Since early times, man has used some type of footwear for protection and comfort. Shoes also protect against the tremendous pressure on the feet while standing and walking. The American Podiatric Medical Association reports an average day of walking puts a combined force of several hundred tons on the feet.
Today, shoppers also select shoe styles based on fashion and/or function. According to the American Apparel and Footwear Association, Americans spent nearly $2.4 billion on footwear in 2007.
The “Fitness” Shoe Craze
Athletic shoes are the second most popular type of shoe purchased in this country. In 2007, more than $334 million was spent in the U.S. for athletic shoes. One of the newest trends in athletic shoes is “toning” footwear. There are several different brands of toning shoes. Generally, they are one of two types of construction. Rocker bottom shoes have a curved or rounded sole (rather than flat). Pod shoes have built-in pockets of fluid or air. With either type, the goal is to create natural instability for the wearer while walking. To maintain balance, a wearer must use muscles that may not normally be used while wearing traditional shoes. Manufacturers claim the shoes tone the leg muscles and buttocks, improve posture and help the body burn more calories.
The new fitness shoes are becoming very popular. There’s even a sandal/flip-flop version. However, the shoes aren’t cheap, ranging in price from about $100 to $245/pair. Researchers estimate Americans would spend up to $200 million on these new fitness shoes in 2009.
Kendrick Whitney, D.P.M., Podiatrist with Temple University School of Podiatric Medicine in Philadelphia, PA, says it takes time to get used to toning shoes. He recommends initially wearing them for no more than 25 minutes a day until a wearer becomes comfortable and secure with the design. Most people will feel minor aches and pain until the body becomes adjusted to the new style. Whitney says these aches are caused by a strain on muscles not normally used during walking. Since the shoes promote imbalance, it’s especially important to be careful when walking on stairs or uneven surfaces.
Rocker-type shoes have actually been used for therapeutic purposes for many years. Whitney says diabetics sometimes use shoes with forefoot rockers to take the pressure off the feet and reduce the risk for foot ulcers. The shoes are not for everyone. People who have ankle instability, foot imbalance, severe flat feet or high arches are at higher risk for overturning their ankles while wearing these shoes and should stick with traditional footwear.
Do They Work?
Recently, the American Council on Exercise (ACE) completed two small studies comparing traditional athletic shoes with some of the toning shoes. In one study the investigators looked at exercise responses to the two shoe groups. The second study compared muscle activation during walking. The ACE researchers found there were no statistically significant differences in exercise response or muscle activation between the two types of shoes.
Cedric Bryant, Ph.D., Chief Science Officer for ACE, says people who wear the toning shoes often assume they are getting an extra workout because their muscles get sore after use. However, over time, as a person gets used to walking in the toning shoes, the body will adapt and soreness will go away. In his commentary on the study, Bryant says the biggest advantage of the toning shoes is that people who otherwise may not have been exercising are now using them to get some physical activity.
American Orthopaedic Foot and Ankle Society, http://www.aofas.org
American Podiatric Medical Association, http://www.apma.org. To locate which shoe brands have the APMA seal of approval, go to http://www.apma.org/athleticfootwear
To see the study by the American Council on Exercise, go to http://www.acefitness.org/getfit/studies/toningshoes072010.pdf
Landry, S., et al., “Standing in an Unstable Shoe Increases Postural Sway and Muscle Activity of Selected Smaller Extrinsic Foot Muscles,” Gait and Posture, May 21, 2010, electronically published ahead of print.
Porcari, John, Ph.D., et al., “Will Toning Shoes Really Give You a Better Body?” San Diego: American Council on Exercise, July 2010.
Ramstrand, N., et al., “Effects of an Unstable Shoe Construction on Balance in Women Aged Over 50 Years,” Clinical Biomechanics, June 2010, Vol. 25, No. 5, pp. 455-460.
Stoggl, T., et al., “Short and Long Term Adaptation of Variability During Walking Using Unstable (Mbt) Shoes,” Clinical Biomechanics, June 25, 2010, electronically published ahead of print.
Wang, C., and A. Hansen, “Response of Able-bodied Persons to Changes in Shoe Rocker Radius During Walking,” Journal of Biomechanics, May 17, 2010, electronically published ahead of print.