Point-Counterpoint: Can Toning Shoes Have A Legitimate Impact?
- Volume 24 - Issue 12 - December 2011
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Although this author acknowledges that toning shoes may have some positive impact for people with certain conditions, he cites biomechanical concerns and a lack of evidence that the shoes cause increased muscle activity and increased toning.
By Eric Fuller, DPM
The most common way to strengthen a muscle is to use it. Conversely, non-use of a muscle results in the muscle becoming soft and a corresponding loss of muscle tone. For a toning shoe to work, it has to make the person use the muscle. For a toning shoe to be better than a regular shoe, it has to work the muscle more than a regular shoe without increasing the risk of injury.
One of the problems with the question of whether toning shoes are effective is that there are so many different modifications of shoes and shoe manufacturers claim these modifications make the shoes toning shoes. However, it is important to consider the biomechanical impact of different aspects of shoes in relation to the shoes’ ability to significantly increase muscle activity.
A Closer Look At The Biomechanical Effects Of Toning Shoes
In a search for toning shoes, I found several different types of shoes with manufacturer claims of being toning shoes. The first category is the sagittally unbalanced shoe. The Masai Barefoot Technology (MBT, MBT Marketing and Trading) is a classic example of this. The thickest part of the shoe’s midsole is approximately 50 percent of its length. If you were to try and stand with the sole of your foot parallel to the ground, you would have to balance on a point. It is like trying to stand on a narrow stick that is perpendicular to the length of your foot. It is possible to balance on this stick but it will take some effort to do so. Some will choose to put all their weight on the heel and stand with the foot dorsiflexed at the ankle. Others may stand in a plantarflexed position with their weight on the forefoot.
In each case, balancing with the foot level and the weight on the heel or the forefoot, the muscles of the lower leg will have to work harder than in regular standing. In regular shoes or even barefoot, the anterior tibial and triceps surae muscles shift weight under the foot to control postural sway in the sagittal plane. If the shoe wearer chooses to put weight on the forefoot, then the triceps surae will be working harder.
Therefore, one can make a case for toning the calf muscles if shoe wearers make the subconscious choice to put weight on the forefoot. The shoe wearers may not necessarily do that because they still have the option of trying to balance with the foot level or putting the weight on the heel. Therefore, there is a potential upside of increased toning.
On the other hand, there is a potential downside to using a sagittally unbalanced shoe. If the shoe wearer chooses to put weight on the heel with the foot dorsiflexed and the anterior tibial muscle contracting, this may cause some injuries. Constant contraction of the anterior tibial or triceps surae could cause tendonitis in the tendons of those muscles. When people are balancing over these shoes, they will be standing on a smaller surface area in comparison to regular shoes. Most normally healthy people should be able to balance over this reduced area but anyone with concerns about balance or falls probably should not use these shoes.
I had a patient recently who had Achilles tendonitis that got worse with wearing this style of shoe. I know many people who choose to wear the sagitally unbalanced shoes for many different reasons. The shoes will change how you walk and this change may benefit some people. These shoes are generally rigid, which can also benefit people with problems like hallux rigidus. However, beyond the effect on the calf muscles, there is no reason to believe the gait changes will firm the buttocks and thighs.