Statistical analysis
An a-priori sample size calculation (see clinicaltrials.gov, ID: NCT04594148) determined that we required 40 participants (20 per group). However, during data analyses, an error was found in that calculation, so an additional sensitivity power analysis was performed. From this, we determined that our sample of 40 is sufficient to detect effect sizes SAS (Version 9.4 of the SAS System for Windows, SAS Institute Inc., Cary, NC, USA) and SPSS (IBM SPSS Statistics, Version 26) was used for data analysis, including all participants. Participant characteristics as well as behavioral and cortical outcomes at baseline were compared between groups with an independent To explain the training effects, Pearson’s correlations between changes in ST weight-shifting speed (pre-post, pre-retention) and participant characteristics (age, MoCA, FES, SARC-F, PSQI, baseline MiniBEST) were calculated, resulting in 12 comparisons. As well, an exploratory correlational analysis (without correction for multiple comparisons) was carried out between changes in cortical hemodynamics for the ROIs that displayed significant interaction effects and weight-shifting performance.