There is scientific evidence that older adults aged 65 and over walk with increased step width variability which has been associated with risk of falling. However, there are presently no threshold levels that define the optimal reference range of step width variability. Thus, the purpose of our study was to estimate the optimal reference range for identifying older adults with normative and excessive step width variability. We searched systematically the BMC, Cochrane Library, EBSCO, Frontiers, IEEE, PubMed, Scopus, SpringerLink, Web of Science, Wiley, and PROQUEST databases until September 2018, and included the studies that measured step width variability in both younger and older adults during walking at self-selected speed. Data were pooled in meta-analysis, and standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated. A single-decision threshold method based on the Youden index, and a two-decision threshold method based on the uncertain interval method were used to identify the optimal threshold levels (PROSPERO registration: CRD42018107079). Ten studies were retrieved (older adults = 304; younger adults = 219). Step width variability was higher in older than in younger adults (SMD = 1.15, 95% CI = 0.60; 1.70; t = 4.72, p = 0.001). The single-decision method set the threshold level for excessive step width variability at 2.14 cm. For the two-decision method, step width variability values above the upper threshold level of 2.50 cm were considered excessive, while step width variability values below the lower threshold level of 1.97 cm were considered within the optimal reference range. Step width variability is higher in older adults than in younger adults, with step width variability values above the upper threshold level of 2.50 cm to be considered as excessive. This information could potentially impact rehabilitation technology design for devices targeting lateral stability during walking.

中文翻译：

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步宽变异性作为与年龄相关的步态变化的鉴别器。


有科学证据表明，65 岁及以上的老年人行走时步幅变化较大，这与跌倒风险相关。然而，目前没有阈值水平来定义步长变化的最佳参考范围。因此，我们研究的目的是估计识别具有正常和过度步宽变化的老年人的最佳参考范围。截至 2018 年 9 月，我们系统地检索了 BMC、Cochrane Library、EBSCO、Frontiers、IEEE、PubMed、Scopus、SpringerLink、Web of Science、Wiley 和 PROQUEST 数据库，并纳入了测量年轻人和老年人步宽变异性的研究以自行选择的速度行走。在荟萃分析中汇总数据，并计算标准化平均差 (SMD) 和 95% 置信区间 (CI)。采用基于Youden指数的单决策阈值法和基于不确定区间法的二决策阈值法来确定最佳阈值水平（PROSPERO注册：CRD42018107079）。检索到 10 项研究（老年人 = 304；年轻人 = 219）。老年人的步宽变异性高于年轻人（SMD = 1.15，95% CI = 0.60；1.70；t = 4.72，p = 0.001）。单决策方法将过度步宽变化的阈值水平设置为 2.14 cm。对于二决策方法，高于上阈值水平 2.50 cm 的步宽变异性值被认为是过度的，而低于下阈值水平 1.97 cm 的步宽变异性值被认为在最佳参考范围内。老年人的步宽变异性高于年轻人，步宽变异性值高于上限阈值水平 2。50厘米被认为是过度的。这些信息可能会影响针对行走过程中横向稳定性的设备的康复技术设计。