Ker R F, Bennett M B, Alexander R M, Kester R C
Proc Inst Mech Eng H. 1989;203(4):191-6. doi: 10.1243/PIME_PROC_1989_203_038_01.
Many force-plate records of human locomotion show an impulse (the foot strike) shortly after ground contact. The authors' hypothesis is that this results from the rapid deceleration of a mass (the 'effective foot') under forces which compress the heel pad. The quantitative implications are investigated through an illustrative calculation. The observations used are (a) the peak force reached in foot strike (b) the vertical velocity of the foot immediately before ground contact and (c) the properties of the heel pad in compression. Data for (a) and (b) are available in the literature; measurements for (c) are presented here. The deductions are: (a) the time taken to reach peak force is about 5.4 ms, which agrees with published measurements; (b) the mass of the effective foot is about 3.6 kg. The effective foot thus includes a substantial portion of the leg: this seems reasonable. The models used for the calculations clarify the relationship between the foot strike and the shock wave, which it generates.
许多人类运动的测力板记录显示，在与地面接触后不久会出现一个冲量（即脚着地）。作者的假设是，这是由于在压缩脚跟垫的力作用下，一个质量体（“有效足部”）快速减速所致。通过一个示例计算来研究其定量影响。所使用的观测数据包括：(a) 脚着地时达到的峰值力；(b) 脚在刚接触地面之前的垂直速度；以及 (c) 压缩状态下脚跟垫的特性。(a) 和 (b) 的数据可在文献中获取；(c) 的测量数据在此给出。推断结果为：(a) 达到峰值力所需的时间约为5.4毫秒，这与已发表的测量结果相符；(b) 有效足部的质量约为3.6千克。因此，有效足部包括腿部的很大一部分：这似乎是合理的。用于计算的模型阐明了脚着地与它所产生的冲击波之间的关系。
