I wear out shoes very fast. In fact, my black dress shoes now have worn down about 50% of the heel on the outside, so I no longer wear them. Do you do this too? If your shoes wear faster on the outside of the heel, why is this happening? Is it causing other problems? Is it a sign of something that needs to be fixed?
The Answer Can Be Found in How You Walk
How you walk varies from person to person. In this case, we are looking specifically at how the foot hits the ground. Some of us have a balanced, or neutral, foot strike on the ground as we walk. Some make contact with the ground with more pronounced inward pressure (pronation) on the foot. While yet others make contact with more pronounced outward pressure on the foot (supination). Our focus today is on supination. If your shoes are wearing faster on the outside, your foot supinates too much when you walk.
It’s important to understand that for a foot to evenly absorb the forces as it hits the ground, neutral contact between the foot and the ground naturally involves slight rolling both inward and outward of the foot. This minimizes the ground forces as they move from the foot and up the leg. But when the foot rolls too much one way or the other, this extra pressure can create problems, such as arthritis, not just in the foot, but all the way up the kinetic chain, into the ankle, knees, hips, and even the spine. Likewise, problems can start at the top of the chain (the spine) and work their way down to the feet, causing supination. Let me explain.
Believe It or Not, Your Supination Problem May Be Caused by Irritated Back Nerves
Supination can be caused by a number of different things. It can be congenital, based on, for example, the angle of your ankle or knee, a hip that sits too far forward or too far backward, or an abnormally shaped or aligned spine (i.e., scoliosis). Additionally, the way your foot is built, such as a super high arch, can cause the foot to supinate too much.
More often than not, however, what we see with supination and other foot problems is irritated nerves in the low back. Back pain may or may not accompany irritated low-back nerves, so just because you don’t have back pain with supination doesn’t mean a nerve issue should be ruled out. How in the world can the nerves all the way up in the back have anything to do with why your shoes wear faster on outside edge of the foot?
The nerves in the low back supply the muscles in your leg and those muscles actually help to control how your foot hits the ground. So if there’s no irritation, those muscles balance the foot; if there is nerve irritation, even slight weakness on one side of the foot can change the strength of the muscles that keep the foot balanced, creating strange angles to the foot as it hits the ground.
How to Treat Supination
If your shoes wear faster on outside of the heel, and you know there is no congenital condition that would cause your feet to supinate, this may be a good indication that you have irritated nerves in the low back that should be treated before they cause more damage. If it isn’t a nerve issue, many times you can strengthen these lower-limb muscles on devices like a BAPS board or use orthotics, and that can really help relieve pressure on the foot, knee, and other joints. However, if you have or develop back issues, or if you just can’t treat and correct your supination conservatively, an X-ray–guided injection of platelet growth factors around the specific irritated nerves can be a good solution.
The upshot? Pay attention to those shoes wearing out more on the outside! This may mean that you have irritated nerves in the low back that are impacting how your foot hits the ground. If so, then there are things you can do to help!