Mobile App-Guided Home Exercise Versus Conventional Pamphlet-Based Instruction After Corticosteroid Injection in Patients with Frozen Shoulder: A Pilot Randomized Trial

Background: Frozen shoulder (FS) is a debilitating condition characterized by pain and restricted range of motion (ROM), often leading to prolonged treatment and economic burden. Home exercise programs are effective for FS, so we developed the Defrozen app to support home exercise. This randomized controlled trial (RCT) compared app- versus pamphlet-assisted home exercise programs in patients with FS. Methods: In this RCT, twenty-one patients with FS who received corticosteroid injections were randomized (2:1) to app or pamphlet-assisted home exercise. Baseline assessments were performed, and all participants initiated their assigned home exercise program, which lasted 4 weeks. Outcomes included shoulder ROM, pain intensity (numeric rating scale, NRS), and functional outcomes (Oxford Shoulder Score [OSS] and Quick Disabilities of the Arm, Shoulder, and Hand [QuickDASH] score). Results: Both groups demonstrated significant within-group improvements in ROM measures, NRS, OSS, and QuickDASH scores (p < 0.05). Between-group comparisons using analysis of covariance (ANCOVA) showed significantly greater gains in shoulder abduction (p = 0.023) and internal rotation (p = 0.020) in the app-assisted group compared with the pamphlet group. Conclusions: A four-week app-based home exercise program provides additional benefits in improving shoulder ROM compared with conventional pamphlet-based instruction in FS after corticosteroid injection.