The 3million-year-old reason we run so well
SCIENTISTS have long puzzled over why human beings, from amateur joggers to Olympic champions such as Usain Bolt, are so good at running.
Now the latest research suggests it is down to the foot’s ‘transverse’ arch, which humans developed over three million years ago.
The curves of the foot prevent it from bending as we run and losing vital energy from the force of hitting the ground – meaning we can run marathons while our chimpanzee cousins struggle to stay on two feet for too long.
But a study, which suggests that stiff feet are important for running, also found that this stiffness comes more from the arch across the top – the transverse arch – than the arch underneath the foot. The transverse runs across the foot in between the metatarsal bones and the ankle.
Researchers from Warwick and Yale universities took human feet donated to medical science and prevented the transverse arch from doing its job, by cutting its ligaments, and found that the feet bent far more easily under mechanical force. It has long been debated whether humans’ ability to walk and run largely relies on the longitudinal curve underneath our feet, from the ball of the foot to the heel. But these findings suggest the transverse may be more important.
The study, published in the journal Nature, concludes that the transverse makes a foot around 50 per cent stiffer, while the arch below it has previously been found to make it only around 25 per cent stiffer.
The authors follow previous researchers in describing the transverse arch as a ‘key step’ in allowing people to evolve to walk upright, and to run, by stopping their foot from bending under a force several times greater than their own weight. Looking at fossils they worked out that ancient humans developed this arch more than 3.5million years before modern humans, or Homo sapiens, came into existence.
The findings may explain why champion runners are given trainers with lots of stiffness and support, to exaggerate the natural advantage of curved feet.