Uchida Thomas K, Seth Ajay, Pouya Soha, Dembia Christopher L, Hicks Jennifer L, Delp Scott L
Department of Bioengineering, Stanford University, Stanford, California, United States of America.
Department of Mechanical Engineering, Stanford University, Stanford, California, United States of America.
PLoS One. 2016 Sep 22;11(9):e0163417. doi: 10.1371/journal.pone.0163417. eCollection 2016.
Tools have been used for millions of years to augment the capabilities of the human body, allowing us to accomplish tasks that would otherwise be difficult or impossible. Powered exoskeletons and other assistive devices are sophisticated modern tools that have restored bipedal locomotion in individuals with paraplegia and have endowed unimpaired individuals with superhuman strength. Despite these successes, designing assistive devices that reduce energy consumption during running remains a substantial challenge, in part because these devices disrupt the dynamics of a complex, finely tuned biological system. Furthermore, designers have hitherto relied primarily on experiments, which cannot report muscle-level energy consumption and are fraught with practical challenges. In this study, we use OpenSim to generate muscle-driven simulations of 10 human subjects running at 2 and 5 m/s. We then add ideal, massless assistive devices to our simulations and examine the predicted changes in muscle recruitment patterns and metabolic power consumption. Our simulations suggest that an assistive device should not necessarily apply the net joint moment generated by muscles during unassisted running, and an assistive device can reduce the activity of muscles that do not cross the assisted joint. Our results corroborate and suggest biomechanical explanations for similar effects observed by experimentalists, and can be used to form hypotheses for future experimental studies. The models, simulations, and software used in this study are freely available at simtk.org and can provide insight into assistive device design that complements experimental approaches.
数百万年来，工具一直被用于增强人体能力，使我们能够完成那些原本困难或不可能完成的任务。动力外骨骼和其他辅助设备是先进的现代工具，它们已帮助截瘫患者恢复了双足行走能力，并赋予健康人超人的力量。尽管取得了这些成功，但设计出能在跑步过程中降低能量消耗的辅助设备仍然是一项巨大挑战，部分原因在于这些设备会扰乱一个复杂且精细调节的生物系统的动力学。此外，迄今为止，设计师主要依赖实验，而实验无法报告肌肉层面的能量消耗，且充满实际挑战。在本研究中，我们使用OpenSim对10名以2米/秒和5米/秒速度跑步的人类受试者进行肌肉驱动模拟。然后，我们在模拟中添加理想的、无质量的辅助设备，并研究肌肉募集模式和代谢功率消耗的预测变化。我们的模拟表明，辅助设备不一定应施加在无辅助跑步时由肌肉产生的净关节力矩，并且辅助设备可以减少未跨过被辅助关节的肌肉的活动。我们的结果证实了实验人员观察到的类似效应，并提出了生物力学解释，还可用于为未来的实验研究形成假设。本研究中使用的模型、模拟和软件可在simtk.org上免费获取，它们能够为辅助设备设计提供补充实验方法的见解。
