2007/05/07 by Randall F. Beer, Michael D. Ellis, Bradley G. Holubar +2
Medicine · #Botulinum Toxin and Related Neurological Disorders #Musculoskeletal pain and rehabilitation #Stroke Rehabilitation and Recovery
paper · doi:10.1002/mus.20817
openalex publication_date 2007/05/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The ability to extend the elbow following stroke depends on the magnitude and direction of torques acting at the shoulder. The mechanisms underlying this link remain unclear. The purpose of this study was to evaluate whether the effects of shoulder loading on elbow function were related to weakness or its distribution in the paretic limb. Ten subjects with longstanding hemiparesis performed movements with the arm either passively supported against gravity by an air bearing, or by activation of shoulder muscles. Isometric maximum voluntary torques at the elbow and shoulder were measured using a load cell. The speed and range of elbow extension movements were negatively impacted by actively supporting the paretic limb against gravity. However, the effects of gravity loading were not related to proximal weakness or abnormalities in the elbow flexor-extensor strength balance. The findings support the existence of abnormal descending motor commands that constrain the ability of stroke survivors to generate elbow extension torque in combination with abduction torque at the shoulder.