Evaluation of a Neuromechanical Walking Control Model Using Disturbance Experiments.
Evaluation of a Neuromechanical Walking Control Model Using Disturbance Experiments.
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DOI：
10.3389/fncom.2017.00015
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发表时间：
2017
影响因子：
3.2
通讯作者：
Geyer H
中科院分区：
文献类型：
--
作者：
Song S;Geyer H
神经力学模拟已被用于研究脊柱对人类运动的控制，这涉及到复杂的机械动力学。到目前为止，大多数神经力学仿真研究都集中在展示所提出的控制模型在产生正常行走方面的能力。由于许多具有相互竞争的控制假设的模型可以产生类似人类的正常行走行为，因此需要进行更深入的评估。在这里，我们对基于脊椎反射的控制模型进行了更深入的评估，使用了五种典型的步态扰动，从电刺激到腿部关节和全身的机械扰动。该模型的肌肉激活的即时变化与人类不同步态阶段和干扰程度的变化进行了比较。大多数被研究的肌肉和实验条件的反应趋势非常相似，这加强了该模型反射回路的合理性。然而，在两个全身干扰的实验中，该模型的反应缺乏幅度，这表明在这些情况下，所提出的反射电路需要通过额外的控制结构来放大，例如特定位置的皮肤反射。一个捕捉到这些选择性放大的模型将能够解释人类运动的稳定和反应性脊椎控制。研究假想控制模型的神经力学模拟是步态实验的补充，可以更好地理解人类运动的控制。
Neuromechanical simulations have been used to study the spinal control of human locomotion which involves complex mechanical dynamics. So far, most neuromechanical simulation studies have focused on demonstrating the capability of a proposed control model in generating normal walking. As many of these models with competing control hypotheses can generate human-like normal walking behaviors, a more in-depth evaluation is required. Here, we conduct the more in-depth evaluation on a spinal-reflex-based control model using five representative gait disturbances, ranging from electrical stimulation to mechanical perturbation at individual leg joints and at the whole body. The immediate changes in muscle activations of the model are compared to those of humans across different gait phases and disturbance magnitudes. Remarkably similar response trends for the majority of investigated muscles and experimental conditions reinforce the plausibility of the reflex circuits of the model. However, the model's responses lack in amplitude for two experiments with whole body disturbances suggesting that in these cases the proposed reflex circuits need to be amplified by additional control structures such as location-specific cutaneous reflexes. A model that captures these selective amplifications would be able to explain both steady and reactive spinal control of human locomotion. Neuromechanical simulations that investigate hypothesized control models are complementary to gait experiments in better understanding the control of human locomotion.