A groove in the middle of the back may be a normal spinal groove, or it may be caused by spinal deformity, vertebral body slippage and other pathological reasons. 1. Normal spinal groove: commonly found in people with thin body or people who have been exercising for a long time, due to the fact that there is less subcutaneous fat in the middle of the spine and there is a groove formed by the muscles on both sides, which is a normal physiological phenomenon. 2. Spinal deformity: due to congenital or acquired diseases and other causes of spinal curvature and convex deformity, the patient can have a groove in the middle of the back. 3. Vertebral body slippage: Due to the degeneration of the spine, the vertebrae slip forward, pulling the corresponding tissues, and the patient may have a groove in the middle of the back. There may be other reasons for a groove in the middle of the back, so it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy if necessary.