FORCE PLATFORMS AS ERGOMETERS
FORCE PLATFORMS AS ERGOMETERS
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DOI：
10.1152/jappl.1975.39.1.174
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发表时间：
1975-01-01
影响因子：
3.3
通讯作者：
CAVAGNA, GA
中科院分区：
文献类型：
--
作者：
CAVAGNA, GA
即使整个步幅的平均速度保持恒定，在水平面上行走和跑步也会涉及外部机械功。这项工作必须由肌肉来完成，以在步幅的某些部分加速和/或提高身体的质心，以补充在步幅的其他部分期间身体减慢和/或跌倒时损失的能量。外部功可以通过测力板进行相当近似的测量，测力板记录身体在整个跨步中施加到地面的合力的水平和垂直分量。水平力和垂直力减去体重以电子方式积分，以确定每个平面的瞬时速度。这些速度的平方并乘以质量的二分之一即可产生瞬时动能。势能的变化是通过将垂直速度作为时间的函数积分以产生垂直位移并将其乘以体重来计算的。作为时间函数的总机械能是通过添加瞬时动能和势能获得的。正外部机械功是通过将整数步幅上的总机械能增量相加而获得的。
Walking and running on the level involves external mechanical work, even when speed averaged over a complete stride remains constant. This work must be performed by the muscles to accelerate and/or raise the center of mass of the body during parts of the stride, replacing energy which is lost as the body slows and/or falls during other parts of the stride. External work can be measured with fair approximation by means of a force plate, which records the horizontal and vertical components of the resultant force applied by the body to the ground over a complete stride. The horizontal force and the vertical force minus the body weight are integrated electronically to determine the instantaneous velocity in each plane. These velocities are squared and multiplied by one-half the mass to yield the instantaneous kinetic energy. The change in potential energy is calculated by integrating vertical velocity as a function of time to yield vertical displacement and multiplying this by body weight. The total mechanical energy as a function of time is obtained by adding the instantaneous kinetic and potential energies. The positive external mechanical work is obtained by adding the increments in total mechanical energy over an integral number of strides.