The purpose of this study was to investigate the effects of gait training with the new wearable hip assist robot developed by Samsung Advance Institute of Technology (Samsung Electronics Co, Ltd, Korea) in patients with chronic stroke.

Seven chronic stroke patients will participate in this study. All subjects will receive training 3 times per week for 8 weeks for 24 training sessions. Each session is directed by a licensed physical therapist and lasted 60 min (including rest period of 10 min). Brain activity and gait assessment will be performed at visits 0 (baseline), 24 (post-test), and at 3 months (follow-up) after training.

Primary objective is to demonstrate the effects of hip assist robot on spatio-temporal parameters measured by motion capture system (Motion Analysis Corporation, Santa Rosa, CA, USA), muscle activation patterns measured by surface electromyography (sEMG) (Noraxon Inc., Scottsdale, AZ, USA), metabolic energy cost parameters measured by portable cardiopulmonary metabolic system (Cosmed K4B2, Rome, Italy) and cortical activation measured by functional Near-Infrared-Spectroscopy (fNIRS) (NIRScout, NIRx, Germany).

Secondary objective is to demonstrate the effects of hip assist robot on motor function improvement evaluated by Berg Balance Scale (BBS), Dynamic Gait Index (DGI), Timed Up and Go (TUG) test, Push and Release (P&R) test, Functional Reach Test (FRT), Korean version Fall Efficacy Scale (K-FES), Manual Muscle Test (MMT) and Range of Motion (ROM).

Inclusion Criteria:

1. Age: between 20 and 84 years
2. ≥ 3 months post stroke
3. Ability to walk at least 10m regardless of assist devices
4. Adequate gait function (FAC > 3)
5. Physician approval for patient participation

Exclusion Criteria:

1. Serious cardiac conditions (hospitalization for myocardial infarction or heart surgery within 3 months, history of congestive heart failure, documented serious and unstable cardiac arrhythmias, hypertrophic cardiomyopathy, severe aortic stenosis, angina or dyspnea at rest or during activities of daily living)
2. Advanced liver, kidney, cardiac, or pulmonary disease
3. History of concussion in last 6 months
4. History of unexplained, recurring headaches, epilepsy/seizures/skull fractures or skull deficits
5. Preexisting neurological disorders such as Parkinson's disease, Amyotrophic Lateral Sclerosis (ALS), Multiple Sclerosis (MS), dementia