Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, MN, USA; Program in Physical Therapy, Mayo Clinic School of Health Sciences, Mayo Clinic College of Medicine and Science, Rochester, MN, USA.
Department of Physical Medicine & Rehabilitation, Mayo Clinic, Rochester, MN, USA; Neurologic Physical Therapy Residency Program, Mayo Clinic School of Health Sciences, Mayo Clinic College of Medicine and Science, Rochester, MN, USA.
Gait Posture. 2020 Mar;77:195-200. doi: 10.1016/j.gaitpost.2020.02.005. Epub 2020 Feb 5.
Treadmill training may be used to improve gait rhythmicity in people with Parkinson's disease. Treadmills, however, alter dynamical stride time fluctuations in healthy adults in a manner that mimics pathologic states, indicating the stride-to-stride fluctuations that characterize healthy gait are constrained. It is unclear if treadmills similarly alter dynamic gait properties in Parkinson's disease.
Do stride time fractal dynamics in individuals with Parkinson's disease differ between treadmill and overground walking?
Fifteen participants with Parkinson's disease and 15 healthy age-similar adults walked for 6 min in a conventional overground condition and on a treadmill while wearing inertial measurement units. Gait speed, stride times and stride time variability were measured. Fractal exponents (α) were computed with adaptive fractal analysis. Inferential statistics were analyzed with mixed model analyses of variance and post hoc simple effects tests.
Mean gait speeds decreased and stride times increased on the treadmill but did not differ between the Parkinson's and control groups. Stride time variability was greater in the Parkinson's than control group in both conditions. Most relevant to our research question, stride time fractal exponents were greater on the treadmill (mean α = .910) than overground (mean α = .797) in individuals with Parkinson's disease, but not in healthy controls.
The fractal scaling exponent α emanating from stride time fluctuations during treadmill walking increased toward a 1/f signal of α = 1.0 that has been interpreted as an optimal structural variability for gait. The clinical implication is that treadmill training may promote more efficient walking dynamics in people with Parkinson's disease than conventional overground training.
跑步机训练可用于改善帕金森病患者的步态节律性。然而，跑步机以模拟病理状态的方式改变健康成年人的动力学步时波动，表明健康步态的步与步波动受到限制。目前尚不清楚跑步机是否以类似的方式改变帕金森病患者的动态步态特征。
帕金森病患者在跑步机和地面行走时的步时分形动力学是否存在差异？
15 名帕金森病患者和 15 名年龄匹配的健康成年人在常规地面条件和跑步机上分别佩戴惯性测量单元行走 6 分钟。测量步态速度、步时和步时变异性。使用自适应分形分析计算分形指数（α）。推断统计采用混合模型方差分析和事后简单效应检验进行分析。
跑步机上的平均步态速度降低，步时增加，但帕金森病组和对照组之间没有差异。在两种情况下，帕金森病组的步时变异性均大于对照组。与我们的研究问题最相关的是，帕金森病患者在跑步机上的步时分形指数（平均α=0.910）大于地面上的步时分形指数（平均α=0.797），而健康对照组则没有。
跑步机行走时步时波动产生的分形标度指数α朝着 1/f 信号的α=1.0 增加，这被解释为步态的最佳结构可变性。临床意义是，与传统的地面训练相比，跑步机训练可能会促进帕金森病患者更有效的步行动力学。
