Mylonas Vasileios, Grioriadis Stylianos, Chalitsios Christos, Stergiou Nick, Nikodelis Thomas
AUTH Biomechanics, Department of Physical Education, & Sport Science, Aristotle University, 570 01, Thessaloniki, Greece.
Division of Biomechanics and Research Development, Department of Biomechanics and Center for Research in Human Movement Variability, University of Nebraska at Omaha, 6160 University Drive South, Omaha, NE, 68182, USA.
Exp Brain Res. 2025 Jun 16;243(7):176. doi: 10.1007/s00221-025-07121-9.
Human movement variability reflects the adaptive capacity of the nervous system, yet how it is influenced by aging and circadian rhythms remain unclear. Therefore, the purpose of this study was to investigate postural sway variability as a function of aging and time of day. Nineteen young and nineteen older adults completed one 60-s quite stance trial with eyes open while standing on a force platform, at 12 p.m. and 12 a.m. Postural sway variability was evaluated regarding both its magnitude (total travel distance and interquartile range) and the complexity (a exponent using Detrended Fluctuation Analysis) of its temporal structure using the center of pressure time series. A two-way ANOVA (2 age groups × 2 times of day) was used. Correlation analysis was also performed to further investigate the relationship between circadian regulation and postural sway complexity. Complexity was higher for the young compared to the older group independently of the time of day. Furthermore, young adults presented higher values during the morning as compared to evening, while older adults did not reveal significant differences within the day. Finally, a strong correlation was found but only for young adults. In general, our results suggested that complexity of postural sway variability is affected both by age and time of day. Aging impacts postural control by reducing the complexity of sway variability and diminishing its sensitivity to circadian influences. Future work will address the effect of chronotype, sleep, and arousal levels on these novel findings and assess their impact on overall health.
人体运动变异性反映了神经系统的适应能力，但其如何受到衰老和昼夜节律的影响仍不清楚。因此，本研究的目的是调查作为衰老和一天中不同时间函数的姿势摆动变异性。19名年轻成年人和19名年长成年人在上午12点和凌晨12点时，睁眼站在测力平台上完成一次60秒的安静站立试验。使用压力中心时间序列，从幅度（总移动距离和四分位间距）及其时间结构的复杂性（使用去趋势波动分析的α指数）两方面评估姿势摆动变异性。采用双向方差分析（2个年龄组×2个一天中的时间）。还进行了相关分析，以进一步研究昼夜调节与姿势摆动复杂性之间的关系。无论一天中的时间如何，年轻人的复杂性均高于年长者。此外，与晚上相比，年轻人在早晨时的值更高，而年长者在一天内未显示出显著差异。最后，仅在年轻人中发现了很强的相关性。总体而言，我们的结果表明，姿势摆动变异性的复杂性受年龄和一天中时间的影响。衰老通过降低摆动变异性的复杂性并削弱其对昼夜影响的敏感性来影响姿势控制。未来的工作将探讨生物钟类型、睡眠和唤醒水平对这些新发现的影响，并评估它们对整体健康的影响。
