Faster top running speeds are achieved with greater ground forces not more rapid leg movements
Faster top running speeds are achieved with greater ground forces not more rapid leg movements
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DOI：
10.1152/jappl.2000.89.5.1991
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发表时间：
2000-11-01
影响因子：
3.3
通讯作者：
Wright, S
中科院分区：
文献类型：
--
作者：
Weyand, PG;Sternlight, DB;Wright, S
我们两次测试了这样的假设：最高跑步速度是由施加在地面上的力的大小决定的，而不是四肢在空中重新定位的速度。首先，我们比较了 33 名不同冲刺能力的受试者在水平跑步机上以最高速度跑步的力学情况。其次，我们比较了五个受试者在下降（-6 度）和倾斜（+9 度）最高速度跑步机上跑步的力学原理。对于这两项测试，我们使用安装在跑步机上的测力台来测量同一只脚的站立周期之间的时间（摆动时间，t(SW)）以及以最高速度施加到跑步表面的力。为了获得与速度相关的力，将垂直于地面施加的力除以身体重量 (W-b)，并在脚与地面接触期间取平均值 (F-avge/W-b)。完成水平跑步机方案的 33 名受试者的最高速度范围为 6.2 至 11.1 m/s，达到了 1.8 倍。在这些受试者中，F-avge/W-b 对最高速度的回归表明，最高速度为 11.1 的跑步者与 6.2 m/s 的跑步者相比，该力大 1.26 倍。相比之下，将肢体摆动到下一步位置所需的时间 (t(SW)) 没有变化 (P = 0.18)。下降和倾斜最高速度相差 1.4 倍（分别为 9.96 +/- 0.3 与 7.10 +/- 0.3 m/s），通过特定质量支撑力实现的更快下降最高速度为 1.3 倍（2.30 +/- 0.06 与 1.76 +/- 0.04 F-avge/W-b），并且最小 t(SW) 相似（+8%）。我们得出的结论是，人类跑步者达到更快的最高速度并不是通过在空中更快地重新定位四肢，而是通过对地面施加更大的支撑力。
We twice tested the hypothesis that top running speeds are determined by the amount of force applied to the ground rather than how rapidly limbs are repositioned in the air. First, we compared the mechanics of 33 subjects of different sprinting abilities running at their top speeds on a level treadmill. Second, we compared the mechanics of declined (-6 degrees) and inclined (+9 degrees) top-speed treadmill running in five subjects. For both tests, we used a treadmill-mounted force plate to measure the time between stance periods of the same foot (swing time, t(SW)) and the force applied to the running surface at top speed. To obtain the force relevant for speed, the force applied normal to the ground was divided by the weight of the body (W-b) and averaged over the period of foot-ground contact (F-avge/W-b). The top speeds of the 33 subjects who completed the level treadmill protocol spanned a 1.8-fold range from 6.2 to 11.1 m/s. Among these subjects, the regression of F-avge/W-b on top speed indicated that this force was 1.26 times greater for a runner with a top speed of 11.1 vs. 6.2 m/s. In contrast, the time taken to swing the limb into position for the next step (t(SW)) did not vary (P = 0.18). Declined and inclined top speeds differed by 1.4-fold (9.96 +/- 0.3 vs. 7.10 +/- 0.3 m/s, respectively), with the faster declined top speeds being achieved with mass-specific support forces hat were 1.3 times greater (2.30 +/- 0.06 vs. 1.76 +/- 0.04 F-avge/W-b) and minimum t(SW) that were similar (+8%). We conclude that human runners reach faster top speeds not by repositioning their limbs more rapidly in the air, but by applying greater support forces to the ground.