Ultrasound (US)-guided injections will be performed with a 5-12 MHz linear transducer (Logic e portable; GE Healthcare, China) by the same physiatrist and injections will be administered into the subacromial bursa with a posterolateral approach. 3 sessions (1 session/week) of 5 mL of ozone (O2-O3) will be injected (with a concentration of 10 μg/mL in the first session, 15 μg/mL in the second session, and 20 μg/mL in the third session).

US-guided injection will be performed with a 5-12 MHz linear transducer (Logic e portable; GE Healthcare, China) by the same physiatrist and injections will be administered into the subacromial bursa with a posterolateral approach. A mixture of 1 mL corticosteroid (betamethasone 3 mg/mL) and 1 mL lidocaine (20 mg) will be injected (1 session).

US-guided injections will be performed with a 5-12 MHz linear transducer (Logic e portable; GE Healthcare, China) by the same physiatrist and injections will be administered into the subacromial bursa with a posterolateral approach. 3 sessions (1 session/week) of 5 mL of ozone (O2-O3) will be injected (with a concentration of 10 μg/mL in the first session, 15 μg/mL in the second session, and 20 μg/mL in the third session).

The Western Ontario Rotator Cuff Index (WORC) is a self-administered assessment tool for rotator cuff disease. WORC has 21 questions in 5 domains consisting of work, physical symptoms, social well-being, emotional well-being, and sports and recreation. Each question is scored on a 100-mm, with higher scores demonstrating larger problems. Turkish validity of the WORC has been illustrated.

The Shoulder Pain and Disability Index (SPADI) is a 13 item self-assessment measurement tool to evaluate disability (8 items) and pain (5 items). The subscales of disability and pain are measured as the average of the corresponding items between 0-100, with higher scores indicating greater disability and pain.

supraspinatus tendon thickness, subacromial bursa thickness and acromiohumeral distance will be measured by US in both groups