New Issue: Orbital Catastrophe Ahead? Read Now

To Walk, You Have to Fall in Step

Motion-capture technology reveals that the body falls forward and sideways as we walk, and the feet come down to restore balance. Karen Hopkin reports

Illustration of a Bohr atom model spinning around the words Science Quickly with various science and medicine related icons around the text

Join Our Community of Science Lovers!


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


How many times has this happened to you? You start to fall, but then catch yourself and continue on your way. Well, new research shows that falling and catching yourself actually happens every time we take a step. And that we precisely place our feet as we walk to avoid taking a tumble during this ambulatory balancing act. The study is in the journal Biology Letters. [Yang Wang and Manoj Srinivasan: Stepping in the direction of the fall: the next foot placement can be predicted from current upper body state in steady-state walking]

When humans walk, we put one foot in front of the other. But the way each foot lands can vary from step to step. This variation in foot placement can appear pretty random. But researchers decided to take a closer look. 

They fitted 10 volunteers with motion caption markers and then watched as the subjects walked on a treadmill. The investigators discovered that that they could predict exactly where each foot would fall based on the movement of the person’s pelvis during the previous step. The body falls forward and sideways as we walk…and the feet come down in a way that restores our balance.

The findings could be useful for developing ways to help people with movement disorders regain their stability. The info could also make walking robots more surefooted. So they don’t, ya know, fall down on the job. 

—Karen Hopkin

[The above text is a transcript of this podcast.]
 

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American

Subscribe