symmetry with head and pelvic asymmetry in horses with naturally occurring gait asymmetries. Objectives To document head, withers and pelvic movement asymmetry and timing differences in horses with naturally occurring gait asymmetries. Study design Retrospective analysis of gait data. Methods Head, withers and pelvic movement asymmetry and timing of displacement minima and maxima were quantified from inertial sensors in 163 Thoroughbreds during trot‐ups on hard ground. Horses were divided into 4 subgroups using the direction of head and withers movement asymmetry. Scatter plots of head vs. pelvic movement asymmetry illustrated how the head–withers relationship distinguishes between contralateral and ipsilateral head–pelvic movement asymmetry. Independent t test or Mann–Whitney U test (P