Straightening of lumbar spine curvature is not much associated with sleeping posture, which is often related to poor posture, chronic strain, lumbar myofasciitis and other factors. 1. Poor posture: prolonged sedentary or stooping labor will lead to overloading of the lumbar spine, thus affecting the muscles around the lumbar spine, ligaments and other soft tissue injuries, which will cause straightening of the physiological curvature of the lumbar spine. 2. Chronic strain injury: lumbar long-term gravity activities, will lead to lumbar soft tissues in a tense state, which is easy to produce fatigue injury leads to soft tissue damage and muscle power imbalance, which will pull the lumbar vertebrae and lumbar vertebrae physiological curvature caused by the straightening of the lumbar vertebrae. 3. Lumbar myofasciitis: lumbar cold or strenuous exercise will lead to lumbar myofascial aseptic inflammation, thus causing muscle spasms around the lumbar vertebrae, so that the lumbar curvature of the phenomenon of straightening. In conclusion, the straightening of the lumbar curvature is less affected by the sleeping position. In order to clarify the cause of this symptom, it is recommended to go to the orthopedic department of the hospital for medical treatment.