The length of the normal adult spine is about 70 cm, slightly shorter in women and the elderly, with four physiological curves in the anterior and posterior directions, from top to bottom, respectively, the cervical, thoracic, lumbar and sacral curves. These four physiological curves are unique to mammals walking in an upright position, so that the spine is like a large spring, which can effectively increase the ability to cushion shock and enhance postural stability. The cervical and lumbar curves of the spine are convex to the front, and the thoracic and sacral curves are convex to the rear. In early embryonic life, the spine is curved in a “C” shape, and the neck is born with a slightly convex bend, while the lumbar region is almost straight, and the thoracic and sacral regions maintain their original bend. When babies start to lift their heads and sit at 2-8 months after birth, the spine of the neck changes and gradually forms a permanent cervical curve, which allows the head to maintain balance on the body; when babies start to crawl at 8 or 9 months, the weight of the abdomen drops so that the lumbar curve gradually forms, you can imagine a crawling baby, with the head raised gradually forms a cervical curve, and the stomach drops and the waist collapses to form a Waist curve, so crawling is an important part of human growth, especially critical to the health of the cervical and lumbar spine. Nowadays, many only children have more chances to be held when they want to crawl, and a little older to be put in a walker, which are not conducive to the cervical and lumbar spine, and is one of the reasons why there is now more incidence of cervical and lumbar spondylosis. In the elderly, due to dehydration of the nucleus pulposus, the intervertebral disc gradually degenerates and the intervertebral space narrows, the cervical and thoracic curves gradually disappear, and the thoracic curves gradually increase, thus forming an age-related hunchback. When people are engaged in long-term work with their heads down or bending over to carry things, the physiological curvature of the cervical and lumbar curvatures can be straightened, thus changing the corresponding intervertebral space and intervertebral foramina and producing back pain and involving the head, upper limbs, lower limbs and other related nerve distribution areas. In addition, the thoracic segment of the spine is often mildly curved to the right, which is formed by the right upper extremity muscle pull and the compression of the aortic arch and upper part of the descending aorta on the spine due to working with the right hand. In the event of lumbar disc herniation, it also often protrudes to the left side, compressing the nerve roots on the left side and showing symptoms of the left lower limb. What does a straightening of the physiological curvature of the lumbar spine mean? The normal spine has four physiological curves, namely: cervical, thoracic, lumbar and sacral. The physiological curvature of the spine plays a very important role in maintaining the balance of various parts of the body and cushioning the pressure. Under normal circumstances, as people age, the intervertebral disc degenerates, and in old age, due to dehydration of the nucleus pulposus, the intervertebral disc gradually degenerates and becomes thinner, the lumbar curve can gradually disappear, the physiological curvature of the lumbar spine becomes straight, and an age-related hunchback appears. In some young people, the physiological curvature of the lumbar spine straightens, which mainly has the following reasons: (1) patients sitting for a long time or a posture for too long, the muscle and ligament strain around the lumbar spine, the stability of the lumbar intervertebral joint is reduced, the physiological curvature of the lumbar spine straightens. (2) Patients with lumbar muscle sprain suffer from severe lumbar pain and sustained muscle and ligament spasms, which pull on the lumbar spine and cause straightening of the physiological curvature of the lumbar spine. (3) Patients with lumbar intervertebral disc pathology may experience straightening of the physiological curvature of the lumbar spine due to degenerative disc degeneration and the corresponding narrowing of the intervertebral space in the front and widening of the back. Straightening of the lumbar physiological curvature and narrowing of the corresponding intervertebral spaces increase the pressure on the intervertebral discs, which may increase the incidence of intervertebral disc pathology. When the physiological curvature of the lumbar spine is straightened, its function of maintaining upper body balance and cushioning pressure is greatly reduced, and it is easy to produce corresponding diseases. The physiological straightening of the lumbar spine is an important aspect in the diagnosis of lumbar spine disease and is a precursor to the development of lumbar spine disease.