The painful area may be located in the middle of the lower back, lumbosacral region, near the iliac crest, buttocks, or with pain in the posterior and lateral thighs, but usually does not exceed the knee joint. When the lumbar spine moves in a certain direction or several directions, the symptoms can be aggravated, and in severe cases, it is even impossible to walk and stand. There may be pressure pain in the painful area, and pressure pain and muscle spasm in the spinous process, small joints and transverse processes in the plane of the affected posterior branch above the painful area. The location of the complainant pain area has a stable relationship with the site of pain compression: if the complainant pain area is within the small joint line, it proves that the medial branch is involved; the injured posterior branch of the spinal nerve can be found in three planes upward from this plane, and the three points of pressure pain in the transverse process, small joint synapse, and spinous process through which the nerve passes and is distributed can be proved by deep pressure dispersion to the complainant pain area. If the painful area of the complaint is outside the small joint line, it means that the lateral branch is involved. According to the anatomical relationship, the more external the painful area complained of, the higher the injury site. 1, pain below the external iliac crest, the point of injury in the ipsilateral L1; 2, hip, posterior femoral pain, the point of injury in L2, 3; 3, sacroiliac joint pain, the point of injury in L4, 5.