Anatomy Of A Running Shoe (And Other Helpful Terms)

Heel drop? Midsole? Supination? What does this all mean? The jargon of the running shoe industry can be confusing, especially when you aren't sure what kind of shoe you need.

March 10, 2016
img ake2m9bvymtsxniowegi

One thing that often surprises new runners is the fact that there is so much more to picking the right running shoe than walking into the store, finding your size, and a color scheme that appeals to you. No—there are many different types of running shoes for all different types of runners, types of terrain, and types of feet. And picking the wrong one could lead to discomfort and even possible injury. Not only is this information overwhelming, but the jargon thrown around when discussing a running shoe can be utterly confusing.

So let me break it down for you. First, we’ve got the anatomy of a running shoe. Although there is certainly more terminology than listed below, these are some of the more common terms you are most likely to hear.

Sole: This one might be obvious to most people, as it is the bottom of the shoe. But in the running world, we break it down into three separate parts: the outsole, the midsole, and the insole.

  • The outsole is the very bottom of your shoe, the part that comes in contact with the ground. It is typically made with a harder type of plastic and is where there is “traction” or grip.
  • The midsole is the layer that sits between the outsole and the upper. (If you’re a visual person, imagine that your foot goes between the midsole and the upper.) The midsole is where you will find the cushioning, if any, of the shoe.
  • The insole, or sock liner, is the first layer of soft foam your foot rests on inside the running shoe.

EVA (ethylene-vinyl acetate): Lightweight, foam-based cushioning used in the midsole.

Polyurethane: A more durable and stable cushioning than EVA, often used in the midsole.

Upper: This is the top half of the shoe, i.e., everything that isn’t the sole. This material is typically softer and lightweight, often made out of a mesh-type fabric to allow for air circulation.

Tongue: This is a separate strip on the upper. It helps prevent the laces from rubbing on your foot. I’m not entirely certain that they didn’t name this piece “tongue” because it essentially sticks out like a human tongue from the opening of the shoe.

Eyelet: These are the little holes the shoelaces go through. You likely remember playing with them when you were learning how to tie your shoes.

Heel collar: The inside back portion of the shoe that provides comfort around the ankle. Often this area is cushioned to help prevent any soreness or chafing around the Achilles tendon.

Heel counter: An internal support feature in the rear of the shoe that conforms to the shape of your heel. This helps prevent your foot from slipping around inside of the shoe.

In addition to the parts of a running shoe, here are some other helpful running shoe terms you may want to know:

Heel drop: Often also referred to as the heel to toe drop or heel-toe differential. This essentially refers to the difference in height between the heel and forefoot (toe area) of your shoe. Many sneakers have added cushioning in the heel for support. So for example, if the heel of your shoe (midsole + outsole) is 22 mm high but the forefoot (midsole + outsole) is 10 mm high, then you have a 12 mm heel drop. For further reference and to better imagine what a heel drop is, picture a bare foot on the ground. Both the heel and the toe are touching the ground, so the drop would be zero. But if you put a 6 mm wedge under your heel, with your bare toes on the ground, the heel drop would now be considered 6 mm.

Supinate: Supinate is a common term for how a runner lands on their foot when running. When there is insufficient inward roll of the foot after landing, this is considered “supination” (or underpronation). Runners who supinate typically land on the outer edge of their sneaker.

Pronate: The opposite of supinate, when runners pronate typically the outside part of the heel makes initial contact with the ground. The foot rolls inward about fifteen percent, coming in complete contact with the ground. The rolling in of the foot optimally distributes the forces of impact, ending with the runner pushing off evenly from the front of the foot.

Overpronate: A runner who overpronates has a foot that rolls inward more than the ideal fifteen percent (as in pronating, above). This means the foot and ankle have problems stabilizing the body, and shock isn’t absorbed as efficiently. A runner who overpronates will push off the ground using mainly the big toe and second toe, which then must do all the work.

Stability shoe: These are designed for runners who overpronate and need maximum cushioning and stability in a running shoe.

Neutral shoe: These shoes are designed for runners who either supinate or do not pronate. In other words, who land neutrally on their foot.

Even though you’ve now read all of these definitions, they still might be a little confusing when you’re trying to figure out what you need in a running shoe. When in doubt, be sure to visit your local running shop. The expert staff will be able to take a look at the wear pattern on your current shoe—or even watch you run—to help you determine what kind of shoe is best for you.