Robot-Assisted Rehabilitation Helps Stroke Patients

Task-specific rehabilitation with an exoskeleton robot leads on average to slightly better results than conventional therapy, according to a new study.

Researchers at ETH Zurich (Switzerland), the University of Zurich (Switzerland) and other institutions conducted a prospective trial that enrolled 77 patients who suffered motor impairment for more than six months and moderate-to-severe arm paresis after a stroke. The patients were randomly assigned to receive robotic (38 patients) or conventional (35 patients) therapy. For both groups, therapy was given for at least 45 minutes three times a week for 8 weeks (total 24 sessions). The primary outcome was change in score on the arm (upper extremity) section of the Fugl-Meyer assessment (FMA-UE).


The results showed that on average the improvement in patients assigned to robotic therapy compared to those in conventional therapy was small, but that those who had more severe paresis made far greater progress with the help of the robot in motor function in the affected arm over the course of the study, as measured by FMA-UE. The study revealed that robotic therapy produced better results in terms of sensory-motor function, but conventional therapy was better in terms of building strength. The study was published early online on December 30, 2103, in the Lancet Neurology.

“Roughly six months after a stroke most patients reach a chronic stage despite therapy in which further treatment would not restore hardly any additional mobility,” said lead author Verena Klamroth, PhD, of ETH. “Overcoming this plateau was a major challenge for clinical research. The fact that we have achieved this with the help of the robot is wonderful and gives rise to hope.”

“An advantage of the therapy robot is not just that this form of therapy is possible for every degree of paresis but also that the patients can train independently, perhaps one day even at home,” added senior author Prof. Robert Riener, PhD, of the ETH Sensory-Motor Systems Lab. “The robot not only supports movement but also motivates the patient via computer game elements. Thanks to these game-like elements patients repeat the exercises more often.”

For the study, the researchers used the ETH arm therapy robot ARMin, which is based on a haptic display with semi-exoskeleton kinematics via four active and two passive degrees of freedom. Equipped with position, force, and torque sensors, the device can deliver patient-cooperative arm therapy taking into account the activity of the patient, and supporting him/her only as much as needed. The haptic display is combined with an audiovisual display that is used to present the movement and the movement task to the patient.

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