Evolution Gave Us Backache!
For decades, scholars have assumed that the reason humans are so commonly afflicted with back problems is because we walk on two legs. A new study, published in the journal ‘Evolution, Medicine, and Public Health’, is the first to show a clear link between the shape of our vertebrae, bipedalism, and the health of our spine.
The researchers used advanced 3D shape analysis techniques to compare the final lumbar vertebrae of humans with and without spondylolysis to the same bones in our closest living relatives, the great apes. The team found that the differences between human vertebrae with spondylolysis and great ape vertebrae were greater than those between healthy human vertebrae and great ape vertebrae. People who developed spondylolysis have vertebrae that are more wedge-shaped, where the front is taller than the back, in addition to other subtle shape differences. The differences are consistent with the vertebrae having ‘overshot’ the optimum for walking on two legs, leaving the individual prone to developing spondylolysis.