Running Shoes: What Flat Feet, Overpronation and Supination Mean

Apr 16, 2010
Debra Peterson

Know Arch Type and Pronation for Running Shoes - Kevin Spencer (flickr, Creative Commons License)

In order to choose the best running shoes, runners need to know what flat feet, overpronation, and supination mean and buy shoes that address those issues.

Runners often use the terms flat feet, overpronation, and supination to discuss their needs in running shoes. Knowing what these terms mean can help a runner narrow down running shoe choices and get a good fit.

Arch Type and Running

All three terms are related to arch type and their effects on running. The arch of the foot helps absorb the impact of movement such as walking and running, supporting the body in an erect position with the least amount of stress. The height of the arch affects both arch type – high, normal, and flat – and pronation, or the movement of the foot.

To determine their arch type, runners can perform the wet test. With wet, bare feet stand or walk across an absorbent surface like paper, distributing the body’s weight evenly to get clear imprints. Then examine the impressions of both feet. (They might reveal different patterns.)

Normal or Medium Arch. A “normal” arch will show a distinct curve along the inside of the foot, what is commonly thought of as a footprint. The foot absorbs the impact of running and the body’s weight evenly. This foot type is also referred to as neutral.
Low Arch. A low arch, which at its extreme means a flat foot, will show almost the entire sole of a foot. This foot’s arch stretches inwards, causing the foot to roll inwards and absorb the impact of running unevenly.
High Arch. A high arch type will show the heel and ball of the foot, but very little of the middle. This foot’s arch tends not to be flexible, rolling very little, and the foot receives a lot of impact.

Normal arches tends to enable runners to adopt efficient pronation, meaning the foot rotates inward slightly as the heel hits the ground before pushing off with the toes. Runners with this gait are referred to as neutral runners.

Runners should also use their shoes to determine pronation. Those with low arches or flat feet are likely to overpronate, while runners with high arches are likely to supinate (underpronate). But runners who have flat feet don’t always overpronate, and those with high arches don’t always supinate. So examine an old pair of running shoes (or regular shoes) to determine if overpronation or supination is actually an issue.

The shoes of runners who tend to overpronate will show more wear on the inside edge of the shoe. When placed on a flat surface, the shoes will tilt inwards. Running shoes of those who tend to supinate will shoe more wear along the outside edge of the shoe and will tilt outwards.

Running Shoes for Flat Feet and Overpronation

With low arches or flat feet and overpronation, the runner’s arches collapse when the feet hit the ground. The ankles twist inwards and the balls of the feet take most of the body’s weight. With overpronation, the knees overcompensate for the movement, which can lead to injury. Overpronation can range from mild to severe.

When choosing a running shoe, runners who have flat feet or overpronate should look for shoes that use the terms support, stability, or motion control in their descriptions. These terms are used across brands to describe running shoe categories. All terms address, to a lesser or greater degree, the excessive movement of the foot.

Runners with flat feet might only require support, or added support, in running shoe specs. Mild to moderate pronators should look for stability running shoes, as do many runners with normal arches. Motion control shoes are stability shoes designed for severe overpronators or heavier runners, offering the benefits of stability shoes for these conditions.

Running Shoes for Supination (Underpronation)

With high arches or supination, also called underprontion, the runner’s feet rotate inwards very minimally and the weight of the body stays on the outside edges. This movement is inefficient and causes extra stress on the feet and lower legs. Shin splints and ankle strains are common injuries for supinators.

Runners with high arches or who supinate should look for the terms cushioning and flexibility in running shoe specs. These shoes tend to have extra materials, especially in the heel and forefoot, to help absorb the impact of movement.

To choose the best running shoes for their particularly needs, runners should also visit a specialty running store for a proper fit and shoe advice. Running shoe stores also often offer free running gait analysis that help identify flat feet, overpronation, and supination issues. Their expertise, and even more so that of a podiatrist or sports medicine specialist, is especially useful for runners new to running, are prone to injury, or those whose running habits have recently changed.