A robotic arm exoskeleton used for motor skill training could help people with post-stroke weakness that affects an entire side of the body.
In a pilot study, researchers compared the extent of motor learning for people with post-stroke hemiparesis to people who have not had stroke and studied whether the use of an upper limb exoskeleton affected the success of stroke recovery.
“Rehabilitation for individuals with stroke is time and labor intensive,” Syed Zain Ali, a medical student at New York Institute of Technology College of Osteopathic Medicine and lead investigator in the study, said in a press release. “Hence, rehabilitation technology is being developed to facilitate more therapy with limited human resources, with the help of robots for rehabilitation.”
He added, “However, the use of robots for rehabilitation may not be a one-size-fits-all approach. We need to understand how to optimize training for individual patients. This study was initiated to understand which facets of robotic training benefit patients at different stages of recovery, so that the right training approach can be chosen for each patient.”
According to the release, the researchers used the CAREX, a lightweight, upper limb exoskeleton developed by Sunil K. Agrawal, PhD, professor of engineering at Columbia University’s The Fu Foundation School of Engineering and Applied Science. The CAREX consists of three lightweight cuffs on the shoulder, arm and forearm that are attached to motor-controlled cables.
The study included 14 people with chronic post-stroke right hemiparesis and seven who had not had a stroke. All participants performed three sets of circle drawing exercises. The robotic exoskeleton was used during the exercises to support the affected arm against gravity, while the wearer drew the circles and assisted in the movement of the arm along a prescribed trajectory. The exercises were used to test the exoskeleton’s functions of gravity elimination and path assistance, both individually and together.
The researchers found participants recovering from stroke deviated off the pre-determined circle trajectory more than those who had not experienced a stroke. In addition, the success of the exercises was affected by the amount of muscle strength and control of the participant.
“We found that higher-functioning patients, those who had muscle strength but not control, benefited from the path-assistance provided by the robot, whereas lower-functioning patients did worse when path assistance was provided. They did better, however, when the arm was supported by the robot,” Ali said.
The next step for the research is a study of the therapeutic effects of CAREX during a longer period of training and follow-up.
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Disclosure: The researchers report no relevant financial disclosures.
