Inclusion Criteria- adults at least 18 years old;
- able to provide informed consent;
- able to follow three-step motor command;
- have a single unilateral stroke;
- medically stable (i.e. asymptomatic for bladder infection, decubiti, osteoporosis, cardiopulmonary disease, pain, or other significant medical complications that would prohibit or interfere with walking;
- able to stand with assistance and/or ambulate 15 meters with or without an assistive device or brace and no greater than standby physical assistance.
Exclusion Criteria- weight > 300 pounds due to limitations in body weight support systems;
- body size which is incompatible with harnesses;
- presence of significant musculoskeletal problems that limit hip and knee extension or ankle plantarflexion to neutral;
- self selected walking speed below 0.3 m/s; and
- history of congestive cardiac failure, unstable angina, or peripheral vascular disease.