The purpose of this study is to determine if treadmill training combined with thera-band resistance to body support and forward propulsion would be more effective than treadmill training alone in improving over-ground walking ability and reducing energy cost in chronic stroke patients. This study will also characterize the neuromuscular and kinematic strategies to adapt to resisted treadmill walking in non-impaired adults and stroke patients.

This study includes chronic stroke patients who will be randomly assigned to treadmill training combined with thera-band or treadmill training alone group to receive 30 min per session, 2 sessions per week for 8 weeks walking training . Functional balance (Berg Balance Scale), gait characteristics during preferred and maximal speed level walking, and oxygen uptake during 5-minute bouts of treadmill walking will be assessed before and after training and at 2-month follow-up. Clinical sensorimotor function assessment, including hand grip strength, plantar sensitivity, stroke rehabilitation assessment of movement and Fugl-Meyer lower extremity motor scale will also be conducted for subject characterization.

Inclusion Criteria:

1. the diagnosis of first time unilateral stroke more than 6 months before
2. the ability to walk for at least 15 m without person assistance
3. apparent gait deficits upon visual inspection by a trained physical therapist or inability in community ambulation, i.e. walking speed < 0.8 m/s
4. resting blood pressure lower than 150/90 mmHg.

Exclusion Criteria:

1. older than 75 years
2. inability to follow the experimental instructions or procedures
3. any pain, inflammation, or other conditions that could affect walking
4. medically unstable.