The causes of back pain in the middle of the spine are more complex, common causes include problems with the spine itself, including lumbar muscle strain or rheumatology and immunology related diseases, etc., as follows: 1, spine problems: lumbar disc herniation and lumbar degenerative scoliosis, etc. will lead to pain in the middle part of the spine; 2, muscle strain: more common muscle strain in the middle part of the spine, such as lumbar muscle strain, etc.. Lumbar muscle strain refers to the lumbar back muscles, chronic injury in the long-term contraction state, mainly manifested in the middle of the spine extensive pain, pain points are not exact, but more distributed in the center of the spine position. It will be relieved through rest and physical therapy, medication and plasters; 3. Rheumatic immune-related diseases: the pain in the middle of the spine may be rheumatic diseases, such as ankylosing spondylitis, etc. This kind of pain usually occurs when resting at night. This kind of pain usually occurs at night when resting, and compared with the spine itself and lumbar muscle strain, the pain occurs more at night than during the day.