Ray McClanahan, D.P.M.
Since much of the current treatment for foot and ankle disorders is centered on supporting the arch, we thought it would be helpful to discuss what arch support really means and discuss whether it is necessary or desired in the active foot.
In order to understand the treatment of rendering arch support, one must understand the architectural principle of an arch, and liken that principle to the multitude of arches that naturally occur in the human foot. When you study the structure of the foot and the shapes of the bones of the foot, you quickly realize that most of the weight-bearing bones of the foot, are indeed arches themselves by being shaped to have support ends at either end of the bone and an open space or boney arch in between the support ends of the bones. For the purposes of the current discussion, we will concentrate on what might be considered one of the primary arches of the foot, sometimes called the medial (inside of the foot) longitudinal arch, the arch that spans between the rearfoot or heel bone and the forefoot or ball of the foot and toes.
Webster’s dictionary defines an arch as “a curved structure that supports the weight of material over an open space.”
Said another way, an arch is a structure that is able to support weight over an open space, by providing support on either end of that open space.
Applying this logical definition to the arches of the foot necessitates support on either end of the arch, and is exactly the opposite of the type of “arch support” that is available to consumers, either over the counter (i.e. Dr. Scholl’s or similar product), or from their healthcare professional (footbed, arch support, orthotic). These products attempt to “support” the arch, not by supporting the ends of the foot arch, but rather by lifting up under the open space of the foot arch. This does not make sense.
True support of the arches of the foot would suggest that the ends of the arches, on either end of the foot’s open space, are the structures to be supported. This would mean that the heel and the forefoot joints (metatarsophalangeal joints and interphalangeal joints) are the structures that should be supported and not the structures in between the ends of the arch.
As was mentioned above, current commercially available “arch supports” (which, by the way, are packaged under a number of names – arch support, footbed, orthotics, etc.) push up under the open space of the foot arch and not up under the ends. Many people feel a positive influence on their posture and walking comfort when wearing the current type of arch support, but this is not because they have a problem foot, but rather, because nearly all footwear that is available to today’s consumer expects the wearer to function well while walking on a ramp (the heel is elevated higher than the forefoot) with their toes bunched together (from tapering the boxes) and the toes held above the supporting surface by footwear industry standard toe spring, which is the elevation of the ends of the toes above the ball of the foot (the metatarsophalangeal joints).
But wait, didn’t we just confirm that in order for the arch of the foot to be supported, we need to support the ends, and not the middle, or open space? Indeed we did, and as you can see from the description above, current footwear available to consumers is improperly positioning the support ends of the arch, by elevating the heel, which is one end of the arch, and unnaturally pinching the toes and holding them above the ball of the foot (metatarsophalangeal joints), which is the other end of the foot arch.
True support of the foot arch would then necessitate getting the heel bone (calcaneus) flat on the ground to provide support for the rearfoot support end, as well as getting the toes flat on the ground as well, so that the toes can help the ball of the foot to provide support for the other end of the foot arch in the forefoot.
Individuals who grow up barefoot, naturally have the support they need for both ends of their foot arch, and this is likely part of the reason why their foot arches function perfectly throughout their lifetimes, and their feet do not break down, unlike 80% of Americans who by nature of their habitual shoe wearing and compromised arches, will suffer some form of foot problem at some point in their lives.
This is not to suggest that we should all ditch our shoes and begin walking around barefoot, but it does suggest that our shoes are made improperly and are the cause of the arch problems and the associated deformities that many Americans experience.
Although there is scientific evidence that spending time barefoot is exactly what our weak arches need, the reason why it would not be a good idea for most Americans is because much of our immediate environment is not compatible with our thin, moist skin and weak arches. We live in a world of cement and asphalt and multitudes of sharp materials, such as glass, that can become embedded into our skin. Interestingly, the skin of the feet becomes thickened and resistant with prolonged exposure to hard objects such as gravel, cement and asphalt. Unfortunately, most Americans will never experience this hypertrophying and strengthening of the skin and arches of the foot, which is taken for granted in many developing countries, where all out sprinting over sharp rocks causes neither pain, nor injury.
What is suggested and recommended is that we make shoes that meet the need for protection of the skin of the feet, and that shoe manufacturers do not presuppose that the fashionable design features of heel elevation, tapering toeboxes, and toespring, are without significant deforming consequences.
In conclusion, the most likely reason for needing arch support, is because today’s footwear removes the structural integrity of the foot arch by altering the support ends in favor of supporting the open end, with is no longer an arch support, but an open space support.
Pushing up in the open space of the foot has the significant long term consequence of weakening of the muscles that span the open space of the arch, which are called the intrinsic muscles of the foot, as well as the numerous muscles in your lower leg which send tendons into their final insertions, many of which are in the ends of the toe.