Estimation of human ankle impedance during the stance phase of walking.
Estimation of human ankle impedance during the stance phase of walking.
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DOI：
10.1109/tnsre.2014.2307256
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发表时间：
2014-07
期刊：
影响因子：
--
通讯作者：
Kuiken TA
中科院分区：
文献类型：
--
作者：
Rouse EJ;Hargrove LJ;Perreault EJ;Kuiken TA
人体关节阻抗是受扰关节位置的差动变化与相应的响应扭矩之间的动态关系；它是支配人类如何与环境交互的基本属性。研究步态阶段的踝关节阻抗特性，对于阐明踝关节阻抗在运动过程中的调节，以及为未来天然仿生动力型假肢及其控制系统的发展奠定基础是至关重要的。在这项研究中，脚踝阻抗是使用一个由刚度、阻尼和惯性组成的模型来估计的。模型能很好地描述踝关节扭矩，其贡献率为98±1.2%。当受试者平均时，阻抗的刚度分量在站立时相的20%到70%之间线性增加，从1.5Nm/rad/kg增加到6.5Nm/rad/kg。结果表明，只有在70%的站立相时，阻尼值才统计上大于零，其值为0.03nms/rad/kg。踝关节扭矩-角度曲线的斜率--即所谓的准刚度--与踝关节刚性值在统计学上没有差别，表现出显著的相似性。最后，利用估算的阻抗，介绍了能够准确模拟人体踝关节运动阻抗的仿生动力型踝关节假体的技术指标。
Human joint impedance is the dynamic relationship between the differential change in the position of a perturbed joint and the corresponding response torque; it is a fundamental property that governs how humans interact with their environments. It is critical to characterize ankle impedance during the stance phase of walking to elucidate how ankle impedance is regulated during locomotion, as well as provide the foundation for future development of natural, biomimetic powered prostheses and their control systems. In this study, ankle impedance was estimated using a model consisting of stiffness, damping and inertia. Ankle torque was well described by the model, accounting for 98 ± 1.2% of the variance. When averaged across subjects, the stiffness component of impedance was found to increase linearly from 1.5 Nm/rad/kg to 6.5 Nm/rad/kg between 20% and 70% of stance phase. The damping component was found to be statistically greater than zero only for the estimate at 70% of stance phase, with a value of 0.03 Nms/rad/kg. The slope of the ankle’s torque-angle curve—known as the quasi-stiffness—was not statistically different from the ankle stiffness values, and showed remarkable similarity. Finally, using the estimated impedance, the specifications for a biomimetic powered ankle prosthesis were introduced that would accurately emulate human ankle impedance during locomotion.