The distal foot power equation is a simple yet powerful tool for estimating the power dissipation or generation within the foot even while modeling it as a rigid body. It was introduced over two decades ago, but has seen a resurgence of use in recent years. Nevertheless, the theoretical justification for this formula has thus far been limited. It is difficult to properly use any equation and interpret the results from analyses using it without a solid understanding of how it is derived as well as its underlying assumptions. In this communication, a thorough derivation of the distal foot power equation is provided first for the case where the foot is interacting with a rigid ground without sliding and then second generalized for situations when the foot may slide relative to a deformable ground surface. For the first case, the derivation makes clear that distal foot power represents the power due to the deviation of the foot from a rigid body state for the portion of the foot between its mass center (or other point of reference) and the center of pressure. For the second case, distal foot power represents not only the internal deformation power of the foot, but also the power due to sliding of the foot on the ground and the power due to deformation of the ground near the point of contact.

远侧足部力量方程式是一个简单但功能强大的工具，即使在将其建模为刚体时也可以估算足部内的功率耗散或产生。它是在20多年前推出的，但近年来却重新使用。然而，到目前为止，该公式的理论依据受到限制。如果没有扎实的理解方程式及其基本假设，就很难正确使用任何方程式并解释使用该方程式进行的分析结果。在此通信中，首先提供了足部远端力量方程式的详尽推导，其中足部在没有滑动的情况下与刚性地面相互作用，然后在足部可能相对于可变形地面滑动的情况下进行了第二泛化。对于第一种情况 该推导清楚地表明，远侧脚的力量代表了由于脚在其重心（或其他参考点）与压力中心之间的部分相对于刚体状态的偏离而导致的力量。对于第二种情况，远侧脚的力量不仅代表脚的内部变形力量，而且还代表由于脚在地面上滑动而产生的力量以及由于地面在接触点附近的变形所产生的力量。