Abstract
Conventional neurodevelopmental therapy for hemiparetics consists of therapist-assisted repetitive manipulation (RM) of the affected limb for one hour, 2–3 times a week over a period of several months. In this study we investigate robot-assisted RM in conjunction with a video game designed to produce more of a sense of agency and increased levels of neural engagement. We suggest that by activating as many neural circuits as possible involved in sensation, proprioception, self-perception, movement and attention, the potential for rehabilitation is maximized. We tested ten recovering stroke survivors with varying degrees of hemiparesis. All participants received each of the following four conditions over a four-month period with hour-long, biweekly therapy sessions. (i) Control: A non-treatment period, (ii) Robot Only: Externally-controlled, robot-assisted movements of the effected arm, (iii) Mirror Illusion: Illusory motion of the affected arm induced through movements of the good arm made in front of a sagittally-oriented mirror, and (iv) Robotically-Mirrored Motion: Actively-controlled, robot-assisted movements of the effected arm that copied motion of the unaffected arm. Each robot was connected to a video game, which increased attention by engaging participants in purposeful movements. To varying degrees, each treatment induced the sometimes illusory sense of agency, which appeared to further engage the patient and enhance enjoyment of therapy. The findings support gains in upper extremity functionality due to treatments facilitating higher levels of neural engagement. The results confirm the clinical value of both robotic-assisted therapy and an integrated therapy structure that allows patients to experience purposeful, if illusory control of movement.