Materials and methods
The prospective randomized control trial was designed specifically for this study. Sixty-four patients were selected during August 2020–May 2021 from the Outpatient Clinic, Department of Orthopedics, Thammasat University Hospital. After the informed consent was obtained for each of the patients on the basics of the inclusion criteria, the data and follow-up of the patients were recorded. The procedure of subacromial corticosteroid injection for each patient was block randomized by the computer randomization program (