Department of Physical Therapy, School of Allied Health Sciences, University of Phayao, 19 Moo 2, Maeka, Muang, Phayao 56000, Thailand.
Unit of Excellence in Neuromechanics, School of Allied Health Sciences, University of Phayao, 19 Moo 2, Maeka, Muang, Phayao 56000, Thailand.
Sensors (Basel). 2022 Oct 5;22(19):7542. doi: 10.3390/s22197542.
Stability during walking is considered a crucial aspect of assessing gait ability. The current study aimed to assess walking stability by applying principal component analysis (PCA) to decompose three-dimensional (3D) whole-body kinematic data of 104 healthy young adults (21.9 ± 3.5 years, 54 females) derived from a depth-sensing camera into a set of movement components/synergies called "principal movements" (PMs), forming together to achieve the task goal. The effect of sex as the focus area was tested on three PCA-based variables computed for each PM: the relative explained variance (rVAR) as a measure of the composition of movement structures; the largest Lyapunov exponent (LyE) as a measure of variability; and the number of zero-crossings (N) as a measure of the tightness of neuromuscular control. The results show that the sex effects appear in the specific PMs. Specifically, in PM, resembling the swing-phase movement, females have greater LyE ( = 0.013) and N ( = 0.017) values than males. Moreover, in PM, representing the mid-stance-phase movement, females have smaller rVAR ( = 0.020) but greater N ( = 0.008) values than males. These empirical findings suggest that the inherent sex differences in walking stability should be considered in assessing and training locomotion.
行走稳定性被认为是评估步态能力的一个关键方面。本研究旨在通过应用主成分分析（PCA）将来自深度感应摄像机的 104 名健康年轻成年人（21.9 ± 3.5 岁，54 名女性）的三维（3D）整体运动学数据分解为一组运动成分/协同作用，称为“主要运动”（PM），共同完成任务目标。以性别为焦点区域，测试了三个基于 PCA 的变量对每个 PM 的影响：相对解释方差（rVAR）作为运动结构组成的度量；最大 Lyapunov 指数（LyE）作为变异性的度量；以及零交叉（N）的数量作为神经肌肉控制的紧密度的度量。结果表明，性别效应出现在特定的 PM 中。具体而言，在类似于摆动阶段运动的 PM 中，女性的 LyE（=0.013）和 N（=0.017）值大于男性。此外，在代表中间站立阶段运动的 PM 中，女性的 rVAR（=0.020）值较小，但 N（=0.008）值大于男性。这些实证发现表明，在评估和训练运动时，应考虑行走稳定性的内在性别差异。
