Nonspecific Low Back Pain

Low back pain typically defined as pain below the costal margin and above the inferior gluteal folds with or without leg pain 1 is worldwide the most prevalent and most disabling of the conditions that are considered to benefit from rehabilitation 2 In a systematic review that included 165 studies from 54 countries the mean point prevalence of low back pain in the general adult population was approximately 12 with a higher prevalence among persons 40 years of age or older and among women the lifetime prevalence was approximately 40 3 Low back pain is classified as specific pain and other symptoms that are caused by specific pathophysiological mechanisms of nonspinal or spinal origin or nonspecific back pain with or without leg pain without a clear nociceptive-specific cause 4 Nonspinal causes of specific low back pain include hip conditions diseases of the pelvic organs e g prostatitis and endometriosis and vascular e g aortic aneurysm or systemic disorders spinal causes include herniated disk spinal stenosis fracture tumor infection and axial spondyloarthritis Lumbar disorders with radicular pain due to nerve-root involvement have a higher prevalence 5 to 10 than other spinal causes the two most frequent causes of such back pain are herniated disk and spinal stenosis 5 The overall prevalence of the other spinal disorders is low among patients with acute low back pain For example among 1172 patients who presented to primary care clinicians in Australia with acute low back pain only 11 0 9 were found to have serious spinal conditions mostly fractures during 1 year of follow-up 6 The authors of a Dutch study that involved primary care patients reported axial spondyloarthritis in almost one quarter of adults 20 to 45 years of age who presented with chronic low back pain 7 although these findings have not been replicated In contrast to low back pain caused by specific identifiable causes nonspecific low back pain probably develops from the interaction of biologic psychological and social factors 4 and it accounts for approximately 80 to 90 of all cases of low back pain 1 Low back pain is usually classified according to pain duration as acute 6 weeks subacute 6 to 12 weeks or chronic 12 weeks