Steroid injections are widely utilized to reduce inflammation and fibrosis in patients with the frozen shoulder. In this study, investigators will compare intra-articular steroid injections with direct coracohumeral ligament steroid injection to conventional intra-articular steroid injection. Investigators will measure the primary outcome as shoulder function improvement and secondary outcomes as ROM, pain scale and stiffness of coracohumeral ligament under elastogram.

Adhesive capsulitis of the shoulder, also known as the frozen shoulder, often leads to severe pain and shoulder range of motion limitation. Steroid injections are widely utilized to reduce inflammation and fibrosis. The thickening of the coracohumeral ligament was thought to play an important role in the pathogenesis of frozen shoulder, resulting in limited external rotation of the shoulder. While the elastogram of coracohumeral ligament will significantly increase stiffness under the shear-wave ultrasound (shear-wave elastography).

Therefore, in this study, investigators will compare intra-articular steroid injections with direct coracohumeral ligament steroid injection to conventional intra-articular steroid injection. Investigators will measure the primary outcome as shoulder function improvement and secondary outcomes as ROM, pain scale and stiffness of coracohumeral ligament under elastogram.

(the patient will not have additional risk of injection under ultrasound guidance)

A.Inclusion criteria：

1. Age 20-80 years old
2. Unilateral shoulder pain more than 3 months
3. At least one shoulder ROM limitation in three dimensions which decreased over 50% (Abduction, Flexion, External rotation)
4. Visual analog scale more than 30 (total 100)
5. No fracture or subluxation or arthritis in shoulder Xray.

B.Exclusion criteria：

1. History of shoulder or chest surgery
2. History of shoulder trauma in 2 recent years
3. Ever receiving shoulder joint injection in recent 3 months
4. With cervical radiculopathy or any central CNS disorders
5. With osteoarthritis or rheumatic arthritis of shoulder
6. Diagnosed as rotator cuff tear, tendon calcification or bursitis
7. Systemic diseases including diabetes or thyroid disorder
8. Allergy history of steroid