Injection with corticosteroid is one of the most common non-operative interventions in the
treatment of subacromial impingement; however, its use is limited by its potential side
effects (e.g. tendon rupture, subcutaneous atrophy, articular cartilage changes). The
objective of this study was to compare the efficacy of subacromial injection of triamcinolone
compared to injection of ketorolac. Thirty-two patients diagnosed with external shoulder
impingement syndrome were included in this double-blinded randomized controlled clinical
trial. Each patient was randomized into the Steroid group or NSAID group.