After rotator cuff injury, the muscle tendon atrophy, first of all, we should treat the damaged rotator cuff, and later promote the recovery of atrophied muscle through rehabilitation training. 1. Rotator cuff injury is generally seen in shoulder joint trauma, in which supraspinatus tendon injury is common, most rotator cuff injuries need surgical treatment, if rotator cuff injury is not treated in time, it will lead to shoulder joint dysfunction, and then muscle disuse atrophy. Therefore, it is necessary to repair the damaged rotator cuff, such as arthroscopic rotator cuff repair. 2. After the rotator cuff is treated accordingly, the function of the shoulder joint will be recovered gradually, and the atrophied muscles can be recovered after systematic rehabilitation training. However, if long-term rotator cuff injury is not treated in time, resulting in serious muscle atrophy, the later recovery is not ideal. Muscle and tendon atrophy after rotator cuff injury needs to be actively consulted and reasonably treated according to the doctor’s prescription.