Piergiovanni Sophia, Terrier Philippe
Haute-Ecole Arc Santé, HES-SO University of Applied Sciences and Arts Western Switzerland, 2000 Neuchâtel, Switzerland.
Sensors (Basel). 2024 Nov 21;24(23):7427. doi: 10.3390/s24237427.
The attractor complexity index (ACI) is a recently developed gait analysis tool based on nonlinear dynamics. This study assesses ACI's sensitivity to attentional demands in gait control and its potential for characterizing age-related changes in gait patterns. Furthermore, we compare ACI with classical gait metrics to determine its efficacy relative to established methods. A 4 × 200 m indoor walking test with a triaxial accelerometer attached to the lower back was used to compare gait patterns of younger (N = 42) and older adults (N = 60) during normal and metronome walking. The other linear and non-linear gait metrics were movement intensity, gait regularity, local dynamic stability (maximal Lyapunov exponents), and scaling exponent (detrended fluctuation analysis). In contrast to other gait metrics, ACI demonstrated a specific sensitivity to metronome walking, with both young and old participants exhibiting altered stride interval correlations. Furthermore, there was a significant difference between the young and old groups (standardized effect size: -0.77). Additionally, older participants exhibited slower walking speeds, a reduced movement intensity, and a lower gait regularity. The ACI is likely a sensitive marker for attentional load and can effectively discriminate age-related changes in gait patterns. Its ease of measurement makes it a promising tool for gait analysis in unsupervised (free-living) conditions.
吸引子复杂性指数（ACI）是一种最近基于非线性动力学开发的步态分析工具。本研究评估了ACI在步态控制中对注意力需求的敏感性及其表征步态模式中与年龄相关变化的潜力。此外，我们将ACI与经典步态指标进行比较，以确定其相对于既定方法的有效性。通过一项在室内进行的4×200米步行测试，将三轴加速度计附着在下背部，比较年轻人（N = 42）和老年人（N = 60）在正常步行和跟随节拍器步行时的步态模式。其他线性和非线性步态指标包括运动强度、步态规律性、局部动态稳定性（最大Lyapunov指数）和标度指数（去趋势波动分析）。与其他步态指标不同，ACI对跟随节拍器步行表现出特定的敏感性，年轻和老年参与者的步幅间隔相关性均发生了改变。此外，年轻组和老年组之间存在显著差异（标准化效应量：-0.77）。此外，老年参与者的步行速度较慢、运动强度降低且步态规律性较低。ACI可能是注意力负荷的敏感标志物，并且可以有效区分步态模式中与年龄相关的变化。其测量的简便性使其成为在无监督（自由生活）条件下进行步态分析的有前途的工具。
