School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Australia.
Sport and Health Sciences, University of Exeter, Exeter, United Kingdom.
Sci Rep. 2018 Jul 12;8(1):10576. doi: 10.1038/s41598-018-28946-1.
The human foot contains passive elastic tissues that have spring-like qualities, storing and returning mechanical energy and other tissues that behave as dampers, dissipating energy. Additionally the intrinsic and extrinsic foot muscles have the capacity to act as dampers and motors, dissipating and generating mechanical energy. It remains unknown as to how the contribution of all passive and active tissues combine to produce the overall energetic function of the foot during running. Therefore, the aim of this study was to determine if the foot behaves globally as an active spring-damper during running. Fourteen participants ran on a force-instrumented treadmill at 2.2 ms, 3.3 ms and 4.4 ms, while foot segment motion was collected simultaneously with kinetic measurements. A unified deformable segment model was applied to quantify the instantaneous power of the foot segment during ground contact and mechanical work was calculated by integrating the foot power data. At all running speeds, the foot absorbed energy from early stance through to mid-stance and subsequently returned/generated a proportion of this energy in late stance. The magnitude of negative work performed increased with running speed, while the magnitude of positive work remained relatively constant across all running speeds. The proportion of energy dissipated relative to that absorbed (foot dissipation-ratio) was always greater than zero and increased with running speed, suggesting that the foot behaves as a viscous spring-damper.
人的脚包含具有弹性的被动组织，具有类似弹簧的特性，可以储存和返回机械能，还有一些组织起到阻尼器的作用，可以耗散能量。此外，内在和外在的脚部肌肉也具有作为阻尼器和发动机的能力，可以耗散和产生机械能。目前还不清楚所有的被动和主动组织的贡献如何结合起来，在跑步过程中产生脚部的整体能量功能。因此，本研究的目的是确定在跑步过程中，脚部是否整体表现为主动的弹簧-阻尼器。14 名参与者在 2.2ms、3.3ms 和 4.4ms 的速度下在测力跑步机上跑步，同时收集脚部节段运动和动力学测量数据。应用统一的可变形节段模型来量化脚部节段在地面接触期间的瞬时功率，并通过整合脚部功率数据来计算机械功。在所有跑步速度下，脚部从早期支撑阶段到中期支撑阶段吸收能量，随后在后期支撑阶段部分地返回/产生能量。负功的幅度随着跑步速度的增加而增加，而正功的幅度在所有跑步速度下保持相对恒定。与吸收的能量相比（脚部耗散比），耗散的能量比例总是大于零，并随着跑步速度的增加而增加，这表明脚部表现为粘性弹簧-阻尼器。
