Kędziorek Justyna, Błażkiewicz Michalina
Akademia Wychowania Fizycznego Józefa Piłsudskiego w Warszawie, 00-809 Warszawa, Poland.
Entropy (Basel). 2020 Nov 30;22(12):1357. doi: 10.3390/e22121357.
Conventional biomechanical analyses of human movement have been generally derived from linear mathematics. While these methods can be useful in many situations, they fail to describe the behavior of the human body systems that are predominately nonlinear. For this reason, nonlinear analyses have become more prevalent in recent literature. These analytical techniques are typically investigated using concepts related to variability, stability, complexity, and adaptability. This review aims to investigate the application of nonlinear metrics to assess postural stability. A systematic review was conducted of papers published from 2009 to 2019. Databases searched were PubMed, Google Scholar, Science-Direct and EBSCO. The main inclusion consisted of: Sample entropy, fractal dimension, Lyapunov exponent used as nonlinear measures, and assessment of the variability of the center of pressure during standing using force plate. Following screening, 43 articles out of the initial 1100 were reviewed including 33 articles on sample entropy, 10 articles on fractal dimension, and 4 papers on the Lyapunov exponent. This systematic study shows the reductions in postural regularity related to aging and the disease or injures in the adaptive capabilities of the movement system and how the predictability changes with different task constraints.
人体运动的传统生物力学分析通常源自线性数学。虽然这些方法在许多情况下可能有用，但它们无法描述主要为非线性的人体系统的行为。因此，非线性分析在最近的文献中变得更加普遍。这些分析技术通常使用与变异性、稳定性、复杂性和适应性相关的概念进行研究。本综述旨在研究非线性指标在评估姿势稳定性方面的应用。对2009年至2019年发表的论文进行了系统综述。搜索的数据库有PubMed、谷歌学术、Science-Direct和EBSCO。主要纳入内容包括：样本熵、分形维数、李雅普诺夫指数用作非线性度量，以及使用测力板评估站立时压力中心的变异性。筛选后，对最初1100篇文章中的43篇进行了综述，其中包括33篇关于样本熵的文章、10篇关于分形维数的文章和4篇关于李雅普诺夫指数的文章。这项系统研究表明了与衰老以及运动系统适应性能力方面的疾病或损伤相关的姿势规律性降低，以及可预测性如何随不同的任务限制而变化。
