Functional Electrical Stimulation (FES) Driven Stepping in Individuals With Spinal Cord Injury

Inclusion Criteria: * Male, Female, age 18-65, all ethnic groups * Spinal Cord Injury, traumatic and non-traumatic * C1-T12 neurological level * ASIA class A-D * Chronic injury \> 6 months from the injury * Visible motor response to FES stimulation (visible muscle contraction evoked with electrical stimulation) * Subjects are medically stable, with no recent (1 month or less) inpatient admission for acute medical or surgical issues * Subjects are able to comply with procedures and follow-up Exclusion Criteria: * Concurrent lower motor neuron disease such as peripheral neuropathy that would exclude lower extremity electrical excitability * History of inability to tolerate electrical stimulation * Cardiovascular disease as defined by previous myocardial infarction, unstable angina, requirement for anti platelet agents, congestive heart failure, or stroke NYHA Class III or IV, history of arrhythmia with hemodynamic instability * Uncontrolled hypertension (resting systolic BP \> 160mmHg or diastolic BP \>100mmHg consistently) * Presence of a pacemaker, an implanted defibrillator or certain other implanted electronic or metallic devices other than baclofen pumps * Unstable long bone fractures of the lower extremities * Presence of stage III or greater skin ulcerations that would preclude application of stimulating pads * Malignancy * History of epileptic seizures * Women who are pregnant * Active drug or alcohol use or dependence that, in the opinion of the site investigator, would interfere with adherence to study requirements * Fractures less than 6 months