Qu Xingda, Nussbaum Maury A, Madigan Michael L
Department of Industrial and Systems Engineering, Virginia Tech, Blacksburg, VA 24061, USA.
J Biomech. 2007;40(16):3590-7. doi: 10.1016/j.jbiomech.2007.06.003. Epub 2007 Jul 12.
Models of balance control can aid in understanding the mechanisms by which humans maintain balance. A balance control model of quiet upright stance based on an optimal control strategy is presented here. In this model, the human body was represented by a simple single-segment inverted pendulum during upright stance, and the neural controller was assumed to be an optimal controller that generates ankle control torques according to a certain performance criterion. This performance criterion was defined by several physical quantities relevant to sway. In order to accurately simulate existing experimental data, an optimization procedure was used to specify the set of model parameters to minimize the scalar error between experimental and simulated sway measures. Thirty-two independent simulations were performed for both younger and older adults. The model's capabilities, in terms of reflecting sway behaviors and identifying aging effects, were then analyzed based on the simulation results. The model was able to accurately predict center-of-pressure-based sway measures, and identify potential changes in balance control mechanisms caused by aging. Correlations between sway measures and model parameters are also discussed.
平衡控制模型有助于理解人类维持平衡的机制。本文提出了一种基于最优控制策略的安静直立姿势平衡控制模型。在该模型中，人体在直立姿势时由一个简单的单节段倒立摆表示，并且神经控制器被假定为一个最优控制器，它根据特定的性能标准生成踝关节控制扭矩。该性能标准由几个与摆动相关的物理量定义。为了准确模拟现有的实验数据，使用了一种优化程序来指定模型参数集，以最小化实验和模拟摆动测量之间的标量误差。对年轻人和老年人都进行了32次独立模拟。然后根据模拟结果分析了该模型在反映摆动行为和识别衰老效应方面的能力。该模型能够准确预测基于压力中心的摆动测量，并识别由衰老引起的平衡控制机制的潜在变化。还讨论了摆动测量与模型参数之间的相关性。
