The reliability and validity of the 30-second chair stand test and modified four square step test in persons with multiple sclerosis

Abstract

Background The 30-second Chair Stand Test (30s-CST) and Modified Four Square Step Test (mFSST) are used to determine the functional status of individuals with multiple sclerosis (MS). No other studies have demonstrated the reliability and validity of the 30s-CST and mFSST. Purpose To identify the test-retest reliability, concurrent validity and the known-group validity of the 30s-CST and mFSST in persons with MS. Methods A total of 64 persons with MS were enrolled. 30s-CST, mFSST, Timed Up and Go Test (TUG) and Five Times Sit to Stand (FTST) tests were performed. 30s-CST and mFSST were conducted again one-hour later. Results The mean age of the persons with MS were 37.9 +/- 11.3 years. The test-retest reliability of the 30s-CST and mFSST were excellent (ICC30s-CST = 0.974, 95%CI: 0.95-0.98; ICCmFSST = 0.992, 95%CI: 0.98-0.99). The 30s-CST was strongly correlated with FTST and TUG (r(1) = -0.871, p(1) = 0.0001; r(2) = -0.741,p(2) = 0.0001). There was a strong relationship between mFSST with TUG and FTST (r(1) = 0.781,p(1) = 0.0001;r(2) = 0.788,p(2) = 0.0001). The SEM95 and MDC95 values of the 30s-CST and mFSST were 0.41/1.13 and 0.34/0.94, respectively. Besides, there were significant differences between the persons with or without fall history in 30s-CST (MD: 1.66, CI: 0.27 to 3.05, p = .019) and mFSST CST (MD:-2.70, CI: -4.73 to -0.67, p = .010) performances. Conclusion The 30s-CST and mFSST are both valid and reliable in mildly-disabled individuals with MS.