The Validity and Reliability of the Four Square Step Test

Participants will be assessed by two physiotherapists on two separate days. Prior to the trial, testing instructions to be delivered to participants will be translated and adapted into Turkish. In order to maximize potential agreement and to improve rating accuracy, reliability, and validity, assessment skills of the raters will be refreshed through training. Administration of the tests will be performed in a corridor of the school. Assessments will be performed in a quiet and adequately lighted environment to minimize the distraction. Participants will be tested with their regular footwear. The demographic information of participants will be recorded. The dynamic balance performances on the four square step test (FSST) and the Timed up \& Go test (TUG) will be assessed by Rater A and B independently and these assessments repeated 24-h later. The participants will be allowed to rest up to five minutes between sessions. A stopwatch will be used to measure time to complete the FSST and TUG test. Evaluations of concurrent and discriminative validity will be based on mean scores from the first measurement of rater A. Pearson's correlation coefficient (r) will be used to assess the concurrent validity of the FSST and TUG tests. Between-groups discriminative validity of the FSST will be evaluated by the one-way analysis of variance (ANOVA) with Bonferroni post-hoc test. Both intra- and inter-rater reliability will be assessed using intraclass correlation coefficients (ICC). ICC2,1 and ICC2,2 estimates and their 95% confidence intervals will be calculated based on absolute-agreement. Bland \& Altman plots will be constructed to demonstrate agreement between TUG and FSST, and between assessments of rater A and B.