Clinical Effects of Peroneal Nerve Functional Electrical Stimulation (WalkAide[R]) for Chronic Stroke Patients

Inclusion Criteria: * 1)First-ever hemiplegic patients 4 months after the stroke onset * 2)Patients whose the lower extremity paralysis is estimated to be stage IV, V or VI according to the Brunnstrom stage * 3)Patients whose spasticity of the plantar flexor muscle is estimated at 2 or less according to the Modified Ashworth Scale * 4)Patients whose ankle dorsiflexion range of motion is 0 degree or more * 5)Patients whose gait performance is estimated to be 5 or 6 according to the FAC * 6)Patients who can understand the purpose and instructions of this study and complete the training * 7)Patients who agree to participate in this study and provide their written informed consent Exclusion Criteria: * 1)Patients whose ankle dorsiflexion is not induced by the WA due to peripheral neuropathy * 2)Patients who are contraindicated for the WA (e.g., patients with a metallic implant or implantable medical electrical equipment such as a cardiac pacemaker, and patients with a previous or suspected history of seizure) * 3)Patients who underwent Botox treatment in the lower extremities within 3 months of this study registry * 4)Patients who have nervous system (excluding stroke), cardio-respiratory system, or musculoskeletal system disorders, which may affect gait and training * 5)Patients who had fallen down within a week prior to the registry and are regarded to be at a high risk of falling down by an attending physician * 6)Patients whose impairment severities changed between the prior and initial assessments * Definition of an alteration 1. Brunnstrom stage for the lower extremity: Confirm whether the stages of the prior and initial assessments are the same value. If these stages are different, this is considered to be an alteration, and the patient with this alteration should be excluded from the study. 2. Lower extremity subscale of the Fugl-Meyer Assessment: Confirm whether the change in the score between the prior and initial assessments is 5 or less. If the change is 6 or more, then this is considered to be an alteration, and the patient with this alteration should be excluded from the study. 3. Functional Ambulation Classification: Confirm whether the categories of the prior and initial assessments are the same value. If these categories are different, then this is considered to be an alteration, and the patient with this alteration should be excluded from the study. * 7\) Patients who are regarded to be ineligible for this study by the principal investigator or co-investigators