Electromyography-controlled exoskeletal upper-limb-powered orthosis for exercise training after stroke.
OBJECTIVE
Robot-assisted exercise shows promise as a means of providing exercise therapy for weakness that results from stroke or other neurological conditions. Exoskeletal or "wearable" robots can, in principle, provide therapeutic exercise and/or function as powered orthoses to help compensate for chronic weakness. We describe a novel electromyography (EMG)-controlled exoskeletal robotic brace for the elbow (the active joint brace) and the results of a pilot study conducted using this brace for exercise training in individuals with chronic hemiparesis after stroke.


METHODS
Eight stroke survivors with severe chronic hemiparesis were enrolled in this pilot study. One subject withdrew from the study because of scheduling conflicts. A second subject was unable to participate in the training protocol because of insufficient surface EMG activity to control the active joint brace. The six remaining subjects each underwent 18 hrs of exercise training using the device for a period of 6 wks. Outcome measures included the upper-extremity component of the Fugl-Meyer scale and the modified Ashworth scale of muscle hypertonicity.


RESULTS
Analysis revealed that the mean upper-extremity component of the Fugl-Meyer scale increased from 15.5 (SD 3.88) to 19 (SD 3.95) (P = 0.04) at the conclusion of training for the six subjects who completed training. Combined (summated) modified Ashworth scale for the elbow flexors and extensors improved from 4.67 (+/-1.2 SD) to 2.33 (+/-0.653 SD) (P = 0.009) and improved for the entire upper limb as well. All subjects tolerated the device, and no complications occurred.


CONCLUSIONS
EMG-controlled powered elbow orthoses can be successfully controlled by severely impaired hemiparetic stroke survivors. This technique shows promise as a new modality for assisted exercise training after stroke.
Stein
Joel
J
Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, USA.
Narendran
Kailas
K
McBean
John
J
Krebs
Kathryn
K
Hughes
Richard
R
D001915:Braces; D004185:Disability Evaluation; D004576:Electromyography; D005081:Exercise Therapy / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010291:Paresis / Q000503:physiopathology / Q000534:rehabilitation; D010865:Pilot Projects; D012371:Robotics; D020521:Stroke / Q000503:physiopathology; D000071939:Stroke Rehabilitation; D016896:Treatment Outcome; D034941:Upper Extremity / Q000503:physiopathology