Functional Electrical Stimulation on Tibial Nerve in Stroke Patients.

8 weeks intervention. 3 sessions per week. Previous to the intervention, volunteers will familiarize with the electrical stimulation by receiving three trials of the stimuli. Electrical current intensity will be set for each volunteers, with the capacity of generating a muscle contraction without inducing discomfort in the volunteer. During the FES program, patient in standing position will perform a step, while electrical current stimulation will be applied to the skin over the tibial nerve on the contralateral of the stimulation side. The FES will be delivered during the paretic plantarflexor activation according to the gait cycle. The FES session will consist of 5-minutes stimulation blocks with breaks between blocks (total session time: 30 minutes). For safety reasons, a physical therapist will supervise all the FES intervention sessions.