Context

Adhesive capsulitis (frozen shoulder or painful stiff shoulder) is relatively common. It is idiopathic: known associated factors include trauma, diabetes, prolonged immobilisation, age, stroke and autoimmune disease. While self-limited, pain and decreased range of motion can last up to 2–3 years. Therefore, there is practical value in therapeutic interventions to hasten symptom resolution. Arthroscopic examination suggests involvement of both the capsule and the rotator interval, defined as the space between the subscapularis and supraspinatus tendons, including the long head of the biceps tendon, the coracohumeral and the superior glenohumeral ligaments, and part of the joint capsule.1 Although corticosteroid injections appear to be more effective …