If you exclude the muscle damage around the waist caused by the strenuous lovemaking process or the lumbar spine slipping, then it may be due to the uterus being in the posterior tilt and retroflexion position, and the stimulation after intercourse causes the uterus to contract and stimulate the retroperitoneum, which can cause back pain in the clinical situation. It may also be due to inflammation of the sacral ligament in women, and pelvic congestion will occur after intercourse, which will aggravate the congestion of the originally congested sacral ligament, and the symptoms of lumbar pain will occur. Therefore, women who have sex with symptoms of lumbar pain, must take a good rest, if there is no relief within a short period of time, the symptoms of lumbar pain in the progressive aggravation, must promptly go to the regular hospital, choose a reasonable treatment, do not delay the disease.