RELIABILITY OF COP-BASED POSTURAL SWAY MEASURES

摘要

Measures of human sway during upright standing are frequently used as indirect measures of thepostural control system. The objective of this study was to assess the reliability of several centerof-pressure-based sway measures. Test-retest reliability was determined both within-days (underdifferent visual and surface conditions) and between-days (5 different days). IntraclassCorrelation Coefficient (ICC), Standard Error of Measurement (SEM), Minimal MetricallyDetectable Change (MMDC), and Coefficient of Variation (CV) were used as reliability indices.Mean velocity was found to be the most reliable measure among those evaluated. Overall,between-day reliability indices were better than within-day reliability. When subjects werestanding on a compliant surface, several measures exhibited better reliability under ‘eyes open’condition. These results can be useful in guiding the selection of postural sway measures andappropriate number of replications to improve sway assessment.