A Runner's Guide to Foot Type and the Right Shoe
by Dr. Jeffrey Ross, D.P.M., F.A.C.F.A.S.

Knowing your foot type and the biomechanics that take place during running can be of great value when attempting to select the right running shoe. A great shoe for one runner may be completely wrong for another. If we all had the same feet and they functioned the same, we would all choose the same shoe.

By now, most runners are familiar with the three various foot types: the flat foot, where overpronation usually takes place; the normal foot type, where a normal amount of pronation occurs; and the high arched foot, where the foot underpronates.

Most runners can determine if they pronate sufficiently by examining their arch height. Another way to test is to wet the foot, stand on a dry surface, and evaluate the footprint that is created. The flat or low arched foot will show a greater surface volume, and its print will show a complete arch. The normal arch will effect a mild scooped-out arch area, whereas the high arched foot will demonstrate a hollowed out arch, barely to the opposite side.

What exactly does pronation mean? After the heel lands on the ground (heel strike), usually to the outside, the foot then rolls inward slightly to a neutral position, making full contact with the ground. This is the mid-stance phase of running gait. Now comes the time for pronation: as the foot begins to roll inwards and downward, it begins to pronate. Now this is a vital motion for the foot due to the fact that it provides for propulsion and impact shock absorption.

When a runner over-pronates, the foot rolls inward excessively, which may lead to a multitude of lower leg injuries such as shin splints, planar fascitis (heel pain), Achilles tendonitis, posterior tibial tendonitis and knee pain. For the runner who underpronates, commonly referred to as a supinator, this rigid foot which does not handle shock absorption very well can also lead to injury. Illio-tibial band syndrome, knee pain, sesamoiditis, lateral ankle sprains and peroneal tendonitis are common to supinators.

Foot type and shoe type. Knowing your foot type will help you select the right shoe. Foot shape goes along with this formula for selecting the proper shoe. Running shoes usually come in three shapes: straight, curved, and semi-curved. These three shapes correspond with the last that the shoe is built upon. Sports medicine podiatrists and other experts generally agree that overpronators (flat feet) should wear a straight lasted shoe, underpronators (supinators) should wear a curve-lasted shoe, and normal pronators should select a semi curved-lasted shoe.

Running shoes also have a number of other characteristics, such as motion control, stability, shock absorption, durability and light-weightness. Depending on your foot type, whether or not you are an over or under pronator, height, weight, number of miles run per week/month, surfaces that you run upon, etc., can also assist you in selecting the right shoe. An overpronator who chronically develops shin splints may look for a motion-control shoe with a straight last. A tall/heavy runner who runs on concrete will be concerned with cushioning and shock absorption. The mid-sole of the shoe where the cushioned material is located may consist of E.V.A., polyurethane, or a combination of the two. The outer sole (rubber layer) is also vital for its durability, particularly on concrete/asphalt surfaces. After all, we don't want the shoe to wear out and break down in less than three months or after only 250 miles.

Where should you look for a new shoe and get rid of the old ones? The rule of thumb here is that after six months or 500 miles the shoes should "hit the road." If you see crushed down E.V.A. and uneven outer sole tread wear, you can bet this will cause uneven heel strike and imbalance in the foot and leg. When you see the outer sole begin to break down to the E.V.A. layer, then you know for sure it's time to go looking for a new pair of "tires."

Speaking of the unevenly worn shoes, there is a reason for this. Remember our overpronator/underpronator? Well, think about A.J. Foyt racing on a front-end that's out of alignment! Those tires would wear down rather quickly. Well, with poor biomechanical alignment, so would a runner's knees, feet and shoes. That's where proper balancing of the lower extremity comes in. Proper evaluation of the runner, both in walking gait as well as running gait, is essential. A sports medicine podiatrist or specialist can analyze the runner's gait, perform videotaping or computer analysis to determine what type of biomechanics of the lower legs are involved, and predict what types of problems could occur. Together with this information, a recommendation of a few shoes could be given. Your specialist has had experience with various shoes, companies and models. You should be able to trust his or her opinion in helping to select the right shoe.

What type of shoe store should I go to in order to select the right shoe? I've often advised runners to a specialty running shoe store. They are usually owned by a runner with a sales force of other knowledgeable runners. They usually have a wide selection of shoes and models. I can assure you that they won't rush you, or try to sell you the first shoe you try on. They'll be very patient and help you with a variety of shoe styles and models.

There are few tips that you may want to remember when you visit that shoe store! Do not buy the shoe in the morning, for that is when the foot is at its smallest size. As the day progresses, the foot usually swells, and this additional volume may make the shoe rather tight. Make sure that the sales person measures your foot properly, and not just one, but both. If your right foot is bigger than your left, it wouldn't be so good if your right big toe hits the end of the shoe while the left is fine. Wear the type of sock you typically run in. If you wear orthotics, bring them with you. Usually the standard inner sole of the shoe may need to be removed before you insert your orthotics into the shoe. The shoe salesperson should also be familiar with your running history, foot type, foot problems, and any special needs. He should be aware of your weight, training history, running surfaces, mileage per week, past history of shoe wear, etc.

If the shoe fits, wear it! Now that you're armed with all this information, what's the bottom line? If the shoe fits, wear it! Fit and comfort are probably two of the most important components to finding the right shoe. There are, however, a few additional hints when selecting the right shoe.

• Make sure that there is adequate length between the end of the longest toe to the end of the shoe.
• Check to see that there is enough toe-box room between the top of the toes to the top of the shoe.
• Make sure that the tongue and laces fit snugly, yet do not create irritation on the instep.
• When you step down, check to see if the heel slides up and down or not. It should also fit snugly: not too tight.

Dr. Ross is a Podiatrist, M.D. in private practice in Houston, TX. To book an appointment with Dr. Ross or find out about his services he can be reached at 713.791.9521.