Fast responses to stepping-target displacements when walking
Fast responses to stepping-target displacements when walking
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DOI：
10.1113/jp278986
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发表时间：
2020-03-27
影响因子：
5.5
通讯作者：
Duysens, Jacques
中科院分区：
文献类型：
--
作者：
Zhang, Yajie;Smeets, Jeroen B. J.;Duysens, Jacques
关键点目标导向的手臂运动可以在较短的潜伏期内调整到目标移动。我们测试了在步进目标移动的跑步机上行走时是否存在类似的调整。参与者在短潜伏期做出反应，对步进目标的微小移动有足够的增益。如果平衡不被破坏，行走过程中脚的移动可以以类似于目标导向手臂移动的方式进行控制。众所周知，目标导向的手运动可以根据目标位置的微小变化进行调整，潜伏期约为100ms。我们测试了当人们在平坦的地面上行走时，当脚部放置的目标位置略有变化时，他们是否会做出类似的快速调整。参与者在投射踏脚石的跑步机上以每小时3公里的速度行走。这些石头在步行方向上相距50厘米。每走5-8步，就会有一块踏脚石意外地向内侧方向移动2.5厘米。位移发生在摆动阶段的前半段。我们发现了脚部轨迹的快速调整，潜伏期约为155ms，由扰动后123ms肌肉激活的变化启动。响应对大约80%的扰动进行了修正。我们的结论是，脚的目标导向运动的控制方式与手的相似，因此也给出了非常快速的调整。
Key pointsGoal-directed arm movements can be adjusted at short latency to target shifts.We tested whether similar adjustments are present during walking on a treadmill with shifting stepping targets.Participants responded at short latency with an adequate gain to small shifts of the stepping targets.Movements of the feet during walking are controlled in a similar way to goal-directed arm movements if balance is not violated.It is well-known that goal-directed hand movements can be adjusted to small changes in target location with a latency of about 100 ms. We tested whether people make similar fast adjustments when a target location for foot placement changes slightly as they walk over a flat surface. Participants walked at 3 km/h on a treadmill on which stepping stones were projected. The stones were 50 cm apart in the walking direction. Every 5-8 steps, a stepping stone was unexpectedly displaced by 2.5 cm in the medio-lateral direction. The displacement took place during the first half of the swing phase. We found fast adjustments of the foot trajectory, with a latency of about 155 ms, initiated by changes in muscle activation 123 ms after the perturbation. The responses corrected for about 80% of the perturbation. We conclude that goal-directed movements of the foot are controlled in a similar way to those of the hand, thus also giving very fast adjustments.