Self-Administered Transcranial Direct Current Stimulation for Pain in Older Adults With Knee Osteoarthritis

tDCS with a constant current intensity of 2 mA will be applied for 20 minutes per session daily for 2 weeks (Monday to Friday) via the Soterix 1x1 tDCS mini-CT Stimulator device (Soterix Medical Inc., NY) with headgear and saline-soaked surface sponge electrodes.

For sham stimulation, the electrodes will be placed in the same positions as for active stimulation, but the stimulator will only deliver 2 mA current for 30 seconds.