Bloorview Research Institute, Toronto, ON, Canada.
Gait Posture. 2010 Mar;31(3):336-40. doi: 10.1016/j.gaitpost.2009.12.002. Epub 2010 Jan 13.
Stride interval series exhibit statistical persistence, and detrended fluctuation analysis (DFA) is a routinely employed technique for describing this behavior. However, the implementation of DFA to gait data varies considerably between studies. We empirically examine two practical aspects of DFA which significantly affect the analysis outcome: the box size range and the stride interval series length. We conduct an analysis of their effect using stride intervals from 16 able-bodied adults, for overground walking, treadmill walking while holding a handrail, and treadmill walking without using a handrail. Our goal is to provide general guidelines for these two choices, with the aim of standardizing the application of DFA and facilitating inter-study comparisons. Based on the results of our analysis, we propose the use of box sizes from 16 to N/9, where N is the number of stride intervals. Moreover, for differentiating between normal and pathological walking with reasonable accuracy, we recommend a minimum of 600 stride intervals.
步长间隔序列表现出统计持续性，而去趋势波动分析（DFA）是一种常用于描述这种行为的常规技术。然而，DFA 在步态数据中的应用在不同的研究中差异很大。我们实证研究了 DFA 的两个实际方面，这两个方面对分析结果有显著影响：盒子大小范围和步长间隔序列长度。我们使用 16 名健康成年人的步长间隔进行了分析，涵盖了在地面上行走、手扶着跑步机行走和不手扶着跑步机行走三种情况。我们的目标是为这两个选择提供一般指导，旨在标准化 DFA 的应用并促进研究之间的比较。基于我们的分析结果，我们建议使用 16 到 N/9 的盒子大小，其中 N 是步长间隔的数量。此外，为了以合理的精度区分正常和病理行走，我们建议至少使用 600 个步长间隔。
