Clayton H M
Department of Veterinary Anatomy, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
Equine Vet J Suppl. 1990 Jun(9):91-4. doi: 10.1111/j.2042-3306.1990.tb04743.x.
High speed cinematography was used to measure the timing and distance characteristics of the trot in five sound horses. Two farriery treatments were compared: (1) normal, in which the dorsal hoof wall was aligned with the pastern axis in all four feet and (2) acute hind hoof angulation, in which the hind toes were allowed to grow relatively longer than the heels, so that the angulation was approximately 10 degrees lower than the normal hind hoof angle for the individual animal. Comparison between the two treatments showed that the acute hind hoof angulation was associated with significant increases in hind limb breakover time (P = 0.001), overreach distance (P = 0.001) and overreach duration (P = 0.017), whereas stride length, forelimb breakover and diagonal distance did not change (P > 0.05). In the majority of horses, limb movements at the start and end of the diagonal stance phase were slightly asynchronous, so that when the hooves were trimmed normally the hind limb more often preceded the diagonal forelimb at impact and lift off. The prolongation of hind limb breakover due to the acute hind hoof angulation was associated with a tendency for the hind limb to lift off later than the forelimb. The difference in lift off sequence between the two farriery treatments was highly significant (P = 0.001). During the swing phase the normal coordination was restored and there was no significant difference in the impact sequence with the normal and acute hind hoof angulations (P > 0.05).
采用高速摄影技术测量了5匹健康马匹小跑时的时间和距离特征。比较了两种蹄铁处理方式：（1）正常处理，即四蹄的背侧蹄壁均与系部轴线对齐；（2）后蹄急性成角处理，即后蹄趾部相对足跟生长得更长，使得后蹄角度比个体动物的正常后蹄角度低约10度。两种处理方式的比较表明，后蹄急性成角与后肢越过时间显著增加（P = 0.001）、前踏距离显著增加（P = 0.001）和前踏持续时间显著增加（P = 0.017）相关，而步幅、前肢越过和对角距离没有变化（P > 0.05）。在大多数马匹中，对角站立阶段开始和结束时的肢体运动略有不同步，因此当蹄子正常修剪时，后肢在着地和离地时比对角前肢更常先着地。后蹄急性成角导致的后肢越过时间延长与后肢比前肢离地更晚的趋势相关。两种蹄铁处理方式在离地顺序上的差异非常显著（P = 0.001）。在摆动阶段，正常的协调性得以恢复，正常和后蹄急性成角情况下的着地顺序没有显著差异（P > 0.05）。
