Pronation is the inward movement of the foot as it rolls to distribute the force of impact of the ground as you run. The foot “rolls” inward about fifteen percent, comes in complete contact with the ground, and can support your body weight without any problem. Pronation is critical to proper shock absorption, and it helps you push off evenly from the front of the foot.
Although pronation is a natural movement of the foot, the size of the runner’s arch can affect its ability to roll, causing either supination (underpronation) or overpronation. If you have a normal arch, you’re likely a normal pronator, meaning you’ll do best in a stability shoe that offers moderate pronation control. Runners with flat feet normally overpronate, so they do well in a motion-control shoe that controls pronation. High-arched runners typically underpronate, so they do best in a neutral-cushioned shoe that encourages a more natural foot motion.
Normal Pronation
The outside part of the heel makes initial contact with the ground. The foot “rolls” inward about fifteen percent, comes in complete contact with the ground, and can support your body weight without any problem. The rolling in of the foot optimally distributes the forces of impact. This movement is called “pronation,” and it’s critical to proper shock absorption. At the end of the gait cycle, you push off evenly from the front of the foot.
Overpronation
As with the “normal pronation” sequence, the outside of the heel makes the initial ground contact. However, the foot rolls inward more than the ideal fifteen percent, which is called “overpronation.” This means the foot and ankle have problems stabilizing the body, and shock isn’t absorbed as efficiently. At the end of the gait cycle, the front of the foot pushes off the ground using mainly the big toe and second toe, which then must do all the work.
Preventing Overpronation Injuries
Overpronation causes extra stress and tightness to the muscles, so do a little extra stretching. Too much motion of the foot can cause calluses, bunions, runner’s knee, plantar fasciitis, and Achilles tendinitis.
If you’re an overpronator, here are a few tips to help you find the right shoes for your feet.
Wear shoes with straight or semi-curved lasts
- Look for motion-control or stability shoes with firm, multidensity midsoles and external control features that limit pronation
- Use over-the-counter orthotics or arch supports
Underpronation (Supination)
Underpronation (or supination) is the insufficient inward roll of the foot after landing. Again, the outside of the heel makes initial contact with the ground. But the inward movement of the foot occurs at less than fifteen percent (i.e., there is less rolling in than for those with normal or flat feet). Consequently, forces of impact are concentrated on a smaller area of the foot (the outside part), and are not distributed as efficiently. In the push-off phase, most of the work is done by the smaller toes on the outside of the foot.
This places extra stress on the foot, which can lead to iliotibial band syndrome, Achilles tendinitis, and plantar fasciitis. Underpronating will cause the outer edge of running shoes to wear sooner. To see if your shoes are unevenly worn, place them on a flat surface. If they tilt outward, supination is the culprit. Runners with high arches and tight Achilles tendons tend to be supinators. Click here to see a wonderful buying guide to choosing running shoes for it band syndrome
Preventing Underpronation Injuries
Supinators should do extra stretching for the calves, hamstrings, quads, and iliotibial band. Wearing the right type of running shoes and replacing worn shoes will also help avoid injuries.
If you’re an underpronator, here are a few tips to help you find the right shoes for your feet.
- Wear shoes with curved lasts to allow pronation
- Look for lightweight trainers as they allow more foot motion
Check for flexibility on the medial (inner) side of the shoe