Simply put - does pronation mean I strike with the inside of my foot first, or the outside of the foot first?
Sorry for the dumb question, but everywhere I look it up gives long medical explanations.
Thanks
Pronation is simply the action of the foot rolling inward. Doesn’t mean that it LANDS on the inside, nor does it mean that the foot flattens out (the arch collapses). It is merely motion IN THAT DIRECTION. Now OVER-pronation is another thing entirely, and is the culprit in many over-use injuries of the knee…
Your foot will strike on the outside edge of the heel. In this position the foot is braced for the impact. Once the “heel bone” everts or moves into back to center. This is the start of pronation. The inward movement of the subtalar joint. (talocalcaneal joint)
overpronation is another thing all together. Its more of an arguement than a discussion. To me, there really is no such thing as “over” pronation.
Why do you ask?
I was asking because of the way I run and I am looking for a new pair of shoes. I land just about mid foot and just slightly on the outside of the foot first and I am wondering whether to get a “stability” shoe or one that is more cushion with less stability. I have been using one of the Asics that I’m told is on the lower end of stability, but still in that category. I was thinking of changing brands for no other reason than I have only ever run in Asics, and Nike seem to be too narrow for my foot. I’m told by friends that New Balance has a wide shoe that is very comfortable.
There are long winded discussions about what pronation is because it is different things depending upon … open kinetic chain (in space) vs. closed (standing/walking/running).
Simply put, it is a triplanar motion (3 different axis) in the front, sagittal and transverse planes. Most people seem to “focus” on the frontal plane (the “collapse” of the arch or foot under the leg).
As LaWoof suggest, the bulk of what most think of pronation occurs at the subtalar joint (the frontal plane and a little in the transverse plane), but the rest occurs (with new research suggesting the most important part) at the talo-navicular and some at the calcaneo-cuboid and midtarsal joint.
Normal running is to land slightly supinated as you are describing, “pronate” some to adapt to uneven terrain for example, then re-supinate at the midfoot to make a rigid “lever” for propulsion. Sprinting this does not occur at all. Heel strikers do “more” because they are on the “ground” for a longer period of time.
I’m at lunch typing away and I just realized this probably didn’t help much at all, sorry 
To understand the type of shoe you need, look at your old shoes. After you have run several hundred miles in a pair of shoes, look at the shoe from behind while putting slight pressure in the shoe about where your heel sits. Do the sides of the shoe still maintain a roughly vertical position? If there is a seem up the back of the shoe that was vertical then the shoe was new, is it still vertical? If so, you are getting plenty of motion control from your current shoes. Or, do your shoes lean towards the inside edge of the foot, with the once vertical seem now tilted in more than about 10 degrees, and the mid-sole broken down from excessive pressure towards the inside (between your feet, or “medial” in medical speak) portion of the shoe? If this is the case, then you are not getting enough motion control from your current shoes. The other way to determine if you are not getting enough motion control is if you have pronation driven injuries like plantar faciaitis, IT band syndrome, posterior tibialis tendonitis, etc.
The best way to find a good shoe is to go to a good running store where they will video your foot strike and put you in shoes that do not allow you to overpronate. Yes, you will pay a few dollars extra, but the service is worth it.
Also, you can overpronate. Just look up PTTD (posterior tibialis tendon dysfunction) for an example. Or, congential flat foot for another. Most people have more subtle issues, but over pronation is a significant source of injuries. The amount of pronation required to cause injuries is very individual, and this is where the conversation gets complicated, so I’ll stop, because you just want to know which shoes to buy.
Paul
Thanks to all. As usual, good information from the ST crowd.
Just FYI, I got some bad advice one time at a running store because the store guy saw my foot pronating and sold me some semi stability shoes. Worst shoes I ever bought. Turns out my foot hits pretty hard to the outside and needs to pronate to get back to a more stable position, and I get much fewer injuries with cushioned shoes that allow the pronation (I thnk because the act of pronation absorbs a lot of the impact energy).