Firming shoes include those with a spherical back. The shoe's rocker sole creates instability, which helps you engage muscles—specifically in your feet, legs, glutes, and stomach—that can potentially lead to fat loss.
Beyond that, the shoes can also improve posture while you're walking, taking pressure off your achy, over-used joints.
After the 2011 Supra Pilot shoes release, you might not mind looking like Skecher Shape-ups' spokesperson Kim "Get in shape without putting a foot in the gym" Kardashian, right?
But are these amazing firming shoes—made by Masai Barefoot Technology (MBT), Reebok, and other companies like Skechers—the cure or the curse?
The lawsuit was filed by Holly Infirmary, an Ohio waitress who claims wearing the Shape-Ups caused significant damage to her hips, leading to physical rehabilitation and getting around with a walker.
Also, firming shoes—initially marketed to women with Supra TK Society Shoes—are now being produced for men and young girls.
Superhero commercials, informing pre-teen girls about the benefits of firming their bottoms and legs with Supra Pilot Hightop shoes at a discount, were found on kid-friendly networks like Nickolodeon and the Cartoon Network.
However, according to Scheels Sporting Goods shoe sales associate Rachel Jacobson, the curvy-heeled shoe remains mostly popular among middle-aged women.
"People who like them, really like them a lot," she said while modeling a pair. "And those who don't, wouldn't be caught dead in them."
Jacobson herself falls into the latter group.
"When you wear them, it's like you're walking in stone dust. Going shoe shopping isn't what it used to be," she explained.
This is the sensation wearers want from other firming shoes, said Sioux Falls podiatrist Paul Coffin.
"It's that difference," he said, "akin to walking on a wobble board and on a soft shore, which requires you to readjust from a distinct set of muscles."
Yet Coffin readily points out that manufacturers' claims of a quick and easy fitness fix are "wildly overstated."
Citing studies done on the performance of firming shoes, he said they "do not make you exercise more powerfully, burn more calories, or increase overall muscle strength and tone."
In fact, rocker-bottom shoes may cause painful injuries such as plantar fasciitis (the connective tissue at the end of your backbone); peroneal tendonitis (which may affect the ankle); and Achilles tendonitis (which affects the calf muscles).
"This isn't a new phenomenon," Coffin noted. "I remember when Soft World shoes were the trend. A full 40 percent of its wearers ended up with Achilles tendonitis due to the shoe."
While acknowledging that the shoes do force the wearer to work different muscles, he said the benefits are not permanent because the muscles quickly adapt to the changes.
Ultimately, Coffin said one-third of people may end up loving firming shoes, one-third may end up injuring themselves, and one-third may choose never to use them.
That is also Jacobson's verdict.
"These shoes are definitely not for just anybody," she said while removing the Skechers from her feet. "Personally, my husband and I prefer workout shoes and hiking shoes."