Whitton Shoeing Study

Background: Hoof trimming and shoeing techniques are used to manage and prevent equine limb injuries. However, quantitative studies comparing the effects of different shoeing techniques on equine joint biomechanics over the full gait cycle are lacking. Objectives: To measure and compare joint motion and net torques at the distal forelimb joints when horses walk overground unshod, with a standard flat shoe, and with a rocker shoe. Study design: In vivo study. Methods: Gait data were recorded from 12 sound horses during walking. Three shoeing conditions were tested: unshod, flat shoe, and rocker shoe. Data were recorded for each shoeing condition immediately after trimming (short hoof condition) and again after 6 weeks of hoof growth (long hoof condition). Three-dimensional motion capture and retro-reflective skin markers recorded left forelimb motion, while synchronised force plates measured the corresponding ground reaction force. Inverse dynamics was used to calculate the net torques developed about the distal forelimb joints. Statistical comparisons were performed with multilevel mixed effects generalised linear models. Results: While there were limited effects of trimming and shoeing, the rocker shoe was associated with higher walking speed (by 9.3±9.7%) and reduced stride duration (by 4.9±6.9%) compared with the flat shoe for the short hoof condition (P<0.001). Throughout the stride cycle, the fetlock joint was less extended (by 9.0±13.7°) while the distal interphalangeal joint (DIPJ) was more extended (by 10.7±16.6°) for both shoeing types compared to unshod regardless of hoof growth (P<0.005). Higher peak torques were generated at the DIPJ for flat shoe compared to unshod (by 0.05±0.27 Nm/kg) in the short hoof condition, and for flat shoe compared to rocker shoe (by 0.03±0.14 Nm/kg) in the long hoof condition (P<0.05 for both). Limitations: The horses were tested at a low-speed walking gait. Conclusions: Forelimb joint biomechanics did not differ substantially across the three shoeing and two hoof-growth conditions. Future studies should test the robustness of these findings at the trot and canter.

背景：马蹄修削与装蹄技术常用于管理和预防马肢损伤，但目前尚缺乏定量研究，对比不同装蹄技术在完整步态周期内对马关节生物力学的影响。
研究目的：本研究旨在测量并对比马匹在无蹄铁、标准平蹄铁以及弧形蹄铁（rocker shoe）三种状态下，平地行走时前肢远端关节的关节运动与净扭矩。
研究设计：体内实验（in vivo study）。
方法：招募12匹健康马，记录其行走时的步态数据。测试三种装蹄状态：无蹄铁、平蹄铁（flat shoe）以及弧形蹄铁（rocker shoe）。每种装蹄状态分别在修蹄后即刻（短蹄状态）以及蹄甲生长6周后（长蹄状态）进行数据采集。采用三维运动捕捉系统与逆向反射皮肤标记物记录左前肢运动，同时通过同步测力板测量对应的地面反作用力。使用逆动力学（inverse dynamics）法计算前肢远端关节的净扭矩。采用多水平混合效应广义线性模型进行统计学比较。
结果：尽管修蹄与装蹄的影响较为有限，但在短蹄状态下，弧形蹄铁相较于平蹄铁可使行走速度提升9.3%±9.7%，并缩短步幅时长4.9%±6.9%（P<0.001）。无论蹄甲生长状态如何，相较于无蹄铁状态，两种装蹄方式下的球节（fetlock joint）屈曲程度更低（伸展角度减少9.0°±13.7°），而远指关节（distal interphalangeal joint, DIPJ）的伸展程度更高（伸展角度增加10.7°±16.6°）（P<0.005）。在短蹄状态下，平蹄铁组远指关节的峰值扭矩较无蹄铁组更高（高出0.05±0.27 N·m/kg）；在长蹄状态下，平蹄铁组远指关节的峰值扭矩较弧形蹄铁组更高（高出0.03±0.14 N·m/kg）（两组均P<0.05）。
局限性：本研究仅在低速行走步态下对马匹进行了测试。
结论：三种装蹄状态与两种蹄甲生长状态下，前肢关节生物力学特征无显著差异。未来研究应在快步（trot）与跑步（canter）步态下验证本研究结果的稳健性。