Wednesday, July 14, 2010

Fat Busting Shoes?

As we have been looking at the advantages and disadvantages of barefoot running I thought it would be appropriate to look at the new revolution of oddly shaped shoes.  These shoes such as “Shape-ups” by Skechers and “EasyTone” by Reebok tout huge fitness results but, the question is, do these shoes produce their advertised results? And, more importantly, do they have the ability to cause injury?  First, an overview….
Reebok’s shoes describes a revolutionary technology where they have pads of moving air on the sole of the shoe which mimic walking or running on an unstable surface.  They explain that this makes your muscles work harder throughout the day, causing increased activation of the gluteus maximus (bottom), hamstrings, and calves.
Skechers “Shape-ups” also describes a ground-breaking technology where they have a dynamic rolling bottom on the sole.  According to Skechers this makes you feel like your heal is sinking into sand as you walk forcing you to activate your muscles more to get towards your next step.  The advertised benefits include more toned legs, back, and abdominal muscles, reduced body fat, improved circulation, and improved posture.
But, if my last two blogs show how we should be decreasing the amount of shoe wear that we put on our feet, is it really good to have these shoes which further alter our gait mechanics?  While Reebok does not actually show us any of their research articles, Skechers reports many clinical case studies that back their findings.  Their articles show an increased amount of weight loss, an increase in hamstring and calf muscle activation, and improvement in low back endurance.
So, do you buy them or not?  First, I must emphasize that under each clinical case study for Skechers there is a statement: “These independent case studies where commissioned by SKECHERS.  Results may vary from person to person”  This breaks rule number one in “research 101.”  You must gain your research based knowledge from peer-reviewed articles that are not endorsed by the company that is selling the product.  There is no way to tell if the money that Sketchers paid the researchers persuaded their outcomes. Second, according to Matt Powell of SportsOneSource, a sneaker analyst, the sales of these shoes “represent the fastest-growing segment of the $17 billion-a-year athletic footwear industry. It's a market driven by a customer base that is 90% women.”2  Anytime we see such a sharp increase in a product we must ask ourselves if this is due to a truly innovative product or fads and good advertising.
Without ever putting a pair of these shoes on I have some problems with their design.  Destabilizing the foot during walking, especially in a deconditioned person, will lead to problems of the knee (knee cap tracking problems causing pain), the Achilles tendon (increased stresses causing pain and possible tears), the plantar fascia (causing arch pain) or even falls causing serious injuries.  I have heard stories of people developing fractures from wearing these shoes after stepping awkwardly and “rolling their ankles.”
Wendy Shore of Johns Hopkins, says “consumers would get the supposed health benefits of toning shoes and save money if they skipped buying the shoes, then bought one less bagel a day — and walked an extra block."2
As a physical therapist I cannot say that I support the use of these sorts of shoes at this time.  Yes, my opinion may change as more peer-reviewed research articles are presented in respectable medical journals but without the evidence of true health benefits along with the high risk of injury these risks of these shoes outweigh their benefits. 
And as mom always told me, if it sounds too good to be true, it probably is.


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