The Evolution of the Human Foot: It's Not as Unique as We Once Thought

The human foot isn't quite as unique as we once thought. Scientists have discovered that the mechanisms of our feet have quite a bit in common with the flexible feet of other great apes, revealing that they're really not all that original.

Our feet are known for one thing--walking. We possess arches in our mid-foot region that allow us to travel long distances on the ground. Yet current understanding of the human food is based on research from the 1930s. That's why researchers conducted a study of more than 25,000 human steps made on a pressure-sensitive treadmill in order to better understand the mechanics of the human foot.

"It has long been assumed that because we possess lateral and media arches in our feet--the lateral one supposedly being rigid and supported in bone--that our feet differ markedly to those of our nearest relatives, whose mid-foot is fully flexible and makes regular ground contact," said Robin Cromptom, one of the researchers, in a news release. "This supposed 'uniqueness,' however, has never been quantitatively tested."

People with feet that make contact with the ground regularly with the mid-foot region have previously been thought to be those that suffer from diabetes or arthritis. Both of these conditions can impact the structure of the feet. Yet with this latest research, scientists found that about two thirds of normal healthy subjects produced some footfalls where the mid-foot touches the ground.

"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," said Karl Bates, one of the researchers, in a news release. "We hypothesize 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 findings reveal how the human foot evolved over time from tree-dwelling to ground-dwelling. More specifically, it shows that our feet actually aren't so dissimilar from the feet of great apes.

The findings are published in the journal Proceedings of the Royal Society B: Biological Sciences.