Statistical analysis
An unpaired t-test for continuous variables (age, grade) and chi-square was calculated by categorical variable (gender). The WORC, DASH and VAS were compared between two groups following a subacromial corticosteroid injection, by using unpaired t-test. 5. The repeated measurement ANOVA analysis is used to a longitudinal during follow-up in this study. Statistical significance was defined as being where a P-value was less than 0.05. The data analyses were performed using SPSS version 20.