Addiction can be physiological or psychological and can take many forms, from our morning Starbucks to chronic spending at the mall. One thing all addictions have in common is withdrawal symptoms upon discontinuation of the addictive activity or substance.
This article concerns the physiological dependence of wearers of supportive shoes, particularly running or athletic shoes (though, in theory this dependence can occur with any supportive shoe).
In the July/August Issue of Canadian Running Magazine the article Stone-Age Stride by Alex Hutchison quotes Benno Nigg, renowned professor of biomechanics at the University of Calgary, as stating that when wearing shoes only two muscles of the ten muscles in our foot are needed to walk.
To be correct, there are actually 20 muscles within our foot (intrinsic muscles) and 12 muscles from our leg that attach to our foot (extrinsic muscles). According to the article, Nigg states that only the tibialis anterior (a shin muscle) and triceps surae (calf) muscles are needed.
In my communication with Nigg, he explained that many muscles are not used (or used minimally) when ambulating in supportive shoes and as a result, these muscles (thirty of them for each foot) lose potential.
Use It or Lose It – Where Did My Foot Muscles Go?
Not using a muscle causes the muscle to weaken. When this happens, the size (girth) of the muscle will diminish. In theory, muscle disuse can lead to atrophy; however, given that most people will remove shoes for a portion of each day (perhaps when in their home) complete atrophy is unlikely.
In general, when the muscles within our feet weaken, most of the joints in our feet lose support. Given that each foot has 28 bones, 33 joints, and 100 ligaments, muscles play a valuable role in supporting these complex structures.
The good news is that while our feet are in supportive shoes, the shoe takes over for the muscles and does their work. Research in runners has shown that the less a foot muscle or foot-related muscle works, the less oxygen (and energy) the runner consumes. The scientific literature takes these findings further and states that the more comfortable a running shoe (as perceived by the wearer) the less the muscles work, and again, the less oxygen consumption needed.
At this point, I imagine that you are thinking it is time to find yourself a comfortable, supportive shoe. However, what happens when you remove these shoes?
Before we discuss that, let’s review the remarkable anatomy of the muscles of the human foot, particularly those on the plantar surface. The bottom of our foot has four layers of muscles.
When these muscles are fatigued (or weak) and supportive shoes (or orthotics) are absent, the arch of the foot lowers/drops and pronation increases (Headleea et al 2008, Wong 2007, Fiolkowski 2003). The foot, lacking shoes and strong, muscular support has increased pronation, a lower arch, more instability, and consequently, is at increased risk of injury, further fatigue, and deformity.
Further, when the four layers of muscles on the bottom of our feet our strong and robust, they provide a measure of protection to our foot during impact. With the muscles weak and frail, that protection is less, increasing the risk of injury (i.e. plantar fasciitis, stress fractures, metatarsalgia etc.)
The person who had been wearing the supportive shoes finds him or herself with achy, sore feet (and maybe even injury) and quickly decides that they need to get back into their shoes. They are hooked! Worse, as their muscles continue to weaken, they will need increasing amounts of support.
Being addicted to supportive shoes (or even orthotics) is not necessarily a bad thing. But, it is a lifestyle choice. If such wearer of supportive shoes chooses to walk or run in non-supportive shoes or barefoot, they are risking injury, fatigue and likely, will experience pain and muscle/foot strain.
How Did the Need for Supportive Shoes Evolve?
Historically, shoes were for protection from the environment: prevention of puncture wounds and warmth. Relatively recently (in the last 40 years), the shoe industry (and some medical experts) told us we needed support and the more support the shoe industry gave us, the more we needed more support. A vicious cycle ensued.
(Keep in mind that research shows that good supportive shoes (and orthotics) help promote muscular development, but primarily the triceps (calf)—not the other 30 muscles unnecessary in supportive shoes.)
Breaking Free of Supportive Shoes
Not everyone should try to give up his or her supportive shoes or athletic shoes. Diabetics and others who have peripheral vascular disease in their legs or decreased sensitivity in their feet should probably resolve to wear supportive shoes whenever walking. For those of us with healthy feet who want to keep them that way, start weaning off your supportive shoes or supportive athletic shoes slowly.
Remove the insole (or sock liner) from your shoes and walk without them for a short time each day. Gradually, build up to wearing the shoes all day without the supportive insoles, and then transition to a less supportive shoe. In time, you may want to consider transitioning to a minimalist shoe such as Nike Free, Vibram Five Fingers or Terra Plana.
Keeping your feet healthy and free of addiction is easy. Next time the salesperson offers you an expensive shoe with great support, pass on it and choose the less supportive shoe. Your feet will be healthier and you’ll save money too!
I hope you found this post thought provoking and would love to hear your comments!
Headlee DL, Leonard JL, Hart JM, Ingersoll CD, Hertel J. Fatigue of the plantar intrinsic foot muscles increases navicular drop. J Electromyogr Kinesiol. 2008 Jun;18(3):420-5. Epub 2007 Jan
Fiolkowski P, Brunt D, Bishop M, Woo R, Horodyski M. Intrinsic pedal musculature support of the medial longitudinal arch: an electromyography study. J Foot Ankle Surg. 2003 Nov-Dec;42(6):327-33.
Wong YS. Influence of the abductor hallucis muscle on the medial arch of the foot: a kinematic and anatomical cadaver study. Foot Ankle Int. 2007 May;28(5):617-20.
Nigg BM. The role of impact forces and foot pronation: a new paradigm. Clin J Sport Med. 2001 Jan;11(1):2-9.
Hardin EC, van den Bogert AJ, Hamill J. Kinematic adaptations during running: effects of footwear, surface, and duration. Med Sci Sports Exerc. 2004 May;36(5):838-44.
De Wit B, De Clercq D, Aerts P.Biomechanical analysis of the stance phase during barefoot and shod running. J Biomech. 2000 Mar;33(3):269-78.
Murley GS, Landorf KB, Menz HB, Bird AR.Effect of foot posture, foot orthoses and footwear on lower limb muscle activity during walking and running: a systematic review.
Gait Posture. 2009 Feb;29(2):172-87. Epub 2008 Oct 14. Review.
McMillan A, Payne C. Effect of foot orthoses on lower extremity kinetics during running: a systematic literature review. J Foot Ankle Res. 2008 Nov 17;1(1):13.