A researcher will test whether brain stimulation combined with gait training can improve patients' ability to walk after a stroke. People 50 or older who have had a stroke will be enrolled in the study and receive gait-training on a treadmill. The treatment group will receive transcranial direct current stimulation prior to gait training. Electrical stimulation will be administered in combination with motor training of the ankle, as a major problem for people trying to walk after stroke is an inability to flex the ankle on their affected side.