Patients with lumbar muscle strain may have low back pain on one side or both sides at the same time, depending on the specific onset. As the muscle tissues on both sides of the waist are in a state of fatigue at the same time, if accompanied by bilateral cold at the same time, it is more likely to have bilateral pain in the waist. Sometimes when performing activities, one side of the muscle is in a state of tension, the other side is more relaxed, such as in the standing position of one side of the weight bearing, it is easy to cause one side of the muscle tissue fatigue, the formation of lumbar muscle strain. There is also a chronic sterile inflammatory lesion in the lumbar region itself, if both sides exist at the same time, it is easy to appear in the same state of both sides at the same time the symptoms of pain. If there is an obvious sterile inflammatory lesion on one side, it will be manifested as a unilateral pain sensation, so it is possible for lumbar muscle strain to have pain on both sides at the same time, or on one side.