Current Topics in Physical Therapy

I often get quizzical looks from first-time patients with low-back pain (LBP) when I ask to see their shoes, feet, and how they walk. While these are not the first things I check, I usually get to them if I do not find a more apparent cause of the pain. When a worker whose back hurts tells me that he was lifting 75 pounds while bending and twisting, for example, I probably will not get to his shoes at all. However, with chronic LBP that has been dragging on for months or years, or when a patient does not really know how the pain started, examination of the shoes, feet, and gait pattern usually becomes part of the initial evaluation.

It helps to think of the body as a chain, with the feet, legs, hips, and spine all linked by way of the joints. During walking, the foot hits the ground with three to five times the force of body weight, generating a chain-reaction all the way up the skeleton. The way the foot moves affects the way everything else on up the chain moves. The foot bones connected to the ankle bone the leg bones connected to the knee bone, and so on. Theoretically, action at the feet could create neck pain, although I have never diagnosed that.

Perhaps the worst culprit for LBP is pronation. Pronation occurs when the foot rolls inward as it drops. This normal movement happens with each step. But when the foot rolls too much, or if it still rolls inward while pushing off the ball of the foot, when it should be rolling slightly outward, abnormal torques can start a chain of events that create pain most often in the foot, knee, and/or low back. It can happen to people young or old, active or sedentary, and athletes are especially susceptible because of the increased stresses their bodies endure.

Abnormal pronation can occur with normal foot types, and it happens often with flat feet. Take a look at your feet and find the telltale signs: Do you have calluses on the inner side of your big toe(s)? Do one or both of your big toes angle toward your middle toe(s)? If so, a gait analysis would probably confirm that you are abnormally pronating, and at risk for bunions, knee pain, and LBP. While abnormal pronation usually occurs in both feet, it can happen in only one foot, or in one foot more than the other.

Inspecting an old pair of your shoes also reveals evidence. The uppers tell some of the story, but check the soles. Wear at the outer part of the heel is normal. Wear at the inner part of the toe area, sometimes accompanied by excessive wear at the middle of the ball of the foot usually signals abnormal pronation.

The shoes themselves may contribute to the problem. Heavily cushioned shoes can increase abnormal pronation, but more importantly, soles that curve substantially at the arch of the foot actually help you abnormally pronate. Knowledgeable sales people at a good shoe store can show you straight-lasted shoes. You will notice the difference in the soles, and when you walk in them. If cushioning is not a major concern, shoes that are both straight-lasted and board-lasted lend greater control, but they may be difficult to find. Many walking and running shoes have rubber of different densities throughout the sole that also aids in correcting the problem.

If changing your shoes solves the problem, congratulations! You have taken the easiest and the least expensive route to reducing or eliminating your pain. If some pain still persists, however, the next step may be purchasing orthotics. They are plastic inserts worn inside the shoes that change the way the feet interact with the ground. Trying to change the way you walk wont work, but you can change the biomechanics of your gait with orthotics. They are custom molded to your foot by a podiatrist or by a licensed physical therapist, and they should do the trick if abnormal pronation causes pain. Orthotics are expensive, and the same product can vary widely in price from practitioner to practioner, so it pays to shop around. Different insurance plans also vary dramatically in their coverage of the costs of orthotics. However, if abnormal pronation causes pain, and changing your shoes does not help, then orthotics are worth the investment.

Foot types other than flat feet can also cause pain. People with especially high arches experience decreased shock absorbtion, like a car with stiff springs. That body receives a greater jolt with each step, and could benefit from a shoe with more cushioning, and possibly orthotics as well. There are many different types of feet, each requiring an individualized approach. If changing shoes does not eliminate your pain, consult a trained professional.

Some last words about shoes: Women should wear high heels sparingly. They look great, but they cause a host of bodily aches and pains. If your shoes are old and worn, THROW THEM OUT! They contribute to your pain, and they can create new problems. So if your back hurts, check your shoes. They may directly cause back pain, and if you know how to read them, they just may be able to tell you how to eliminate your pain.