Overpronation is a phrase that creates a great deal of concern among podiatrists and running footwear retailers mainly because it causes a whole lot of misunderstandings and controversy. Pronation is a motion of the foot where the ankle rolls inwards and the mid-foot (arch) of the foot collapses. This is a normal healthy motion which is important for normal foot biomechanics and shock reduction. Overpronation is supposed to be the term employed to describe should there be too much of this normal pronation. The initial aspect of the controversy is just what is normal and what's abnormal and exactly where could be the threshold of the split between normal pronation and overpronation. There are actually robust opinions on all sides of this debate and there doesn't seem to be any solution in the controversy coming.
The reason this issue generates so much dialogue is that overpronation has been considered a key aspect in overuse injuries in runners. Podiatrists frequently use foot orthotics to treat the problem and running shoe producers design running shoes to help runners which may have the condition. This suggests there is lots of vested interest in this. The issue arises is that the scientific evidence shows that, yes, overpronation is often a risk factor for a running injury, but it is not much of a major risk factor. It's further complicated by a lot of runners who may have fairly severe overpronation and never develop any problems and do not need foot orthoses or running shoes using the motion control design features. That doesn't help solve the debate nor help clinicians make decisions re foot orthotics and for running footwear sellers on advice in regards to what ought to be the right running shoe. It really comes down to clinicians and running shoe retailer’s individual experience and expertise and making decisions in the context of precisely what is best for the individual athlete.