Dr. Rob Rinaldi on how to reduce running injuries

The Andrew Wakefield golden ass award goes to Dr. Rob Rinaldi, DPM, for making the claim that 85% of all running injuries could be prevented if we'd only run in the right shoes (that is matching our foot kinematics with the shoe). Where did mr. Rinaldi get the 85% figure? Not from any research because there isn't any that would support this claim. But alot of the beginning of his article talks about his gut feeling, so most likely, he pulled it from where he felt it.

Although there are zero papers showing that correctly matched running shoes reduce injury rate, there is a single paper, published in 2006 and available to Rinaldi when he did his 10 months of research for the article, showing that runners fit by the Sports Science Institute of South Africa Sports Medicine running shoe clinic had an equal frequency of injuries in the year following shoe purchase to matched runners that had not been to the clinic. Since some of the control group (those that had not been to the clinic) were getting professional advice on shoe fit, we might expect the difference in injury rate to be small. Indeed, if all of the control runners were getting professional advice, we expect the injury difference to be zero (assuming the advice was the same).

So maybe both groups were just getting good advice and the frequency of injury in both groups was low? The authors do not report the percentage of runners who were injured in the year following running shoe purchase, only the raw number of total injuries. The shoe-clinic group had 93 injuries and 94 runners. The control group had 115 injuries and 83 runners (note that the control group ran more and the frequency of injury/running day were very close). Clearly some runners had multiple injuries. Regardless, these must reflect high injury rates (typical statistics are something like 50-80% or runners are injure per year). So there is no evidence from this one study that correctly matching foot kinematics to running shoe will reduce injury rates at all much less 85%.

Schwellnus, MP and G Stubbs (2006). Does running shoe prescription alter the risk of developing a running injury? International SportMed Journal, Vol.7, pp. 138-153.

Born to Run

Born to Run: A Hidden Tribe, Superathletes, and the Greatest Race the World Has Never Seen
by Chris McDougall has the difficult task of living up to its reputation. After the first few chapters, I had my doubts that it could. But doubt gave way to intrigue, then to fun, and then thrill. The book reads like a novel. It's hard to put down, because the short chapters end with little mysteries that are only uncovered in the next chapter. Kinda like The DaVinci Code, only better. Two chapters could be excerpted as stand-alone essays, one on running shoes and injury, and one on the running man theory of human bipedalism. The running man chapter should be nominated for the Best American Science Writing series.

That said, I do have some criticisms. I'm skeptical of the romantic portrait of the tarahumara that McDougal paints, but that is a small issue. I'm also skeptical that the tarahumara do not get running injuries. McDougal states this several times but doesn't offer any evidence other than anecdote. Indeed, one of the tarahumara has a typical running injury during the Leadville race but this is dismissed as a function of running in running shoes for the first time. But he was also running in Colorado for the first time so maybe that was the cause? Or more likely, Tarahumara are humans like the rest of us and get injured. This is an important point because McDougal is building the case that there is way to run injury free, and this way includes both running techique and avoiding modern running shoes. McDougal quite correctly asks why running isn't like every other sport, that is, one requiring practice of a certain techniqe. Nevertheless, while the evidence that certain kinematics (such as "overpronation") cause injury is, essentially non-existent, there also isn't good evidence that running a certain way (such as chi or pose running) reduces injury. Ditto for shoes. McDougal makes the oft-heard claim among barefoot runners that running injuries have increased since the advent of the modern shoe. I've not found the citation documenting this but even if it is true, that doesn't necessarily implicate the modern running shoe. Since the 70s (when the first modern shoes started to appear), americans have also gained alot of weight and become more sedentary. We drive cars *everywhere*. And modern marathon advertisers have spent big money to get the couch-to-5K crowd running 26.2. So while I'm sympathetic to the idea that certain running kinematics and retro shoes are less likely to contribute to injury, I want to emphasize "contribute" because the one variable that we do know that causes an increased rate of running injury is running itself.

But I shouldn't (and didn't) focus on the science. It is part of the message but not critical. What is the message? That running is fun (indeed it evolved to be fun). Mixed in with the message and the science are fun biographies/stories of some of the big names and personalities in the sport of ultrarunning. And fun histories of some of the big ultra races. But the story behind the story is the mysterious Caballo Blanco and his quest to get the best North American ultrarunners to race in his Copper Canyon ultramarathon with the turahumara runners. The science, the biographies, the histories weave in and out of this central story and the story doesn't close, as it should, until the final chapter. It's a fun run to the finish.

Running Shoes

I finally opened my May 2009 issue of Outside magazine and turned immediately to "Spectrum: different runners require different shoes. Our guide to your perfect fit". The single page highlights three shoes, one lightweight cushiony trainer for the neutral runner, one stability shoe, and one motion control shoe. Note that the lightweight trainer is 12 oz (341 grams). Note also that they state that, combined, 80-85% of runners need a shoe to deal with moderate to severe overpronation. I'm sure this statistic is accurate, but the immediate response should be, "wait what?" If 80% of overpronate, maybe overpronation is not so bad?

I'm picking on Outside but they're just parroting the dogma from nearly every running shoe company, shoe store fit specialist, podiatrist, sports medicine M.D., chiropractor, and textbook. The only contrarians seem to be the loud-mouthed minimalists on letsrun.com, the hippy barefoot runners, and everyone who has recently read Born to Run. But given the universal acceptance of the "personally fit running shoes are necessary to reduce injury" model, you'd think there would be more evidence for this than something like, say, the ability of psychics to predict the next bus bombing. Here is the abstract of a recent paper from the British Medical Journal.

Published Online First: 18 April 2008. doi:10.1136/bjsm.2008.046680
British Journal of Sports Medicine 2009;43:159-162

Copyright © 2009 BMJ Publishing Group Ltd & British Association of Sport and Exercise Medicine.

Reviews

Is your prescription of distance running shoes evidence-based?

C E Richards^1,2, P J Magin¹ and R Callister²

¹ Discipline of General Practice, School of Medicine and Public Health, University of Newcastle, Australia
² School of Biomedical Sciences, University of Newcastle, Australia

Correspondence to:
Dr C Richards, Discipline of General Practice, Bowman Building, School of Medicine and Public Health, University of Newcastle, University Drive, Callaghan 2308, Australia; craig.richards@newcastle.edu.au

Objectives: To determine whether the current practice of prescribing distance running shoes featuring elevated cushioned heels and pronation control systems tailored to the individual’s foot type is evidence-based.

Data sources: MEDLINE (1950–May 2007), CINAHL (1982–May 2007), EMBASE (1980–May 2007), PsychInfo (1806–May 2007), Cochrane Database of Systematic Reviews (2^nd Quarter 2007), Cochrane Central Register of Controlled trials (2^nd Quarter 2007), SPORTSDiscus (1985–May 2007) and AMED (1985–May 2007).

Review methods: English language articles were identified via keyword and medical subject headings (MeSH) searches of the above electronic databases. With these searches and the subsequent review process, controlled trials or systematic reviews were sought in which the study population included adult recreational or competitive distance runners, the exposure was distance running, the intervention evaluated was a running shoe with an elevated cushioned heel and pronation control systems individualised to the wearer’s foot type, and the outcome measures included either running injury rates, distance running performance, osteoarthritis risk, physical activity levels, or overall health and wellbeing. The quality of these studies and their findings were then evaluated.

Results: No original research that met the study criteria was identified either directly or via the findings of the six systematic reviews identified.

Conclusion: The prescription of this shoe type to distance runners is not evidence-based.