The Effect of Adding a Large Dose of Shoulder Strengthening to Nonoperative Care for Subacromial Impingement on Shoulder Disability, Quality of Life, Sick Days, and Surgery Rates: 1-Year Results From a Pragmatic, Double-Blind Randomized Controlled Trial (SExSI).

Background: Subacromial impingement syndrome (SIS) is the most common and costly cause of shoulder pain. Recent guidelines emphasize reducing surgical interventions in favor of exercise-based care, but many patients experience suboptimal outcomes. Purpose: To investigate the effect of prescribing a large dose of resistance exercises in addition to nonoperative care compared with nonoperative care alone, in patients with long-standing SIS at 1-year follow-up, on the following outcomes: shoulder disability, health-related quality of life, number of days of sick leave, and surgery rates. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: This study analyzed the effect at 1 year after randomization in the Strengthening Exercises in Shoulder Impingement (SExSI) trial, a pragmatic, double-blinded randomized controlled trial with a 2-group parallel design. A total of 200 participants with long-standing SIS were randomized to 16 weeks of standard nonoperative care alone (control) or standard nonoperative care plus a large dose of progressive resistance exercises targeting the shoulder (intervention). Outcomes were assessed at 1 year and included shoulder disability (using the Shoulder Pain and Disability Index [SPADI]), health-related quality of life, days of sick leave due to the shoulder disorder (reported weekly through text messages), and surgery rates. Results: At 1 year, no significant differences were observed between groups for improvements in SPADI scores (mean difference, 4 [95% CI, -13 to 5]) or quality of life. We observed no difference in the odds of any sick leave (odds ratio, 0.84 [95% CI, 0.30-2.30]). For those reporting sick leave, the duration was 12% shorter in the intervention group (mean ratio, 0.88 [95% CI, 0.38-2.02]), but this did not constitute a significant difference. We also did not observe any difference in surgery rates between the control and intervention groups (12.1% vs 10.8%, respectively; risk difference, -1.3% [95% CI, -10.9% to 8.3%]). Conclusion: Adding a large dose of shoulder strengthening exercises to nonoperative care for 16 weeks did not significantly improve long-term outcomes in terms of shoulder disability, health-related quality of life, sick leave, or surgery rates at 1 year. This demonstrates that adding a structured, high-volume exercise program to exercise therapy may not provide further benefits in the long-term management of SIS. Registration: NCT02747251 (ClinicalTrials.gov).