Transcranial Direct Current Stimulation, Functional Activity, Stroke, RCT

Group 1: Active tDCS combined with dual-task stepping (Experimental A) Participants in this group will receive anodal tDCS applied over the ipsilesional primary motor cortex (M1) at C3 or C4 (based on the 10-20 EEG system), with the reference electrode positioned over the contralesional supraorbital area. Stimulation will be delivered at an intensity of 2 mA for 20 minutes, During the stimulation period, participants will perform dual-task stepping exercises on unstable surfaces. The stepping program stepping on a foam pad (5 cm thick, 20 cm wide, 12 cm long). Each stepping session lasts 10 minutes and is immediately followed by overground walking at a comfortable speed for 10 meters, while simultaneously performing a cognitive task of counting backwards from 99 to 0. Participants are instructed not to pause or stop while performing the dual task. If they stop for more than 5 seconds, it is considered an error, which will be recorded.

Group 2:This group follows the same stepping and dual-task walking program as Group 1 (stepping on foam pad for 10 minutes, followed by overground walking with backward counting for 10 minutes). However, instead of active stimulation, participants receive sham tDCS.

Group 3:Participants in this group will receive anodal tDCS only, without any dual-task or stepping training.