By Sima Kotecha
Newsbeat US reporter
Jonathan FitzGordon has been teaching Kathleen the art of walking correctly
Books on the head, chest back and swing those hips...
We may have all heard about those old-school deportment classes when young ladies from days gone by learnt how to walk properly.
But believe it or not, in America, they're back in a big way.
Hundreds of New Yorkers are signing up to walking classes that teach you how to put one leg in front of the other without stressing your ankles, knees or thighs.
In the Big Apple, walking is a major part of city life. On a daily basis, hordes of people manoeuvre between the high concrete buildings, bashing into one another as they rush to their destination.
30-year-old Kathleen Hahn is one of them. She's a personal trainer and spends most of her days walking from one street to another.
But her thin and lean body used to ache because it couldn't deal with the amount of pavement pounding she had to do in order to see her clients.
She said: "I had pain in my hip and my back. I had hip issues and I really noticed it when I was walking how it bothered me. Everything felt out of alignment."
And that was when her yoga teacher suggested she take professional walking lessons with him.
Walking in pain
Jonathan FitzGordon runs a yoga centre in Brooklyn. But that's not the only thing he teaches.
He recently set-up the FitzGordon method walking programme. It focuses on getting people to relax their buttocks, evenly distribute their body weight and stand tall when moving.
"No one knows how to walk," he said.
"If you go outside and watch people walk, what you'll see is one variation or another of pain.
"People turn their feet out like a duck, and their thighs sit forward and their shoulders fall back. Essentially we want to be long and tall as we move."
His students are mostly people who have some kind of muscle or joint pain and are desperate to find a solution to stop it.
He claims his programme differs from traditional yoga and pilates because it's about incorporating a technique in your everyday life, rather than going to a class and doing an exercise for the time you're there.
"I'm here to help, and I really love the fact that I've come up with a method that can help people in a really simple way, if you make the leap of faith that you need the help."
But not all New Yorkers believe the classes are worth it.
After all, walking is something most of us begin to do as toddlers. Ryan Cook is 23 years old and lives in Queens, New York.
"It's ridiculous. How stupid? It's just another way to get money out of people. How to walk isn't genius, you know? And I wouldn't pay to be taught it for sure."
The FitzGordon walking programme isn't cheap either. It costs around £450 for eight sessions.
Newsbeat asked Mr FitzGordon what he would say to those like Ryan Cook.
"For the most part people come to me in pain. I do want their money, but I really want to get them out of pain too."
Kathleen Hahn said the programme has made her think totally differently about the process of walking.
"My body feels so much better. I feel more aligned. And I get really excited when I know I'm going to go outside and take a walk. Like now, I'm getting really excited".