Implant for Walking After Stroke

Inclusion Criteria: * At least 6-months post stroke * Age 21 to 75 years old * Able to ambulate, but does not require the assistance of more than one person * Walk slower than 0.8m/s during a 10m walk test * Lower extremity Fugl-Meyer Motor Assessment (FMA) \<= 20 * Reduced peak hip, knee and/or ankle range of motion during stance or swing phases * Modified Ashworth Scale (MAS) \<= 2 at the above joints during passive flexion and extension * Innervated and excitable lower extremity and trunk musculature * Appropriate body habitus (height and weight within acceptable limits as determined by study physician) * Adequate social support and stability * Willingness to comply with follow-up procedures * Neurologically stable as determined by a physician Exclusion Criteria: * Non-English speaking * Significant range of motion limitations (lacking hip extension, etc.) * History of spontaneous fractures or other evidence of excessively low bone density * Acute orthopedic problems (severe scoliosis, joint dislocations, etc.) * Medical complications (cardiac abnormalities, skin breakdowns, uncontrolled seizures, immunological/pulmonary/renal/circulatory compromise, additional neurologic conditions etc.) * Cardiovascular or pulmonary disease * Uncontrolled diabetes or hypertension * Presence of a demand pacemaker or cardiac defibrillator * Pregnancy * Complications of stroke that result in an increased risk of falls (apraxia, uncompensated hemineglect, hemianopsia etc.) * Significant history of repeated falls * Severely impaired cognition and communication * Any other medical or psychological condition that would be a contraindication