Back kinematics at take-off in elite showjumping horses over an upright and parallel-spread fence forming part of a three-fence combination

The objective of this study was to evaluate head, neck and back kinematics during take-off in elite level horses jumping, and to compare these over an upright and parallel spread fence. Ten mixed-breed elite-level showjumping horses were opportunistically evaluated jumping the same 15-fence course (1.35 m) during a British Equestrian Federation World Class Performance three-day training session. Two fences were evaluated using high-speed motion-capture (250 Hz). Head, neck and back kinematics of the horse were determined at take-off, at vertical orientation of leading and trailing third metacarpus/tarsus and as the trailing hindlimb left the floor. Very consistent patterns between all horses over both upright and spread fences were observed in neck-trunk (NT) angle, lumbosacral (LS) angle, the angle of the thoracolumbar (TL) to horizontal and of LS to horizontal. Head-neck (HN), TL angle and distance to fence showed moderate variation between horses. There were no significant differences between fence-typ...