Effects of different shoeing conditions on equine cervical and back kinematics during walking and trotting on a soft surface

There is a paucity of scientific data on the effect of shoeing on equine neck and back kinematics during locomotion over commonly used sand training surfaces. A better appreciation of how alterations at hoof-ground interface influence equine upper body movements is relevant for improving horse's health and performance. Our objectives were to determine the effects of different shoeing conditions on equine neck and back kinematics at walk and trot in straight line over sand. Two-dimensional kinematic video analysis was performed under seven shoeing conditions: front feet shod with aluminum shoes and hind feet with steel racehorse shoes (REFSHOD), front aluminum shoe and hind feet unshod (FORESHOD), front feet unshod and hind steel race shoes (HINDSHOD), all four feet unshod (UNSHOD), front feet shod in combination with hind egg bar shoes (hEGGBAR), hind wide toe shoes (hTOE) and hind reverse shoes (hREVERSE). Data indicated that joint angles in the cervicothoracic junction were four times more likely to be significantly affected by the shoeing condition than in the back and sacrum. FORESHOD largely modifies the kinematics in comparison to REFSHOD or UNSHOD, with respectively a 6-11±1-2° (P<0.001) increased cervicothoracic extension at walk and trot, and a 3-4±1° (P<0.05) increased thoracolumbar flexion at trot. In comparison to REFSHOD, hEGGBAR, hTOE and hREVERSE induce a 5-7±1-2° (P<0.05) increased cervicothoracic extension at trot and walk respectively, and UNSHOD induced cervicothoracic flexion at trot (6±2°, P<0.05). In conclusion, shoeing conditions impact equine neck and back position, which should be considered during clinical examination, rehabilitation and training.