A disorder characterized by an abnormal increase in the curvature of the lumbar portion of the spine. [CTCAE] The anterior concavity in the curvature of the lumbar and cervical spine as viewed from the side. The term usually refers to abnormally increased curvature (hollow back, saddle back, swayback). It does not include lordosis as normal mating posture in certain animals ( = POSTURE + SEX BEHAVIOR, ANIMAL). [MeSH]
