This study aims to provide an adjunct to accelerate neurorehabilitation for stroke patients. The MAHI EXO-II, a physical human-robot interface, will be combined with a non-invasive brain-machine interface (BMI) to actively include the patient in the training of upper extremity motor functions.
Inclusion Criteria: 1. Diagnosis of unilateral cortical and subcortical stroke confirmed by brain CT or MRI scan; 2. Subacute or chronic stroke; interval of at least 3month and interval of at least 6 months from stroke to time of enrollment, respectively; 3. No previous clinically defined stroke; 4. Age between 18-75 years; 5. Upper-extremity hemiparesis associated with stroke (manual muscle testing score of at least 2, but no more than 4/5 in the elbow and wrist flexors); 6. No joint contracture or severe spasticity in the affected upper extremity: i.e., significant increase in muscle tone against passive ROM is no more than ½ of full range for given joint e.g., elbow, wrist and forearm movements. 7. Sitting balance sufficient to participate with robotic activities; 8. No neglect that would preclude participation in the therapy protocol; 9. Upper limb proprioception present ( as tested by joint position sense of wrist); 10. No history of neurolytic procedure to the affected limb in the past four months and no planned alteration in upper-extremity therapy or medication for muscle tone during the course of the study; 11. No medical or surgical condition that will preclude participation in an occupational therapy program, that includes among others, strengthening, motor control and functional re-training of the upper limbs; 12. No contraindication to MRI; 13. No condition (e.g., severe arthritis, central pain) that would interfere with valid administration of the motor function tests; 14. English-language comprehension and cognitive ability sufficient to give informed consent and to cooperate with the intervention.- Exclusion Criteria: 1. Orthopedic limitations of either upper extremity that would affect performance on the study; 2. Untreated depression that may affect motivation to participate in the study; 3. Subjects who cannot provide self-transportation to the study location. Inclusion and Exclusion Criteria for Health Subjects: Inclusion criteria: - able to understand and sign the consent form - age 18-65 Exclusion criteria: - Previous history of or MRI findings consistent with brain tumors, strokes, trauma or arterial venous malformations - Contraindication to MRI - Pregnancy