Step kinematic variability, which has been associated with gait-related fall risk, is thought to be attributed to neuromotor noise. Altered neuromotor control of step kinematics would be expected to manifest as changes in the noise-related characteristics of the step kinematic time series. This study determined the effects of eliminating feedback from the lower visual field and reducing treadmill-belt width on the noise characteristics of step width time series and statistical measures of step width variability during treadmill walking. We hypothesized that eliminating feedback from the lower visual field and reducing treadmill-belt width would both alter the noise characteristics of step width time series, reflected by decreased fractal scaling, and increase statistical measures of step width variability. Eighteen young adults performed four randomly ordered walking trials during which we manipulated visual feedback from the lower visual field (normal and obstructed) and treadmill-belt width (wide and narrow). Reducing treadmill-belt width, but not eliminating feedback from the lower visual field, significantly reduced the fractal scaling of step width time series, indicating a shift towards white, uncorrelated noise. These results suggest that accounting for the influence of treadmill-belt width on step width time series may be an important consideration in both laboratory and clinical settings. Further work is needed to clarify the effects of vision on measures of step width, identify the mechanism(s) underlying the observed shift towards white, uncorrelated noise associated with reduced treadmill-belt width, and to assess the potential relationship between the noise characteristics of step width time series and fall risk.

步态运动变异性与步态相关的跌倒风险有关，被认为归因于神经运动噪声。步进运动学的神经运动控制发生变化，将有望表现为步进运动时间序列的噪声相关特征的变化。这项研究确定了消除来自较低视野的反馈并减小跑步机皮带宽度对踏步时间序列的噪声特征以及踏步机行走过程中步幅变异性的统计测量的影响。我们假设消除来自较低视野的反馈并减小跑步机皮带的宽度都将改变步长时间序列的噪声特征（由减少的分形缩放反映），并增加步长可变性的统计度量。18名年轻人进行了4次随机排序的步行试验，在这些试验中，我们操纵了下部视野（正常和受阻）和跑步机皮带宽度（宽和窄）的视觉反馈。减小跑步机皮带的宽度，但并不能消除来自较低视野的反馈，显着减小了步长时间序列的分形缩放比例，表明已向不相关的白色噪声转移。这些结果表明，考虑跑步机皮带宽度对步长时间序列的影响可能是实验室和临床环境中的重要考虑因素。需要做进一步的工作来阐明视觉对步幅测量的影响，确定观察到的向白色，与跑步机皮带宽度减小相关的不相关噪声的转变所基于的机制。