A model-experiment comparison of system dynamics for human walking and running
A model-experiment comparison of system dynamics for human walking and running
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DOI：
10.1016/j.jtbi.2011.09.021
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发表时间：
2012-01-07
影响因子：
2
通讯作者：
Seyfarth, Andre
中科院分区：
文献类型：
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作者：
Lipfert, Susanne W.;Guenther, Michael;Seyfarth, Andre
人类肌肉骨骼系统非常复杂，因此很难确定双足运动的基本原理。为了应对这一挑战，一种常见的方法是消除复杂性并制定简化模型。非常简单，双足弹簧质量模型可以很好地预测人类步态动力学，但是，尚未充分研究模型与人体在较宽速度范围内随步行和跑步时间的质心运动是否具有可比性。为了测试模型在这方面的能力，我们比较了速度范围从 0.5 m/s 到 4 m/s 的模型和人体数据的矢状质心轨迹。为了进行模拟，系统参数和初始条件是从 28 名受试者的实验观察中提取的。腿部参数刚度和长度是从受试者腿部力-长度曲线的功能拟合中提取的。通过腿部触地角度和顶点质心垂直位置的微小变化，我们成功地进行了中等步行和中等跑步速度的弹簧质量模拟。对矢状质心轨迹和地面反作用力的预测很好，但它们的幅度被高估，而接触时间被低估。在较快的步行速度和较慢的跑步速度下，我们没有发现在允许的参数变化范围内成功的模型运动。我们的结论是，可以通过增加模型的复杂性来改善现有的限制。 (C) 2011 Elsevier Ltd. 保留所有权利。
The human musculo-skeletal system comprises high complexity which makes it difficult to identify underlying basic principles of bipedal locomotion. To tackle this challenge, a common approach is to strip away complexity and formulate a reductive model. With utter simplicity a bipedal spring-mass model gives good predictions of the human gait dynamics, however, it has not been fully investigated whether center of mass motion over time of walking and running is comparable between the model and the human body over a wide range of speed. To test the model's ability in this respect, we compare sagittal center of mass trajectories of model and human data for speeds ranging from 0.5 m/s to 4 m/s. For simulations, system parameters and initial conditions are extracted from experimental observations of 28 subjects. The leg parameters stiffness and length are extracted from functional fitting to the subjects' leg force-length curves. With small variations of the touch-down angle of the leg and the vertical position of the center of mass at apex, we find successful spring-mass simulations for moderate walking and medium running speeds. Predictions of the sagittal center of mass trajectories and ground reaction forces are good, but their amplitudes are overestimated, while contact time is underestimated. At faster walking speeds and slower running speeds we do not find successful model locomotion with the extent of allowed parameter variation. We conclude that the existing limitations may be improved by adding complexity to the model. (C) 2011 Elsevier Ltd. All rights reserved.