Barefoot running - the safe neutral ground

Barefoot running:  Finding the neutral view in a lively discussion

Thanks to everyone for the lively discussion on the previous post on the recent observation (not scientific study!) on a rise in the number of injuries associated with barefoot running.  It certainly stimulated much more debate than I could keep up with, especially while traveling back from the UK.

I know we've received many, many comments in response, and many readers don't read those comments (though if you have some time, there are some good views), so I felt I'd try to wrap up the barefoot post with a final word of my own (I am 100% sure that this topic will come up again in the future, so don't worry)

A debate where the prudent approach is the only one...for now

It strikes me that of the many issues in sports science, this is the one where taking the neutral, fence-sitting position is really the only option until proven otherwise.

Those who follow the site will know that I'm not usually a "fence-sitter" and I don't need much encouragement to throw out the clear and unambiguous opinions - for example, Caster Semenya shouldn't run against women, Oscar Pistorius has an advantage, dehydration doesn't cause cramp, South African sports administrators are mostly corrupt or incompetent.

But on this one, I just don't can't commit to such an extreme view, either way.  And reading through all the debate in the last few days does little to convince me otherwise.  We've heard many testimonies about people who have switched to barefoot or minimalist shoes with great success.  Well done, and good for you!  If it has solved your injury problems, or opened up a world of running to YOU, then long may it continue!

But occasionally, we hear from someone who tried and failed and wishes they'd never discovered barefoot running.  I maintain that this latter group is in the minority - most people who try it out, fail, and get injured, will go back to shoes and keep running, sometimes injured, sometimes well.  These people, I suspect, don't often share their views, and certainly not as passionately as those who have succeeded, in large part because the blame for "failure" is often placed at the feet (yes, I know, sorry) of the person who has just failed!  Seriously, who wants to own up to failing at the transition when dozens will simply say "You didn't do it right"?  Not as many as will share success stories, that's for sure.

And yes, I hear you on the possibility that these "failed" conversions have erred in their training.  It is a very valid point, one which I think may be true in many of the cases.  But not all.  At least, not until you can prove it to me!   And herein lies the crux.

Testimonies that should be heeded

The point is that guys like Matt have tried barefoot running.  They're not simply dismissing it out of hand.  And I know Matt, and respect him highly, and he's a guy who is really open to innovation.  When we wrote our book together, we actually argued on certain areas where I was being more "conservative" than he was with regards to training techniques!  He is someone who will not approach the issue in a closed-minded manner, as his books have demonstrated.  He has shown a willingness to learn, to dismiss "dogma" and to challenge beliefs, and those who are being very critical of his views (and ours) should bear this in mind.

So his views, while more extreme than my own on this topic, should be heard, because if you're a barefoot supporter, and someone has tried everything, right from running 1 MINUTE a day barefoot to train gradually, and still failed (and they're also in the top 5% of runners, I might add, not 120kg back-of-the-pack 6 hour marathon runners), then we all need to take heed.

Failure to do so is not only reckless to all those who are hanging on this barefoot movement as the solution, it's presumptuous to those who have tried and failed.

My thought is that if someone is injured, then it's likely their training is at fault, regardless of what they have on their feet.  There are some for whom a switch to barefoot will change training and mechanics (especially the knees, as we've had pointed out, thank you to those who've brought it up).  There are others for whom it will initiate a lifelong series of problems, potentially putting an end to running as they know it.

And that alone makes me cautious.  I'd be very hesitant to commit one way or the other.  And so personal testimonies are very welcome, but to apply a testimony of one (or even a group) to many, that leaves a lot of room for catastrophe!

Thanks again for all the comments, great discussion!

Forthcoming attraction - the FIFA 2010 Football World Cup in SA, and the Science of Football

So I mentioned earlier that I've just arrived back from the UK, in what was ultimately a disappointing end to the Sevens Season.  If I had a blog devoted to the sport of rugby, and if I had a following mostly in South Africa, I would fill a month of reading with the reasons and the issues facing the sport.  But alas, I don't.

I do however know that the biggest single sports event in the world is now imminent here in South Africa.  From arrival at the airport, all the way to my home, the signs for the FIFA 2010 World Cup are everywhere.  The news has been dominated by the build-up, and it promises to be a magical four weeks.

And there will be no better opportunity than this to look at the Science of Football in the coming weeks.  The physiology, performance analysis, altitude, aerodynamics, crowd support and penalty shoot-out dilemmas faced by teams should make for some great discussion.

So look out for that!

Thanks once again!

Ross

Barefoot running and injuries

Barefoot running - it was a stimulus plan for physical therapists after all

About four months ago, we did a lengthy series on barefoot running, which began with this post on the latest research from the Harvard lab looking at how habitual barefoot runners' mechanics different from shod runners'.  That was followed up by a six-part series, done in Q & A format, where we looked at the evidence for barefoot running as a means to prevent injury.

In that very first post, looking at the Harvard study, we made mention of barefoot running being a "stimulus plan for physical therapists".  This was entirely predictable, because the media jumped all over the Harvard study and reported it as "proof" that running barefoot was less likely to cause injury as a result of the lower impact forces it caused.  This was despite the paper actually reminding people that it had NOT shown this at all.  Its final sentence was "controlled prospective studies are needed to test the hypothesis that individuals who do not predominantly RFS either barefoot or in minimal footwear, as the foot apparently evolved to do, have reduced injury rates". 

This research came along into a "market" that was increasingly moving towards barefoot running.  The book "Born to Run" described the feats (pardon the pun) of a tribe of Mexican Indians, and gave legs to the movement that was picking up followers all over the world.  Barefoot was suddenly the way of the future.  It inspired our series, and much debate on the issue.  All the while though, people were trying to advocate caution, warning that simply going from shoes to barefoot would guarantee injury.

Increased injury rates - the stimulus plan is working

It should come as no surprise that medical doctors and physical therapists are now beginning to pick up on a potential fall-out from the "Born to Run" movement.  Our friend (and book co-author) Matt Fitzgerald has hunted a few down, and his report details of a sudden increase in injuries caused by barefoot running. According to those he interviewed, the nature and number of injuries has changed in recent times.

There is however a missing piece of the puzzle here.  First, the increase in the number of people running barefoot would produce more barefoot injuries even if the relative risk was the same.  Imagine that in a community, 100 people run, 80 of them in shoes and 20 of them barefoot.  If the injury rate is equal for both at 10%, therapists will treat 10 patients, 8 who run in shoes, 2 who run barefoot. 

But if a book or research studies plus the media inspires 40 people to switch to barefoot running rather than shoes, the split would now be 40 in shoes, 60 barefoot.  Now, even if the injury risk stayed the same, they'd suddenly treat fewer injuries from shod runners (4) and more from barefoot runners (6).  Has barefoot running caused more injuries?  Or has running caused the same injury rate, regardless of what is on the foot?  That's why properly controlled prospective studies are still needed. 

However, one of the doctors who Matt interviews is still of the opinion that the barefoot running is responsible for specific injuries.  He explains how plantar fasciitis injuries are on the rise, and attributes this not to overuse, but to barefoot running.  He also pins down why those who swtich to barefoot running often don't report injury.  His words: “There are a fair amount of people who have tried it but have stopped pretty quick, just because they realized that it was not going to work for them,” he says.

The spike in injuries - the stimulus plan

The potential spike in injuries is similar to that which I once saw reported as a result of Pose.  I recall reading how therapists always saw increased patient numbers about two weeks after a Pose running course had been held in the city.  Runners, armed with a new, injury-preventing running technique, were going away to implement what they had learned without due caution, and breaking down at either the calf, foot or Achilles tendons.

The same will happen for barefoot running, unless the runner is a) very, very careful to manage the transition slowly, and b) mechanically able to do it.

I raise point b) because this is something we don't fully understand yet, but I am convinced that there are individuals who simply cannot get away with barefoot running.  I may yet be shown to be incorrect, but only evidence will convince me of this, not the anecdotes of the few who are successful at making the transition.  Those who fail rarely speak out - they just switch back to shoes.  Those who are successful tend to be vocal, and I believe this is why the risk has been under-recognized.

Having said all this, I don't believe that barefoot running is without its merits.  And please, before I get slated for selling out to shoe-companies, take some time to read the series we did on barefoot running (especially Part 5).  I know it's long, but it lays out all the thoughts, and ultimately concludes that there is merit, but that caution must be used, and if you advocate that barefoot is the only way to go, you're making the same 'extremist' error that shoe-companies are being accused of making.  I don't want to rehash all the same arguments again - they're in that series. 

Conclusion - universal truth doesn't exist

But bottom line - don't buy into the hype.  Try it out, with caution.  See if you enjoy it (it is a lot of fun), see if you feel different and then build it slowly into the programme. But if it doesn't work, don't believe the 'criticisms' that it's your fault.  I've heard these re both Pose and barefoot running - if you run Pose and get injured, you may be told that it's because you've failed to do it right.  If you run barefoot with injury, you will be told that it you haven't made the transition gradual enough, or that you're landing with a stiff ankle, or pointing your toes, or some variation which ultimately boils down to "It's you, not the concept".

It is not true.  It may just be that you cannot do it.  One-size-fits-all fits exactly no-one.  So rise above the generalization and hype!

Ross

Barefoot running and shoes Part 5

Barefoot running and shoes - the Q & A Part 5

This is the final installment of the Q & A on barefoot running vs shoes.  I'm sure next week will bring further discussion and probably a post or two on unanswered questions, but the interview done earlier this year with Run2Day is at an end.  A short post today, and some practical applications, which are my suggestion for how barefoot running would be introduced into running to avoid the very likely overload on the calves and Achilles tendons early on.

What's struck me most in this discussion, apart from that it's so passionately debated (which we knew before the series began) is how large the range of approaches to the subject is.  There are biomechanical angles, historical angles (the Roman army features as protagonists), anthropological angles, economic perspectives, evolutionary arguments, and so on.  Many of which support running barefoot, many which do not.  So thank you for educating me on those topics.

I think it's safe to say that there is no obvious answer, as is the case for many questions.  But it's an intriguing debate, and it will be interesting to track how the 'movement' progresses in the next few years.  What would be really cool, for example, would be to track the sale of Vibrams across the US to see how the consumer responds to all this information, because the surest test  of whether it works will be resale of Vibrams - if people buy the third and fourth pair, then they've converted.

Anyway, here goes with the final few questions.

14. Do you have any news on innovations or research related to this subject which you’d like to share with us?

Not so much an innovation, but a concept that I think is also important for understanding why running barefoot might reduce injury risk. We have heard so often in this series, and elsewhere, that people who switch to barefoot running find that they can run injury free. We look at biomechanics as the explanation for this, when in fact the more simple answer is right in front of us.

That is, if you run barefoot, your training volume is limited by what your feet allow you to do. For example, if you take two runners, equally untrained and with equal risk of injury, and you give one of them a pair of shoes and the other runs barefoot, I guarantee you that the barefoot runner will do LESS training in the first month than the runner in shoes. Why? Because his feet will hurt, his calves will be much stiffer, his ankles will hurt, and his distances, which he can select for himself, will be cut down substantially.

The runner in shoes, on the other hand, has only a stiffness barrier to overcome. He is stiff for a day or two after this first run, but that soon disappears, and then he can increase the distance without restraint. Pretty soon, he’s doing 4 or 5 runs a week, total of 50 km a week, which may be too much, too soon. His barefoot companion, however, has been forced to increase much more gradually. He also gravitates towards softer surfaces, offering more variety in landing type.

The guy likely to get injured in the above scenario is the shod runner. And so when you read testimonies from people who have thrown away their shoes and run barefoot and they proclaim that being barefoot has cured all their injury concerns, you need to ask very seriously – was it being barefoot that sorted out their injury, or did being barefoot alter their training, which sorted out their injuries?

This is why the only “perfect” study that will prove (to me, anyway), the benefit of running barefoot, is a study that forms three groups. All runners must have identical histories, demographics, injury risks (there goes the study right away, of course. But within reason, this is doable). Group 1 gets shoes and chooses their own training volumes. Group 2 runs barefoot and chooses their own training based on feedback and their perceptions around pain and recovery. Group 3 is in shoes, but they run according to a very conservative programme, which increases their distance by about the same amount as the barefoot group would select by themselves. This controls for self-selected increases in workrate.

In the short term, the rates will not be different. Yes, there is a long-term consideration and that is why this study would have to continue for at least a year, probably more. I honestly don’t know what would be found if this is done. But to address the common perception that being barefoot is a ‘cure’ for injuries, you have to question whether it’s a consequence of the impact on training volume.

I cannot stress enough that the reason for injury is training, which brings us full circle and back to the study of van Gent. Shoes, running technique and so forth are factors, yes, but the only factor that is KNOWN to cause injury is training too long, too hard, too soon (or combinations of the three). And so when you approach this debate on shoes vs barefoot and injuries, it’s vital to bear this in mind – training is key and any runner who trains at the right level for their history and circumstances (this is where strength, flexibility, stability come into it), will not get injured.

15. With all research in mind, what would you opt for: choosing either barefoot or padded running (for maximum adaptation to one style) or choosing a mixed training (to keep the body alert to changes and train different groups of muscles)?

Mixed training, without a doubt. Again, hypothetically speaking, if you took a group of runners and you attempted to put them all on a barefoot programme, I would put forward that a third of them will pick up a limiting injury within 3 weeks. A calf or Achilles injury, most probably. They’ve probably overdone the limit and trained too much, of course, but their failure is a training one, and it’s for this reason that Daniel Lieberman, and others are trying so hard to advocate a prudent approach to training.

The irony is that even podiatrists are not against the idea of barefoot running. At least, not the ones I know of. But they’re just adopting a cautious approach, in the absence of evidence to the contrary, and they recognize that one approach does not fit all.

However, if the return to barefoot is managed very carefully, with short distances, and infrequent runs, then it would be possible to see positive outcomes. And I’d even say this is desirable. Barefoot running does affect running mechanics, and I believe it affects them positively. It’s also a lot of fun – I’ve got two pairs of Vibrams and I run in them once a week and it’s really very enjoyable, a different feeling and a stimulating way to train. Having started out with slow, and very short running, I’ve been able to build the distance to the point where I can finish normal sessions. But it’s been 6 months and my soleus muscle still hurts the day or two afterwards, and I can’t imagine being more conservative with how I’ve increased the volume of training. Therefore, I view barefoot running as a training tool, with mechanical and muscular benefits, but I can’t, at this stage, see the feasibility of going all the way to half marathons in Vibrams. Lightweight shoes, yes, but not all the way. And that’s fine, just as it is for a few other runners who I’ve advised on the same thing.

In terms of applying this to training, conservative is key. My advice would be that if you’re keen on barefoot running, you limit it to once a week at first, and you limit the length of each run to 50% of your normal distance, and you break it up into intervals of about 5% with walking between.

For example, if your average run is 60 minutes, then my advice is that you head out for 30 minutes, but that you run for 2 minutes, walk for 1 minute, 10 times. At least for the first few week or two, and then gradually increase the running from there, if you feel your feet, ankle and calves are up to it.

16. Conclusion: Barefoot running/Natural Running: Religion or Ratio?   

Ratio, given those two options. The neutral view is likely the best and most accurate one in this particular debate. The shoe industry made the error of positioning itself as the “solve-all” for runners when it said that it would reduce injury risk. I wasn’t around at the time, but I’d be willing to be that in the 1990s, if you didn’t have the latest gadget or gizmo on your shoe, along with rather large cushioning, your running was doomed to failure…We’ve looked at evidence to the contrary in the last few posts. So I think it’s important not make the same error now and dismiss out of hand what many runners have succeeded with.

It’s very easy to point to high injury risks of runners (60 to 70%) and say that shoes don’t help these runners. But there’s no control group, and one might equally argue that it’s incredible that the injury rate is not higher than 70%. As I said yesterday, we are a desk-bound society, which is inactive as children and which takes to a 60 minute a day run on unforgiving surfaces as though we expect our bodies to handle it. We carry with us years of “neglect” and weakness is stabilizing muscle groups, and we pay little attention to training strength. We also recklessly increase training volume, and yet are surprised when we pick up injuries (I myself am just as guilty of this!). And then we find the culprit – the shoe!

Balance is key. There are people who may not be able to run barefoot, however slowly they increase their volumes. There are people who find that they can. Perhaps some day everyone will be running barefoot or in lightweight shoes, who knows? But right now, with the sum of the available evidence, I’m happy to say that barefoot running is a great way to train, it’s different and stimulating and offers many mechanical benefits, but like most things, generalizing will wrongly influence too many people for it to be dogma.

Looking ahead

As I said, next week will probably see some more discussion on the topic.  I'm in Hong Kong for the next Sevens tournament, maybe it's time to do a little bit of rugby science posting to pass the last week of the tour.  And the marathon season is slowly approaching, which promises to provide a lot of discussion and interesting analysis, so that's something to look forward to!

Ross

Barefoot running and shoes Part 4

Barefoot running and shoes - the Q & A Part 4

Thanks to everyone for the discussion around the previous post.  I've really enjoyed the debate.  I must make the point that any views here are obviously opinion.  Why?  Because there's no conclusive evidence that putting a runner who has run in shoes for 20 years into either lightweight shoes, Vibrams, or barefoot, will reduce their risk of injury.  Until someone produces that prospective, well-controlled study over a long period, anyone's "answer" in this debate is going to be opinion.  Yes, there is a lot of evidence against shoes, but that's because science seeks to disprove the current hypothesis, and little has been done to show up problems with barefoot running - it's too soon. 

And what we've seen so far is the running shoe equivalent of the "shark attack" phenomenon, where the occurrence of an event is greatly inflated by a reporting bias (shark attacks are exceedingly rare, yet we are all terrified of them, because the media coverage given to them is disproportionately high).  Similarly, I really do believe that there is bias in barefoot running reporting, because the people who come forth with their stories are those who have succeeded.  No one has yet documented the failure rate - people who have abandoned the barefoot campaign.  And yes, these people are likely to have failed because they made an error in increasing their volume or intensity too rapidly, but equally, those who get injured in shoes can be accused of the same thing (van Gent, 2007).

As this series progresses, I'll move towards stating what I would recommend as as a practical approach to barefoot running, based on the evidence like that discussed yesterday, and which will be described more today, as well my own experience and work with runners.  But the best part of being able to discuss this topic is to share in those opinions - as is typical though, when people disagree with them, they tend to take out the "you're losing objectivity" club.

Today's post delves a little more into the shoe evidence, looking particularly at the "intelligence" of the body with and without shoes.  Then I end off with some discussion around the whole argument that our ancestors and the Tarahumara Indians run barefoot, and therefore so should we.

Again, in isolation, this post will be strong theoretical evidence for barefoot running, which I hope most have gathered is a recurring theme.  I'm actually very positive about barefoot running and the role it can play in every runner's training and development.  I'm just trying to maintain some balance, lest the movement become, in the words of a respected colleague, "a stimulus plan for physical therapists and podiatrists"!  And believe me, they've made a good few new patients as a result of over-zealous implementation!  Here goes, with questions 10 to 13.

10. There is research (Robbins and Gouw 1991) that says that running with cushioned shoes leads to the fact that the perceived impact on the body is lower than the actual impact (or: our body is fooled by the cushioning). How do you interpret this research?

This body of research is extremely interesting. It’s been borne out by a number of studies which have looked at impact, soft tissue vibration and muscle activation. Benno Nigg has proposed “muscle-tuning” where the degree of muscle activation, especially pre-activation (which is the muscle activity immediately before the foot strikes the ground) is adjusted depending on the impact conditions in order to defend the soft tissue vibration (Boyer & Nigg, 2007). In other words, the body is “smart” enough to anticipate the impact conditions, and whether the cushioning exists and then it regulates impact and vibration by adjusting muscle activation. The simple analogy is that if you stand up on your office chair and jump off it, you can land extremely hard if you just let gravity work on your ‘dead weight’, or you can cushion your landing through anticipation of the impact and the correct muscle activity. That’s what the body is doing in mid-flight, which is quite remarkable.

Whether the perception of impact is important or not, I’m not convinced either way. Let’s say that you run in a highly cushioned shoe, and you perceive the impact to be much lower than it actually is. So what?  Some would say this is a favourable outcome, because any time you can perceive less impact, it’s good. What Nigg is proposing with muscle-tuning concept is that the forces and the vibration of the soft tissue are being regulated. So perception is not reality, in this case. And the impact forces may not be higher – studies seem to disagree on this particular aspect. So I certainly believe that the perception is altered, but I don’t necessarily agree that the body is being “fooled” by this – the perception is being fooled, yes, but the brain and the muscles may be managing it quite appropriately!

What is significant, and this is a strong argument for why bulky shoes do have a negative effect, is that the ability to “feel or sense” the ground may be altered by shoes. Sensory information from the foot, which tells the brain of underfoot conditions, surface hardness, slopes, objects, is certainly altered by shoes, and this may affect the timing of muscle activity, as well as the degree, particularly towards the end of races, when fatigue is a factor.

Incidentally, the same scientists did a really interesting study a few years later, in 1997, where they made people step onto a material that was the same as is used in the midsole of running shoes (Robbins & Waked, 1997). They did this a number of times, but the difference was that they were either told that the material was a state-of-the-art cushion, with all the latest technology to minimize injury (they even drew graphs and made up fake endorsements from athletes), or they were warned that it was the same as the material used in cheap shoes, responsible for many injuries. This is the WARNING trial shown in the graph below. Effectively, they were evaluating how belief about cushioning affected impact.

It turned out that when subjects thought they were landing on the soft, high-tech material (Deceptive trial), the impact forces were actually HIGHER than in the Warning trial when they expected the cheap and ineffective material. And barefoot had the lowest impact forces of all. The other amazing finding, as is shown in the graph above, is that in the barefoot and cheap material trials, the impact forces get lower and lower as the subjects repeat the step, which shows a learning effect that is not present in the ‘Deceptive’ trial where subjects thought they were landing on a soft material. So this is remarkable – it shows how an expectation of impact can actually alter impact, and again, it supports what Benno Nigg and others are saying about anticipation of impact, with the ability to adjust muscle activity to defend some other variable.

This is why it’s possible to run barefoot – the body is a remarkable machine, able to make in-flight adjustments to provide the optimal landing, and this is a strong argument for why being barefoot might give some advantages. At the very least, when people stare in wide-eyed horror at those who run in either light-weight shoes, or Vibrams, or bare-foot, because “you’re running without essential cushioning”, they’re reacting to a misperception – the body can provide cushioning.  And there is evidence for this - from Daniel Lieberman's latest study, from Nature.  We looked at this in a little more detail recently, but the graph below shows one of many interesting findings.

Here, the impact forces are shown for three groups:  First, on the far left, are runners who normally wear shoes, running barefoot. In the middle, runners who are wearing shoes, and on the far right in the shaded box, habitually barefoot runners, who strike forefoot.  Clearly, the impact force is reduced in the forefoot strikers when barefoot. 

However, there's a catch to this whole argument.  The danger is that in order to provide this cushioning, muscles are working harder.  In my answers to an earlier question (Q 4, in Part 2 of the series), we looked at some of the changes in running patterns when barefoot.  The knee is more flexed, the ankle more plantar-flexed, and the landing point more at the forefoot.  These changes are responsible for helping with the cushioning, but mean greater load on the calves (particularly the soleus muscle) and Achilles tendon, which rises substantially, and now you can see why this is happening – it cushions the landing very effectively. When this cushioning response is used, those muscles and tendons are taking enormous strain, and if they are not adapted or eased in, they break down. So again, we have a situation where theoretically, there’s a lot to be said for barefoot/minimal cushioning, because it allows the body to do what it does best. But there’s a real danger there too, which has to be acknowledged, and then managed very carefully.

11. One of the claims of barefoot runners is that most of the modern shoes (which have serious heel cushioning) take away essential sensory information while the barefoot runners' body uses the rich sensory information the foot provides. Nike Free’s, Vibram Five Fingers also work in the sense that they do not ‘disconnect’ the sensory input of the foot. Is that a valid argument? If so, what are the benefits?

Yes, and I think this is a strong argument for barefoot running. Whether the sensory “barrier” still exists in minimalist shoes, I’m not sure. The advocates for barefoot running say that the shoes, no matter how similar to barefoot running, do affect sensory feedback. My experience is also that they do, but not nearly as much as a normal cushioned or stability shoe. The Vibrams in particular feel remarkably similar to barefoot running – studies suggest that the mechanics are the same, and the sensory feedback is as near to barefoot as is possible – it’ll never be the same, because there’s a 4 mm barrier between the foot and the ground. But it’s close, and this may have beneficial effects. Again, that’s never been proven – it is a theoretical position only, but it does offer a potential upside to barefoot/minimal shoe running.

12. Another claim is that modern shoes are considered to act like corsets: they give support but also make the muscles lazy and therefore weaker. Is there any proof that this statement is correct?

The study we looked at yesterday, by D'Aout, showed how chronic shoe use changes the morphology and biomechanical function of the foot.  So it's certainly true that way.  Also, if you go out and run barefoot, even for a short time, you’ll discover muscles in the foot and calf that you had long ago forgotten you had! The stiffness and some of the muscle sensations you feel when you run barefoot is completely unexpected – this suggests that running in shoes involves very little work from those muscles. So from that point of view, it’s easy to say that, yes, running in shoes does reduce the work done by certain muscles of the foot.

However, to extend that position and say that this increases the risk of injury while in shoes is a stretch for which I don’t believe there is proof yet.  What this evidence does is explain why it's so difficult to run barefoot when you've been in shoes for a long time, but I don't think it translates the other way.  Similarly, if one runs barefoot and these muscles are developed, will it reduce the risk of injury when you then run in shoes? It sounds reasonable, certainly, but it could equally be true that when you wear shoes, those muscles do not need to work and therefore can be weaker.

The analogy is that you can become wastefully strong, and we tend to balk at the idea that we can “afford to be weak”, but it all comes back to what is required in order to do a specific task – a marathon runner, for example, may not have a strong upper body, but training the arms and improving their strength by 50% doesn’t produce a faster runner. So is it possible that shoes have created a situation where the work required of the foot is reduced, and this is acceptable, provided the runner continues to be in shoes? Again, no one has really provided proof to answer these questions.

However, I believe that barefoot running offers the potential to help improve foot strength, which may reduce injury risk, if it is managed correctly. A number of coaches, for example, will have athletes to a small amount of running barefoot, and I think that is reasonable, even recommendable, because it helps with the strength of these muscles. Overdo the barefoot running early and you’re headed for disaster, however, as I said previously.

13. Then there is the antropological view: we ran for millions of years on our bare feet; our bodies are not made for walking on running on shoes which have a heightened heel (ranging from high heels to air in sneakers). Do you agree?

I’ve heard this position, and while I can see the merit to the thinking, I think it’s probably the weakest argument for why we should run barefoot, for a couple of reasons:

First, the conditions under which we run today could not be more different than they were millions of years ago. The hardness of running surfaces has changed, the terrain is completely different, and even the way we run is different – a structured 60 minute training is vastly different to a 8 hour migration or hunt that may involve walking, climbing, crawling and resting.

Second, we are different. I’m no anthropologist, but I’d like to see a profile of what the individuals looked like in these “endurance runner” communities. Were some of them 100kg or heavier?  Did they all have a natural inclination for running? In a village of say 100 people, did 100 of them run successfully in order to hunt? Or was the hunting and locomotion done by 20 out of the 100, with the others doing other things that perhaps did not involve such a great deal of endurance work – perhaps some were fishermen, while others hunted? Just as today, if you took 100 people at your running club, you might find 5 great runners, 25 good runners, 50 average runners and 20 non-runners, there’s no guarantee that our ancestors all run well (please note that I'm illustrating a principle here, so please don't attack the numbers...). Unless I’m missing something? So perhaps it’s possible we are comparing those hunters, the “elite runners” of those communities, to our struggling runners, when we should be saying that guys like Ryan Hall or Dathan Ritzenheim – they run just as well as any ancestor did?

And then perhaps most crucially of all, and this is the biggest flaw in this particular argument, there is very little in our lifestyle that is similar to what it was or is in these communities! For example, 2010 man is sitting at a desk for 8 or 9 hours a day, driving a car 80% of the time of locomotion, and spending maybe one hour a day doing exercise. Even as children, we are less active, playing less outside and more on computer games. Many years ago, hunter-gatherer humans were playing, physically active for 12 hours a day and thus developing the strength that perhaps allowed them to run for enormous distances without the same injuries. And yes, they happened to be barefoot! But there are about a hundred things they also did differently. Yet for some reason, we’ve looked at this picture and said “The big difference between us and them is that they were barefoot”. We’ve spotted the wrong difference – the reason they did what they did is because they were stronger in the supporting muscles as a result of their lifestyle. We are weak, unprepared for hours of impact while running, and shoes just happen to be a new addition while this has happened.

Bottom line, don’t blame the shoes for the injuries, look at the training and degree of physical readiness for running, because 9 hours of desk work and years of inactivity produce weakness and inflexibility that is found out by 60 to 70 km a week of training.

Part 5 next

So that's Part 4 done. Apologies for a long post today, but hopefully it stimulates the same kind of discussion!  Tomorrow may be the last post, certainly it will be the last of the interview, and then I may manage to squeeze in a post at the end to wrap up.  So join us tomorrow! 

Ross

Barefoot running and shoes Q & A Part 3

Barefoot running and shoes - the Q & A Part 3

Today we forge ahead with the Q & A I did earlier this year with Run 2 Day magazine, which I've cut into segments to make up a series while I'm traveling.

Yesterday, I posted twice, dealing collectively with some the questions around barefoot running and running shoes, the mechanical changes they cause, and some of the possible physiological consequences of these changes.  Clearly, there is a lot more to be said than even what I did, but I'm moving on with Part 3 today, and looking at some of the shoe research out there.  After the information overload yesterday, I'm going with only two questions today - 8 and 9 in the series, looking at some of the questions around shoes in particular.  Enjoy!

8. Is there any evidence that either (shoe or barefoot) is better in terms of both performance and injury prevention?

No conclusive evidence, as I’ve mentioned in the previous posts.  There is however some circumstantial evidence for both sides – the shoe industry didn’t grow into a billion dollar one based on rumor only – there is some science behind it. It’s just that it’s pretty weak, failing to show that the prescription of certain shoes to certain individuals actually does anything to prevent injury (Richards et al, 2009), and failing to show that the shoes contributed to the injury in the first place.

A study published in 2007 attempted to pull together all the research on running injuries (van Gent et al, 2007), and a few things were pretty clear. First, there were very few good, scientifically sound studies investigating running injuries and their cause. Incredibly, given that running is the most studied sport, and that the prevalence of injury is up above 60%, only 17 studies were deemed of sufficient standard to be included in the review. It’s quite amazing. The only thing that study really concluded was that training volume was highly predictive of injury.

On the other side of the table is a growing body of circumstantial evidence for why shoes may not work. For example, the loading forces are not different in new and old shoes, because runners change their kinematic patterns (Kong et al. 2009).  The table below shows the measured changes in the study.  I apologize for not redrawing it for you, but time is tight.  I've highlighted the main finding, which is that the maximum vertical force (Fmax) and the maximum loading rate (Gmax) are not different in worn shoes (200 miles of running).  The study also found that there is less forward lean and more plantar flexion in worn shoes, and that stance time was greater in worn shoes.

What the study didn't measure was muscle activation, which is something I discuss in Question 10 (tomorrow, probably), because that would likely have been different too, as the runners adjust their muscle activity to maintain constant tissue impacts - this is called muscle tuning, a concept that is really important in how we understand the body's cushioning ability.

The eventual conclusion of the Kong et al study was that runners should choose shoes based on properties other than cushioning, because the body will find the ideal cushioning anyway. This doesn’t suggest that the gadgets designed to prevent injury through cushioning would be that effective (or, of course, that shoes wear out, if you wish to adopt that position!).

Another study found that runners who ran in the most expensive shoes were just as likely to get injured as those who ran in the cheap shoes, lacking all the protective gadgets and functions (Clinghan et al, 2008). Here, there is the counter-argument that the runner who buys the very expensive shoe might be more injury-prone to begin with – perhaps they buy the shoe because they have a history of injuries, whereas those who settle for the cheap shoe do so because they’ve never been on the receiving end of running injuries (the study did control for running volume, by the way, in case you’re sharp enough to be wondering if the cheap shoe buyers ran less).

We also know that the shape of the foot is altered by wearing shoes, and so is its function (D'Aout et al, 2009). This study was brought to my attention yesterday, and it’s interesting because it shows that the “natural” shape and function of the foot changes with chronic shoe-wearing, which provides something of an explanation for why it’s so difficult to go from years of wearing shoes to running barefoot.

And then most recently, it’s been found that if you prescribe shoes to runners based on the shape of the foot and arch (as is typically done, because people who pronate are supposed to have flat feet – this is often called the “wet test”, where you have to look at the wet footprint left behind to tell you whether you need a motion control shoe or a cushioned, neutral shoe) there's no difference in injury rates. Even controlling for physical fitness and age, you do no better at reducing injury rates than if you just give every runner the same shoe (Knapik et al. 2010).

So the idea that you have to prescribe certain shoes to certain runners, because the shoe is going to help prevent injuries is not borne out by research. That’s not the same thing as saying shoes are unnecessary, mind you, but it does challenge the conventional wisdom. And this is a movement that is gaining momentum all the time.

So currently, there’s little conclusive evidence. Both sides are poking holes in the other’s arguments, pointing out the lack of evidence, but we still await a definitive answer, one that will only really come when a long-term, prospective study is done. As I said, it’s incredibly difficult to find, because injuries are so complex and difficult to predict, and the study to answer this question may be hypothetical only.

9. If there is evidence for the opposite, why does everyone - including manufacturers - believe that shoes prevent injury?

Well, for the manufacturers, the answer is obvious – they have a strong incentive to believe their product is not only effective but indispensible. For everyone else, thirty years of investing, marketing and belief, is the simple answer. The shoe industry grew rapidly in about the 1970s, co-inciding with the huge running boom of the time. Until that point, shoes were really minimalist. If you ever have the opportunity to look at the shoes that runners used prior to about 1970, you’ll be amazed at how basic they were. In fact, they resembled the modern day lightweight shoe. No gel pads, air cushions, torsion devices, and certainly no built up heel.

The explosion that accompanied the running boom saw massive financial incentives created, and I don’t think it’s oversimplifying things to say that a market was suddenly created, that this market had a need for a product, and it was lucrative. Then, I’m sure a good number of people with good intentions started to theorize about how they could help reduce injuries, and the concept was born. Once it became conventional wisdom, it was difficult to reverse, just as most things are, I guess. The pervasive message has always been that shoes are vital. It's not difficult to get this message out, because you have to remember that a runner only really thinks about one piece of equipment, which is also his "interface" with the road.

However, and this is the side that none of the barefoot advocates wish to hear, part of the reason we believe shoes help prevent injury is that it’s possible that shoes DO prevent injury, or at the very least enable people to start running! I’ve spoken about the lack of evidence for either position, but there’s good reason to believe that some people’s shoes really do help them run, or run more than they would be able to in those light shoes.

Take a 100kg (220 lbs) man who wants to take up running. Remember, prior to 1970, he would never consider running a marathon. Today, he can, which is a great plus for our sport. However, he may be coming to running from 20 years of inactivity, with weakened supporting muscles, he’s heavy. He may be doomed if he could not get a shoe that provided some support and cushioning, purely because the first few weeks would be so uncomfortable, even in a minimalist shoe, that he may really struggle. Perhaps one day, with enough training, he’d succeed in light shoes (or barefoot), but you would have to work very hard to convince me that this person would ever get off the ground without more supportive shoes. This man, straight into a lightweight pair of shoes, would not be a runner, I have no doubt about this, and so it would be false to say that shoes don’t help at least some of the time.

Next up: Shoe-cushioning, muscle-tuning and intelligent muscles

That's it for now - I know it's probably frustrating when posts end "in the middle of nowhere", but hopefully you can forgive the lack of smooth continuity in favour of shorter, manageable posts. I don't think I've yet figured out how to do these long series!

Next up, I answer a few questions on the cushioning properties of the muscles, as opposed to shoes, and how the body "senses" the ground. But that's for tomorrow, so join us then!

Ross

Barefoot running and shoes Q & A Part 2

Barefoot running and shoes - the Q & A Part II

Earlier this morning, I started a series on the barefoot vs shoes debate, intended to debate the current move towards running "natural" (that is, without shoes).

This is a topic that always inspires passionate responses from both sides of the aisle, so to speak, and the post this morning didn't take long to stimulate debate. Generally, both sides dismiss the other argument out of hand.

I earlier posted the answers to the first three questions of an interview I gave to a Dutch running website earlier this year.  It turns out that perhaps I should have posted the first seven questions, because I've created the impression that I'm totally against barefoot running, which is not true. As the interview will make clear, I think there is substantial merit to the barefoot position, which we recently covered in our post on Daniel Lieberman's research on barefoot running.  

So I've decided to get the next part of the series up as quickly as possible, lest I am seen to occupy the same position as most others in the debate.  I'd like to think I'm objective on this issue, but clearly that is never the case, for anyone.  But here are questions 4 to 7, discussing some issues on the other side of the debate.

4. Our first experience (and the claims of barefoot ambassadors) is that 'barefoot' running forces you to land more midfoot/forefoot, simply because it hurts to land on the heel. This makes your step automatically shorter and keeps your knee bent when landing. Natural running proponents claim this way of running makes the runner less prone for injury. Would you agree that midfoot/forefoot landing, bended knees and shorter steps benefits the runners body? 

The changes in landing and kinematics (knee angle, ankle angle) when you shift from shod to barefoot running are pretty well established. So you’re exactly right – the most noticeable change when you run barefoot is that you land further forward, your knee is bent, and also your ankle is more in what is called plantar-flexion – your foot and toes are pointed away from the body. One of the consequences of these adjustments is that your stride is shortened, but this is at least partly made up for by an increase in stride rate. This is easy to test for yourself – you can run 100m in shoes and without, and count the strides, feel the landing of your foot, and you’ll have confirmed the running science within 30 seconds!

There’s also evidence that the pattern of muscle activation – when different muscles are active during the stride – changes in the final few hundred milliseconds before your foot strikes the ground, and that’s because the brain, anticipating that there is no longer an air cushion or gel pad inside a soft heel, is going to do the job of ‘softening the landing’ for you.  The body is remarkable this way, and this "natural" response to being barefoot is, I believe, one of the most compelling arguments for barefoot running.  The best study showing this cushioning response is Lieberman et al's recent study in Nature, which we posted on previously, and is also summarized on their excellent website.

As for the second part of the question, whether it’s better to run this way, the full body of evidence does not exist, yet.  What has been shown is that a shift in running technique can change the loading patterns, so that the eccentric loading on the knee is reduced when the forefoot/midfoot landing is used.  In contrast, the ankle loading rises compared to heel striking.  This has important consequences, which we'll definitely discuss later on.  Changing the loading pattern and the eccentric loads in particular will affect injury risk.

However, nobody has yet done the study that changes a runner's technique and then tracks them over many months, or years even, to see how their injury rates change.  This would be a mighty difficult study to do – it would have to be very long-term, and control for a number of other factors (weight, running speed, training volume, training history, skeletal dimensions because there would be considerable individual variation between people, and so on – too many factors contribute to injury for there to be a keyhole study to find the answer). But the key is that nobody has really provided the evidence.

And in theory, the verdict could go either way. Either you are an advocate for barefoot running, and you believe that the bent knee and forefoot landing is protective, and you cite studies that have found reduced impact forces when running barefoot, such as the recent work by Lieberman et al, which is really provocative and breaks through this argument for the first time. Even here, the practical application of the research is not so simple – just because the impact force, particularly that initial impact, is reduced, does not mean that a habitually shod runner switching to barefoot running will reduce injury risk.

Or, on the other hand, you might choose to adopt the position that being barefoot simply changes the loading patterns, not the load, and that the extra work being done on the calf and tendons is worse for you. You therefore decided that you need the stability provided by the shoes and that barefoot running will never work. Note here that you don’t exactly have a lot of evidence to support this position either!  30 years of shoe research has not shown that shoes protect runners against injury.  Neither side has this study.

But apart from all the scientific debate, and the discussion around whose evidence is stronger, what it means, there is a practical problem with making the change from shoes to barefoot running, and that’s what the marketers have overlooked.

This is my biggest word of caution in this whole debate. When you run barefoot, you are changing loading patterns and muscle activity considerably. Your calf muscles and ankle joint, in particular, do  more work running barefoot than in shoes. The same is true for newly-trained Pose runners incidentally – the loading on the ankle goes up while the loading on the knee decreases. The problem is that the calf, Achilles tendon and ankle are not used to this and you pretty much guarantee injury.

This is why the scientists who are arguing the merits for barefoot running (Lieberman et al) are being so careful to encourage a prudent approach to barefoot (or Vibram) running. Unfortunately, that prudent approach has not been shared by media or marketers, which is why they had to issue a statement on the front page of their website after their paper in Nature.  That statement is testament to the challenge faced by runners who switch to barefoot and it should be cold water on the hostility they often show towards anyone who dares to suggest that they are at risk.

This situation is much worse if you force the forefoot landing, which is what many people do when they read the marketing hype – they go out and force themselves to land on the forefoot, which is a recipe for disaster, because the only way they can achieve this is to point their toe down, by actively contracting the calf. Suddenly, four times your body weight is being thrown onto a contracted calf muscle, and the only outcome is a very hurt soleus muscle, or worse.

So the short answer to your question is that if you’re not careful about how you run barefoot (or mid/forefoot, in the case of Pose), and how you teach your body to do it, you basically guarantee yourself an injury, which makes you worse off than running in shoes.

I think that people will under-appreciate how difficult the switch can be, and a lot of people will injure themselves because of misinterpreted science. Out of 100 people to attempt barefoot running, I’d be surprised if 30 pull it off without some ‘trauma’, and I’d be willing to be that at least 30 pick up an injury that forces a long lay-off, maybe a return to shoes.  Of course, 30 will succeed and be much better off, which may power the movement even more.  You are far more likely to hear about the success stories than about the guy who damages his Achilles tendons in a week and abandons the plan.  And well done to those who succeed - they've found a solution.  But to suggest that this solution will work for everyone may be making the same error that others have made before.  Quite what determines who succeeds, I don't know.

5. What about the act of shifting the pelvis as chi running proposes and the relationship to mid/forefoot landing?

This is the correct way to change the body position during running, and you see it in a number of athletes who run efficiently (and who have never heard of Pose or Chi, incidentally!). You simply cannot run when you are leaning backwards, with your weight behind you. So by getting your pelvis forward, you bring your body more into an effective running position, and one of the consequences is that your footstrike will move forward slightly, since your feet will be moving under your body, rather than reaching out for the landing on the heel.

But the key, again, is that you can’t control the landing cognitively, it is the consequence of otherwise good form. And crucially, you can have this good form and still land on the heel! You cannot judge a runner’s efficiency by looking solely at their footstrike, and this is a problem I have with how the whole debate has been positioned. The contact point of the foot is a consequence of numerous other factors, pelvis position being one of them. It’s not the diagnostic, or the fingerprint that identifies good vs bad technique, and a lot of runners would be better off not worrying about the foot.

6. The above is a health perspective on the advantages of running with a shorter stride and lending on the mid/forefoot. What do you think about the claim that the runner is faster in this way of running, due to the fact that it is a less energy consuming way of running (obviously speed over longer distances, we’re not talking sprint here)?

Same as for the injury aspect – there’s no evidence for this. The theoretical argument once again works both ways – there are some studies that suggest that landing on the heel produces the most efficient energy return and produces the lowest oxygen consumption for a given speed (which immediately contradicts the basis for the question). However, other studies have shown the opposite, which means your question is valid after all! So the jury is well and truly out on this one!

It’s interesting Haile Gebrselassie is very clearly a heel striker during marathons, though he was a famously reported forefoot striker when on the track, often being pointed to as the unwitting endorser of forefoot landings.

There is also the practical issue that someone who is a heel-striker, and who suddenly decides to switch to a mid-foot or forefoot landing because they think it might be more efficient is highly unlikely to be able to run very well, and risks injury anyway (see Q4)

And finally, a study on Pose found that months of supervised Pose training succeeded in shifting the landing point to a more forefoot one, but the runners were LESS efficient than before, by a considerable margin. So the possible benefits of forcing yourself to land on the mid-foot may be small (or non-existent), whereas the downside includes serious injury to calf, Achilles or ankle, and overall, I wouldn’t force it in a runner until evidence is absolutely convincing.

That’s not to say you cannot introduce training methods that very gradually, and unconsciously, help to improve running by (among other things) changing running form. Form drills, uphill running, sprinting are all training methods that will have natural effects on form. I see these as distinct from cognitively changing technique, which is what this debate leads to.

7. There seems to be lot of debate between researchers at the moment on the subject. Which of the two parties (barefoot vs. modern running shoe) do you see as having the most valid research outcomes at this moment?

At the moment, the barefoot position is in the ascendancy. I realize that in this interview, I’ve said that evidence is lacking, but I still believe they have merit. The problem is that neither extreme is likely correct.

The extreme view that shoes protect against injury and are necessary and should be prescribed according to specific tests like foot shape is very much in doubt. That’s why the barefoot group occupies the stronger position – their ability to cast doubt on conventional wisdom is better than that of the shoe advocates to criticize the position that being barefoot is better. I think the conventional wisdom about shoes is changing, more and more people are recognizing that all the gadgets sold as injury prevention devices are not effective, and so the minimal movement gains momentum.

Having said that, the extreme view that we should be barefoot or in minimal shoes is just as likely incorrect. There will be a middle ground where the best scenario for the most people exists. I believe that shoes are crucial for some runners, who would be unable to run without the level of cushioning and support they offer. In theory, maybe barefoot works for everyone. But years of deconditioning and wearing shoes, along with biomechanical factors, may make it absolutely impossible for some people to make the transition. So now you have a choice - run in shoes and keep going 10km a day, no problem. Or shift to barefoot and run a few hundred METERS a day and break down injured. It's just too difficult, practically, for some people to shift.

For others, perhaps a majority, smart training and gradual progression can see them running successfully and injury-free in lightweight shoes. And “smart training” includes some barefoot running, even if it is once or twice a week, for reduced distances. I’ve no doubt that it helps and may protect against injury, and I think it is a matter of time before there is some evidence for this. But neither side is going to convince me that they’re 100% correct in the extreme, and shoes are not endangered species just yet!

Looking ahead to Part III

So again, I apologize for the information overload today. Two posts in a day is a lot. Next time, hopefully there'll be only one. So far, I've looked at the issue from the side of the barefoot. Tomorrow, we'll look more at shoes, and why this perception exists that shoes prevent injury, how marketing messages have shaped those beliefs, and what scientific exists (or is lacking, as the case may be) supporting shoes.

Join us then!

Ross

Barefoot running and shoes Q & A

Barefoot running and shoes - the Q & A Part I

Greetings from Adelaide, where jetlag sees me writing at 3am. At least I have time on my hands! I’m currently on the road again – this time it’s Australia and then Hong Kong, a two week long trip that takes me right up to the Easter weekend in April. For Jonathan, there is also travel on the horizon – a conference in South Africa on heat stroke, and I’m sure we can look forward to some interesting conclusions and discussion from that meeting, with a few posts the outcome for the site!

Running shoes vs barefoot – a Q & A 

For now though, I have decided to tackle an issue that, with the exception of the Caster Semenya controversy, usually generates the most chat on this site – running shoes vs barefoot running. We’ve covered this issue before, but there is so much to it that, both theoretically and practically, that we can return to it over and over without ever finding resolution. And when the debate starts on running shoes, it quickly switches to running technique. Here, I’m speaking specifically about the foot strike. There is of course a lot more to running style than how the foot hits the ground – the head, shoulders, arms, hips, knee drive etc are all part of it, and I certainly don’t mean to dismiss their importance. But, the huge debate in running circles exists around how the foot lands and whether we should run in shoes – these two questions have become controversies and are inter-linked thanks to the philosophy of how one affects the other, and the advent of commercialized running techniques based on this link.

So the series of posts starting today will address these issues. I’m going to look at it slightly differently, and that’s partly because of my travels which have in the past prevented any posts. So what this series will consist of is a question and answer session, a total of 16 questions that were recently put to me by Run 2 Day, a Dutch-based running website (Run 2 Day for our Dutch readers). Thank you to Erno for the questions and for allowing my modified and translated answers to be republished here.

So it should be a four, perhaps 5 part series, looking at four or five questions per day. Obviously, this format means that there will be topics not covered in each post, but possibly addressed in future posts. Bear with me on that aspects – a single post on such a diverse topic is not possible!

Also, as always, we aim to have the first word in the debate, not the last. And so your feedback is most welcome (usually, you don’t have to invite runners to discuss this issue. Perhaps because the shoe is really the only equipment we need, runners don’t hesitate to throw their hat into the ring!). I’m going to apologize right now if I can’t respond to all your questions – I’ll do my best, but time is limited (except at 3am in the morning, it seems). Here goes:

Interview 1: Introduction, terms and concepts

What do you think about the term ‘natural running’? Clearly this term by itself is already marketing. It positions running with shoes with little cushioning as ‘natural’ vs ‘un natural running’.

Simple question, very complex answer! Perhaps over the course of the next 16 questions, my thoughts will become clearer, but the short answer is that “natural” seems to be whatever you wish to define it as.  Those who start from the point of believing that we need to change our technique will define natural running in a way that is similar to barefoot running. On the other hand, if you start out of the opinion that our default technique is better, then natural means ‘without intervention’.

It also depends on context – since this particular debate is about shoes vs barefoot, and the resultant changes in running technique, I’ll limit my definition to that.

To some, the concept of teaching running form is already unnatural. If someone goes out for a run and without any intellectual input, falls into a particular stride and footstrike, that is “natural” in that it is the default option. Taught technique would thus be unnatural.

However, the argument is a little more complex that that – we look at the Kenyan running champions as “natural” because they run without the technical analysis that we subject ourselves to, and they also run without shoes. And I guess this forms the basis for what is defined as “natural” within the context of the current argument. Here, people are looking at these athletes who often learn to run without shoes, and they observe a number of things:

1. Fewer injuries
2. Faster running
3. Apparently “smoother” running

Note that all three are somewhat subjective. There is no causal link between their being barefoot and running faster, and while I suspect it’s probably true, I haven’t seen evidence of fewer injuries, let alone the association with how they run.

In any event, people then create in this picture the definition of the term “natural” running. In the hands of marketers, natural becomes better (perhaps given added fuel by the current global trend towards going “green”), and the concept is born.

So the issue has been simplified right down to a very basic level, as you say – natural means running barefoot (or in lightweight shoes), whereas unnatural means following conventional wisdom and believing that shoes do have a role to play in preventing injury. Those are the two extreme positions – which is correct? Hard to say, and the middle ground may be the ultimately safe destination.

Is there ‘a natural way to run’? And if so, how would you describe ‘the natural way to run’?

If I were pushed to commit to a definition of “natural running”, I would (rather conservatively and certainly more literally) say that natural running form is the form you adopt without any external input, or any conscious thoughts about how to run. It is the way you run when you simply run, no cognitive thoughts of how to position your arms, how to land, how to lift the heel versus driving the knee forward – in the absence of all those instructions, we run ‘naturally’.

Note that I am not saying that this is better. I am not one who prescribes to the view that natural is best, and for this reason, there are a number of very important and effective adjustments that can be made to the running technique. Time and space don’t allow me to go into all of them right now, but some will emerge later in this series, others are not relevant right now anyway.

But I believe the natural way to run is the unadjusted one, but the best way to run is the modified natural form. And of course, equipment will influence this.

While on that point, there is a significant logic problem in play here. If we define “natural” as how we run without shoes (refer to Q1), then the change in mechanics that occurs when we run with shoes has been deemed to be ‘unnatural’. Yet the natural response to wearing shoes is to shift the landing to the heel. Now, this is defined as bad, according to the argument. However, one must explain why the body, which is clever enough to ‘naturally’ force us to land on the front of the foot when we take shoes off, is suddenly “fooled” into landing badly (on the heel) when we wear the shoe. We could quite easily land on the forefoot when in shoes – plantar flex at the ankle, bend the knee, make the same kinematic changes as when we are barefoot (see Q4). But we don’t, we are either “fooled” into landing on the shoe’s elevated heel, or we allow the heel-strike because we know that forcing a forefoot landing may be equally bad (or a combination of the two).

This is why the argument that “natural is better” is flawed – either natural is not always better, or running in shoes combined with the change in mechanics is still optimal. So I think upfront, we must put behind us the marketing message that has convinced us that barefoot is better, and actually evaluate the evidence objectively.

I believe the term ‘natural gait’ was used in the 80’s already related to running. Are we talking here about the same thing?

I’m not sure – the people who used the term in the 1980s would have done so in a very specific context, and not knowing that, it would be dangerous to say yes or no with any certainty. I suspect, based on my reading of some books from that era, that their definition of ‘natural’ was a more global one, referring to the arms, the position of the head, the hips, the stride. Part of it would have overlapped, but I think this is a slightly different argument. It’s certainly much more specific, because the debate now revolves around the footstrike and the influence of shoes, which will have been rather minor back then.

Next up: changes in mechanics and shoes

Tomorrow we'll move onto changes in running technique caused by the shift from shoes to barefoot running, and whether it prevents injury and makes you a faster runner.

Ross

Running barefoot vs shoes

Barefoot running - new evidence, same debate

It's been a rather frantic week, and I know there is a series on weight hanging in between Part 3 and Part 4.  I'm hoping to get to that next week, when hopefully I'll have a little more time!

But today, I have to comment on this latest study, which I know will become bigger in the coming days - it is a new study that will reignite the barefoot vs. shoe debate, one of the more controversial issues in running.

I am actually planning a whole series on this topic, because I was recently interviewed by a Dutch Running magazine, Run2Day, and I'm going to post that entire interview (with additions) on the site at some point in February.

The study 

For now though, the paper is called Foot strike patterns and collision forces in habitually barefoot versus shod runners, and it is published in Nature (Full reference: Lieberman et al., Nature, 463, 531 - 535).

The scientists took five group of runners and had them run both barefoot and in shoes. The groups were: Habitually shod adults in the USA, Recently shod adults in Kenya, Habitually barefoot adults in the USA, Barefoot adolescents in Kenya, and Shod adolescents in Kenya.

Each group ran in shoes and barefoot and they measured foot-strike pattern (whether the runner lands on the heel, midfoot or forefoot) and kinematic and kinetic variables like impact force, loading rate, and joint angles.

The findings - a shift in landing, a reduction in force


It turns out that people who run barefoot, even when shifting from shoes to the barefoot condition (the habitually shod groups),  shift the landing point to the forefoot.  There's nothing new there - it's been known for many years that running barefoot changes the footstrike.  Hundreds of studies exist to show this.  The next difference is the ankle angle - the barefoot runner has a more plantarflexed ankle when they land - what this means is that the toe is pointed away from the body more (compared to dorsiflexion, when you pull it back towards you at the ankle).  Again, hundreds of studies have shown this.


Next are the impact forces.  Here's where there is some disagreement.   Previous studies have occasionally disagreed on how barefoot running affects impact forces - some say it actually increases them, with high variability between individuals.  Most suggest a reduction, particularly early on during impact (first impact).   The Nature study has found that being barefoot AND landing on the forefoot reduces both the loading rate and the peak impact force.  In fact, it's three times lower in barefoot runners who forefoot strike (which is most of them) than in heel strikers wearing shoes.  In theory (though this too is disputed), higher impact forces and loading rates equals greater injury risk, and so the study is suggesting that perhaps people who are barefoot or minimally shod have a better chance of avoiding injury.

A stimulus plan for physical therapists and podiatrists?

And here is where it gets tricky.  I must point out that the title of the paper is Foot strike patterns and collision forces in habitually barefoot versus shod runners.  I highlight the word "habitually", because it's quite important to appreciate the impact that this word may have on how you apply this finding.

I guarantee that the media are going to be all over this and they are going to tell you that you should be running barefoot or in Vibrams.  You will hear how science has proven that being barefoot will prevent injuries, and that those of you who are injured should blame your shoes as you lob them into the garbage bin.

None of these suggestions is true, yet.  And Dan Lieberman who headed up this latest study would not even be suggesting this himself.  The final sentence in the paper in fact reads "controlled prospective studies are needed to test the hypothesis that individuals who do not predominantly RFS either barefoot or in minimal footwear, as the foot apparently evolved to do, have reduced injury rates" (good science always recognizes what it DOESN'T say, and Lieberman and co fit this category).

What the Nature study hasn't measured is the long term (or even the short term) effects of the change on loading rates on different joints.  If you wish to guarantee yourself an injury, then go out for a 2km run barefoot on a hard surface, and you will be asking your calf muscles and Achilles tendons to do work that for perhaps 30 years, they haven't had to do.

And I will illustrate this with our own insight into footstrike and injury.  When the Pose research was done in Cape Town, athletes basically had their footstrike patterns changed through 2 weeks of training in the new method.  The biomechanical analysis found lower impact forces (sound familiar? Same as the Nature paper), and even less work on the knee joint.  This was hailed as a breakthrough against running injuries, because lower impact plus lower work on the knee meant less chance of injury.  Jump ahead 2 weeks, and 19 out of 20 runners had broken down injured.  Why?  Because their calves and ankles were murdered by the sudden change.  And the science showed this - the work on the ANKLE was significantly INCREASED during the forefoot landing.  

The point is, changing how you run, whether by technique training or a change in shoes (like running barefoot) will load muscles that may be very weak, and joints and tendons well beyond their means.  If however, you are a habitually barefoot runner, then you can do this, because your body has been prepared for it.  For everyone else, I think we may be underestimating the time it will take to transition successfully to barefoot running (or forefoot striking, if you're going to force that change 'unnaturally').

And there is my point - taking this kind of interesting study, and dispensing advice, is a risky business.  As a friend pointed out yesterday - the media's interpretation of this study will be a "stimulus plan for physical therapists and podiatrists".  Going from years of shoes into minimal shoes or barefoot will injure you if you are not careful. 

Conclusion

The Nature study provides a good discussion point.  It's intriguing, and certainly does suggest advantages to barefoot running.   It is not the last word, but rather the latest word in this debate.  Nor is it revolutionary, because for many years, we've known that being barefoot changes ankle angle on impact, footstrike and loading rates (though quite how they change is not agreed upon).

I'm sure a lot more will be written - I'll even cover some of it when I do that interview series on this topic in the coming weeks.  For now, that's the last I'll say on this particular issue, but debate is always welcome!

Ross

P.S.  Daniel Lieberman has launched a website on this topic, and it's well worth a look.  It is obviously based on his research (this study forms the bulk of it), but it's a good, clear explanation of the concepts.  Again, the same word of caution applies - don't jump from one to the other.  If there is one section of that website that you should read over and over, it is the Training tips section.  Most will not, and they'll become the statistics (and the stimulus for physical therapy), but if you manage it right, then the site will be a great help to you!

Running technique: The Footstrike

Heel vs. Midfoot vs. Forefoot: How do elite runners land?

I've finally gotten around to this post, which is probably two weeks in the making, and it follows on from our recent series on running shoes. That series began by looking at whether shoes are in fact as much a cause of injury as a cure, and then evolved into a discussion of how the running market is evolving. Twenty years ago, it was all about motion-control shoes preventing overpronation to prevent injury. Today, it's all about running "barefoot in your shoes", as companies try to go back to "natural" without selling you "the Emperor's clothes", in effect! (It's quite a long post, my apologies, but a lot of important information to get through...)

The next logical question is to ask how is the foot supposed to land during running? This question evolves out of the discussion of shoes. vs barefoot running, and is often at the heart of discussions on running technique. Very often, debates of "technique" tend to start from the feet, jump to the knees ("lift your knees") and then skip to the arms, and that's about it! We won't go into too much detail on technique today, focusing instead on only one of many aspects - the landing of the foot, and particularly, whether the elite runners tend to land on the heel, the midfoot, or the forefoot.

Elite runners footstrike patterns

Perhaps surprisingly, there are very few studies looking at elite runners and footstrike patterns during actual races. Despite this, until recently, the overwhelming majority of coaches and experts were advocating that heel-striking was the most effective technique, simply because most athletes did it. That claim will come up again, but the perception that it was most effective has, over the last few years, been changing. And with the advent of Pose and other running techniques, as well as the observation that not all elite runners are landing on the heel first, people have now begun to advocate that forefoot landing is better! So we have this 180 degree shift, often in the absence of any substantial data to support the claim.

I am sure that many will have seen this kind of assertion (this one is from Wikipedia):

Leaning forward places a runner's centre of mass on the front part of the foot, which avoids landing on the heel and facilitates the use of the spring mechanism of the foot. In other words, landing on the heel is bad, to be avoided...

Or there is this, from Gordon Pirie (admittedly somewhat older):

"Running equals springing through the air, landing elastically on the forefoot with a flexed knee..."

But what is "better"? Where science has yet to catch up with opinion

It's important at this point to ask the very pertinent, but infrequently asked question: "What does 'better' mean?". In other words, when people are advocating that it's 'better' to land on the forefoot, what do they mean? Is it faster? More efficient? Less injury-prone? The fact is, the word "better" is used without studies specifically looking at any single one of these aspects. And the 'prudence concept', as applied to science, says that you cannot say something is "better" unless it's been studied and compared to the alternatives. Unfortunately, the science lags behind in this regard.

So for example, above you have the quote that you are supposed to land elastically on the forefoot. That implies performance and efficiency, which might be true for short exercise, lasting a minute or two. But in an event like the marathon, are we sure it remains the "better" option? If you went out and ran 2 hours today, landing on your forefoot instead of landing as you've always done, what would be the likely outcome? Chances are, you'd be hurting for a few days, with calf muscles that you had perhaps forgotten you had! Worst case scenario, you'd be injured for months with an Achilles tendon injury. That is certainly not a desirable outcome. So there are problems with making sweeping statements about landing patterns.

But more than this, these kinds of statements are never grounded in proof. So for example, when it's written that you land "elastically", has anyone ever done the study of elastic energy return in different types of running? They haven't, but there is theory about it, and that's where these recommendations come from. So the approach in the discussion that follows is for me to adopt the role of "questioner", playing Devil's Advocate, with the humble admission that science simply does not know the right answer, only the possibilities...

Looking at one particular study - elite 21 km runners

So in the current climate where real evidence is scarce and opinions hold sway, let's take a look at one study that has examined footstrike patterns during running events. It was done in 2004 in Japan, and published in 2007 in the Journal of Strength of Conditioning (not sure of the reason for the delay - it happens sometimes in science!). The full reference, for those interested, is Hasegawa et al., J Strength & Cond., 2007, (21), 888-893

It was performed at the 2004 Sapporro International Half Marathon in Japan. The scientists set up a high speed camera (very important for accurate collection of information - beats YouTube science any day!) at the 15km mark of the race, and captured most of the runners coming through. In total, they were able to observe the foot strike of 248 men and 35 women, and characterize them as either heel-strikers, mid-foot or forefoot strikers. They also measured Ground Contact Time at the 15km point.

The finding - what do you expect?

Before giving their main finding away, take a moment to guess what they would have found...If you are anything like me, and have read the substantial amount on the internet and in books about how it's "better" (there's that word again) to land on your forefoot, then of course, your expectation might be that they found:

• The majority of runners land on the forefoot
• Those that DO NOT land on the forefoot are the runners who finish towards the back of the field

Well, if that's what you thought, you'd be completely incorrect...! Because the finding is the following:

• The vast majority (75%) of the elite runners land on the heel
• About 1 in four (24%) runners landed on the mid-foot
• Only 4 out of 283 runners landed on the forefoot

Those runners that landed on the forefoot did not finish in the first four positions, so the common argument (a flawed one) that the best athletes are forefoot strikers is not supported by this finding.

Possible conclusions - how you read the study is influenced by what you wish to prove...

So, given this, one is tempted to say that the landing of the foot makes no difference to overall performance. Of course, this is not necessarily true. As I wrote above, science is often taken out of context, and this is one such example. You cannot, for example, rule out the possibility that these heel-strikers might be a few seconds or minutes faster if they just learned to land on their forefoot! Personally, I think that's highly unlikely, and what is more likely is that they'll end up in rehab for Achilles injuries, but even that is a "bald assertion", based only on opinion!

Now, however, here is where it gets interesting, and this is where the forefoot advocates got quite excited. When the researchers divided the finishers into groups of 50, they started to see something of a change in mid-foot landing as you moved further down the list. In otherwords, there was a higher percentage of midfoot strikers in the first 50 runners than in the second, and then third, and so on. The graph below shows this for heel-strikers and mid-foot strikers (I haven't shown forefoot, because it's so tiny and insignificant by comparison):

At first glance, the conclusion from this graph is that if you want to be a faster runner, finishing higher up in the overall order, then you should be a midfoot striker, not a heel-striker. That's how many people interpreted the finding. And this may well be true. Unfortunately, there is another possible reason it looks like it does - perhaps it's simply a function of running faster.

Speed and footstrike

In otherwords, you naturally shift your contact point with the ground further forward when you run faster. The average speed, incidentally, of the first 50 runners was 3 minutes 3 seconds per kilometer. The second group of 50 runners averaged 3 minutes 10 seconds per kilometer. Hardly a big difference, but given the range (the 50th runner is at least a minute behind the 1st runner), is it possible that groups of 50 is too big, and that all this "finding" represents is a speed effect on footstrike?

The point is, this study does not allow you to differentiate between three possibilities:

1. Faster runners are midfoot strikers (could be co-incidence or some other cause); or
2. Midfoot strikers are faster runners (and therefore we should all change our running style and land on the front part of the foot more); or
3. All runners would eventually be midfoot strikers, if they just ran fast enough!
   

This is another classic example of how a scientific result can be taken out of context and applied to give advice that may not be 100% correct.

Personal opinion and implications of this study

My personal reaction to this research, when it came out, was that it disproved the popular theory that all runners should be aiming to become midfoot or forefoot strikers. Most of us (well, I'm in this group, apologies if you are not) are nowhere near the elite level, and we're often told by experts and coaches that the elite are landing on the ball of the foot or the midfoot, and so we should too.

But the next time you think of running like Gebrselassie and trying to land mid or forefoot, consider this: if you go out and sprint 100m, you're likely to run on your toes the whole way - because you're running faster, you land more on the mid-foot, or even the forefoot.

Sprinting as you are, you'll probably cover 100m in 14 seconds, which puts you only 1 second ahead of a Bekele or a Gebrselassie in a 5000m race, so is it any wonder they are midfoot strikers on the track - they're running as fast as most of us sprint? The point I'm trying to make is, if you ran the speed they did, you'd be a mid-foot striker too! But just as I suspect they change as they slow down, we all do. So why, and on what basis, should you try to run with the same foot strike when you are running perhaps 3 minutes per kilometer SLOWER than them? Again, these are relatively bald assertions, but hopefully you recognize the implication of speed on foot strike.

So when you go out and run a 3 hour, or a 4 hour marathon, that's another story altogether. And what the Pose running study at UCT showed me a few years ago is that if you change the landing of the foot, you predispose the athlete to injury - that study took a group of runners and within two weeks had them all running on the midfoot (please don't write in to say that Pose doesn't mean midfoot, because Romanov was the coach and he was happy with their technique!). Two weeks later, they all broke down with Achilles tendon injuries!

Why? Because sitting where you are right now, if I was to walk into your office or your home and take you outside and ask you to please run landing on your forefoot or midfoot, I can pretty much guarantee that the way you would achieve this is to point your toe down...you're probably doing this as you read this - contract the calf, and point your toe away from your body, like in ballet. Now imagine your body weight landing on that contracted calf muscle 85 times a minute for 4 hours. That, simply put, is a recipe for disaster.

However, if you can gradually change your landing, then I do believe that you can shift your footstrike. But it's a gradual process. And more important, what is the point? There is no evidence that heel-strikers are injured more, no evidence that mid-foot runners are faster and perform better than heel-strikers, and so the ultimate question is:

Why would you want to change your foot landing to begin with? Science has little to offer you in support of this. And so my advice, having read this far (well done!), is to forget about the possibility that you're landing "wrongly", and just let your feet land where, and how they land, and worry about all the other things you can when you run!

If there is one thing you change in your running, don't focus on your footstrike, but rather on WHERE your feet land relative to your body. Because if you are over-reaching and throwing your foot out in front of you, that's a problem, but what happens when the rubber meets the road is less relevant!

I'm sure there's more to this topic, based on your questions and comments. As usual, fire away! And remember the humble admission from earlier - science, believe it or not, does not know the answer definitively! (just as we can't tell you why Bekele is so dominant in World X-Country!)

Ross

Late edit to the post - the comments section of the post has been closed (29 Aug 2009) - too many comments flying in to respond (on top of the other 20 posts still getting comments! And I don't want to ignore people!)

I would recommend that you click on "Running technique" in the tabs at the top of the page, and read through those posts to get the full picture and context to this post