(a) Ankylosing spondylitis and psoriasis: main target areas on vertebral column and girdle joints (b) Crohn disease and ulcerative colitis: main target areas of enteropathies. Reactive arthritis targets the lumbar spine and sacrolial joints only. Source: Low back pain, Murtagh's General Practice, 6e Citation: Murtagh J. Murtagh's General Practice, 6e; 2015 Available at: https://murtagh.mhmedical.com/DownloadImage.aspx?image=/data/books/1522/murtagh6e_ch38_010.png&sec=116029019&BookID=1522&ChapterSecID=116028840&imagename= Accessed: November 05, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved