Magnetic Resonance Imaging of Pseudo-impingement of Rotator Cuff with Strength Training

Objective: The objective of this study was to outline a novel unique concept of secondary impingement of the muscles, myotendons, and tendons of the rotator cuff from hypertrophy as a result of strength training exercises. Methods: In this retrospective observational study, 58 patients were referred for an magnetic resonance imaging (MRI) by the orthopedic surgeon to the radiology department over a period of 1½ years. All patients gave a history of strength training exercises and presented with clinical features of rotator cuff impingement. Results: We identified features of hypertrophy of rotator cuff muscles, myotendons, and tendons in 12 of these 58 patients. This was the only abnormality on MRI. The hypertrophy of rotator cuff muscles and tendon bulk completely filling the subacromial space to the point of overfilling and resulting in secondary compressive features. Conclusion: Rotator cuff impingement is a common phenomenon that can occur with various inlet and outlet pathological conditions. However, rotator cuff impingement may also result from muscle and tendon hypertrophy from strength training regimens. Hypertrophy of the rotator cuff can result in overfilling of the subacromial space, leading to secondary impingement, which we have termed as “pseudo-impingement.”