Biomechanical and Neural Mechanisms of Post-stroke Gait Training

Functional electrical stimulation (FES) is a targeted intervention that provides motor level stimulation-induced cues to improve ankle propulsion. An electrical stimulator will be used to deliver stimulation during walking (Grass S8800 stimulator with SIU8TB stimulus isolation unit; UDel stimulator). A customized, real-time system will be used to control the stimulator and deliver stimulation during appropriate phases of the gait cycle. Stimulation will be delivered to the ankle dorsiflexors when the subject's foot is in the air (swing phase). Stimulation will be delivered to the ankle plantarflexors during the terminal stance phase of gait. 30-Hz variable frequency stimulation trains 170 will be delivered during gait. The intervention comprises 3 training sessions per week for a total of 12 training sessions. FES intensity is determined at the start of every training session as motor-level stimulation that elicits appropriate functional movements.

Fast treadmill walking (Fast) is a non-targeted intervention where no specific instructions are provided to target practice to the paretic leg or specific ankle deficits. The intervention comprises 3 training sessions per week for a total of 12 training sessions. Each training session includes six 6-minute walking bouts with 5-minute breaks between bouts.