Anodal Transcranial Direct Current Stimulation Enhances Short-Term Balance During Locomotive Training in Older Adults...

Background/Objectives: Locomotive syndrome (LS) is associated with impaired balance and functional decline in older adults. Although locomotive training (LT) improves mobility, whether central neuromodulation enhances short-term balance adaptation remains unclear. This pilot randomized controlled trial examined the additive effect of anodal transcranial direct current stimulation (tDCS) with LT on balance. Methods: Sixteen community-dwelling adults aged ≥ 65 years with LS were randomized (1:1:1) to anodal tDCS + LT (n = 6), sham tDCS + LT (LT group, n = 6), or anodal tDCS alone (n = 4). Participants underwent five consecutive days of intervention. The primary outcome was eyes-open single-leg stance time, assessed before stimulation and at 10, 20, 50, and 80 min during and after stimulation on days 1-5. Group × time interactions were evaluated using linear mixed-effects models adjusted for baseline and age. Long-term outcomes were assessed on days 1, 5, and 12. Results: In the primary analysis, a significant group × time interaction for right-sided single-leg stance time was observed between the anodal tDCS + LT and the LT groups (F(1,58) = 6.08, p = 0.017; β = 0.966), indicating greater within-day improvement with combined therapy, but not in sensitivity analyses treating time as a categorical variable. No significant interactions were observed on the left side. Secondary outcomes showed time-dependent improvements without consistent group-specific effects or significant group × day interactions over the long term. No serious adverse events occurred. Conclusions: Anodal tDCS with LT improved short-term balance in the primary analysis; however, these effects were model-sensitive and not sustained over 12 days. These findings should be considered preliminary and hypothesis-generating. Larger trials are needed to determine optimal stimulation dosing and long-term efficacy.