Action News Anchor Margot Kim takes a look at the trend, and the word of warning from a South Valley woman who says she stepped into trouble.
Eva Burguis: "I'm gonna die. I really thought so. And I knew I broke my neck."
Eva Burguis has been trapped in a head and neck stabilizing device called a "halo" for over four months. The 77-year-old broke the second cervical vertebrae in her neck in a bad fall near her Exeter home while doing the activity she loves most.
Eva Burguis: "I was walking and my head snapped back. I guess I just passed out, I was in terrible shock."
Eva walked along a country road near her home, twice a day, every day. But it took one misstep and a split second to keep her confined in her home for months. Eva believes her injuries wouldn't have been so devastating if she weren't wearing her "toning shoes". She believes the "rocker bottom" of the shoe didn't allow her to break her fall.
Eva had been wearing her Skechers Shape-Up shoes for three months before her fall. She's not taking any legal action for her injuries but believes the shoe might not be as safe as a regular sneaker, if you start to stumble.
Eva Burguis: "The rocking motion of the shoe gets so much since the other foot rocks also you don't stop with the other foot."
Eva's doctor, Ron Marconi at Kaweah Delta Rehabilitation Hospital says Eva will recover but it will take many more weeks. He says people who use fitness gear like toning shoes, should take it slowly at first and be aware of the way they can change the body's movement.
Ron Marconi: "Footwear is an important part and it needs to be stable under those circumstances. If I'm going to exercise and wear a special shoe to increase my calf muscle or whatever, I should be thinking about that."
The promise by footwear companies of exercise with every step has motivated millions of women and men to buy toning shoes. The shoes have exploded into a billion dollar business. Skechers, based in Manhattan Beach, California has one of the most well known styles. But an Ohio woman says instead of getting healthy, she got hurt in Skechers Shape-Ups.
She talked to ABCNews about her lawsuit against the company, claiming the shoes led to stress fractures in her hips.
Holly Ward: "The extended use of these shoes has injured me catastrophically."
Skechers Shape-Ups come with an instructional DVD and the company acknowledges the shoes lead to a different way of walking. The president of Skechers fitness group provided Action News with a video statement about the safety of Shape-Ups.
"Skechers Shape-Ups are made to walk on stable surfaces, so stay out of the mud, stay out of rocks and make sure you proceed always with common sense. We've sold millions of Shape-Ups to satisfied consumers and received thousands of unsolicited testimonials from people who absolutely love the product."
Nurses at Saint Agnes Home Health and Hospice believe toning shoes are not only safe, but keep them in shape.
Fresno nurse, busy wife and mom of three, Carolyn Wilson says she first tried toning shoes, walking around an amusement park. Now she wears them for long hours on her feet at work and has seen results.
Carolyn Wilson: "They were fabulous, I felt great. It definitely takes some getting used to but I could feel the benefits up my legs."
These nurses also did some research on toning shoes and found, the concept isn't new. Podiatrists have used rocker bottom shoes to treat patients with foot problems because they force the foot to walk from heel to toe.
So before you try to tone up with toning shoes, doctors we spoke with say, take a step back, to make sure they're the right fit for you.
Women we spoke with who wear toning shoes say there is a period of time when they had to "learn how to walk" in the shoes, and they avoided working-out with the shoes in the gym during that learning period, to avoid any potential injuries.