The presence of physiological curvature of the lumbar spine means that the lumbar spine is currently curved and within a normal range. Patients can simply interpret this to mean that the current curvature of their lumbar spine is normal. The human spine does not look like a straight line from the side, but has a bend, which is very important for the human body to stand upright. In the human spine, there are four major physiological curves: forward convexity in the cervical spine, backward convexity in the thoracic spine, forward convexity in the lumbar spine, and backward convexity in the sacral spine. These physiological curves play an important role in keeping the body upright and in maintaining balance. Once the relevant physiological curves disappear or become straight, it suggests a series of degenerative changes in the spine, which may lead to local pain, stiffness, unfavorable activity, strange noises, radiating pain around and a series of symptoms.