For anyone who knows me, you know I love to run. You also know I get hurt a lot and that it frustrates me a great deal. Barefoot running and minimalist running are something I have been reading up on for a while-years actually. For those who are unfamiliar, the barefoot/minimalist movement is based on the theory that all of the cushioning in modern running shoes forces our feet, knees and hips into unnatural positions leading to a higher rate of injury. Therefore they recommend either running barefoot or in shoes that have minimal padding so your feet can strike the ground the way they want, as opposed to the way the shoes force them to. Although it makes sense to me logically that minimalist running would lead to more efficient running and lower injury rates due to the “naturalness” of it, there are actually few to no valid studies to prove this. The study I am going to discuss here actually looks at the difference between runners who rearfoot strike (the heel hits first) versus those who forefoot strike (those who land on the ball of their feet and then the heel hits). The reason the topics are linked is because modern running shoes pretty much force a runner to heelstrike, while minimalist or barefoot running encourages forefoot striking. With that ridiculously long intro, here we go.
The article was a retrospective study of endurance runners (mid to long distance) on the Harvard track team. The researchers looked at 52 runners (29 males, 23 females), studied their foot strike and examined their rates of injury. 16 were classified as forefoot strikers and 36 were classified at rearfoot strikers. Because forefoot strikers have more movement at the ankle joint and rearfoot strikers have more movement at the hip and knee joints, the researchers predicted increased injuries of the hip and ankle in rearfoot strikers and increased ankle and foot injuries in forefoot strikers. Over the time period studied, there were a total of 181 repetitive injuries (traumatic injuries were disregarded). Rates of mild and moderate injuries were 2.5 times higher in rearfoot strikers vs forefoot strikers, and moderate and severe repetitive injuries were 1.7 times more frequent in rearfoot strikers. When looking at the injuries the authors predicted would be higher in rearfoot strikers (those of the hips and knee), it turns out they were right. There was a 2.7 times greater incidence of those injuries in rearfoot strikers. Interestingly, the injuries they predicted to be higher in forefoot strikers showed no significant difference between groups.
Several things to note about this study. One is the small sample size. For a topic such as this, 52 is a relatively small number of subjects to examine. Another is the lack of variability among the subjects. These are all healthy, trained runners under the age of 22 with BMIs under 25. All had history of injury, and all run high weekly mileage. While this can certainly limit the generalizability of the results, I also wonder if it naturally controls for all of those factors.
For me the biggest thing to consider and certainly the most relevant for all of us mortal runners is we do not know if the subjects who were forefoot strikers trained themselves to run in that manner or do so naturally. If they do so naturally, you could argue that they have a lower incidence of injury because that is their natural form, and those who are natural rearfoot strikers would not see the same benefits if we tried to force ourselves into a forefoot striking technique. The authors also address the fact that this particular study does not look at what would/does happen in the transition period from rearfoot striking to forefoot striking. Although I have never seen a study that shows an increase in rate of injury in forefoot strikers compared to rearfoot strikers, I have seen many instances of people getting hurt because they do not make the transition slowly and properly. Word of warning.
A final note: VibramUSA gave a “gift” towards the funding of this research. Just saying.
There are many other topics they discuss in the article that I will not get into here, but it is really interesting. If anyone would like to read the full article let me know and I will scan it and send it to you. Otherwise, does anyone have any thoughts or anecdotes to share? Has anyone tried minimalist or barefoot running? I will tell you that I have tried minimalist running, and I did not like it. However I also did not put the effort into learning the proper technique of forefoot striking, so I continued to heelstrike in my minimalist shoes. No bueno. Severe low back pain and almost developed a stress fracture in my foot. In case you did not pick up on my previous word of warning. Do this the right way if you are going to give it a try.
Daoud, A. et al. Foot strike and injury rates in endurance runners: A retrospective study. Medicine & Science in Sports & Exercise. 2012;44(7):1325-1334.