Lieberman on foot strike and injuries on Harvard’s XC team

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Does how you run cause (or prevent) injuries? Everyone has a theory, but no one has much data. Into the breach steps Dan Lieberman, with a new Vibram-funded study of injury rates on Harvard’s cross-country team between 2006 and 2011, just published online at Medicine & Science in Sports & Exercise. He looks at 52 runners — 36 rearfoot strikers and 16 forefoot strikers — all of whom recorded their daily training on an online running log during the study, and whose injuries were precisely recorded by the team’s trainers.

The results?

Approximately 74% of runners experienced a moderate or severe injury each year, but those who habitually rearfoot strike had approximately twice the rate of repetitive stress injuries than individuals who habitually forefoot strike.

Now, this is a very interesting and significant result. It also has limitations, which the authors take great pains to detail in their discussion. Probably the most important: this is a retrospective, non-randomized study. That means, for example, that it doesn’t address what happens if a habitual, lifelong rearfoot striker switches to a forefoot strike, which requires stronger calf and foot muscles.

Another point that the authors make is the presence of considerable individual variation. Here’s some of the data:

(The caption reads “Repetitive injuries/10,000 miles; moderate and severe.” Not sure why Harvard is apparently using a Commodore 64 hooked up to a dot-matrix printer to generate its graphics!) Anyway, the point is that some people seem to do just fine with their rearfoot strike, while others are frequently injured with their forefoot strike:

[M]any runners who [rearfoot strike] in shoes do not get injured or get injured rarely even when they train at high intensity. We predict that these runners have better form than those who do get injured: they probably land with less overstride and more compliant limbs that generate less severe impact loading and generate less extreme joint moments… These predictions are supported by several recent studies, and they emphasize the hypothesis that running style is probably a more important determinant of injury than footwear (with the caveat that footwear probably influences one’s running style).

So there you have it. The study’s not perfect, and it doesn’t settle these debates once and for all. But it takes us closer by offering some straightforward data — and that’s how science should work.

32 Replies to “Lieberman on foot strike and injuries on Harvard’s XC team”

  1. Thanks for sharing this. More evidence to suggest running form, not shoes, is the big factor in determining running injuries.
    Interested to see how the study is received. Critics are sure to highlight the fact that the study was sponsored by a minimal shoe company, plus emphasize the limitations of the study.

    All told, another step in the right direction in the aim to support the benefits of natural running scientifically.

  2. “74% of runners experienced a moderate or severe injury each year”

    Sounds like the right conclusion is: stop running!

  3. And minimalist shoes won’t “change” your form either!

    Dave Robertson :Thanks for sharing this. More evidence to suggest running form, not shoes, is the big factor in determining running injuries.Interested to see how the study is received. Critics are sure to highlight the fact that the study was sponsored by a minimal shoe company, plus emphasize the limitations of the study.
    All told, another step in the right direction in the aim to support the benefits of natural running scientifically.

  4. Science is important, but what about the history of your sport? It’s time for you to honour the achievements of Abebe Bikila. Alex, lose the shoes and unlock the beast within! Masters running vs. reading scientific studies. Which do you prefer?

  5. From the abstract I gather that, besides foot strike, “sex, race distance, and average miles per week each correlate significantly with repetitive injury rates”. How were the other factors distibuted in the foot strike groups?

  6. This is great stuff here. I’ve always thought that how you run is likely more important then what type of shoes you run in. The only thing is though if you’re running naturally, with barefoot running biomechanics (ie. shortened stride, increased cadence, forefoot landing ect.) then why do you need the shoes? The only times I can think of is extreme temperatures (too hot, or cold), or if the terrain is very, very unforgiving.

  7. Nice research, small population.
    @KRS I think shoes CAN make you run a certain way, if you train on minimilistic shoes you’ll likely hurt your knees and ankle if you heelstrike and thus will try to prevent that with mid-forefoot landing.
    @Zerodrop, a lot of history has been made with heelstriking.
    @Alex the last years a lot of people have been converting to minimalstic shoes and started barefoor running, it would be great to start a prospective studie all over the world doing the same thing but taking into account more variables, as milage, weight, frequentie of buying new shoes, if its trail or brick running, lsd or interval based, frequentie of training etc, etc.
    But this probaby wishfull thinking!

  8. Its my opinion that the study shows that it ISN’T necessarily forefoot or rearfoot strike, or the type of shoe, that determines rate of injury, its more likely to be the quality of the movement, overall balance within the body (strength and length), and specific functional strength.

    Coach Al Lyman, CSCS, FMS, HKC
    http://pursuit-athletic-performance.com/blog

  9. Seems like a “duh” result to me.

    Overstriding increases running injury risk.

    It’s harder to overstride with a forefront strike, but it’s entirely possible to avoid overstriding with a heel strike if you work at it.

    Hence, learn not to overstride and treat footstrike as a separate, independent variable according to your preferences.

  10. A thought here from an uncoached runner who never “ran” competitively
    During my 20’s I would run 4 miles (4-5xwk) on a local boardwalk. After about a year I found I was running at a pace that was starting to approach some of the more talented/trained runners in the area. As I increased fitness, speed and distances, injuries began to set in; mainly foot pain, knee pain and shin splints.

    I began thinking, perhaps a boardwalk is not cushioning my foot strike as many suggested. But maybe it is more dynamic in the way it vibrates and transfers the vibrations back to the body. Seeking to cushion the blows, I started running on the beach itself. Not near the water as it sloped and caused hip/back discomfort… but next to the boardwalk. Almost immediately my pains diminished greatly.

    HERE is the important part… in hindsight after reading the above, I realize something that I discounted back then; running on/in soft sand requires one to change the way they run. Sand running did eliminate micro-vibrations from boards when I struck between nail sets on the boardwalk. And sand would flow away (cushion) with each foot strike. But now I note something else apparent; one can not heel strike effectively in soft beach sand like that at the Jersey shore. You tend to pick up your knees a little higher, you land mid to fore foot (to avoid sinking too much with each step), you tend to push yourself forward and out (of the hole you’re creating) in a slight thrusting motion, your knee never comes close to locking out and it is near impossbile to overstride.

    Other muscles needed more recruitment and did pay a price while getting acclimated to the pliable environment underfoot. However, I was able to continue with my healthy habit with a reduction in injuries.

    At the time I thought my larger frame was the reason for my unfortunate injuries and the cushioning effect of the sand was offsetting the pounding. Only recently retraining and reading about the foot strike debate, I think my experience lends itself to this debate and the need for further research and individual assessment/testing. And I would also suggest to anyone injury prone, who lives near a beach, to hit the sand. Your lower leg pains will diminish; even while some other body parts become humbled.

  11. @Zero Drop
    Science.
    Abebe Bikila was obviously like the guy at the bottom-right of the graph. The rest of the graph, is the rest of us.
    It’s not time Alex lost his shoes. It’s time people understood science.

  12. @Zero Drop
    Sorry, I didn’t mean to sound as if you don’t understand science.
    I meant I disagree with your statement. Sorry for being insulting.
    I think that we need to stop worshiping legends and start paying more attention to science for recommendations to the general public.

  13. Yes form matters but volume & recovery are vitally important. I’m pretty sure most of these kids had pretty decent form and had the anatomy and physiology that made them suited to running fast over distance. And 74% of them still got hurt! Getting runners to better understand their individual adaptation process to training is an important element to reducing injuries.

  14. I’d like to see the injury rate when you get habitually rear foot strikers to go forefoot! An old in grained motor pattern won’t just change with a pair of new shoes, minimal or conventional. Running is a skill, not everyone learns (even able too) at the same rate!! Changing motor patterns (running form) is not just about where your foot lands especially if you force it

  15. I would like to see if these rear foot strikers developed this running pattern by running habitually in modern running shoes. It would be interesting to test kids running barefoot to see what people do in their younger years verses their older years after developing good or bad running habits.

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