Fixed unilateral sleeping for a long time may cause shoulder internal buckling. Normal people sleep at night, will be in the left side position, lying position, right side position repeatedly change, in this case, unilateral sleep generally does not cause shoulder internal buckle. If you are forced to sleep unilaterally for physical reasons or have the habit of sleeping unilaterally for a long period of time, the ligament muscles around the unilateral shoulder joint will be compressed for a long period of time, which may lead to the formation of shoulder internal buckling. This may cause unilateral shoulder pain and bilateral shoulder asymmetry. It is possible to reduce the pressure on one shoulder by consciously changing the unilateral sleeping habit or increasing the height of pillow to reduce the shoulder impingement. If unilateral shoulder impingement is caused by sleep, it is recommended that the patient go to the hospital to clarify the cause of the disease and receive regular treatment.