Lumbar muscle strain is often caused by chronic inflammatory reaction, unhealed acute injury, congenital developmental deformity and so on. 1. Chronic inflammatory reaction: mostly seen in the waist for a long time engaged in heavy labor or long-term waist posture, resulting in local muscle and ligament aseptic inflammation. 2. Acute injury is not healed: may be an acute sprain after the occurrence of muscle and ligament and other tissue damage, but did not take timely treatment, delayed into chronic inflammation. 3. Congenital developmental deformity: for example, congenital arch root fracture, etc., will easily lead to lumbar muscle and ligament balance imbalance, easy to appear chronic lumbar muscle strain. Lumbar muscle strain may also be induced by some other reasons, it is recommended to go to the hospital in a timely manner, with the doctor to take treatment.