It is normal to have a slight curve forward in the lumbar region after standing up straight, but if the curve is too large or the curve is opposite, it may be caused by pathologic factors such as lumbar back muscle strain and lumbar degenerative changes. The normal physiological curvature of the lumbar spine is within a radius of 19-24 centimeters, from the topmost first lumbar vertebrae to the bottom fifth lumbar vertebrae, forming an angle of approximately 26°. This physiological structure will lead to a certain curvature of the lumbar region when standing, due to the external tissue covered by skin, this curvature may not be obvious, but there is still a certain arc. If you usually do not pay attention to the sitting and standing posture, it is easy to cause the lumbar curvature to become straight after a long period of time, which will cause lumbar dorsal muscle strain, which should be corrected in time with exercise to prevent the lumbar curvature from further abnormality. If the patient suffers from lumbar spondylolisthesis and other diseases, it should also be treated in time to prevent lumbar curvature abnormality. Patients can go to the regular hospital for physical examination, if the lumbar curvature is not normal, resulting in pressure and pain and other symptoms should receive timely treatment.