Background

During everyday locomotion, we cope with various internal or external perturbations (e.g. uneven surface). Uncertainty exists on how unpredictable external perturbations increase noise within the motor system and if they are compensated by employing covariation of the limb joints or rather due to decreased sensitivity of an altered posture.

Research question

Do continuous stochastic perturbations affect the structure of gait variability in young and healthy adults?

Methods

In a cross-over study, gait kinematics of 21 healthy young sports students were registered during treadmill walking with and without continuous stochastic perturbations. Using the TNC method, the following aspects were analyzed: (a) the sensitivity of body posture to perturbations (‘tolerance’) decreasing gait variability, (b) the unstructured motor ‘noise’ increasing gait variability and (c) the amount of ‘covariation’ of the limb joints.

Results

Compared to normal walking, gait variability was significantly increased (p < .001) during walking with perturbations. The negative effect of noise was partly compensated by improved ‘covariation’ of leg joints (p < .001). The aspect ‘tolerance’ had a small effect on increasing gait variability during stance phase (p < .001) and decreasing gait variability during swing phase (p < .001).

Significance

Increased motor noise due to external perturbations is partly compensated by improved covariation of the limb joints. However, the effect of an altered posture slightly affects gait variability. Further studies should focus on different populations (e.g. older participants) to see if they use the same mechanism (improved covariation) to compensate for stochastic perturbations.

中文翻译：

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在健康的年轻人中行走时的随机时间连续扰动的补偿：步态变异性结构的分析。

背景

在日常运动中，我们应对各种内部或外部干扰（例如不平坦的表面）。不确定的外部扰动如何增加电机系统内的噪声，以及是否通过采用四肢关节的协变来补偿它们，或者是由于降低的姿势变化敏感性而存在不确定性。

研究问题

持续随机扰动会影响年轻和健康成年人的步态变异性结构吗？

方法

在一项交叉研究中，在跑步机行走过程中有或没有连续随机扰动的情况下，对21名健康的年轻体育学生的步态运动进行了记录。使用TNC方法，从以下几个方面进行了分析：（a）身体姿势对摄动的敏感性（“容忍”），降低步态变异性；（b）非结构化运动“噪声”，增加步态变异性；以及（c）“运动”量肢关节的协变”。

结果

与正常的步行相比，步行过程中的步态变异性明显增加（p <.001）。噪声的负面影响部分通过腿部关节的“协变”得到了补偿（p <.001）。方面的“容忍度”对于在站立阶段的步态变异性增加（p <.001）和在挥杆阶段的步态变异性减少（p <.001）产生很小的影响。

意义

由于外部干扰而增加的电动机噪音可通过改善肢体关节的协变部分地得到补偿。但是，姿势改变的影响会稍微影响步态的可变性。进一步的研究应针对不同的人群（例如，年龄较大的参与者），以查看他们是否使用相同的机制（改进的协方差）来补偿随机扰动。