Water and speed affect upper body kinematics and limb timing in horses walking on a water treadmill

Abstract

This study aimed to describe upper body movement and limb timing in horses walking on a dry treadmill (DT) and water treadmill (WT) at incremental belt speeds. Upper body vertical range of motion (ROMz) and limb timing variables of twelve owner sound Warmblood horses were collected on a DT and WT. Water was set at the height of 30 cm and horses were measured at five different speeds (0.9-1.2 m/s) using ten IMU sensors (EquiMoves®, 200 Hz) attached to the head, withers, 15th thoracic vertebra, tuber sacrale, both tuber coxae and mid-lateral aspect of the cannon bones. Linear mixed models were used, with horses as random effect and the interaction of speed with treadmill condition (DT/WT) as fixed effects. Significance was set at P