Abstract
This study was undertaken to determine whether or not some upper extremity muscle groups are affected more than others after a stroke, and subsequently to identify which muscle group was impaired the most in each of three pairs of opposing muscle groups. The static force production (strength) of seven upper extremity muscle groups was assessed bilaterally in 69 patients, all of whom had suffered an initial stroke. When compared with the values obtained in the nonparetic extremity, the relative strength was not consistent across the seven paretic upper extremity muscle groups. Paretic elbow extensor strength was preserved more than elbow flexor strength. In the paretic shoulder, internal rotator and extensor strengths were preserved more than external rotator and abductor strengths. The muscle strength imbalance, which tends to exist between the paretic shoulder depressors and elevators, and its possible influence on other problems that can occur in the hemiparetic shoulder are discussed.