A feasibility study to determine whether neuromuscular adaptations to equine water treadmill exercise can be detected using synchronous surface electromyography and kinematic data.

Abstract

Despite a growing evidence-base on the adaptive movement patterns that horses adopt during water treadmill (WT) exercise, underlying adaptations in muscle activity remain uninvestigated. This feasibility study aimed to develop a method for the synchronous measurement of muscle activity and movement of horses during WT exercise. Combined surface electromyography (sEMG) (2000 Hz) from selected hindlimb (biceps femoris, gluteus medius, tensor fascia latae) and epaxial (longissimus dorsi) muscles and three-
dimensional kinematic (200 Hz) data from the back and pelvis of one (n=1) horse were collected during overground (OG), dry treadmill (TM), and WT walking conditions. Statistical parametric mapping evaluated differences in time- and amplitude-normalized sEMG and thoracolumbar and pelvis kinematic waveforms between conditions. Distinct, significant (p<0.05) adaptations in hindlimb and epaxial muscle activation patterns, as well as axial and pelvic kinematics, were observed in this horse across exercise conditions. Adaptive muscle activity was most pronounced in this horse during WT, compared to OG walking. These findings demonstrate the feasibility this method, which combines sEMG and motion capture technologies to synchronously quantify equine movement and muscle activation patterns during WT exercise. This justifies replication of this work in a larger sample of horses to inform evidence-based training and rehabilitation programmes.