Spinal Posture and Pathology in Modern Humans

Humans are the only living hominoid that habitually stands upright and walks on two legs. The adoption of erect posture as habitual imposed substantial changes on spinal morphology and biomechanics. One of the major morphological changes is the increased curvatures found in the human spine. There is an ongoing debate about whether humans “pay” for becoming bipedal by suffering from a high prevalence of back pain and spinal pathology. In order to answer this question, we explored the relationship between sagittal spinal posture and spinal pathologies, back pain, and health-related quality of life. We found that spinal posture closely correlates with spinal pathology. Individuals with a well-aligned spine—within the neutral zone defined as moderate spinal curvatures and the line of gravity close to the acetabulum—have a better quality of life, less back pain, and less spinal pathology. Individuals out of the neutral zone, with accentuated or with decreased pelvic incidence and spinal curvatures, are at a higher risk for developing spinal pathology, back pain, and reduced quality of life. All of this indicates that adopting an erect posture and bipedalism has an impact on human’s spinal health because variation in curvatures outside the neutral zone is associated with more spinal pathology, back pain, and lower quality of life, than those within this zone.