Doyle Richard J, Hsiao-Wecksler Elizabeth T, Ragan Brian G, Rosengren Karl S
Department of Kinesiology, University of Illinois at Urbana-Champaign, IL 61801, United States.
Gait Posture. 2007 Feb;25(2):166-71. doi: 10.1016/j.gaitpost.2006.03.004. Epub 2006 Apr 19.
Center of pressure (COP) measures are commonly used as indicators of balance and postural control. At present, there are no universally accepted standards in research investigating fluctuations in the COP with regard to the number of trials or the length of a given trial. The purpose of this study was to use the tools of Generalizability Theory (G-Theory) to investigate the reliability of COP measures of quiet standing and to establish an optimal measurement protocol. G-Theory provides a tool that allows us to break down the sources of variation, or facets, in a measurement procedure and ultimately design a protocol that provides optimal reliability. Fifteen participants completed 10 90-s trials with eyes open and closed. COP measures of anterior-posterior standard deviation (SD(AP)), medial-lateral SD (SD(ML)), average velocity (Vel), and 95% confidence ellipse area (Area) were calculated using the first 30, 60, and 90s of each trial. A G-study and follow-up D-studies were performed to estimate reliability coefficients (G-coefficients). The results of the G-Theory analysis suggest that these COP measures reached acceptable levels of reliability (G>or=0.70) with at least five 60s trials.
压力中心（COP）测量通常用作平衡和姿势控制的指标。目前，在研究COP波动的试验次数或给定试验时长方面，尚无普遍接受的标准。本研究的目的是使用概化理论（G理论）工具来研究安静站立时COP测量的可靠性，并建立最佳测量方案。G理论提供了一种工具，使我们能够分解测量过程中的变异来源或侧面，并最终设计出具有最佳可靠性的方案。15名参与者完成了10次90秒的睁眼和闭眼试验。使用每次试验的前30秒、60秒和90秒计算前后标准差（SD(AP)）、内外侧标准差（SD(ML)）、平均速度（Vel）和95%置信椭圆面积（Area）的COP测量值。进行了G研究和后续D研究以估计可靠性系数（G系数）。G理论分析结果表明，这些COP测量值在至少5次60秒试验时达到了可接受的可靠性水平（G≥0.70）。
