High Vs Low Intensity Virtual Reality Gait Training in Individuals with Chronic Stroke

Inclusion Criteria: * Unilateral deficits following stroke \> 6 months prior; however individuals \> 4 months post-stroke are eligible for consenting, but final eligibility and potential enrollment will not occur until \> 6 months * Age 18-85 years * Weight \< 350 pounds * Able to follow a 3-step command * Able to ambulate with self-selected gait speeds between 0.01-1.0 m/s without physical assistance, but with below knee bracing and/or assistive device as needed * Lower extremity Fugl-Meyer \< 34 * Medical clearance to participate Exclusion Criteria: * Evidence of cerebellar ataxia * Uncontrolled cardiopulmonary or metabolic disease that limits exercise participation, active heterotopic ossification, recurrent history of lower extremity fractures, previous orthopedic or other peripheral or central neurologic injury that may impair locomotor activities * Currently participating in other physical therapy * \> 50 units of Botox in the lower extremity OR in the lower extremity, but above the knee if the participant wears an ankle-foot-orthosis (AFO) within the past three months. Note that participants may be consented prior to 3 months post-injection; however, eligibility will be determined post 3 months. * Unable to read \> 50% of the letters on the 20/70 line of the Snellen Chart with customary eye wear at a distance of 20 feet