CIPER, Neuromuscular Research Lab, Faculty of Human Kinetics, University of Lisbon, Lisbon, Portugal.
Egas Moniz Center for Interdisciplinary Research (CiiEM), Egas Moniz School of Health & Science, Campus Universitário, Quinta da Granja, Monte da Caparica, 2829 - 511, Caparica, Portugal.
Sci Rep. 2023 Nov 25;13(1):20721. doi: 10.1038/s41598-023-47828-9.
It has been found that fractal-like patterns are present in the temporal structure of the variability of healthy biological rhythms, while pathology and disease lead to their deterioration. Interestingly, it has recently been suggested that these patterns in biological rhythms are related with each other, reflecting overall health or lack of it, due to their interaction. However, the underlying neurophysiological mechanisms responsible for such dependency remain unknown. In addition, this relationship between different elements needs to be first verified before we even pursue understanding their interaction. This study aimed to investigate the relationship between two elements of the neuromuscular system, gait and muscle activity variability patterns in older adults. Twenty-one older adults walked at their preferred walking speed on a treadmill. Inter-stride intervals were obtained through an accelerometer placed on the lateral malleoli to assess the temporal structure of variability of stride-to-stride fluctuations. Inter muscle peak intervals were obtained through the electromyographic signal of the gastrocnemius to assess the temporal structure of the variability of the simultaneous muscle activity. The temporal structure of variability from both signals was evaluated through the detrended fluctuation analysis, while their magnitude of variability was evaluated using the coefficient of variation. The Pearson's Correlation coefficient was used to identify the relationship between the two dependent variables. A significant strong positive correlation was found between the temporal structure of gait and muscle activity patterns. This result suggests that there is an interdependency between biological rhythms that compose the human neuromuscular system.
已经发现，健康生物节律的可变性的时间结构中存在分形样图案，而病理学和疾病导致其恶化。有趣的是，最近有人提出，由于它们的相互作用，生物节律中的这些模式彼此相关，反映了整体健康或缺乏健康。然而，导致这种依赖性的潜在神经生理机制尚不清楚。此外，在我们甚至追求理解它们的相互作用之前，需要首先验证不同元素之间的这种关系。本研究旨在调查神经肌肉系统的两个元素之间的关系，即老年人的步态和肌肉活动可变性模式。21 名老年人在跑步机上以自己喜欢的步行速度行走。通过放置在外侧踝骨上的加速度计获得步间间隔，以评估步间波动的可变性的时间结构。通过腓肠肌的肌电图信号获得肌肉间峰值间隔，以评估同时肌肉活动的可变性的时间结构。通过去趋势波动分析评估两个信号的可变性的时间结构，而使用变异系数评估其可变性的幅度。使用 Pearson 相关系数确定两个因变量之间的关系。发现步态和肌肉活动模式的时间结构之间存在显著的强正相关。这一结果表明，构成人体神经肌肉系统的生物节律之间存在相互依存关系。
