Abstract
Isokinetic tests of seven patients presenting with symptomatic posterior shoulder subluxation were studied. Patients were tested over a velocity spectrum from. 100–400 deg/sec in two diagonal shoulder motions and internal/external rotation at 45 deg abduction. Torque curve abnormalities were seen from approximately 70–110 deg with the flexion/abduction/external rotation diagonal and 85 deg with the extension/adduction/internal rotation diagonal. These defects were present both while the patient was symptomatic and asymptomatic. In conclusion, posterior rotator cuff insufficiency at the specific position of torque suppression was responsible for the abnormal finding in flexion. Posterior labral tearing with an associated clunk test created the positive finding on the extension curve.