Overpronation has become the most misused and confusing words in running and health professional communities, specifically when it involves the prescription of running shoes. The whole conventional model of the design of different running shoes are derived from the idea of the normal or neutral posture of the feet. Pronation happens when the foot rolls medially at the rearfoot and the arch collapses. Supination happens when the feet rolls outwards at the rearfoot and the mid-foot height increases. They are normal healthy motions that are needed for normal biomechanics of the feet. It is the way the foot adapts to uneven surfaces and absorbs impact. There is nothing unhealthy with the motions of pronation or supination.
The phrase overpronation is used to infer if there is too much pronation. The reason why it becomes an issue is that overpronation is believed to be a risk factor for numerous different running injuries. For this reason, running shoes are made with design characteristics in them which are thought to help stop this overpronation. These design features include medial heel posts, dual density midsoles in addition to rigid heel counters. These footwear are supposed to be prescribed for those who overpronate. Those who tend not to overpronate will need to use shock absorbing neutral shoes.
The problem with this principle is that the term is misused considerably. There’s no general opinion regarding the cut-off stage between normal pronation and overpronation. There is hardly any evidence associating overpronation to running injury and if there is any, it’s showing that it really is only a very small risk factor. Lots of runners overpronate significantly and don’t have issues. Similarly, there are numerous runners which do not overpronate that have a lot of problems. Because of this confusion, there’s been a recent change in using the phrase and the comprehension of overpronation in connection to overuse injury and the use of running shoes.