Earlier today I was doing a phone interview with a reporter from the Chronicle of Higher Education and she asked me a question that I have been asked a lot lately: “How would you describe good running form?”
This is a question that a lot of people have opinions about (sometimes very strong opinions), but I still find it to be a really difficult question to answer. There are a lot of things I can point to that I consider to be aspects of bad form, such as overstriding, excessive side-to-side movement, etc., but really nailing down what represents “good form” can be tough, for reasons that I will outline below.
Whenever I think about the concept of “good” form, the evolutionary biologist in me perks up and turns the question around a bit and asks instead: “How are humans supposed to run?” I’m a firm believer that just like every other animal on this planet, we humans evolved to run in a certain way. The problem is that in modern society, the vast majority of us don’t run that way because we wear shoes. We did not evolve to run with shoes on our feet. I’m not passing judgment or trying to say that shoes are good or bad (I am a shod runner after all), I‘m merely pointing out the fact that wearing shoes changes our biomechanics in some fundamental ways.
So, if I were to attempt to answer the question of how we humans are supposed to run, I would say you simply need to look to people who have never worn shoes and figure out what the majority pattern is. Turns out, Daniel Lieberman did this work for us, and found that the typical running form exhibited by habitually unshod runners looks more-or-less like this:
This child is forefoot striking and landing with a bent knee and a roughly vertically oriented lower leg – many suggest these days that these are the elements of good form, and I would not disagree. Just because Lieberman found that most habitually unshod individuals run with form like this does not mean that habitually unshod runners forefoot strike with every footstep (he observed a few habitually unshod heel strikers, and I have seen my kids do the same on occasion when running barefoot). Rather Lieberman demonstrated that most habitually unshod runners seem to forefoot strike most of the time. However, they also probably land on their midfoot sometimes, and on their heels sometimes as well.
Shoes are a game changer when it comes to our running mechanics because they alter the sensory information that comes in from our feet. I witnessed this firsthand a few months back when I ran a little experiment with some students in my Exercise Physiology class. We had been talking about running mechanics, and I decided to take them down to the lab for a little experiment. I had four students run on a treadmill in their shoes, then had them take their shoes off and run in their socks. All the while, I was filming them in slow motion at 300 frames/second. As the students were running, I asked the other students who were watching to tell me what they saw. In particular, I asked them how the runner’s foot was hitting the treadmill surface (note: this is a much softer surface than asphalt or concrete).
Upon reviewing the video with them, it turned out that all four students were heel strikers with their shoes on (one was asymmetrical with a midfoot strike on one side), and all switched to forefoot striking when they took their shoes off. No fancy analysis was needed – the kinematic change was as clear as day. One of the students who had participated claimed that it was “like magic,” and many were surprised to realize that their initial thoughts about what the runners were doing based on observations from just a few feet away were completely wrong.
The above anecdote demonstrates two things. First, removing their shoes fundamentally changed how each of these students ran. The reality is that there was no magic involved – removing their shoes altered the sensory feedback coming in from their feet, and they adapted accordingly. Second, form analysis is really hard to do with the naked eye – high-speed video is really necessary to accurately determine foot strike.
Our body is remarkably good at figuring out what to do in a given situation, and it’s for this reason that our form changes from what I consider to be “natural” when we put shoes on. It therefore comes as no surprise to me that the vast majority of runners in modern running shoes are heel strikers, and a substantial number of them are horrific overstriders (I’ve watched more than enough slow-motion race video to be pretty certain about this). There aren’t a whole lot of good data linking mechanics or footwear to specific injury risk, but I continually come back to the question of whether wearing shoes that dramatically change our form from what might be deemed “natural” might have some unintended or even possibly deleterious consequences. The human body seems to have evolved to move in a certain way when we allow it to run in its natural state, and monkeying around with that might not be such a good idea. Or maybe it is, as other human inventions have allowed us to do things in ways that we couldn’t otherwise. For example, my glasses/contact lenses allow me to read, and maybe cushioned shoes improve my ability to run on asphalt.
I’m not saying everyone should run barefoot or even necessarily in minimalist shoes, or that these are even necessarily better, but rather asking the question: Are modern running shoes and the biomechanical changes they allow/cause a good thing? What is the empirical evidence that a 12mm lifted heel and extensive cushioning are positives for our feet and legs? I for one don’t believe this question has been answered, though others involved in the shoe industry would appear to disagree. Take these responses by ASICS International Research Coordinator Simon Bartold to questions posed by Sneaker Freaker Magazine:
Do we really need shoes? There’s plenty of dudes running around the Kalahari in barefeet!
I think we do, especially in Western societies. We have been wearing shoes for thousands of years and have actually evolved to adapt to a ‘shod’ situation. There’d be many people who argue with that, but I think that we’ve now pretty much established that it’s good to have the heel raised in shoes. About 12mm is a good thing biomechanically, because you’re in a more efficient position. If you’re running around the Kalahari Desert you develop a lot of calluses, but it’s probably still desirable to have a decent pair of shoes rather than doing that barefoot.
You mentioned before about a 12mm heel height being ideal? Why is that the standard?
Well, that’s a very interesting question because it hasn’t been settled on at all. With ASICS we’ve always worked on a 10mm gradient. That’s the difference between the height of the forefoot and the height of the rear foot, so if you’ve got a cushion type shoe it might be 24mm and 14mm off the ground. A racing flat might be slimmer at 10mm and 20mm. We’ve done a lot of research on this and we understand that it actually puts your foot in a mechanically better position, makes it more stable, takes a load off the Achilles tendon… so there’s a lot of positives. There’s a lot of myths and all that sort of crap and the problem is that every time you add a little raise, people are going to say ‘oh but you’re removing the foot from the ground therefore you’re going to make it more unstable and you’re more likely to sprain an ankle’, which is complete nonsense. That’s scientifically unsustainable. There’s no evidence to say that happens at all.
Ok. Myth #2. Running in barefoot is the best.
Instantaneous bullshit detection going on! This is very popular at the moment and there’s a lot of companies that have websites saying that barefoot running is the way to go. But I think if we look at everything that science tells us, which is what we have to place our belief in, then that statement would not ever be supported because of the ability of shoes to help improve biomechanics.
I agree with Bartold that shoes are generally a good thing, and I genuinely don’t think that barefoot running is going to be the answer for the vast majority of runners (myself included). However, I’m not so sure that there is a lot of published empirical evidence demonstrating that a 12mm lifted heel is ideal. Does a 12mm lifted heel make you faster, more efficient, or less likely to get injured? Why not 10mm, or 8mm, or 6mm, or 4mm, or 2mm? Do shoes really “improve biomechanics” as Bartold suggests? How do you define “improved biomechanics” anyway – what is the measure of improvement? Bartold even goes on to say in the interview that “…the thing about kids these days is that hopefully they’re pretty active, which means they will need some sort of meaningful midsole and elevated heel.” Does one really follow from the other? Have studies been published in peer reviewed journals that active kids are better off in shoes with thick midsoles and elevated heels? Seems that many of the kids that grow up running barefoot in Africa like the one in the video above turn out just fine when they compete at the international level as adults…
Another point to consider here from the above interview is that although I don’t think we have evolved to be shod, most of us who have been wearing shoes our entire lives have certainly adapted to them in ways that might make running unshod difficult, at least initially. Shoes can not only change our biomechanics the moment we put them on, long term shoe use can actually alter the anatomy of our feet and legs (e.g., hallux valgus due to wearing of shoes with highly tapered toeboxes, weakened bones in the feet, weakened calf muscles due to continued use of heel lifts). The consequences of this might be manifesting themselves in the form of injuries like metatarsal stress fractures in people who jump into barefoot or barefoot-style running too quickly. This is a whole different topic for discussion…
So, when I think about all of this in relation to the question “What is good form?”, I find myself thinking that good form in the shod condition might not be the same thing as good form in the unshod condition. Good form in a shoe with a 12mm heel lift might be different than good form in a zero drop shoe. Good form might be different on a track vs. a trail vs. a road. Good form might be different for a 4:00 miler vs. a 12:00 miler. Maybe trying to forefoot strike in a 12mm lifted shoe is a bad thing – maybe your body is heel striking because that’s what’s best in that condition. When you attempt to forefoot strike in a 12mm lifted shoe your foot is likely plantarflexed way more than it would be when barefoot so that you can land on the forefoot before the heel touches down, and perhaps that has deleterious consequences as well. Maybe a 12mm heel lift is good for your Achilles, but bad for your knees. We have tons of open questions, and hopefully answers will come with time. For now we are each left to experiment and find what works best for us on an individual level – maybe this is the best we’ll ever be able to do.
These are the reasons why I have trouble answering the question of what is good form. The logical answer to me as an evolutionary biologist is to run how we evolved to run. Is barefoot running form “good form?” I’d say yes, if you are barefoot, and perhaps in some kinds of shoes (for me up to about a 4mm heel lift I think). Is barefoot running form “good form” when wearing a pair of Brooks Beasts or Asics Kayanos? Maybe, but my gut tells me that you may be forcing your body to do something it doesn’t want to do in those shoes, and maybe that’s just as bad as heel striking when running barefoot on asphalt.
So, at the end of this giant brain dump, what have I concluded? Basically, I’m pretty convinced that we know how humans evolved to run (mostly, but not necessarily exclusively, like the Kenyan child in the above video), but translating that into the shod world is where things get difficult. I suspect that there is a point at which attempting to run barefoot-style in shoes might become counterproductive, but I’m not sure I know where that threshold is, or if it might be the same for every person. I have a gut feeling that trying to forefoot strike in a motion control shoe is ill-advised, just as transitioning too fast into zero drop shoes is a bad idea. Ultimately, I’m starting to feel like I should just defer to the wisdom of my own body – I feel like it knows what to do given the conditions I present it, and I’m finally starting to get a handle on which conditions it likes best (a benefit of having run in so many pairs of shoes the past few years). For me, those conditions don’t involve a 12mm lifted heel. Maybe your ideal conditions are different – your job is to experiment and find your comfort zone. Maybe that will look like the video above, maybe it won’t, but the journey can sure be a lot of fun.