Overpronation has become the most overused as well as misunderstood terms in running and health professional groups, particularly when it comes to the use of running shoes. The whole typical model of the design of different running shoes are derived from the idea of the normal or neutral posture of the foot. Pronation occurs when the foot moves inwards at the ankle joint and the arch collapses. Supination is when the foot rolls outwards at the rearfoot and the arch height rises. These are normal healthy motions that are required for normal function of the foot. It is how the feet adapts to irregular surfaces and absorbs impact. There is nothing wrong with the motions of pronation or supination.
The name overpronation is used to explain if there is increased pronation. The reason that it becomes an issue is that overpronation is considered to be a risk factor for a lot of different running injuries. For this reason, running shoes have got design features within them that are designed to help stop this overpronation. These design characteristics include medial heel posts, dual density midsoles and rigid heel counters. These running shoes should be sold to those that overpronate. Those who don't overpronate should really use shock absorbing neutral shoes.
The issue with this theory is that the name is overused a lot. There isn't any agreement regarding the cut-off position between normal pronation and overpronation. There is also minimal research linking overpronation to running injury and if there is any, it is showing that it is actually only a tiny risk factor. Lots of runners overpronate significantly and don't have problems. Likewise, there are many runners who don't overpronate that have plenty of issues. Due to this misunderstandings, there has been a recent change in using the phrase and the idea of overpronation in connection to running injury and the use of running shoes.