Among patients with chronic stroke and severe contralesional impairment, targeted ipsilesional arm training supported significant and sustained improvements in ipsilesional motor performance vs best practice therapy.
Importance Ipsilesional upper-limb motor deficits after stroke are functionally important yet largely neglected in rehabilitation. Remediation may improve motor outcomes in individuals with severe contralesional arm hemiparesis.
Objective To determine whether training of the ipsilesional arm improves motor performance in chronic stroke with severe contralesional impairment and significant ipsilesional arm motor deficits.
Design, Setting, and Participants This 2-site, parallel-group randomized clinical trial with blinded outcome assessment was conducted from February 2019 to August 2024, with follow-up through 6 months posttreatment. Data analysis was performed from August 2024 through August 2025. The trial was conducted at outpatient research laboratories at Penn State College of Medicine and the University of Southern California among adults with radiologically confirmed unilateral middle cerebral artery stroke, severe contralesional upper-extremity impairment (Fugl-Meyer score ≤28), and ipsilesional motor deficits. Participants were randomly assigned with equal probability to 2 treatment groups and stratified by sex.









