Empowered Relief and Exercise Rehabilitation for People With Subacromial Shoulder Pain

Inclusion Criteria: * Age 18 to 65 years, inclusive. * Shoulder pain for at least 3 months. * Sufficient Danish language proficiency to understand study information, follow instructions, and complete questionnaires. * Diagnosis of subacromial pain syndrome (SAPS), confirmed by either: * an existing clinical diagnosis provided by a referring clinician, or * a standardized study-based clinical examination with at least 3 of the following 5 tests positive: Painful Arc test, Empty Can (Jobe's) test, Neer's test, Hawkins-Kennedy test, and External Rotation Resistance test. * Pain Catastrophizing Scale (PCS) score greater than 16. Exclusion Criteria: * Current regular use of strong analgesic medication, excluding over-the-counter medication. * Pregnancy. * Referral for postoperative shoulder rehabilitation. * Corticosteroid injection in the affected shoulder within the past 2 months. * Current fracture of the affected shoulder, radiographically verified. * Glenohumeral osteoarthritis in the affected shoulder, radiographically verified. * History of shoulder dislocation or subluxation in the affected shoulder. * Suspected labral lesion of the affected shoulder. * Suspected full-thickness rotator cuff tear. * Suspected frozen shoulder (adhesive capsulitis). * Presence of competing conditions that may explain the shoulder pain or interfere with participation, including but not limited to cancer, inflammatory rheumatic disease, neurological disorders, fibromyalgia, or severe psychiatric disease.