Lower back pain (LBP) is one of the most common and costly medical problems today [1, 2]. Pain is usually transitory and can arise from the intervertebral discs, bones, ligaments and muscles of the spine. Risk factors for LBP include genetic, environmental, psychosocial and biomechanical influences [3]. However, although 85% of LBP cases have no clear etiology, 97% may be due to musculoskeletal issues [4]. Lumbar curvature (lordosis) is one factor that generates shearing between adjacent vertebrae and at intervertebral joints. People with high degrees of lumbar lordosis, including pregnant women, can experience excessive shearing (Fshear) and compression (Fcompression) forces between lumbar vertebrae, most often between the last lumbar and the sacrum [3, 5]. In addition to other factors, including age-related spinal degeneration, high levels of Fshear and Fcompression can lead to painful muscle strain, joint capsule pain, disc herniation, inflammation (spondylitis), bone degeneration (spondylolysis) and vertebral displacement (spondylolisthesis) [3–5]. Evolutionary perspectives