Lin Dingding, Seol Hyang, Nussbaum Maury A, Madigan Michael L
Department of Industrial and Systems Engineering, Virginia Tech, Blacksburg, VA, USA.
Gait Posture. 2008 Aug;28(2):337-42. doi: 10.1016/j.gaitpost.2008.01.005. Epub 2008 Mar 7.
The objectives of this study were to assess the within-day and between-day reliability of several center of pressure (COP)-based measures of postural sway and identify whether there were age-related differences in reliability. Thirty-two healthy individuals (16 younger and 16 older) participated. COP was recorded during quiet upright stance on 4 different days, and a variety of measures determined: mean velocity, median power frequency, RMS distance, sway area, and two fractal measures derived from Hurst rescaled range analysis (HR/S) and detrended fluctuation analysis (DFA). Intraclass correlation coefficient (ICC) and standard error of measurement (SEM) were used to quantify reliability. Mean velocity was the most reliable measure. DFA exponents had relatively better reliability than HR/S exponents. In general, within-day reliability was better than between-day. In comparison with younger participants, older participants exhibited better relative reliability (ICC) for all COP measures and comparable absolute reliability (SEM) except for mean velocity and sway area. These results may be useful in guiding the future selection and interpretation of COP-based measures.
本研究的目的是评估几种基于压力中心（COP）的姿势摆动测量指标的日内和日间可靠性，并确定可靠性是否存在年龄相关差异。32名健康个体（16名年轻人和16名老年人）参与了研究。在安静直立姿势下于4个不同日期记录COP，并确定了多种测量指标：平均速度、中位功率频率、均方根距离、摆动面积，以及从赫斯特重标极差分析（HR/S）和去趋势波动分析（DFA）得出的两个分形测量指标。组内相关系数（ICC）和测量标准误差（SEM）用于量化可靠性。平均速度是最可靠的测量指标。DFA指数的可靠性相对优于HR/S指数。总体而言，日内可靠性优于日间。与年轻参与者相比，除平均速度和摆动面积外，老年参与者在所有COP测量指标上表现出更好的相对可靠性（ICC）和相当的绝对可靠性（SEM）。这些结果可能有助于指导未来基于COP的测量指标的选择和解释。
