Goldie P A, Bach T M, Evans O M
Department of Physiotherapy, Lincoln School of Health Sciences, LaTrobe University, Victoria, Australia.
Arch Phys Med Rehabil. 1989 Jul;70(7):510-7.
The reliability and validity of force platform measures used to evaluate steadiness of stance were investigated in a group of 28 healthy subjects in four basic stance positions: two-legged, step, tandem, and one-legged stance. In each stance position five indices of steadiness were obtained by sampling the three orthogonal force signals and the two horizontal center of pressure (CP) signals for 15 seconds and computing the standard deviation for each signal. Correlations between these five indices derived from the force platform showed that the relationship between force and CP measures was generally weak. In fact, approximately 40% of the correlations were nonsignificant (p greater than .05). There was a strong trend for the retest reliability of force measures to be higher than the retest reliability of CP measures. The difference was statistically significant in three stances (p less than .05). Force measures were more sensitive than CP measures in discriminating the changes in steadiness which resulted from alterations to the base of support in the four stance positions. Factor analysis showed that force measures were the best predictors of steadiness in each stance, but the axis varied according to the particular stance condition. Although it may be appropriate in some cases to justify the choice of measure according to the nature of the clinical condition being studied, these results provide a rationale for choosing force measures in preference to CP measures on the fundamental principles of reliability and validity.
在28名健康受试者中，研究了用于评估站立稳定性的测力平台测量方法在四种基本站立姿势（双脚站立、单脚跨步站立、前后脚站立和单脚站立）下的可靠性和有效性。在每个站立姿势下，通过对三个正交力信号和两个水平压力中心（CP）信号进行15秒采样并计算每个信号的标准差，获得了五个稳定性指标。测力平台得出的这五个指标之间的相关性表明，力与CP测量值之间的关系通常较弱。实际上，约40%的相关性不显著（p大于0.05）。力测量的重测可靠性有高于CP测量重测可靠性的强烈趋势。在三种姿势下，这种差异具有统计学意义（p小于0.05）。在区分因四种站立姿势下支撑面改变而导致的稳定性变化方面，力测量比CP测量更敏感。因子分析表明，力测量是每种姿势下稳定性的最佳预测指标，但轴会根据特定的姿势条件而变化。尽管在某些情况下根据所研究临床状况的性质来证明测量方法的选择可能是合适的，但这些结果基于可靠性和有效性的基本原则，为优先选择力测量而非CP测量提供了理论依据。
