Retest Reliability of Centre of Pressure Measures of Standing Balance in Healthy Older Women

Centre of pressure (COP) measurements have been frequently used in the evaluation of postural control, especially in the elderly. Despite this, the retest reliability of these measures has not been well investigated in this age group. This study investigated the retest reliability of COP measures using a force platform in 17 women with a mean age of 69.5 years. Results indicated low correlations between test occasions for static stance postures with Intra class Correlation Coefficients (ICCs) ranging between 0.27 and 0.55. In contrast, ICCs were high (between 0.81 and 0.92) for test conditions involving angular perturbation of the support surface. Investigation of test durations of 10 and 25 second length did not indicate any significant difference between these two test durations (p>0.05). The study also revealed no series effects using twelve consecutive 25 second tests on the force platform. These results support further investigation of dynamic standing balance in older women using the test protocol described in this study, including whether these tests are able to discriminate between fallers and non fallen, and their predictive validity.