The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)


3D Vertebral morphology, locomotion, and human spinal health

KIMBERLY A. PLOMP1, UNA STRAND VIDARSDOTTIR2, DARLENE WESTON3,4 and MARK COLLARD1,5.

1Human Evolutionary Studies Program, Department of Archaeology, Simon Fraser University, 2Department of Anthropology, Durham University, 3Department of Anthropology, University of British Columbia, 4Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, 5Department of Archaeology, University of Aberdeen

March 26, 2015 1:15, Grand Ballroom E/F/G Add to calendar

Recently, we investigated the relationship between locomotion, spinal pathology, and the 2D shape of the final thoracic and first lumbar vertebrae in humans, chimpanzees, and orang-utans. The spinal pathology we focused on was Schmorl’s nodes, which are depressions on the vertebral body resulting from vertical herniation of the intervertebral disc. We found that pathological human vertebrae share more similarities in shape to chimpanzee vertebrae than healthy humans do. This suggests that the occurrence of inter-vertebral disc herniation may be influenced by a particular vertebral shape that is more susceptible to the stress placed on the spine during bipedalism.

To further explore this possibility, we initiated the investigation of the 3D shape of human, chimpanzee, and orang-utan first lumbar vertebrae using geometric morphometrics. The analysis of 3D landmarks enables a more detailed exploration of vertebral shape than is possible with 2D analysis. Our preliminary findings are consistent with the results of our previous, 2D study. They indicate that the 3D shape of L1 human vertebrae with Schmorl’s nodes again share similarities in shape with chimpanzee vertebrae. The results of a Canonical variates analysis found that the Mahalanobis distances were significant between all inter-taxon comparisons, except between healthy and pathological humans, and pathological humans and chimpanzees. These results should contribute to the understanding of why humans are so often afflicted by back problems and may also have diagnostic value for clinical medicine.

This research was funded by Mitacs and the Social Sciences and Humanities Research Council, Canada Research Chairs Program, Canada Foundation for Innovation, BC Knowledge Development Fund, and Simon Fraser University.