Pain in the spine may be related to the following causes: 1. Local muscle spasm may be present. This is often seen when the patient has been cold in the past, or due to the effects of poor posture, resulting in muscle spasm in this area, which then causes pain. 2. There may be small joint misalignments in the spine. This is most common in the thoracic spine, for example, due to strenuous activities, poor posture, resulting in misalignment of the small joints of the spine, then the pain on the side of the spine. 3. may be due to the existence of injuries around the spine, such as acute lumbar sprain, often manifested as pain in the lumbar muscles on the side of the spine, and there is a serious restriction of movement. 4. There may be some internal diseases. For example, during an attack of coronary heart disease, pain on the left side of the spine may occur. In the case of nephritis and kidney stones, the pain is often on one side of the back.