Chapman A E, Lonergan R, Caldwell G E
Med Sci Sports Exerc. 1984 Aug;16(4):382-8.
One female sprinter was filmed at the 100-m mark (speed 6.5 m X S-1) of a 400-m run. Four moments occurring at each end of the thigh and shank segments during lower-limb recovery were calculated. These were: proximal and distal net muscle moments, a moment due to proximal joint accelerative force and, a moment due to distal joint-force resulting from motion and inertia of the distal connected segment. Individual contributions of each moment to segmental angular displacement were calculated by double integration, and angular velocity at toe-off was multiplied by time to yield its contribution. Contributions of the proximal muscle moments throughout recovery were 21 rad and 7.5 rad for the thigh and shank segments, respectively. Such large angular displacements did not occur because the three remaining moments opposed the proximal muscle moment. These large moments are mutually offsetting and interactive, acceleration of proximal joints provides a substantial moment during contralateral stance, and segmental angular velocity at toe-off is a significant contributor. Consequently, a phenomenon producing a change in any moment (e.g. muscular fatigue, slippery surface) will require modification of other moments for angular displacement to be maintained within reasonable limits.
一名女短跑运动员在400米跑的100米标记处（速度为6.5米×秒⁻¹）被拍摄。计算了下肢恢复过程中大腿和小腿段两端各出现的四个时刻。这些时刻分别是：近端和远端净肌肉力矩、由近端关节加速力产生的力矩以及由远端相连段的运动和惯性产生的远端关节力力矩。通过双重积分计算每个力矩对节段角位移的单独贡献，并将离地时的角速度乘以时间以得出其贡献。在整个恢复过程中，大腿和小腿段近端肌肉力矩的贡献分别为21弧度和7.5弧度。如此大的角位移没有出现是因为其余三个力矩与近端肌肉力矩相反。这些大的力矩相互抵消且相互作用，近端关节的加速在对侧站立期间提供了一个相当大的力矩，并且离地时的节段角速度是一个重要的贡献因素。因此，任何一个力矩发生变化的现象（例如肌肉疲劳、表面打滑）都需要对其他力矩进行调整，以便将角位移保持在合理范围内。
