The Effect of Heels on Legs

A scientist at the University of Arizona asked two groups of humans to help him with his experiment. He found that when we humans land on our heels, it actually makes our legs longer than if we were to land on our toes. It's a trick of evolution because a long, long, long time ago, our human ancestors probably stood on their toes. But over time, their bodies evolved or changed. And eventually, over millions of years, their feet got smaller and their heels dropped to the ground.