Human Performance Lab, Department of Health, Nutrition and Exercise Sciences, University of Delaware, 541 S. College Ave., Newark, DE 19716, USA.
Hum Mov Sci. 2009 Aug;28(4):515-28. doi: 10.1016/j.humov.2009.02.001. Epub 2009 Apr 1.
We investigated the effect of joint immobilization on the postural sway during quiet standing. We hypothesized that the center of pressure (COP), rambling, and trembling trajectories would be affected by joint immobilization. Ten young adults stood on a force plate during 60 s without and with immobilized joints (only knees constrained, CK; knees and hips, CH; and knees, hips, and trunk, CT), with their eyes open (OE) or closed (CE). The root mean square deviation (RMS, the standard deviation from the mean) and mean speed of COP, rambling, and trembling trajectories in the anterior-posterior and medial-lateral directions were analyzed. Similar effects of vision were observed for both directions: larger amplitudes for all variables were observed in the CE condition. In the anterior-posterior direction, postural sway increased only when the knees, hips, and trunk were immobilized. For the medial-lateral direction, the RMS and the mean speed of the COP, rambling, and trembling displacements decreased after immobilization of knees and hips and knees, hips, and trunk. These findings indicate that the single inverted pendulum model is unable to completely explain the processes involved in the control of the quiet upright stance in the anterior-posterior and medial-lateral directions.
我们研究了关节固定对安静站立时姿势摆动的影响。我们假设，在关节固定的情况下，压力中心（COP）、漫游和颤抖轨迹会受到影响。10 名年轻人在力板上站立 60 秒，分别在不固定关节（仅膝关节固定，CK；膝关节和髋关节固定，CH；膝关节、髋关节和躯干固定，CT）、睁眼（OE）和闭眼（CE）的情况下进行。分析了 COP、漫游和颤抖轨迹在前后方向和内外方向上的均方根偏差（RMS，平均值的标准差）和平均速度。对于这两个方向，视觉的影响相似：在 CE 条件下，所有变量的幅度都更大。在前后方向上，只有当膝关节、髋关节和躯干固定时，姿势摆动才会增加。对于内外方向，当膝关节和髋关节以及膝关节、髋关节和躯干固定后，COP、漫游和颤抖位移的 RMS 和平均速度减小。这些发现表明，单倒立摆模型不能完全解释前后方向和内外方向控制安静直立姿势的过程。
