1. Therapeutic exercise, especially stretch exercise and joint mobilization, remain the mainstay of conservative treatment of frozen shoulder.

   1. Nevertheless, shoulder pain during the physiotherapy reduces the treatment effect.
   2. Manipulation or arthroscopic release under general anesthesia may avoid pain during the intervention; however, increased risk of humeral shaft fracture and failure of release of pathological tissue were reported.

2. We consider intra-articular injection is a compromized way, from a practical point of veiw, to reduce the pain during physiotherapy.

3. We hypothesize that, intra-articular injection with lidocaine before joint mobilization and stretch exercise, can make the patient pain-free during physiotherapy, and the effect of combined therapy is superior to physiotherapy alone in the treatment of frozen shoulder.

A randomized controlled trial to compare the effect in treatment of frozen shoulder between combined intra-articular injection with lidocaine plus physiotherapy and physiotherapy alone.

Inclusion Criteria:

• Clinically diagnosed as unilateral frozen shoulder, with the definition as more than 50% loss of passive movement of the shoulder joint relative to the non-affected side, in one or more of the three movement direction (ie. abduction in the frontal plane, forward flexion in sagittal plane, or external rotation in 0 degree of abduction)
• Duration of complaints of more than three months
• Ability to complete questionnaires in Chinese

Exclusion Criteria:

• History of shoulder fracture, dislocation, or trauma
• History of Rheumatic arthritis, tumor, or other diseases in the shoulder joints
• Receive intra-articular corticosteroid injection or manipulation therapy in shoulder joint in recent four weeks
• Pregnancy or breast feeding
• Allergic to lidocaine