Normal people lie down, the waist will usually sink, does not appear to be hanging is a normal situation, if there is hanging may be lumbar spine bony changes, muscle tension and other reasons. Although the normal spine will have a certain degree of physiological curvature, but in lying down, due to the role of gravity, the waist will sink, and the bed surface fit, generally does not appear to be suspended in the state, if there is a significant suspension, indicating the existence of local pathologic changes, such as lumbar spine bony anomalies, muscle tension, acute lumbar sprain, lumbar muscle strain, and other diseases, need to be treated symptomatically. If there is lying down after the lumbar hanging too much accompanied by lumbar discomfort, it is recommended to seek medical advice in a timely manner, under the guidance of the doctor to take standardized methods of treatment, to promote symptomatic relief.