- Prof Daniel Howell, an anatomy professor from Liberty (USA), known as the "barefoot professor"
- Simon Barthold, who formerly worked as a podiatrist but who now works in biomechanics and is Asics global research consultant
- Prof Benno Nigg, one of the world's leading biomechanists
- Dr Mathias Marquard, a clinician and running coach (who would go on to become the voice of reason in many of the more hostile aspects of the debate, as I'll describe!)
- Prof Daniel Lieberman, evolutionary biologist from Harvard, who as you may know, recently published the Nature studies looking at how habitually shod and barefoot runners differ, and who wrote a key paper on how humans are adapted (skeletally and physiologically) to run long distances
A debate, however, is not linear, but circular, or more like a "vortex", in that different threads are whirling around together, and I think it can be an uncomfortable way to discuss data. The risk is always that every statement made by one person contradicts another's views, and they want to respond to it, so we would basically get sucked down and never move forward.
Let me digress and state my view on that question, since I didn't get to state it at UKSEM! I believe that EVERYONE can benefit from some barefoot running. That is, I think that barefoot running is, at worst, a good training modality that may have benefit for running performance, even when wearing shoes. We know from research and simple experience that there are significant differences in muscle activation and loading patterns when running barefoot, and these are all potentially favourable, even if barefoot running is used only as a training method. In fact, I'd go so far as to encourage all runners to try barefoot running, even if it is only during a warm-up or cool-down, or once a week for a short time.
By extension then, there may well be people who simply cannot adapt to barefoot running. In fact, I'm certain this will be the case. They break down and get new injuries, usually of the ankle, calf, Achilles tendon or foot. And these individuals may never take fully to barefoot running. I still think that the fact that they do pick up these injuries indicates the 'stress' and if the body adapts positively to stress, then they too can benefit from barefoot training, if not fully immersing themselves in it. However, for them, it must be recognized that shoes may be the only thing enabling them to run (regardless of whether it is "natural" or not).
Back to the debate...
Prof Daniel Howell, the barefoot professor, was asked to elaborate on the evidence for barefoot running. Remember, the panel had all agreed that evidence was lacking, so the next question I put is "what evidence do you need, and what do you have?"
Howell's response was that "barefoot running is natural". We are not born with shoes, our ancestors did not run in shoes, and it is therefore natural for us to run barefoot too. To live barefoot, in fact. What is not always as clear is that somewhere along this logic, "natural" becomes a synonym for "better". Howell at one point challenged Simon Barthold, asking him to justify why he said that people need shoes (I agree with Barthold on this one, by the way. At least for some people).
That is, take the shoes off and you get a pretty dire picture - these individuals continue to heel-strike, at least for a short time, which predisposes them to very high ground reaction forces and a huge vertical loading rate, both of which are surmised to be linked to injury risk. Also, the muscles and tendons are unconditioned for barefoot running, and are then suddenly loaded differently, which further increases the injury risk.
Anecdotally, and from my own coaching (and Lieberman's observations which he shared with me over lunch), new barefoot runners make some fundamental errors because they don't adopt what seems to be the optimal barefoot running gait right away.
This is a recipe for disaster, since it loads the ankle joint on a contracted muscle, and probably led to so many Pose runners breaking down when we monitored a group who'd just learned this technique. I suspect the same risk exists for barefoot running, but it happens "naturally" and if you adopt the historical hypothesis as "proof", then you are blind to this possibility. On the whole, I think that Howell does a disservice to his own advocacy by being blind to the evidence.
There are some very theoretical questions about the use of this model, and Benno Nigg commented on this, but overall, this was an argument that didn't help the debate, because it obscured the point about impact forces. I think an analogy was mistaken for a literal explanation and Lieberman's website became the focus of argument when we might have been discussing the mechanics a little better. I eventually had to dismiss this discussion and move on, because nothing good was going to come out of it, because Berthold had pursued it down a blind alley to a point where Lieberman couldn't defend the analogy anymore, and Lieberman was getting flustered as a result. End of discussion.
There was some disagreement over cushioning as well. Lieberman's "model" is that part of the benefit of being barefoot is that it reduces the loading rate and effectively removes the impact transient. For this to be beneficial, as opposed to having purely academic value, it has to be shown that these forces on landing are linked to injury. There is some evidence of this from Irene Davis' work, and Lieberman mentioned in the debate that the higher impact forces and loading rates have been linked to injuries like shin-splints and potentially knee problems.
But that will come in due course!