The difference between frozen shoulder and rotator cuff injury is mainly different in etiology, clinical manifestation and treatment. 1. Etiology: Frozen shoulder is caused by chronic strain injury or degenerative changes of shoulder joint, and the tissues around the joint are widely adhered, causing aseptic inflammation. Rotator cuff injury is mostly caused by trauma to the shoulder joint, and a small part of it is caused by degeneration of the shoulder joint. 2. Clinical manifestations: frozen shoulder pain in the shoulder joint at night, shoulder joint active and passive activities are limited. In rotator cuff injury, pain in abduction activities, lifting weakness, shoulder joint active activities are limited, passive activities are normal. 3. Treatment: Frozen shoulder take non-steroidal anti-inflammatory drugs such as diclofenac sodium extended-release tablets, ibuprofen extended-release capsules, etc., take rehabilitation exercises, massage and other methods. Rotator cuff injury small tear shoulder joint abduction brace fixed for a month, if the tear is relatively large line arthroscopic surgical repair. The above aspects are the main difference between frozen shoulder and rotator cuff injury, when the shoulder joint pain, activity limitation timely medical treatment.