Evaluation of Apparent and Absolute Supraspinatus Strength in Patients With Shoulder Injury Using the Scapular Retraction Test

Background: Physical examination of patients with shoulder injury not involving actual rotator cuff tears frequently demonstrates decreased rotator cuff strength on manual muscle testing. This decrease has been attributed to supraspinatus muscle weakness, but it may be owing to alterations in scapular position.Hypothesis: The position of stabilized scapular retraction, by minimizing proximal kinetic chain factors and providing a stable base of muscle origin, positively influences demonstrated supraspinatus strength.Study Design: Controlled laboratory study.Methods: Supraspinatus strength was tested in 20 injured patients and 10 healthy controls in both the empty-can arm position and a position of scapular retraction using a handheld dynamometer. Pain in both maneuvers was measured by use of a visual analog scale.Results: Paired t tests indicated the scapular retraction position resulted in statistically significantly (P = .001) higher supraspinatus strength values within both groups. There was no signific...