The possible causes of lumbar pain are acute lumbar sprain, lumbar fracture, ankylosing spondylitis, lumbar tuberculosis and so on. 1. Acute lumbar sprain: mostly seen in long-term ambulatory or sedentary people, sudden change of position such as bending over to pick up something or lift heavy objects, or even sudden sneezing, will induce acute sprain of lumbar muscles, resulting in lumbar muscle spasms, pain, accompanied by lumbar spine activity is limited, can not straighten up, and so on. 2. Lumbar spine fracture: mostly due to violence and trauma, or osteoporosis triggered by the elderly, can appear lumbar pain, activity is limited, can not straighten the waist phenomenon. 3. Ankylosing spondylitis: Ankylosing spondylitis is a chronic inflammatory disease that originates from the sacroiliac joints and can involve the whole spinal column. Initially, patients mainly manifest lumbosacral pain or discomfort, and with the development of the disease, it can lead to spinal stiffness, and even lumbar vertebral kyphosis, that is, the waist can not be straightened up. 4. Lumbar spine tuberculosis: lumbar spine tuberculosis patients mainly manifested as lumbar pain, tuberculosis bacillus seriously damage the lumbar vertebrae anterior column, which can cause the vertebral body in front of the collapse and lumbar vertebrae kyphosis deformity, lumbar pain can not be straightened up the phenomenon. In addition to the above diseases, lumbar intervertebral disc herniation, neuromuscular diseases, congenital kyphosis, etc. can cause lumbar pain accompanied by lumbar straightening performance, it is recommended that patients go to the hospital as soon as possible, under the guidance of a professional doctor for standardized treatment.