Lamoth Claudine J C, van Lummel Rob C, Beek Peter J
Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, The Netherlands.
Gait Posture. 2009 Jun;29(4):546-51. doi: 10.1016/j.gaitpost.2008.12.006. Epub 2009 Jan 9.
Recent studies on postural control have shown that the variability of body sway during quiet standing may provide valuable information to characterize changes in postural control due to age, pathology, skill and task. The aim of the present study was to determine - as spade work for possible clinical applications - whether body sway measured with a three-axial accelerometer at the trunk can differentiate between three healthy young populations that differ in athletic skill level. The three groups in question (group size: n=22) consisted of regular bachelor students, physical education students and physical education students specialized in gymnastics. Data were recorded during tandem stance with eyes open or closed and while standing on foam. The acceleration time-series were analysed in anteriorposterior and mediolateral direction. Differences in postural control were quantified in terms of variability, spectral properties and stochastic dynamical measures, i.c., regularity (sample entropy, long-range correlations) and local stability (largest Lyapunov exponent). The results were clear-cut. Standing with eyes closed and on foam increased variability. Compared to standing with eyes open, standing with eyes closed resulted in less regular sway patterns but with greater local stability, whereas standing on foam had an opposite effect. With greater gymnastic skills, acceleration time-series were less variable, less regular and more stable. These results imply that quantifying the stochastic-dynamical structure of postural sway using ambulant accelerometry may provide a useful diagnostic tool.
近期关于姿势控制的研究表明,安静站立时身体摆动的变异性可能为表征因年龄、病理、技能和任务导致的姿势控制变化提供有价值的信息。本研究的目的是——作为可能的临床应用的前期工作——确定用三轴加速度计在躯干处测量的身体摆动是否能够区分运动技能水平不同的三组健康年轻人群。所讨论的三组(每组人数:n = 22)分别由普通本科生、体育专业学生和体操专项体育专业学生组成。在睁眼或闭眼的串联站立以及站在泡沫垫上时记录数据。对前后方向和内外侧方向的加速度时间序列进行分析。姿势控制的差异通过变异性、频谱特性和随机动力学指标进行量化,即规律性(样本熵、长程相关性)和局部稳定性(最大Lyapunov指数)。结果很明确。闭眼站立和站在泡沫垫上会增加变异性。与睁眼站立相比,闭眼站立导致摆动模式规律性降低但局部稳定性更高,而站在泡沫垫上则有相反的效果。体操技能越高,加速度时间序列的变异性越小、规律性越低且越稳定。这些结果表明,使用便携式加速度计量化姿势摆动的随机动力学结构可能会提供一种有用的诊断工具。