Main content

The right way to walk this way

Walking is something most of us do every day.

Walking is something that we all do every day. But you probably don’t think twice about this seemingly mundane task — unless you’re Ohio State researcher Manoj Srinivasan.

Srinivasan has studied the science of walking and running for 15 years and shared insights on why we move the way we do — and how the concept of wasted energy can be a great strategy for those with fitness on their minds.

What led you to study the science of walking and running?

Everyone who is able to walk, walks, and we don’t think twice about it. Some of us run. And it’s surprising that even though most of us do it all the time, you can ask relatively simple questions about human walking and running that are really hard to answer.

Questions like, “What is it about the way our body is built or the way our brain works that keeps us stable while walking and running?"

There are lots of reasons study it. A: It’s interesting. B: It has lots of different applications for something that we do all the time, so we want to find out more about it.

What discoveries have you made from this research?

Two or three years ago, we did a study trying to understand why people walk some of the time and run some of the time.

Imagine the situation where you’re going to a room. You start from your office, you’re running late and you have to get there by a certain time. So, you have a distance to be traveled and a time by which you have to be there.

That’s the situation that we face all the time, many times a day. What do people do?

Of course, if you give people a lot of time, they walk all the way. If you give them a little bit of time, they run all the way. If you give them an intermediate amount of time, they walk for a little while and run for a little while. Not surprising. To minimize energy, you want to do this mixture of walking and running.

We have this principle called “energy minimization,” which states that our body roughly moves in a manner that minimizes energy. We use this principle here to predict how a person might move in a particular circumstance.

We can take that hypothesis and make a mathematical model. Whatever a human can do, the model can do.

Then the computer goes through hundreds of thousands of possible movements and figures out what is the optimal way to accomplish forward movement. It naturally discovers things that sort of look like human walking, even though it could have hopped, skipped or jumped, and produces something that looks like human walking.

If you vary your speed or walk in a curve, it will cost you more energy than walking in a straight line.

Share on Twitter
Manoj Srinivasan, On burning calories faster
How can people apply your findings to their everyday lives?

Sometimes people are interested in this energy efficiency and what aspects of human walking take more or less energy. People ask, “Are there morals for losing weight?”

We generally say, sure if you walk at a constant speed, that saves more energy than walking at a variable speed, as we showed in another recent study. So if you vary your speed or walk in a curve, it will cost you more energy than walking in a straight line.

If you just want to waste energy, there are lots of ways to do that — such as running really fast or waving your hands wildly while sitting down. There are lots of weird ways to waste energy.

Our general goal is to understand human movement. That’s the overarching goal, from an engineering perspective. It’s prediction. Being able to understand human movement so we are able to understand what will happen in a given situation.

If you have the predictive tool, you can apply it to a million different situations and designs. You can imagine lots of devices, not just prosthetics and shoes, but anything that can impact you while walking or running, like shaky pedestrian bridges.