Kilby Melissa C, Molenaar Peter C M, Slobounov Semyon M, Newell Karl M
Department of Kinesiology, The University of Georgia, 330 River Rd, Athens, GA, 30602, USA.
Department of Human Development and Family Studies, The Pennsylvania State University, 315 Health and Human Development East, University Park, PA, 16802, USA.
Exp Brain Res. 2017 Jan;235(1):109-120. doi: 10.1007/s00221-016-4769-3. Epub 2016 Sep 19.
The experiment was setup to investigate the control of human quiet standing through the manipulation of augmented visual information feedback of selective properties of the motion of two primary variables in postural control: center of pressure (COP) and center of mass (COM). Five properties of feedback information were contrasted to a no feedback dual-task (watching a movie) control condition to determine the impact of visual real-time feedback on the coordination of the joint motions in postural control in both static and dynamic one-leg standing postures. The feedback information included 2D COP or COM position and macro variables derived from the COP and COM motions, namely virtual time-to-contact (VTC) and the COP-COM coupling. The findings in the static condition showed that the VTC and COP-COM coupling feedback conditions decreased postural motion more than the 2D COP or COM positional information. These variables also induced larger sway amplitudes in the dynamic condition showing a more progressive search strategy in exploring the stability limits. Canonical correlation analysis (CCA) found that COP-COM coupling contributed less than the other feedback variables to the redundancy of the system reflected in the common variance between joint motions and properties of sway motion. The COP-COM coupling had the lowest weighting of the motion properties to redundancy under the feedback conditions but overall the qualitative pattern of the joint motion structures was preserved within the respective static and dynamic balance conditions.
该实验旨在通过操纵姿势控制中两个主要变量（压力中心（COP）和质心（COM））运动的选择性属性的增强视觉信息反馈，来研究人体安静站立的控制。将反馈信息的五个属性与无反馈双任务（看电影）控制条件进行对比，以确定视觉实时反馈对静态和动态单腿站立姿势下姿势控制中关节运动协调性的影响。反馈信息包括二维COP或COM位置以及从COP和COM运动中导出的宏观变量，即虚拟接触时间（VTC）和COP-COM耦合。静态条件下的研究结果表明，与二维COP或COM位置信息相比，VTC和COP-COM耦合反馈条件下的姿势运动减少得更多。这些变量在动态条件下也会引起更大的摇摆幅度，表明在探索稳定性极限时采用了更渐进的搜索策略。典型相关分析（CCA）发现，在关节运动和摇摆运动属性之间的共同方差所反映的系统冗余方面，COP-COM耦合对系统冗余的贡献小于其他反馈变量。在反馈条件下，COP-COM耦合在运动属性对冗余的权重中最低，但总体而言，关节运动结构的定性模式在各自的静态和动态平衡条件下得以保留。
