Evolutionary biology: bad back? Blame the chimpanzees

An international study has confirmed the old idea that human back problems are linked to the stress of walking upright with a spine that has not fully adapted to bipedalism. The researchers found that people susceptible to back pain are more likely than the general population to have ape-shaped vertebrae.

The study, published in the journal BMC Evolutionary Biology, focused on a lesion of the spine called Schmorl's node - a hernia in the cartilaginous disc between vertebrae often linked with back pain.

The researchers at Aberdeen University in Scotland and Simon Fraser University in Canada compared the shape of many human spines with those of chimpanzees. The last common ancestor of the two species lived about eight million years ago. Since then, humans have evolved to walk on two feet while chimps are knuckle-walkers.

The striking finding is that in people with Schmorl's node the last thoracic and first lumbar vertebrae (in the middle of the back) have a shape that is statistically indistinguishable from chimp vertebrae. In other people these vertebrae are distinctly different from those of chimps.

The results support the "ancient shape hypothesis", which holds that evolution of the human backbone proceeded unevenly, leaving some people with vertebrae less able to stand the pressures of bipedal walking.

"The findings not only have potential clinical implications but also demonstrate the benefits of using the theories and methods of evolutionary biology and bioarchaeology to bear on modern health issues," says Keith Dobney, Aberdeen's professor of human palaeoecology.

© The Financial Times Limited 2015. All rights reserved.
FT and Financial Times are trademarks of the Financial Times Ltd.
Not to be redistributed, copied or modified in any way.
Euro2day.gr is solely responsible for providing this translation and the Financial Times Limited does not accept any liability for the accuracy or quality of the translation