Shoulder disorders that cause shoulder pain seriously affect patients' daily life and work capacity. Rotator cuff tear (RCT) is one of the most common shoulder diseases leading shoulder pain, with higher prevalence in the elderly. However, the etiology of RCT is not clear at present. Some studies have found that patients with RCT have scapular dyskinesis (SD) . In recent years, more and more studies have begun to pay attention to the relationship between SD and RCT, and therapy aiming to SD can reduce the symptoms of shoulder pain in patients with RCT and improve their function. Therefore, understanding the SD may be of great significance to the prevention, diagnosis and treatment of RCT.