Effects of Multiple Practice Sessions of Isometric Reaching on Upper-Limb Muscle Synergies in Chronic Stroke Survivors

We investigated the effects of practicing an isometric reaching task in virtual reality for multiple sessions on muscle synergies and motor function of stroke survivors. We observed significant improvements in clinical outcomes, as indicated by increased clinical scores and enhanced task performance metrics over multiple sessions. Analysis of muscle synergies revealed initial disparities in muscle activation patterns between stroke and healthy control groups, which were reduced following therapy. Additionally, we observed a progressive alignment of synergy subspaces between the affected and unaffected arms as therapy progressed. These findings underscore the potential of virtual reality interventions to modify muscle synergies and improve motor recovery in stroke rehabilitation.