A new study has revealed that, despite many runners craving high-tech footwear than boosts our natural rhythm, the human foot has remained a resolutely low-tech organism through the millennia.
Research published this week by Robin Huw Crompton, a physical anthropologist at the University of Liverpool’s Institute of Ageing and Chronic Disease, has shown that human feet have evolved surprisingly little since over thousands of years and that we share striking similarities with our simian tree-dwelling cousins, who are known to have flexible, resilient feet – and who do not wear shoes at all.
In great apes, the mid-foot is fully flexible and makes regular contact with the ground. It has long been thought that human feet, more adapted to walking, are markedly different. Some shoe manufacturers even warn that sport shoes and inserts are essential to keep the human arch stiffly supported to ensure no damage is done.
Crompton, however, said his findings suggest that the outer arch of the healthy human foot is actually much more flexible than previously thought.
‘The idea before was that if this arch wasn’t stiff, it probably required treatment. But based on what we found, I don’t think that’s true,’ he told NPR.
Scientists studied more than 25,000 steps made by volunteers – 45 healthy male and female volunteers — most under 30 years old and all with sound feet – during five-minute spells on a pressure-sensitive treadmill. This was covered with thousands of tiny sensors that simultaneously sampled the precise pressures exerted across the entire foot many times a second, Crompton says.
The research, published in the journal Proceedings of the Royal Society B, showed that two thirds of the study’s participants produced footfalls where the mid-foot touched the ground – something previously believed to characterise diabetes or arthritis, both of which can alter foot structure.
Study leader Dr Karl Bates, from the University of Liverpool’s Institute of Ageing and Chronic Disease, said: ‘Our ancestors probably first developed flexibility in their feet when they were primarily tree-dwelling, and moving on bendy branches, but as time passed and we became more and more ground-dwelling animals, some new features evolved to enable us to move quickly on the ground.
‘Our limbs, however, did not adapt to life on the ground anywhere near as much as those of other ground-dwelling animals such as horses, hares and dogs. Our tests showed that our feet are not as stiff as originally thought and actually form part of a continuum of variation with those of other great apes.
‘We hypothesise that despite becoming nearly exclusively ground dwelling we have retained flexibility in the feet to allow us to cope effectively with the differences in hard and soft ground surfaces which we encounter in long distance walking and running.
The team are now looking to test this theory, looking to see if it can offer some answers to other questions, for example, how humans can sometimes outrun horses over long distances on irregular terrain.