狗或许是人类最好的朋友，但是当提到竞赛，我们却与马有更多的共同点。
通过测量马匹在两场马球比赛和56场赛马中的位置和速度，研究人员发现，与人类一样，马匹在进入一个弯道时也会减速。当转弯时，所有动物都需要产生一个与其前进运动成直角的作用力。否则它们便会向外滑倒。狗会将这种力转移到它们的前腿，留下自由的后腿继续为它们的前进运动提供动力。但是与人类一样，马无法将它们的重量从全部4条腿上卸掉；通过让马蹄在地面上停留更长的时间，马匹用附加的力进行了补偿。研究小组在日前的英国《皇家学会学报B》网络版上报告说，这一过程产生了摩擦力，并减缓了动物的速度。如果一匹马想要跑得更快，那么它必须要抄近道。（生物谷Bioon.com）
生物谷推荐原文出处：
Proc. R. Soc. B. doi: 10.1098/rspb.2010.2395
Grip and limb force limits to turning performance in competition horses
Huiling Tan and Alan M. Wilson
Abstract
Manoeuverability is a key requirement for successful terrestrial locomotion, especially on variable terrain, and is a deciding factor in predator–prey interaction. Compared with straight-line running, bend running requires additional leg force to generate centripetal acceleration. In humans, this results in a reduction in maximum speed during bend running and a published model assuming maximum limb force as a constraint accurately predicts how much a sprinter must slow down on a bend given his maximum straight-line speed. In contrast, greyhounds do not slow down or change stride parameters during bend running, which suggests that their limbs can apply the additional force for this manoeuvre. We collected horizontal speed and angular velocity of heading of horses while they turned in different scenarios during competitive polo and horse racing. The data were used to evaluate the limits of turning performance. During high-speed turns of large radius horizontal speed was lower on the bend, as would be predicted from a model assuming a limb force limit to running speed. During small radius turns the angular velocity of heading decreased with increasing speed in a manner consistent with the coefficient of friction of the hoof–surface interaction setting the limit to centripetal force to avoid slipping.
