The odyssey of sagittal pelvic morphology during human evolution: a perspective on different hominoidae

Abstract The importance of sagittal spino-pelvic alignment for posture and upright human spinal biomechanics, and its role in the etio-pathogenesis of different spinal pathologies is well recognized. In human evolution, morphological changes of the pelvis are believed to be a crucial step forward towards pertinent bipedalism. By comparison of sagittal pelvic morphology within the superfamily of Hominoidea, we have the perspective that in the course of human evolution, development of a lordosis between the ischium and ilium, and the consequent increase in pelvic incidence allowed for ambulation in a fully upright position while maintaining the lever arm of the ischial musculature. Ischio-iliac angle and pelvic incidence increased from 1° and 27° in human-like primates, to 22° and 33° in early Hominins , to 19° and 39° in modern human children and 26° and 48° in modern human adults, respectively.