Fig. 1

Overview of the study design. A cross-over, double-blind, randomized, sham-controlled tDCS pilot study, comparing three conditions. Visit 1 consisted of obtaining informed consent, familiarization with tDCS (the participants received some stimulation), and collection of subject data and demographics. During visit 1, subjects were also tested on all of the outcome measures that were used in subsequent visits to help to reduce any learning or practice effects. During each of the three subsequent evaluation sessions, gait, postural sway, and cognitive function were assessed before and after a single 20-min session of tDCS + walking, tDCS + seated, or sham + walking. Visit 2, 3, and 4 consisted of pre-test, intervention, and post-test. The intervention condition order was randomized across visits 2, 3, and 4. Each intervention session was separated by at least 3 days