Robot-assisted rehabilitation therapy for adhesive capsulitis

BACKGROUND: Adhesive capsulitis, commonly known as frozen shoulder, presents with pain and restricted movement. Treatments include physical therapy focusing on stretching exercises, intra-articular corticosteroid injections, and surgical intervention if conservative management fails. The efficacy of robot-assisted rehabilitation therapy (RART) for adhesive capsulitis remains unexplored, necessitating clinical application and analysis. METHODS: A prospective, randomized controlled trial was conducted involving patients aged 20 to 60 years diagnosed with adhesive capsulitis. Participants were randomized into case and control groups. RART was administered using the Resilion U30A model (U30A, HEXAR Humancare, Gyeonggi-do, Republic of Korea). Subjective and objective clinical assessments were collected at baseline (pretreatment), phase 1 (1 month posttreatment), and phase 2 (3 months posttreatment), and subsequently analyzed. RESULTS: A total of 23 and 22 participants in the case and control groups, respectively, completed the study. While the overall objective clinical functional score did not differ significantly between the 2 groups, the case group showed statistically significant improvements in numeric rating scale scores and American Shoulder and Elbow Surgeons scores at phase 2 (3 months posttreatment) compared with the control group (P = .028 and .046). Notably, external rotation significantly improved over time in the case group (P = .042). CONCLUSION: This pilot study establishes the feasibility and tolerability of RART in patients with adhesive capsulitis and provides preliminary, exploratory evidence of beneficial effects on pain and range of motion. Given the underpowered final sample size (post hoc power: 68%-70%), these findings should be interpreted with caution and require confirmation in adequately powered future trials.