It gets really scary when you surf around the blogosphere and see how ‘pronation’ and ‘overpronation’ is being pontificated on by pseudo-experts and giving advice when they clearly have no idea what they are talking about. This is very common in the running community and is a flawed basis for the prescription of running shoes. There is so much of what is written about it that is pseudoscience, yet is accepted as fact by those who are not familiar with the whole body of evidence on the topic. There is a lot of cherry picking of flawed studies to make a point and and ignoring of what the more powerful meta-analyses and and systematic reviews are showing.
“Pronation’ and ‘overpronation’ in the running community are probably the most misused and misunderstood terms in relationship to injury and running show prescription. See: The nonsensical understanding of ‘overpronation’.
The most recent example of this is the recent study that came with a press release that was widely picked up on running websites and forums about ‘busting the pronation myth‘ in which the authors claimed to have shown that pronation was not a risk factor for injury in runners. Those with agendas widely trumpeted that press release and running websites parroted from that press release. There was very little critical appraisal of the actual research that underpinned the press release.
Basically the study was a prospective risk factor study. They used the Foot Posture Index (FPI) and found that those runners with a higher FPI did not get more overuse injuries. BUT if you actually read the paper:
1. They eliminated all those wearing foot orthotics from the study. The assumption would be that if they are wearing foot orthotics, then they are probably a pronator at risk for injury. So if you eliminate all those pronators who are at risk for and injury, you are left with the pronators who are not at risk for an injury! So, of course they will then find that ‘pronation’ is not a risk factor! I can’t believe how dumb this was to do and how all those parroting the study did not see this as an issue.
2. They also used an FPI of 7 as the cut off point of the neutral vs pronated category. While this is based on normalized data, there would hardly be any clinician familiar with the FPI that would accept that. This means that most of the feet in their ‘neutral’ group were probably pronated!
3. Another study came out around the same time that showed the exact opposite of this study. Why did those parroting the above study not mention this one? This was cherry picking at its worse.
At the end of the day, there is more than enough studies on ‘overpronation’ and injury risk to combine all the data from all the good ones into a meta-analysis and systematic review. The most recent one to do that concludes that ‘overpronation’ is a small, but statistically significant risk factor for injury. This data is much more powerful than individual studies and should be the one that we focus on to avoid the use of cherry picking one study or another to promote an agenda.