The condition is often caused by strain on soft tissues such as muscles, tendons and ligaments in the lower back, combined with cold. Because of the strain, a sterile inflammatory lesion will be formed, which will cause the surrounding muscles to be in a state of tension and contraction, and the small blood vessels passing through them will contract, resulting in a decrease in blood supply. After the venous return is affected, it will lead to the accumulation of inflammatory metabolites, which will lead to tightness in the lumbar region, and the muscles will become tense and feel inflexible when moving. In addition, it may also be due to cold, as cold causes blood circulation to become slower, resulting in decreased blood supply, and the muscles become more tense due to cold, therefore, also aggravating the feeling of soreness and tightness.