What Is Pronation?
It's the natural rolling of the foot when walking at any pace faster than mall walking. (When mall walking, one walks heel to toe at a very slow pace.) The way one actually walks is by hitting the outside of the heel and gently rolling in, pushing off your big toe on the inside. That natural roll is called pronating.

Overpronation vs. Underpronation. If you step on the outside, curl right in and wind up on the inside of your foot — that's over-pronating. New Balance builds up the arch on specific models to force your foot out so as not to let your whole arch collapse too soon. Other people hit on the outside of their heel and stay on the outside of their foot as they walk — like a duck almost — that's called under-pronating or supinating.

How do you know what you are? You can look at old shoes and see where the front of the shoe is worn.

• If the front of the shoe is worn on the outside then you're not rolling in.
• If the front of the shoe is all worn off on the inside then you're rolling in, too far too fast, and you are over-pronating and walking on your arch.
• If you are hitting on the outside rolling in and the middle of the shoe is worn, then you're walking properly which means you would choose a neutral shoe that wouldn't push you in and wouldn't push you out.

Which models are made specifically for over-pronators? The Running 1123 is the best example of a shoe that pushes you out. The 817 is another great example of a running shoe model which has the inside ROLLBAR®, and these Motion Control shoes provide the best support for over-pronators. Walking shoes such as the 927, 845 and 811 are also excellent.

New Balance also uses the TS-2 (transitional-2) system in running shoes to provide arch support, which assists with over-pronation. Stability shoes in this category include the 1224 and the 769 running shoes.

The newly developed Stabilicore™ system is replacing the TS2 Medial Posting technology. This system offers exceptional pronation control and is utilized in the new 850 running shoe, the update of the 859 and will be used in the upcoming 760 and 1220 series.

Stabilicore™ is a medial support system that provides an extremely smooth transition from heel strike to toe-off. It is made from an injection molded engineered thermoplastic that offers a great deal of precision and consistency. Unlike foam posting systems it provides a continuous range of stiffness for optimal transition.

Neutral shoes such as the 993 give arch support but don't push you out. They are for neutral runners or under-pronators. 

Under-pronators should not wear shoes made specifically for over-pronators, such as the running 1123, 850 or 817 or the 845 walking shoes.