School of Kinesiology and Health Science, York University, Toronto, ON M3J 1P3, Canada.
Sensors (Basel). 2024 Nov 8;24(22):7175. doi: 10.3390/s24227175.
Stride-to-stride fluctuations during walking reflect age-related changes in gait adaptability and are estimated with nonlinear measures that confine data collection to controlled settings. Smartphones, with their embedded accelerometers, may provide accessible gait analysis throughout the day. This study investigated age-related differences in linear and nonlinear gait measures estimated from a smartphone accelerometer (SPAcc) in an unconstrained, free-living environment. Thirteen young adults (YA) and 11 older adults (OA) walked within a shopping mall with a SPAcc placed in their front right pants pocket. The inter-stride interval, calculated as the time difference between ipsilateral heel contacts, was used for dependent measures calculations. One-way repeated-measures analysis of variance revealed significant ( < 0.05) age-related differences (mean: YA, OA) for stride-time standard deviation (0.04 s, 0.05 s) and coefficient of variation (3.47%, 4.16%), sample entropy (SaEn) scale 1 (1.70, 1.86) and scale 3 (2.12, 1.80), and statistical persistence decay (31 strides, 23 strides). The fractal scaling index was not different between groups (0.93, 0.95), but exceeded those typically found in controlled settings, suggesting an upregulation in adaptive behaviour likely to accommodate the increased challenge of free-living walking. These findings support the SPAcc as a viable telehealth instrument for remote monitoring of gait dynamics, with implications for unsupervised fall-risk assessment.
步长波动反映了与年龄相关的步态适应性变化，这些变化可以通过将数据收集限制在受控环境中的非线性测量来估计。智能手机内置的加速度计可以在一天中的任何时候提供可访问的步态分析。本研究调查了在不受约束的自由生活环境中，从智能手机加速度计 (SPAcc) 估计的线性和非线性步态测量值与年龄相关的差异。13 名年轻人 (YA) 和 11 名老年人 (OA) 在购物中心内行走，将 SPAcc 放在他们的右前裤袋中。步长时间是通过计算同侧脚跟接触之间的时间差得出的，用于依赖测量值的计算。单向重复测量方差分析显示，步长时间标准差 (0.04 s, 0.05 s) 和变异系数 (3.47%, 4.16%)、样本熵 (SaEn) 标度 1 (1.70, 1.86) 和标度 3 (2.12, 1.80)、统计持久性衰减 (31 步，23 步) 存在显著的年龄相关差异 (0.04 s, 0.05 s) 和变异系数 (3.47%, 4.16%)、样本熵 (SaEn) 标度 1 (1.70, 1.86) 和标度 3 (2.12, 1.80)、统计持久性衰减 (31 步，23 步)。组间分形标度指数无差异 (0.93, 0.95)，但高于通常在受控环境中发现的值，表明适应性行为的上调可能是为了适应自由生活行走的增加的挑战。这些发现支持 SPAcc 作为一种可行的远程监测步态动力学的远程医疗工具，对非监督跌倒风险评估具有重要意义。
