Test-retest reliability of static postural control in people with multiple sclerosis

[Purpose] The purpose of this study was to analyse the intraday test-retest reliability of stabilometric measurements on the Centre of Pressure (CoP) in persons with Multiple Sclerosis. [Subjects and Methods] The measurements were taken with the subject standing on the force platform with both feet together, in four different conditions: eyes open and closed whilst standing on both a rigid surface and then on foam. The measurements were taken on three occasions with intervals of 20 minutes between them. 18 persons with confirmed Multiple Sclerosis (MS), (aged 44.4 ± 13.3 years and 3.5 ± 1.5 EDSS) participated in the study. Relative reliability was measured using the intraclass correlation coefficient (ICC) and the 95% confidence interval (95% CI); and the absolute reliability using the coefficient of variation (CV) and standard error of measurement (SEM). [Results] The measurements of the CoP in all of the variables in each of the four conditions, showed a reliability of good to excellent (ICC=0.69-0.92) in the intraday test-retest. The variables which showed greatest consistency with repetition were X Speed, Y Speed and Side Length. [Conclusion] Given the results it would seem that the best variables for monitoring postural control in persons with MS are Speed on X and Y along with Side Length.