82 patients, between the ages of 18 and 67 years of age, showing clinical signs of chronic tendinitis for at least 6 months, were randomly assigned into one of two treatment groups (intervention or placebo) to test the effect of radial extracorporeal shock-wave therapy (rESWT) on patients with chronic tendinitis of the rotator cuff, 6 months after treatment. The results of the study demonstrated that rESWT lead to similar pain, Constant-Murley, and Simple Shoulder Test scores at final follow up, indicating that low-dose radial extracorporeal shock-wave therapy does not reduce pain or improve function in patients with chronic rotator cuff tendinitis when compared to a placebo treatment.