Treadmill vs. overground walking: different response to physical interaction
Treadmill vs. overground walking: different response to physical interaction
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DOI：
10.1152/jn.00176.2017
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发表时间：
2017-10-01
影响因子：
2.5
通讯作者：
Hogan, Neville
中科院分区：
文献类型：
--
作者：
Ochoa, Julieth;Sternad, Dagmar;Hogan, Neville
人类运动功能的康复是一个日益重要的问题，人机交互机器人提供了有前途的潜力，以满足需要。然而，对于下肢，机器人辅助治疗已被证明具有挑战性。为了告知机器人步态治疗的有效方法，重要的是要更好地了解未受损的运动控制：其对不同机械环境的敏感性及其对扰动的反应。本研究评估了14名健康受试者的行为，他们穿着外骨骼踝关节机器人在电动跑步机和地上行走。他们对一系列周期性踝关节跖屈扭矩脉冲的反应进行了评估，以确定是否发生步态夹带，它如何在不同的条件下不同，以及适应运动行为是否在扰动后持续存在。运动控制的某些方面对行走环境非常敏感，而其他方面则不然。在地上行走过程中，步态更频繁，更迅速地夹带，然而，在所有情况下，夹带步态同步的扭矩脉冲与踝关节蹬离，在那里他们提供了协助推进。此外，受试者夹带到扰动期间，需要适应较慢的节奏，即使脉冲采取行动加速步态，表明神经适应运动控制。最后，在15扰动后的步伐，夹带步态期间观察到持续更频繁地在地上行走。这种持续性与在夹带步态期行走的步幅数相关（即，更长的暴露时间），这也表明了一种神经适应。新&值得注意的是，我们表明，人类运动对物理相互作用的反应在跑步机和地上行走之间是不同的。受试者被一系列周期性的踝关节跖屈扭矩脉冲所吸引，这些脉冲改变了他们的步态节奏，使踝关节蹬离与脉冲同步（以便它们辅助推进），即使步态节奏减慢。夹带是更快的地上，并在去除扭矩脉冲，夹带步态期间持续更突出地上，表明运动控制的神经适应。
Rehabilitation of human motor function is an issue of growing significance, and human-interactive robots offer promising potential to meet the need. For the lower extremity, however, robot-aided therapy has proven challenging. To inform effective approaches to robotic gait therapy, it is important to better understand unimpaired locomotor control: its sensitivity to different mechanical contexts and its response to perturbations. The present study evaluated the behavior of 14 healthy subjects who walked on a motorized treadmill and overground while wearing an exoskeletal ankle robot. Their response to a periodic series of ankle plantar flexion torque pulses, delivered at periods different from, but sufficiently close to, their preferred stride cadence, was assessed to determine whether gait entrainment occurred, how it differed across conditions, and if the adapted motor behavior persisted after perturbation. Certain aspects of locomotor control were exquisitely sensitive to walking context, while others were not. Gaits entrained more often and more rapidly during overground walking, yet, in all cases, entrained gaits synchronized the torque pulses with ankle push-off, where they provided assistance with propulsion. Furthermore, subjects entrained to perturbation periods that required an adaption toward slower cadence, even though the pulses acted to accelerate gait, indicating a neural adaptation of locomotor control. Lastly, during 15 post-perturbation strides, the entrained gait period was observed to persist more frequently during overground walking. This persistence was correlated with the number of strides walked at the entrained gait period (i.e., longer exposure), which also indicated a neural adaptation.NEW & NOTEWORTHYWe show that the response of human locomotion to physical interaction differs between treadmill and overground walking. Subjects entrained to a periodic series of ankle plantar flexion torque pulses that shifted their gait cadence, synchronizing ankle push-off with the pulses (so that they assisted propulsion) even when gait cadence slowed. Entrainment was faster overground and, on removal of torque pulses, the entrained gait period persisted more prominently overground, indicating a neural adaptation of locomotor control.