A leg lift and put down the lumbar vertebrae at the thumping sound may be physiological popping, may also be pathological factors, such as lumbar spine instability, small joint disorders caused by the lumbar vertebrae at the thumping sound. 1. Physiological factors: when a leg is lifted, the main reason for putting down the lumbar spine with thumping sound is the friction sound of the small joints moving in the lumbar spine, which is generally known as physiological thumping sound. If accompanied by other symptoms, please consult a doctor. 2. Lumbar spine instability: due to lumbar some old injury caused by lumbar muscle relaxation, lumbar ligament toughness reduced, resulting in lumbar spine instability appeared thumping sound. For example, patients with lumbar spine old, compression fracture will be accompanied by a series of symptoms. 3. Lumbar spine small joint disorder: lumbar spine small joints lose the normal relationship between the joints, the patient lifts the leg down when the joints wear and tear, the joints rattle. At the same time, the patient will have lumbar pain and activity limitation. Diseases such as sacroiliitis and ankylosing spondylitis can cause similar symptoms. In addition, herniated disc or spinal stenosis and other factors can cause a leg lifting and lowering the lumbar vertebrae at the thumping sound of the symptoms, to rule out physiological factors, it is recommended to consult a doctor in a timely manner, please ask the doctor to clarify the cause of the disease, the symptomatic treatment, and early recovery.