The most common cause of loss of lumbar major shadow is pelvic and spinal fracture, accounting for about 2/3; followed by rupture of retroperitoneal organs (kidney, bladder, duodenum and pancreas, etc.) and large vessel and soft tissue injury. The following are the main clinical examinations: 1, pressure pain in the low back is widespread, and the pressure points are mostly in the sacrospinous muscle, the transverse process of the lumbar spine and the posterior edge of the iliac crest. 2, muscle spasm: on palpation, the lumbar muscles are tense and spastic, or there are hard knots and hypertrophy. 3.X-ray examination: a few patients may have congenital malformation and osteophytes in elderly patients, the rest have no abnormal findings. 4.Older or osteoporotic patients can choose ECT examination and bone density examination. At present, there is a view that osteoporosis can also cause chronic low back pain. 5.X-ray examination: mostly no abnormalities, a few and can have osteophytes or spinal deformities.