Barefoot Running Debate

As a shoe fitter this fact makes me thinking.
We are starting to hear some people from the footwear industry talking about the future footwear been all minimalist.
I imagine that a few companies will be smart enough to offer shoes for every particular running characteristics, but in the end of the day the numbers are the real decision maker's: If the runners all suddenly decide to buy minimalistic footwear, the market will move in that direction, damaging a few runners unable to find the type of footwear they need.

 

Kevin,

The reason you bend your knees when you land from a jump is to reduce your stiffness and impact loads to the body. There is clearly evidence that higher leg stiffness is related to injury. I am happy to provide you those references if you like.

We don't know whether performance is better barefoot or shod - there is no evidence on this topic. You may be correct. However, there is evidence that shoes add weight and therefore increase O2 consumption and negatively impact performance - especially in longer runs such as marathons. It is why racing flats are often used in these situations. So, removing the weight all together could have a positive influence on performance. I have heard many anecdotal reports of personal best performances either barefoot or in minimal footwear, and seldom hear that runners become slower once they toss their shoes or go to minimal footwear. More research is clearly needed.

My focus is, and always has been, the mechanics related to running injuries. I want to see people be able to run throughout their life, and whether they ever run in a race is not my concern. That is honestly what I felt the book, Born to Run, was about - the simple joy of running - and being able to do it injury-free. Your statement "However, since most runners run in shoes with relatively few injuries" is, unfortunately, far from the truth. There have been numerous studies that report up to 75% of runners get injured in a given year. My hypothesis - based on scientific evidence - is that it is related, in part, to impacts associated with heelstriking - that we weren't designed for.

My hope is that my profession of physical therapy, as well as other related professions, remain open to new information that may change the way we think about footwear and treating the foot.

Irene

 

Irene,
While the extra mass of shoes seems to increase metabolic cost, softer surfaces appear to decrease metabolic cost too. Which has the bigger effect? Leg stiffness is interesting, we increase leg stiffness on softer surfaces, you maintain that this is linked with injury. What's interesting is that while McMahon reduced surface stiffness, which should have resulted in increased leg stiffness, he also claimed a reduction in injury rate of around 50%. This seems at odds with your contention, Irene. What is the optimal leg stiffness?

See paper attached.

Would be great if you could attach the papers you referred to, Irene.

 

Irene:

The problem with your hypothesis that heelstriking running impacts are the cause of running injuries is that 80% of runners heel strike and most of them are uninjured. Go to any road race throughout our nation, look at the heel strikers which make up 80% of runners, and if they are completing the race then they can be assumed to be non-injured. Now try to find the barefoot runners and see that they make up less than 0.1% of runners completing the race. Maybe all the barefoot runners are so injured from running barefoot that they can't even enter the race? The evidence from my being a runner for 40 years tells me that heel striking running is not only safe, but preferred by most runners and produces less injuries than barefoot running. That is why so many choose to run in softer soled shoes, so many choose to heel strike and so few choose to run barefoot, because running in softer shoes with protection for the foot produces less injuries and is more comfortable than running barefoot.

To say that running injuries are only related to heel striking, and not related to training errors, not related to the increased ground reaction forces of running, not related to the increased pronation magnitudes of running, not related to the increased body mass of today's runners, etc would certainly not be consistent with what we know about the biomechanics of sport injuries. I always remain open to new evidence to change my opinions. So far, however, the evidence that barefoot running is either better, faster or less injury producing is simply not there. In fact, the overwhelming evidence from the performance of elite runners, world records in shoes, no world records while barefoot, is that barefoot running is slower and possibly more risky than running in shoes.

When do we get to run barefoot together??:drinks

 

P.S. Which should result in faster running speeds for a given individual: lower or higher leg stiffness?

 

Five minute search suggests that both higher and lower leg stiffness are related to injury- just a different variety:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1748411/
"When the runners' injury histories were examined, those with increased limb stiffness (high arched) were more likely to develop bony injuries, such as stress fractures in the tibia, and those with lower limb stiffness (low arched) were more likely to develop soft tissue injuries on the medial side of the lower extremity. 19"

Reference 19 is one of yours Irene.
Williams DS, III, McClay IS, Hamill J. Arch structure and injury patterns in runners. Clin Biomech (Bristol, Avon). 2001;16:341–347.

So, too much leg stiffness equals injury, too little leg stiffness equals injury; somewhere in the middle there is a zone of optimal leg stiffness (ZOOLS). We can calculate leg stiffness, we can calculate surface stiffness of a road / track/ shoe- one way to manipulate the variables and optimise performance and place the limb within the ZOOLS is via footwear modification. On the plus side footwear provides environmental protection, on the downside it adds mass. Alternatively, you could look to optimise hip, knee and ankle kinematics to achieve a similar aim when running barefoot. On the plus side we can reduce mass, on the downside we run the risk of injury via laceration etc. Skinning cats; two different ways of achieving the same goal. Interesting- which is the easier way to get the runners limb within the ZOOLS?

Here's what I think: firstly, the human being is a magnificent machine. Secondly, the kinematics adopted whether wearing shoes or running barefoot are the body's attempt to be the most efficient and pain-free that it can be. Thus, the differences observed between barefoot and shod kinematics can be explained by the body attempting to maintain the lower limb within it's ZOOLS for a given environment while maintaining the tissues within their zones of optimal stress (ZOOS). Viz. the "preferred movement pathway model" proposed by Nigg.

So, we need to focus our attentions on identifying the ZOOLS and ZOOS, and working out how to maintain the limb within those zones in the face of changing environment, muscular fatigue etc. What if we had a magic material that could adapt its stiffness depending on the loading forces? Errr, like a non-Newtonian fluid? Yeah, that'll do it.... Brooks Glycerin with "DNA technology" looks interesting..... http://www.brooksrunning.com/Technology/ What if we had a human body that could modify its leg stiffness to try and keep it in ZOOLS and ZOOS? Here's the secret: we have. The question is: why does it sometimes fail?

Like I said, just skinning cat's again- why haven't I got a job with Nike, Asics, Adidas, Puma, Saucony, Brooks, etc?

 

Kevin,

It is well-documented that up to 75% of runners get injured in a given year. We have a database of over 500 runners that we have followed prospectively monthly for 2 years and very few of them have been uninjured (I can get numbers to you if you are interested).

I do not believe all injuries are related to heelstriking, nor do I think that all heelstrikers will get injured - I stated they were related, 'in part', to the impacts associated with heelstriking. No one would argue that the etiology of running injuries is multifactorial.

I am not ready to state that either barefoot or shod running are less risky. There is just not enough information to support either position. But I believe we all need to remain open to either possibility. It is likely that each are associated with their own sets of injuries.

Simon,

Agreed that there is an optimal level of stiffness needed for performance. Based upon the results of the Williams et al study, we focused our research on the impact loading of runners with bony injuries (stress fractures). We definitely were not looking for it, but found impact loading to also be associated with a soft tissue injury, plantar fasciitis - and more recently, patellofemoral pain syndrome. These three injuries are among the most common that runners sustain. It has been enough to give us pause regarding these impacts that perhaps we weren't designed for (ie, we don't tend to run with a heelstrike barefoot or in minimal footwear). A recent study by Edwards et al, MSSE (Dec) 2009, suggests that longer stride lengths assoc with higher impacts leads to quicker failure of bone than shorter stride lengths - even with greater numbers of cycles.

I have tried to reference the articles I mention - am happy to attach them, but am not sure how to attach documents that I have.

Irene

 

Irene, when you are replying to a post scroll down, you will see a button that says "manage attachments"= hit this button, choose your file, click upload. Job done.

So, increased stiffness = bony problems, decreased stiffness = soft tissue problems- right? I don't suppose the specific injuries were associated with specific ranges of leg stiffness? i.e., is there a range that equals medial tibial stress syndrome, another for plantar fasciitis? That would be too nice. How strongly did leg stiffness and/ or, impact loading predict these conditions?

Impact forces occur whether we strike heel first or forefoot first- so what's the difference? Position/ magnitude of the net GRF vector relative to the joint axes- right?

 

Simon,

....one more thing - we have not found that the peak vertical ground reaction force (the second peak in a RFS) is different between those who get injured and those who do not. All of our studies point to the initial impact forces.

Irene

 

So braking / shock attenuation is key, rather than propulsion- right? I'm familiar with vertical GRF patterns for rearfoot strikers, how does it differ for forefoot striking? Also, in rearfoot strike, centre of pressure (COP) progresses from proximal to distal along the plantar foot whereas in midfoot striking we see an initial movement from distal to proximal. What does the CoP do in forefoot strikers? What differences in ankle, knee and hip joint moments between forefoot and rearfoot strike?

 

Irene:

Certainly, an injury a year is not uncommon for runners, especially for those who are pushing their mileage, speed and intensity of training for a certain event or race. The question is whether this is related to the impact peak (i.e. passive peak) of the ground reaction force curve seen exclusively in rearfoot striking runners, or to the other factors I mentioned earlier. Other researchers feel this impact peak has no association with injuries. Obviously you do.

I agree with you that barefoot and shod running will each have its own characteristic sets of injuries, just as heel strikers vs midfoot vs forefoot strikers will also have its own characteristic sets of injuries. Different running styles will produce different loads on different structural components of the foot and lower extremity and therefore, will tend to produce their own characteristic sets of musculoskeletal injuries.

However, how can you explain why barefoot running is so much slower than running in shoes? I think this is the most interesting question because the majority of the running-racing community could care less what the middle of the pack or back of the pack runners are doing (where most of the barefoot runners are). Instead they care more what the top 1-2% of runners are doing to get faster. And for the past 49 years, 99.9% of these elite runners have worn shoes to win races and break records. The question I want answered is why does running barefoot cause runners to be slower in races when it should, with decreased mass on the foot, make them faster??

 

Simon,

To answer your question about impacts.....Attached is the vertical ground reaction force data of a rearfoot strike, midfoot strike and forefoot strike of a representative runner. Note the impact transient in the rearfoot strike that is missing or significantly attenuated in the MFS and FFS pattern (and in barefoot strikes - which are either MFS or FFS). This impact peak of the RFS results in significantly higher load rates (steepness of the initial rise to peak). We have found that high load rates to be related to plantar fasciitis, tibial stress fractures and recently patellofemoral pain syndrome. (By the way, in the walking literature, high loadrates are associated with knee OA). As I said, neither we, nor others have found that the actual peak ground reaction force discriminates those who get injured and those who do not. All our studies of forces (including our modeling work of tibial strains) point to the impact period.

hope this helps.

Irene

 

Kevin,

Just to be clear, my position on the relationship between loadrates and injury is based upon data and not opinion. The argument that some make is that loading is important to healthy bone. I couldn't agree more. However, there is a tipping point and too much loading may not be healthy.

In terms of speed, I don't believe we know that barefooters are slower or faster.

I've cluttered the airwaves enough and am going to sign off.

Irene

 

Irene:

Thanks for taking the time to discuss these interesting subjects with us and for coming here onto Podiatry Arena so that the discussions are public, for all to see. Your contributions to our understanding of the biomechanics of the foot and lower extremity over the years have been exceptionally valuable and particularly to the podiatric medical community.

Even though I can't agree with everything you say, it is always a pleasure to have these discussions with you since I always come away from our discussions with a sense that I have learned something new. Hopefully we can get together again soon so we can have some more fun with our lively talks.

Maybe i-FAB in Seattle in September??

 

As I´ve read thru the updates this morning, a couple of things that have been said have got the brain ticking over.

Kevin stated that the stride length maybe one of the key points here. I tend to agree. Ive drawn some very basic pictures.

By having a shorter stride the foot impacts the ground under the body which I´m thinking will mean that it will be able to use the knee to a greater extent to shock absorb or maintain ZOOLS. Stronger joint, more muscle to control position, mostly single plan motion. This would tie in with some of my thinking on Niggs work.

So I´m not sure on this Irene, Simon and Kevin when they are testing impact in studies do that make the person perform the different strinking patterns with the same stride length ? or do they just say run with RF,MF,FF strike ?

If a heel striker shortened their stride length, brought it under the body, less bracing impact, use of knee to maintain ZOOLS ?

Just thinking out loud

 

I'll second that. Thank you, Irene. Just a shame you don't want to hang around to discuss it more. It was just getting interesting.

 

What about glass?

Here is an excerpt from Chris McDougall's blog on why he thinks glass in a non-factor for injury in barefoot running (Chris wrote the semi-fiction novel, "Born to Run"):

Actually, one of the greatest track stories of all time involved an athlete running barefoot and stepping on glass and lacerating his plantar foot just before one of the most important races of his life. John Landy (Australian) was the second man, behind Roger Bannister (English), to break the 4 minute barrier in the mile. At the British Empire Games in Vancouver in August 1954, two nights before he was competed against Roger Bannister in the "Dream Race" event, John sliced open his foot with a two inch laceration by stepping on a piece of glass while running barefoot on some grass. Even though Landy bravely denied the cut foot affected his race, it is quite likely that his choice to run barefoot that evening could have made him take second place to Roger Bannister by 0.8 seconds (Bannister 3:58.8, Landy 3:59.6) during the Dream Mile race (Bascomb N: The Perfect Mile. Mariner Books, 2004. pp. 233-255). Those of you who love track and field like myself, will love this book.

So if anyone doesn't know this story about a famous runner getting injured while running barefoot, now you know......the rest of the story.:drinks

 

Today I remembered that in my shoe collection I have a pair of Adidas SL-76, the real deal that I got from a sports shop that was closing down about 13 years ago; not the re-issue ones. They were new old stock from back in the day- I've only worn them a few times as they are lime green with day-glow yellow stripes- subtle 1970's. My dad always took me and my brother to this little independent shop and I remembered seeing these and wanted them back in the day, but they were too expensive! When I saw them in the closing down sale in their by then battered box, I had to have them. This pair had been collecting dust in the stock room all those years, waiting for my feet to grow to the right size for them and for me to have "my own money to spend on trainers!"- K.E. Spooner

As far as I can work out "SL" stands for super light and the number denotes the year, I think they released them to coincide with olympic years because I also had a pair of SL 80's in 1980. I think they were the model Adidas packed with their latest technology and ideas before adistar came along, these have a primitive midfoot cut-away. I know the other Adidas shoes of the time that I had, Bamba, Samba, Kick, Blackbird etc didn't have this. Anyway, they are pretty minimal by modern running shoe standards with soles (including outersole and tread of about 15mm at the heel and 10mm at the forefoot. As far as I can tell the midsole has a 2mm layer of eva and then some denser rubber (about 3mm in the forefoot, approx 12mm heel). I'm going to do some running in them, I'll let you know how I get on...

P.S> if you google "adidas sl 76" you can get images of the re-issue shoes so you can see what I'm going to be wearing

 

Another well written and objective blog from Ross Tucker and Jonathan Dugas:

http://www.sportsscientists.com/2010/03/barefoot-running-and-shoes-part-4.html

PS - Simon, I'm looking forward to your report from your run - just saw an image of the SL76 - you are kicking it old skool man. Me - I've asked the Mrs for a pair of Vibram Five Fingers for my birthday

 

That's me - old skool. I still have to look longingly into the shop window at the five fingers. "Dad, dad, I've got my eye on a new bike" "Keep your eye on it son because you'll never get your arse on it." Roysten Vasey.

 

update on my SL-76 study: after wearing these shoes for standing and walking for a few hours yesterday and today, I developed pretty severe medial knee pain in my left knee (good knee!) to the point were I had to take them off. I replaced them with my Nike Zoom Elite with an almost immediate reduction in pain. It's still pretty painful so I've just taken 400mg of ibuprofen. I was hoping to do some sagittal plane kinematic studies comparing the SL-76 with the Zoom Elite, but I think we'll leave that for today.

 

I find the "you could step on something" argument a bit lacking for two reasons.

1) My hunch (and I don't have data to prove it) is that the number of laceration injuries to barefoot runners is statistically small, that we hear about the anomalous cases which then are used as scare tactics

2) It's easily solvable with a pair of huaraches running sandals. Granted, I'm biased in this position since, after making huaraches for myself and a few dozen other runners, I started a website about them.

Regardless, the "you could hurt yourself" argument seems to be a red herring, even if there are the occasional stories of someone getting hurt. And, besides, nobody complains about running shoes being dangerous even if someone gets into an accident specifically due to wearing shoes (e.g. tripping on a lace, falling after getting a "flat tire", etc.)

BTW, I used to walk on broken glass for a living -- I was a street performer in NYC. In 5 years, I only got one cut... I chalked it up to the cost of doing business.

-Steven

 

Steven:

That's nothing. I walk on barefoot runners for a living. Haven't been cut yet!

By the way, Steven, running in haraches is not barefoot running. It is called shod running.

 

http://en.wikipedia.org/wiki/Huarache_(shoe)

Steven,
The words "bandwagon" and "jumping on" spring to mind. :dizzy:

Is that the motivation behind your post here?

 

Taken from the website http://www.invisibleshoe.com/

"The biggest problem with barefoot running, not surprisingly, is all the stuff on the ground that can hurt and cut your feet, plus all the dirt you have to wash off when you’re finished running.

That’s why you’ll want a pair of Invisible Shoes."

?????

 

Kevin -- I know some anti-barefooters who would like to run on that same surface, but with track spikes on ;-)

Timm -- thanks for pointing out that line... I wrote it 4 months ago and it's not totally accurate, obviously. a) There may be "bigger problems"; b) The stepping on/in stuff issue is what people *worry about*, but isn't really a big problem IMO (as I said in my post), and; c) The dirty feet thing is something that some barefoot runners complain about. I'll have to edit that to be more accurate.

Simon -- my primary motivation, since I got into barefoot running last year and noticed dramatic changes in my body and in my running, is to participate in the conversation and, sometimes, to pick at (or apart) the bad rhetoric that often appears as discussion. I began joining those conversations before my wife and I started our running sandal biz 4 months ago (which happened on a whim... semi-long story).

Obviously, pointing to our website, which contains free videos and other info, in addition to the kits and custom sandals we sell, piggybacks on my continued participation in the ongoing conversation.

 

I'm devasted to have found out that the Zoom Elite will be replaced . . .

 

Obviously.

 

Found an interesting Blog.

The Biomechanist in me sees considerable interest in the debate re muscle function and sports injuries and such.

The "Chiropodist" in me reads it and weeps!:empathy:



http://barefootjason.blogspot.com/2010/03/barefoot-runners-are-stupid.html

 

Obviously

 

Hi All:

As I have been reading through this forum it has made me think about the role of arch height. I have been told by some barefoot runners that after running barefoot they now have a much higher arch when standing statically (this is self report). But what does this mean functionally?

Does arch height correlate with speed? Is it the combination of arch height and strike pattern that may increase and/or decrease ones speed?

Just throwing this out there, I did a cursory look of the literature but was unable to find evidence that pointed in this direction. If there is, please share that information.

Best Regards,

Eric

 

And here is the paradox. They tell us barefoot running has made their arch height increase (usually suggesting intrinsic muscle weakness/atrophy such as seen in motor neuropathy/diabetic intrinsic minus foot), yet they also tell us barefoot running strengthens their foot intrinsic foot musculature...

 

Because... In their world- running magazines etc. Low arch = bad. Viz, y arch is higher = good. `people who have no concept of foot and lower limb biomechanics "blogging". Look at it, say what it is.... pile of sh!t. Say it after me, pile of sh!t. Worthless, hyperbole.. read my signature.

 

So where is the notion that higher or a more "normal" arch is good? Has there been evidence to suggest these individuals are indeed faster, stronger and able to leap tall buildings in a single bound???

Best Regards,

eric

 

Not really, but you may want to examine the relationship between leg stiffness and arch height. Does greater leg stiffness = faster running... theoretically it probably should do. Will we have a stiffer leg barefoot or in cushioned shoes? Cushioned shoes.

 

Excellent way to look at it. Of course we are neglecting foot strike pattern.

But along with this logic if someone trained barefoot, then saw an increase in arch height (not quite sure how) they would then run their fastest in cushion shoes. As we saw in the previous posts with the marathoner.

Best Regards,

Eric

 

Nice logic.

 

So... (assuming for a moment their arches are actually getting higher) -> they think this is a good thing -> and generally speaking higher arched feet are more rigid/stiff -> and we know ground reaction and impact forces do not significantly differ for feet of different arch height (Ref).

So if barefoot running does increase arch height then theoretically this could result in a decrease in leg stiffness when running -> and theoretically this would make them slower?

 

That point needs to be re-emphasised: Weak intrinsic muscles of the foot lead to a higher arch!

 

Simon posted the full paper in the leg stiffness thread.Leg stiffness thread post 14 I think.

Edit I thought that it a good discussion for the for the leg stiffness thread so did some cut and paste and put some thoughts in as well