training the ‘good’ arm improves skills

Train the arm Wellthat is, the least affected, after a chronic stroke improves motor skillsboth coordination and speed and movement control.

This is revealed by a new study, published in the journal JAMA Neurologywhich points out that, unlike traditional rehabilitation therapy in these cases, focused on recovering strength and movement of the most affected side of the body, Therapy focuses on the less affected arm, significantly improving movement and control.

To reach this conclusion, this randomized clinical trial, led by researchers at Penn State and the University of Southern California (USC), compared this new approach to the standard best-practice therapy currently used. They participated in the study 53 people who had suffered a chronic stroke at least three months before. All of them had a severe disability in one arm and depended on the other for daily tasks.

During the trial, they received rehabilitation therapy three times a week for five weeks. Twenty-five of them received therapy on the less affected arm, which included skill training focused on daily activities and virtual reality games; while the remaining twenty-eight were assigned to the control group and received standard therapy.

“By training the less affected arm, the patients improved“explains Candice Maenza, project director of the Neurorehabilitation Research Laboratory at Penn State College of Medicine and first author of the study.”This could improve quality of life and reduce the burden of care for caregiversas stroke survivors with severe paralysis on one side rely on this arm for everyday tasks such as eating or dressing.”

For his part, study co-author Robert Sainburg, the Dorothy F. and J. Lloyd Huck Distinguished Professor in Kinesiology and Neurology at Penn State, explains that traditional physical rehabilitation focuses on the most affected side of the body because the lack of strength and movement is so evident that the other side of the body appears to be able to retain normal function. But this side, even though it is the least affected, also loses a significant functionhe points out, causing slow and poorly coordinated movements, which makes it difficult to compensate for the reduced capacity of the other, more affected arm.

“The effect of the stroke on the less affected arm has added a additional deficitlet’s say one loss of motor coordination of between 10% and 25% in the hand with greater function. “This is very important in terms of which tasks you can do yourself and which require assistance,” he explains.

With this in mind, this study, conducted at Penn State and USC, and based on a previous pilot study by Sainburg and Maenza, is the first to “use a rigorous randomized clinical trial design to investigate the use of ipsilesional limb training (training of the less affected arm) in chronic stroke survivors with severe paresis,” says Carolee Winstein, professor emeritus and associate professor in biokinesiology and physical therapy at USC and co-principal investigator of the study.

“What we are doing is a remediation never done before. We are modifying the function of the less affected hand so that your daily activities are more efficient“, he points out, and explains that standard therapies, although they involve the less affected hand, only do so to compensate for the use of the other but not to restore its capacity before the accident.

Significant improvements

The results are clear, and the participants who trained the less affected arm showed significant improvements in the motor function of the arm compared to the control group, being able to complete a standard skill check 12% (nearly 6 seconds) faster than at the beginning.

“Stroke patients could do things like fasten a button, but it took so much time that it wasn’t worth doing it alone. Being a little faster makes them want to try it themselves“, notes Maenza. “This can change the life not only of the patient, but also of their spouse or caregiver, since the burden of care is reduced”.

It should be noted that These improvements lasted until at least six months after completing therapy.. “Targeted intervention places patients in what therapists call a virtuous circle“Sainburg explains. “Once you get a little bit of functionality, you use it and things keep getting better.”

“Our results open the door to future research directionssuch as multimodal approaches where ipsilesional limb training is combined, as was done here, with training targeting both arms, where each side is uniquely controlled by the nervous system,” says Winstein.