Rotator cuff injury and frozen shoulder are two different types of diseases and it is impossible to compare which disease is more serious. The common feature of rotator cuff injury and frozen shoulder is that both can cause joint pain and joint movement limitation. However, the causes of pain and joint limitation are different. Rotator cuff injury is due to rotator cuff strain or rupture, due to the mechanical structure of the abnormalities caused by the shoulder joint activities and pain. Frozen shoulder is caused by adhesion of tendons, ligaments, joint capsule and other tissues around the shoulder joint, resulting in limitation of movement and pain. Rotator cuff injury and frozen shoulder are treated differently. Rotator cuff injury can be treated by suspension braking to promote the recovery of rotator cuff strain, while rotator cuff rupture needs to be treated by arthroscopic surgery. Frozen shoulder treatment is the opposite of rotator cuff injury, and it is necessary to strengthen the functional exercise of the shoulder joint in order to be able to recover faster.