Are Your Running Shoes Right For You?
Chris Reed MPT, OCS, ATC
Agile Physical Therapy

The spring running season is upon us. Time to dust off the old running shoes and donate them to the FIT running shoe drive. “Wait,” you say, “I just bought those shoes last October! I only have maybe 100 miles on them.” Well, your shoes will be shipped to One World Running in an effort to promote an awareness of health, fitness, and nutrition around the world. Now that you have donated your shoes to a great cause, it is time to buy yourself a new pair. But before you do, let’s discuss how shoes are designed, how to pick the right running shoe for you, and go over a few guidelines on when to replace your shoes. Remember, it is not always about how they look.

Shoe Design

It is important to understand some of the terminology used to describe feet and why different designs work for different feet. The first thing we need to discuss is what happens when your foot hits the ground. Most recreational runners have some sort of a heel strike as the initial contact of the foot with the ground. This is often on the outer edge of the heel. In order to absorb the shock as the rest of your foot hits the ground, your arch lowers. This is called pronation. As your weight shifts onto the ball of your foot, your arch is reformed to provide a rigid lever arm to propel yourself forward. This is called re-supination. You will often hear someone say that they are an overpronator. This means that once their foot has gone into pronation, they never re-supinate as their weight moves onto the ball of the foot. This is commonly seen in someone who has a very low and loose arch. In this case most of your shoe wear will be on the medial side of the shoe’s forefoot. Less commonly someone will be a supinator. This means their foot does not go into pronate to absorb the shock of the foot hitting the ground. This is commonly seen in someone who has a very high and rigid arch. In this case most of your shoe wear will be on the lateral side of the shoe’s forefoot. If you have even shoe wear across the forefoot, then you likely have a neutral gait pattern.

Another way to determine your foot type is the Wet Test. To perform this test, you must wet the bottoms of your feet. Then stand on a piece of paper or cardboard. After a minute, step off and look out your footprint. If there is not much of a curve to your arch, you have flat feet. If there is a very large curve to your arch, then you have high arches. If there is just a mild curve, then you have a neutral arch.

Next we need to go over the different components that make up a shoe. The first is called the last of the shoe. This is used to describe the amount of curvature in the shoe from the heel through the forefoot. Shoes come in three different lasts: straight, modified, and curved. A straight last shoe has lots of support on the inner side of the shoe. These are generally good shoes for the severe overpronator, as they will provide the most support of the arch. A modified last shoe has a slight curvature between the heel and forefoot of the shoe. This is the most common type of shoe on the market. These shoes are good for most foot types and often there is extra material added to the midsole of the shoe to restrict overpronation. We will discuss this more in a little bit. The final type of last is a curved last. This is often found in racing flats due to the lightweight nature of the shoe. This shoe lacks stability and is often good for the supinator foot type as long as enough cushioning is provided.

The upper is the top part of the shoe including the tongue, laces, and material surrounding the top of the foot. It is important that materials of the upper be lightweight and breathable.

The outer sole is what we commonly refer to as the tread of the shoe. It is often composed of a high-grade carbon rubber. A combination of high-grade carbon rubber in the rear foot and a lighter weight rubber in the forefoot is commonly used as well to decrease the weight of the shoe. The surface that you are running on will help determine the make up of the outer sole you will want. In a running shoe the tread is designed for straight-ahead movements, while in cross trainers the tread is designed more for lateral movements.

This midsole is the section of the shoe between the upper and the outer sole. The midsole contains either ethylene vinyl acetate (EVA) or polyurethane foam. EVA is a soft, lightweight, and flexible. It can be formed into different densities within the same midsole. Polyurethane is more durable and stable than EVA. It provides excellent shock absorption, but is firmer, heavier, and stiffer than EVA. This is the area that the shoe companies have spent the majority of their time researching. The midsole is where the intrinsic stability that controls pronation is built into the shoe. Companies use all different types of materials to achieve this including denser foam (usually indicated by a darker color), Kevlar, plastic components, multi-compartment air bags, and various gel materials.

Shoe Guidelines

Now that we know about determining your foot type and how the shoes are put together, it is time to discuss some tips for picking out the correct shoes for your summer runs. First and foremost, it is important that you go to a specialty running shoe store. The salespeople at these stores understand runners and are knowledgeable about running shoes and running styles. Many of them can do a quick evaluation of your gait pattern and recommend the appropriate shoes for your foot type. It is a good idea to bring your old shoes so the salesperson can look at them to evaluate your wear pattern. Make sure to shop near the end of the day or after a workout when your feet have expanded. Don’t forget to bring the socks you would run in as well as any orthotics you may wear to get a true fit of the shoes.

You want to make sure you get a shoe that fits properly. The shoe should have enough room in the toebox that you can press your thumb between the end of your longest toe and the end of the shoe. There should be enough room for the widest part of your foot to fit snuggly in the shoe. You don’t want it to be too tight nor too loose as this could result in blister formation. Your heel should not slide up and down as you walk. You should not have any pressure points on any area of the foot. It is recommended that you take the shoes for a test run either in the store or down the block from the store to make sure they feel good while running.

Now that you have your new shoes, make sure to break them in properly. It is recommended that you limit your first run in the new shoes to an easy 3 miles and to keep the distances short during the first 100 miles. Most of all do not run a race in your new pair of shoes until they are broken in.

Your shoes have a lifespan of between 350 and 550 miles. It is also important to remember the EVA material used in the midsole has a shelf life of between 6 and 9 months prior to beginning to break down in the box. So remember, before going out to purchase your new MoGo’s, take those old worn out shoes out of the closet and bring them down to the shoe drive at FIT. The shoes that are unsuitable for running in will be sent to Nike to be ground up and made into running tracks and playgrounds through the Reuse-a-Shoe program. Those that still have a little life left in them will be sent to those in need around the world.

Happy Running!!!


References:

1. Selecting a running shoe. Available from URL:
http://www.aapsm.org/selectingshoes.html (Accessed April 2007).
2. Key insights on recommending running shoes. Available from URL: http://www.podiatrytoday.com/article/4629 (Accessed April 2007).
3. How to chose running shoes. Available from URL: http://www.therunningadvisor.com/running_
shoes.html?gclid=CIzPwP6Bo4sCFQ_rYAod1yMlig (Accessed April 2007).