Lumbar lordosis: Inward curvature of the lumbar spine in the low back, which is normal to a certain extent. Musculoskeletal disease or poor posture can cause the curve to be greater than usual.See also lordosis. SLIDESHOW Back Pain: 16 Back Pain Truths and Myths See Slideshow From Back Pain Resources The Pain of Ankylosing SpondylitisIs Your Back Pain Ankylosing Spondylitis?How Well Are You Living With AS? Featured Centers Good and Bad Foods for PsoriasisVideo: Getting Personal on Life With MS Health Solutions From Our Sponsors Shot-Free MS Treatment Your Child and COVID-19 Reviewed on 12/24/2019 References J. Larry Jameson, et al. Harrison's Principles of Medicine. McGraw-Hill Professional Publishing Published: July 23rd 2018; Edition: 20.