Evolution of Bipedalism and Its Role in Low Back Pain

Low back pain (LBP) is one of the leading causes of disability worldwide and represents a major socioeconomic and healthcare burden. Although numerous biomechanical, genetic, and psychosocial factors have been implicated in its pathogenesis, an evolutionary perspective provides additional insight into the inherent vulnerabilities of the human lumbar spine. The transition from quadrupedalism to habitual bipedal locomotion, a defining feature of human evolution, required profound anatomical and biomechanical adaptations, including the development of lumbar lordosis, pelvic reorientation, and modifications in vertebral morphology. While these changes enabled efficient upright posture and locomotion, they also increased axial loading, shear stresses, and mechanical demands on the lumbar spine. This chapter reviews the evolutionary origins of human bipedalism and examines how adaptations associated with upright posture contribute to susceptibility to low back pain, disc degeneration, spondylolisthesis, and other degenerative spinal disorders. It further explores the concept of evolutionary mismatch, whereby modern sedentary lifestyles, prolonged sitting, and repetitive loading patterns interact with a spinal structure optimized for ancestral patterns of movement rather than contemporary behaviors. Comparative anatomical evidence from non-human primates, sex-specific adaptations of the lumbar spine, and recent findings from evolutionary biomechanics are discussed to provide a comprehensive framework for understanding lumbar pathology. Recognizing low back pain as an evolutionary consequence of structural compromise rather than solely a pathological condition may improve approaches to prevention, rehabilitation, and future spine research. An evolutionary framework integrates anatomy, biomechanics, anthropology, and clinical science, offering a broader understanding of why low back pain remains highly prevalent despite advances in modern medicine.