Department of Health and Human Performance, The University of Texas at Brownsville, REK Building 2.638, Brownsville, TX 78520, USA.
Neurosci Lett. 2013 Aug 26;548:176-80. doi: 10.1016/j.neulet.2013.05.068. Epub 2013 Jun 12.
The present study examined the coordination dynamics of the head and center of mass (COM) using accelerometry in quiet 1 and 2 leg stance with and without vision. The root mean square jerk of effectors was greater in 1 leg stance and without vision, and was greater for the head in 2 leg stance and greater at the COM for 1 leg stance. The coordination of the COM and head was more variable in 1 leg stance with vision than in the other stance and vision combinations. Both grouped and individual participant data showed metastable coordination dynamics with the presence of ghost attractors on both axes of motion that varied with the task. The findings indicated that stance and visual information conditions acted as control parameters, with increments in task difficulty increasing relative phase variability until a bifurcation in the metastable dynamics occurred in 1 leg stance without vision.
本研究使用加速度计考察了安静状态下单腿和双腿站立时有无视觉条件下头和质心（COM）的协调动力学。在单腿站立和无视觉条件下，效应器的均方根急动度更大，在双腿站立时头的急动度更大，在单腿站立时 COM 的急动度更大。在有视觉的单腿站立时，COM 和头的协调比其他站立和视觉组合更具变异性。分组和个体参与者数据均显示出亚稳定的协调动力学，运动的两个轴上存在幽灵吸引子，其随任务而变化。研究结果表明，站立和视觉信息条件作为控制参数，随着任务难度的增加，相对相位的可变性增加，直到在无视觉的单腿站立时发生亚稳定动力学的分岔。
