“Overpronation” is a frequently used and abused phrase by runners and health care professionals in the context of oversue injuries as well as the design of running footwear. Pronation is really a perfectly normal motion of the foot in which the ankle tilts medially and the mid-foot of the foot fall. This is what the foot is supposed to do as it is how the foot adapts to irregular surfaces and absorbs shock. It is very normal and there is absolutely nothing wrong with it. The way some runners speak about what they have read about it, you would believe that they have some type of disease.
Where the issue arises is that it is widely considered a risk factor for an overuse injury when running. For this reason, there are design characteristics in running shoes which are thought to assist runners with this alleged too much pronation. They are what are called the motion running shoes. In contrast, the neutral running footwear do not have these types of design characteristics aimed at getting rid of the so-called too much pronation.
The challenge with the perception of Overpronation is that there is no consensus on what is ‘normal’ what is actually 'too much'. Some runners with significant overpronation get no problems and other runners with only small amounts get plenty of problems. The actual evidence linking too much pronation to injury is also very weak. The agreement of the systematic reviews of the evidence is that it is only a small risk factor, making it not really a major problem as a result of so many other variables that go into runners getting an overuse injury.
So should too much pronation be treated? Yes, if it is bringing about the issue. No, if it is not contributing to the problem. This is often difficult to determine. A key in identifying if it is contributing to the problem is to decide if the forces in the tissues that it is causing are enough to damage the tissues. The supination resistance test can be helpful here in helping decide this. If that test is high, then the loads are high, so the overpronation should probably be treated. When the loads are lower, then it may not be important to treat it.
If it does need to be managed, then the cause of the problem should be addressed. There is not a one-size-fits-all with regards to too much pronation. If a muscle weakness could be the reason for the too much pronation, then exercises like the short foot exercise will help (it won’t help other causes). If tight calf muscles are the issue, then stretching is what is needed (muscles strengthening or foot orthotics will fail in these); if a bony alignment, for example forefoot varus, problem is the cause, then only foot supports can help (strengthening the muscles and calf muscle stretching will fail); and so it goes on. The reason must be dealt with.
There are lots of myths and half truths being perpetuated about overpronation. An important red flag is that whoever is talking or writing about it is, if they promote a one-site-fits-all when it comes to it, then they most likely have no idea of what they're writing about.