I’ve been thinking a lot lately about the relationship between footwear (or lack thereof) and how it affects my running footstrike. Over the past year I’ve been running in everything from full-blown, pronation-control stabilty shoes (Saucony Progrid Guides, Brooks Adrenaline GTS 8) down to Vibram Fivefingers KSO’s, which are about as minimalist as you can get without being barefoot. Like many other runners, I read “Born to Run,” Christoper McDougall’s great book on the joy of running, the reasons why we humans should run, and the potential dangers of modern footwear. I took many of the lessons from that book to heart, foremost that we humans evolved to be distance runners, and that messing with what we do naturally is probably not a good thing. However, in my mind the great unanswered question remains: What is natural when it comes to running?
I find myself in a unique position to begin trying to provide at least a little additional insight into the answer to this seemingly simple question. I am a biologist with a background in anatomy and biomechanics [although my research has mostly focused on frogs (yes, frogs!), the basic principles are the same], and I teach Human Anatomy & Physiology at a small college, and will be teaching Exercise Physiology for the first time next semester. I admittedly don’t have a background in human research, but I’m learning a lot in this process, and we’ll see where it goes. I have a small lab, a troupe of research students, and some funding and equipment that allows me to do some things that are not easily done at home (e.g., high-speed video cameras). Perhaps as important as my biological background, I’m also a fanatical runner, and this is really what drives my interest in trying to answer questions like that posed at the end of the opening paragraph. This new line of work has quickly become my passion, and I’m excited to be heading in this new research direction. We have some interesting projects already underway, most notably a high-speed video analysis of footstrike patterns in over 900 runners from the 2009 Manchester City Marathon that was run in early November – details and video clips (like this one) from that project will hopefully begin to trickle out over the next few months.
Before getting into the videos that follow, I’d like to state a bit about my philosophy about science, academics, and research. I, like all other other academic scientists, use scholarly journals as a primary outlet for disseminating the data I collect (you can view my work webpage here). This allows for review by our peers to control quality of data and soundness of interpretations, and scholarly publication is required in most institutions if we want to get tenured and keep our jobs. I see a lot of value in scholarly publication, but unfortunately these publications often get missed by those who might most benefit from their content. Journal articles can be highly technical and hard to read, they usually do not get wide circulation unless picked up by the media (and trust me, tadpole research doesn’t usually attract much attention), and their conclusions are often hedged due to the nature of scientists to not want to take a firm stand on a given issue (the old, hypotheses can’t be proven, only “supported” or “not supported” by the data philosphy that we get drilled into us early on). I publish, but I’m not hung up on counting articles – at the end of the day, I’d feel more gratification if one of my blog readers decided to get off the couch and start running than if I added another paper to my CV. In fact, one of my primary reasons for starting this blog back in January was to find a more open forum to bring some science out in a more understandable and conversational fashion. I am first and foremost a teacher (this is the part of my job I enjoy the most!), and my hope is that through posts like this I can teach a bit about how academic science works, as well as present some scientific data in a readable, and hopefully entertaining way. If any of my students happen to be reading this, they can vouch for me that this is my approach in the classroom as well.
Now, back to the videos. Like any good scientist, I tend to think a lot about the things that I study. Project ideas (as well as blog posts like this!) often come to me on my runs, and so it was the other night that I was trying out a pair of Newton Sir Isaac shoes that had been sent to me (Newton’s are designed to facilitate a forefoot strike) when I decided to film myself running on a treadmill in just about every shoe condition I could think of. Several running friends on Dailymile have suggested this as well (e.g., Matthew L., David H. to name a few), so yesterday I finally took the plunge. As an honest scientist who respects statistics, I should point out very clearly at the outset that I am a sample size of one, and although I did my best to control conditions, what follows is merely a first look and nowhere near a true scientific study (coordinating turning on and off of the camera while hopping on and off the treadmill was quite a challenge in and of itself and made for some interesting slow motion video footage!). I shot the following videos mainly to provide some food for thought for myself and for you reading this, and as a way of generating some ideas for projects for my research students and Exercise Physiology class next semester. I’d love to hear what you think – any and all thoughts/suggestions/criticisms/ideas are welcome, and I truly mean that!
So here are the relevant details about what I did yesterday. All of the videos below were filmed in an approximately 20 minute session in fairly rapid succession. I ran five minutes to warm up, then haphazardly changed from one pair of shoes to another (in no particular order). For each condition, I filmed myself for about one minute at 300 frames-per second with a Casio Exilim EX-F1 digital camera. Each clip below is a small segment of the total video clip pulled from the end of the one-minute session (this was plenty of time to get into a comfortable running gait). Speed was the same in every single video (7 mph). Below each video is a brief summary of what it contains, and what I could gather from looking at my footstrike. The videos tend to stutter a bit, which is either a result of the conversion process during upload, or something to do with the Vimeo site (they are apparently working on the issue). The raw videos are perfectly smooth.
Brooks Adrenaline GTS 8 from Pete Larson on Vimeo.
Slow motion video of treadmill running in Brooks Adrenaline GTS 8’s – definite heel strike here. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.
Brooks Launch from Pete Larson on Vimeo.
Slow motion video of treadmill running in Brooks Launch – mild heel strike here, but extremely smooth heel-toe transition (this is my current go-to shoe). Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.
Newton Sir Isaac from Pete Larson on Vimeo.
Slow motion video of treadmill running in Newton Sir Isaac shoes – used my natural gait, and still have a heel strike here (I’m a newcomer to Newton’s – only one 5-mile run so far). Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.
Newton Sir Isaac from Pete Larson on Vimeo.
Slow motion video of treadmill running in Newton Sir Isaac shoes – tried to shift to a more forefoot footstrike here, but still feels strange (I’m a newcomer to Newton’s – only one 5-mile run so far). Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.
Nike Free 3.0 from Pete Larson on Vimeo.
Slow motion video of treadmill running in Nike Free 3.0 – mild heel strike. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.
Saucony Kilkenny 3 from Pete Larson on Vimeo.
Slow motion video of treadmill running in Saucony Kilkenny 3 cross-country flats – appears to be a midfoot strike. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.
Running in Vibram Fivefingers KSO from Pete Larson on Vimeo.
Slow motion video of treadmill running in Vibram Fivefingers KSO’s – appears to be a midfoot strike. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.
Smartwool Ph.D. Socks from Pete Larson on Vimeo.
Slow motion video of treadmill running in Smartwool Ph.D. socks – appears to be a midfoot strike. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.
Barefoot Running on Treadmill from Pete Larson on Vimeo.
Slow motion video of barefoot treadmill running – appears to be a nice midfoot strike (this was my first ever attempt at running barefoot on a treadmill). Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.
So what can I conclude from this very simple experiment? First, I am definitely a heel striker in stability shoes like the Brooks Adrenaline and neutral shoes like the Brooks Launch and Nike Free 3.0. When switching to cross-country racing flats (Saucony Kilkenny 3) or Vibram Fivefingers KSO’s, I take on a more midfoot strike, which is also clearly present in the sock and barefoot conditions. What I find particularly interesting is that when trying to run naturally in the Newton’s (which as mentioned above are designed to facilitate a forefoot strike), I still tend to heel-strike, and only when I consciously forced the issue was I able to shift to a forefoot landing. Forcing the forefoot landing did not feel comfortable to me, and in no other case did I exhibit a forefoot strike (not even when barefoot).
My gut feeling is that at least for me, midfoot may be the most natural landing style since I do it when barefoot, but much more work needs to be done before any generalizable conclusions can be made (reminder – I am a sample size of one, I ran at one speed, and am not an experienced barefoot runner!). I plan to give the Newton’s more time (I’ve only done one 5-mile run in them), but from watching marathon videos, my sense is that a “true” forefoot strike is biomechanically very different from midfoot/heel striking. It seems that I can get to midfoot relatively easily from a heel-strike, and it seems to be related in me to footwear type (less/no shoe = midfoot strike). Those “true” forefooters I have seen so far mostly seem to land way up on the outside of their forefoot, and would probably do so wearing a shoe with twice the heel of my Brooks Adrenalines. I should point out that none of this really argues one way or another as to which style of landing is “best” – we may never have an agreed upon answer to that question. It’s all very interesting, and I haven’t quantiifed anything yet, so stay tuned!
I’ll finish by repeating what I said earlier – I’d love to hear feedback/ideas/suggestions, so don’t hesitate to leave a comment!
You might also like:
Ryan Hall in Slow Motion from the 2010 Boston Marathon
Footwear and Pronation – A Slow-Motion View from Behind
Vibram Fivefingers and Barefoot Running: Does Removing Heel Cushion Change Footstrike?
Slow Motion Video of Elite Women at the 5th Avenue Mile Road Race
Science of Marathon Running: Great Video From It’s OK To Be Smart
About Peter Larson
Very cool stuff. Thanks for sharing!
I’m also curious as to how the different footwear affects the amount of time that one’s foot remains on the ground, since that is also a measure of efficiency. It’s hard to tell with the naked eye, and a treadmill affects that too, but I think I can see some differences as to where you pick up your feet as well as how/where you put them down.
Did you feel any of the differences while you were running or was it mostly noticeable when you checked the video?
Justin,
I’d put money down that my contact phase is shorter and cadence higher in XC flats, Vibrams, and barefoot. Shouldn’t be too hard to put some numbers on that from the raw videos. I hope to get some of my students on film next semester to boost the sample a bit as an exploratory pilot study, and then I have an XC runner that may take this on as a full-blown project next year.
Pete
Wow, thanks for sharing the videos. It’s interesting to see a slight shift in gait with the more minimal footwear. I agree that a comparison of cadence would also be interesting and also wonder if the distance covered per footstrike/gait is different – though that would be extremely hard to measure on the treadmill.
Very interesting post! After reading “Born to Run”, I tried running barefoot on the road and was blown away at how good – and natural – it felt. Then I developed shin splints from it. Now that I’ve finally recovered (4 months later) from the shin splints, I’m trying to find a balance between what is “natural” and what I’ve been doing all along, since I feel that, ultimately, my barefoot gait is more efficient.
I look forward to reading about larger studies you do with your students.
Thanks for the comment! I use the Vibrams once a week right now to help with form/strengthening, trying not to overdo it. I think if you build up slowly, it’ll reduce the chance of injury. Have you tried a lightweight
racing shoe as a compromise? -Pete
Thank you for this incredibly interesting post! I am looking forward to your continued research in this area.
Nice videos, but as a minimalist runner (vibram kso/treks exclusively), pretty much all your foot strikes appeared to be either heel or flat. For a good forefoot-midfoot strike, your feet should be more-or-less directly below your knees; in all of your videos, it seems your lower legs are all extended in front. You want a faster cadence with shorter steps (for minimal/barefoot running; I cringed when I saw your KSO form.) For an excellent video, watch this one: link to youtube.com…
It shows a child running with awesome form (something I try to imitate every time I run.) It’s a good video overall, but you can skip to 2:15 and on for good slow-mo video of her form.
Jason
Jason,
I think the jury is still out when it comes to proper form-footstrike –
curious as to your basis for thinking a forefoot strike is most natural? I’d
agree that heel-striking is probably not what we evolved to do, but I
believe mid-foot vs. forefoot is an open question. I run in KSO’s fairly
regularly, and have no problems using a midfoot strike like that in the
video – the only time I tried to force a full-on forefoot strike in Vibrams
I strained something in my foot, it just doesn’t feel right for my
biomechanics. I liked that video on YouTube, but I couldn’t conclusively say
that she was forefoot or midfoot at the framerate it was recorded. You might
be interested in this one I shot of my son running barefoot – almost pure
midfoot: link to vimeo.com. It’s all very interesting, and I
think there’s a lot of research that needs to be done on these questions.
Thanks for the comment! -Pete
Pete, looks like the following comments have surpassed my basic view of the issue ;) My view of the ‘correct’ form is mostly from reading all the various articles regarding running, shoes and walking form:
http://www.popularmechanics.co…
link to kk.org…
link to dailymail.co.uk…
link to blog.wired.com…
link to nymag.com…
http://www.popularmechanics.co…
as well as personal experience. I’m fairly new to running. I’ve had a pair of Brooks trail shoes for a while but only started to ‘really’ run this year. I’d alway felt running to be a ‘jarring’ experience, mostly as I was running heel-toe (landing on heel, launching from toes) and was pretty uncomfortable with it. I started reading the above articles, found vibram shoes then started running more and more, as Vibrams, and their necessary barefoot-style running form, allowed me a more comfortable run (less jarring on bones and joints.) The way I see it, the foot is a really good spring-loaded lever. By landing on the front half of the foot (including the mid-foot), it seems you allow that spring-loaded lever to function as it shoud, as opposed to landing on the pivot point (ankle), bypassing the ‘spring’ (achilles/calf.) I didn’t mean to imply that your videos above didn’t show fore or mid-foot landing, it just seemed to me not as obvious as I’d thought it would. I’ve not seen myself in such a manner, so I could probably be landing just the same. It just feels a bit more pronounced when I’m actually running.
Jason,
Your reading list includes a lot of the articles that got me interested in the question of proper footstrike, and trust me, I don’t claim to be an expert at all at this point. I’m also a relatively new runner (about 2.5 years), but that combined with my teaching area and biomechanics background has led me into this field – there are a lot of questions that remain to be answered. Regarding my videos, in no case would are really say that I’m forefoot striking, mostly flat or mildly on the heel. You can probably try filming yourself with a standard video or digital camera at 30 frames-per-second and at least get a rough approximation of what you are doing (it will be a bit choppy, but if you shoot for a minute or so you should get plenty of footstrikes). If you wanted to try it outside, set a camera a bit off the ground and run by it a few times – I’ve learned a lot by watching my own stride!
By the way, here’s a blog by an exclusive Vibram runner that you might find interesting: link to runluaurun.wordpress.com
Thanks again for the comment,
Pete
Nicely compiled videos. A couple of things to consider for future testing:
1. Treadmills tend to pull your foot back on the belt since wind resistance and inertia are absent. A good way to simulate an outdoor gait is to use a bungee system pulling back from about the center of gravity of the runner. This allows your limbs to be propulsive.
2. Contact time (as pointed out below) and vertical force are a good measure of the effect of footwear geometry. This can be measured from the videos knowing the strain (deflection) of the treadmill.
3. Geometry is very important in where and how you load your leg during the gait cycle. If you cut open the shoes, you will see the following heel to forefoot drop (center of heel to ball of foot): Barefoot 0 mm, Sock 0 mm, Vibram 0 mm, Sir Isaac 5 mm, Kilkenny 8 mm, Launch 12 mm, Adrenaline 13 mm, Crocs 12 mm?, Nike Free 12 mm.
4. Foot strike definition is not well defined. Newton Running regards a midfoot/forefoot strike as under the metatarsals heads, basically the ball of the foot. Strict forefoot is more like Pose running (closer to a sprinters gait). Midfoot is often described like Chi Running, landing flat.
5. A heel lift inevitably causes your leg to load early in the gait cycle, before your leg is properly (and protectively) flexed. Anyone using running shoes since the early 1970s most likely has been conditioning themselves to heel strike. Guaranteed you didn’t as a kid running barefoot.
Disclaimer: I’m director of product development and education at Newton Running Company, and like Peter am a University lecturer, lifelong runner (former professional endurance athlete) and worked with the likes of Nike and Salomon for many years.
Ian,
Thanks for the comment – this kind of feedback is invaluable to a newcomer
to the field like me. Regarding the points you made:
1. I’ll be the first to agree that treadmills are very different than
overground running – I actually hate running on a treadmill in most cases.
We started out shooting outside, mostly just playing around, and I hope to
get back to it in the Spring or next Fall. The bungee idea is an
interesting one.
2. Contact time is one thing I definitely plan to look at – I have the
strong sense that I’m in contact during stance for a shorter period of time
when barefoot or in Vibrams, but haven’t put any numbers on it yet.
Regarding vertical force, how would you measure strain in the videos? I can
definitely see the treadmill bed drop at foot contact – is this what you’re
referring to? I’d like to get force plates or pressure mats, but don’t have
the funds yet.
3. I definitely see the correlation between heel to forefoot drop and
footstrike – I’m landing much more flat-footed as the drop decreases.
4. Regarding footstrike, I’m using midfoot as equivalent to flat foot. No
matter what we do, it seems we are trying to create categories for what may
essentially be a continuous spectrum of strike positions from hard heel to
pure forefoot. Even among heel strikers, I’ve seen a huge degree of
variability in slow motion videos we shot at the Manchester Marathon. Some
are striking way at the back of the heel with the toes pointing way up, and
others have a more mild heel strike like my own. The distinct forefoot
strikes I’ve watched almost always seem to land way up on the lateral
forefoot – very interesting and very different.
5. I’m in total agreement that the heel-lift plays a major role in forcing a
heel-strike. My question is how good/abundant are the data showing that a
heel-strike is a bad thing? I think that’s a question that people would
like to see answered in a conclusive way. Based on what I’ve seen and read,
I’d probably agree right now that a heel strike is not the way we naturally
run, but is more a result of conditioning or being forced by our footwear.
For example, my kids land almost pure flat-footed when I filmed them running
barefoot (3 and 5 at the time I filmed them). Are there papers correlating
footstrike patterns with injury likelihood? I’ve been reading mostly
straight biomechanics literature so far, haven’t gotten much into the injury
data.
Pete
1. A few of the high end treadmills have bungee systems. The Woodway Force is an example link to woodway.com…, expensive at about $8,000 but guaranteed for 200,000 miles, so actually a good value. I had a Desmo HP on loan for a year and it was by far the best I’ve run on.
2. Stress and strain are related in a simple linear formula for most elastic materials link to en.wikipedia.org…. If you know the force (stress) it takes to deform (strain)the treadmill frame, you can work out the constant. In a simpler form you can measure how much the frame bends for each shoe you run in. The more bending of the frame, the more force. You could get fancy and put a strain gauge on the frame and measure the electrical resistance as you bend it under load. Progressively load gym weights on the belt where you land and plot the curve. You would need a lot of weight to get a useful curve, probably >300 kg.
3. You will see this even more in the real world, or using resistance which causes increased forward lean, as if inertia and wind resistance were present.
4. Foot strike categorization is interesting, and I believe a great deal of misconception and misunderstanding in the general runner population. There are many and varying definitions and as you point out there is a continuum with some overlap.
My contention is that no one truly heel strikes when running on a flat natural surface (packed dirt, sand etc.) with bare feet – unless they are conditioned from wearing a heel lifted shoe. Regardless, it extremely unlikely anyone will heel strike more than a few times if they take their shoes off and run on the pavement. At Newton Running we’ve observed thousands of people try this, and with one known exception everyone adopts a midfoot/forefoot strike barefoot. The exception was very stubborn and probably ended up with very sore feet and possibly injured.
Back to the point of foot strike categorization, the factor that is absent in most studies is what the runner would have done without shoes? A recent Japanese study looked at footstrike and described it as where the *shoe* hit the ground. If you followed the natural trajectory of the runners gait without the shoe (and heel lift) you would see very different results.
Technically the forefoot is the front half of the foot, forward of the arch. Midfoot is under the arch, so a midfoot landing is essentially flat and a forefoot landing is on the ball of the foot. When observing people’s barefoot gait on a natural surface we see:
WALK: heel strike, roll through, toe off
JOG: midfoot strike, roll through, toe off
RUN: midfoot to forefoot strike, roll through, toe off
SPRINT: forefoot, toe off
DECELERATE/BRAKE: heel strike, roll through, toe off
5. There is surprisingly little data showing heel strike is a bad thing until you realize the relationship between running injuries and shoe geometry. It is clear that running injuries became prevalent when modern running shoes with a heel lift were introduced. Prior to that (before the 1970s,) running injuries were unusual. Several arguments have been proffered to explain this; too few runners, not enough data, runners used to be all elite and self selecting to be able to run. There may to some truth to these ideas, but I don’t buy it on the whole. Why? Because we see thousands of people who suffered from a multitude of “running injuries” and now run injury free in Newton Shoes. This due to the geometry of the shoe facilitating good (injury protective) running form and the shoe’s vastly improved shock absorption.
The University of Newcastle (Australia) is currently in their second round of controlled studies with Newton shoes and other running shoes looking at injury rates and performance. This study is in numbers supporting a high level of statistical significance.
Studies and data aside, most people understand that keeping straight legs in any sport where you land on the ground causes injury. No one jumps rope, shoots a hoop in basket ball, skis, hops, skips or does long jump and lands with strait legs, so why is this the case with modern running shoes?
A couple more comments on shod gait:
a. If you superimpose the foot inside the shoe on still images of a shod runner, you can see how ground contact is altered by the shoes geometry. This seems intuitively correct, but you can actually see it knowing the shoes’ geometry (heel to forefoot drop.)
b. If you do a. you will also notice any given runners gait is essentially the same until the shoe first hits the ground. This is when your body senses contact (afferent feedback), and with conditioning is integrated into proprioception (your sense of where you body is in relation to itself and the surroundings.) Wearing a shoe is like driving a car in this respect. Good drivers have a precise understanding of where the vehicle (or shoes is) on the road. Gymnasts develop highly tuned proprioception so they can perform their routines with precision.
I know that when I run on a treadmill my foot strike isn’t that normal as running on a treadmill isn’t really running normally. I think an ideal way to film all these would be to do it outside or on a track some how.
I used to run in Adidas Control 7, which caused me to run as a total heal striker and resulted in many injuries, switched back to my old Brooks Trance 7 shoes and i was running back on the fore foot.
Recently made the switch to the Newton’s and i’m a sold forefoot striker now, and running some of my fastest times in years. It also took me about 2 months of running in them to feel good running in them and develop the foot muscles necessary to run in them.
Sean,
Yeah, treadmill is tough to run on for me as well. Reality is that a lot of
people run on them, some almost exclusively, so treadmill data are valuable
for that population – just have to be careful not to generalize patterns to
outdoor running without confirming outside. I’ve got tons of film from the
Manchester Marathon which will help me look at that.
Thanks for the comment!
Pete
Great post! I think with stability shoes it’s always going to be hard to not heel strike given that the heel has so much cushioning. A little bit like high heels, it’s hard to strike anywhere besides the heel. It is so interesting to see video of barefoot running. I also read Born to Run, and didn’t really believe it until I started looking up videos of barefoot runners. It really is amazing how differently the foot lands without the traditional running shoe. I’ve been thinking about trying a pair of racing flats. I’m not sure I’m ready for the Vibram’s. I’ve also been thinking about trying some barefoot running on the treadmill.
I don’t have any real suggestions for you, but being an engineer I loved seeing the videos.
Katie,
Thanks for the comment – I run almost exclusively in lightweight trainers or
flats, and am glad I made the switch. The Vibrams are nice – I use them
about once a week, but they are pricey for what they are. A more runner
specific model called the Fivefingers Bikila is coming out next year.
Regarding barefooting on the treadmill, the friction can do a number on your
feet, so I’d recommend at least a pair of socks.
Pete
Be careful of racing flats because most are anything but flat. Part of my work involves dissecting shoes and we’ve found that heel lifts are pervasive in the industry. HBelow is a sample of what we have found.
Lift = difference between the height of the shoe under the center of the heel and height of the shoe under the metatarsal heads (ball of foot) in mm. Gradient (rise / run as a %, same as road gradient) is for a men’s US 9. As a reference, a 6% road grade is the point at which most countries post warning signs for trucks.
Barefoot: 0 mm, 0%
Track spike: 1, 0.7
Newton Racer: 4, 2.7
Newton Trainer: 5, 3.3
Asics Prianha 3 (ultralight weight racing flat): 6, 4
Biom: 8, 5.3
Nike Free: 10, 6.7
Nike Zoom Streak XC: 11, 7.3
Nike Luna: 12, 8.0
Brooks T5 (distance racing flat): 13, 8.7
Saucony Hurricane: 14, 9.3
Mizuno Waverider: 15, 10.0
Saucony Omni 6: 18, 12.0
Asics 2100 series: 21, 14.0
We also measured a Nike Shocks with a lot of wear and the compression of the foam in under the met heads increased the gradient lift and gradient to 24, 16. This is typical of foam shoes (not Newton shoes).
Ian,
Interesting data, and particularly intersting that you mention the Nike Shox – they’re surprisingly popular as running shoes on my campus, and I couldn’t imagine running in those things. They look like high heels to me. Have you seen these: http://www.zcoil.com? Insane!
Pete
Peter,
This is great initial research. Since I don’t have access to a lab and funding I will have to live vicariously through your research.
I have a couple recommendations for future research.
-Use individuals not aware of the test purposes. They may consciously modify their running technique if they understand the test purposes.
-Do study participants exhibit a measurable change in foot strike over a set time period when switching from Stability to Barefoot shoes?
-Is there an increase in injury rates when consciously switching to forefoot strike? I have heard many coaches, including Joe Friel state that switching to a forefoot strike will increase injury levels. I wonder if this proves true and if so under what conditions.
As always, there are a lot more questions then answers, so I don’t expect everything to be answered.
David,
I was just going through my e-mail and realized that I never responded to
your comment on my blog regarding barefoot running research. To answer some
of your questions, yes, going forward I hope to use “naive” subjects who
have not run barefoot previously to see what happens when they don’t know
what to expect. Tracking over time is trickier since you’d need someone to
commit to running barefoot or in something like Vibrams. Given that some
people do get injured doing this, I’d be hesitant to put myself in a
position to ask someone to do it for a length of time given the potential
for liability. It would be nice to do, but it would more likely have to be
someone who approachs me with the idea. Third, regarding injuries with
forefoot striking, I’m still unsure, though any major change in gait carries
with it a risk of injury until the body can adapt to new forces it is placed
under. I’ve read some of Joe Friel’s thoughts, and tend to agree with him
on many things.
Thanks for taking the time to post a comment!
Pete
I think the most important piece of data here (being your sample is one person) is which shoe/stride felt the most comfortable to YOU?
That’s exactly the point – when you wear a shoe with a cushioned heel,
it allows you to heel strike comfortably. When you run barefoot or in
Vibrams, you cannot heel strike comfortably, and a mid foot or
forefoot strike is much more comfortable. Lieberman has shown that
forefoot striking is likely the default state for humans, so why do we
wear shoes that force/allow us to alter that state? There’s a lot of
research still to be done on these questions, which is why I’m so
fascinated by the topic.
Pete
Does foot strike differ between treadmill and road running, even if the pace is the same?
I can’t speak for others, but mine doesn’t change from treadmill to road or to rough trail. Leg angle might change a bit, but foot landing is almost always the same (for me): I almost always tend to land on the outside edge of mid-foot, with a rolling motion towards the big toe. In appearance, it probably looks much closer to a flat-footed landing, but it really isn’t.
You need to consider the kinetic chain of the body column (head to toe) when looking at the effect of a treadmill on your running biomechanics.
There are measurable changes in joint angles, body position and impact force with different heel heights on a shoe.
Treadmills remove some inertial and resistance forces compared with running on stationary ground.
The primary kinematic change for a runner on a treadmill is to stand more upright. This is required because of the absence of wind resistance etc.
Bio-mechanically a treadmill runner is not activating their propulsive musculature to move the body mass forward, only to move their limbs.
Net result is generally (not always) over striding and heel striking more than on level ground. If you increase the treadmill’s gradient you introduce a more acute dorsi flexion angle at the ankle, but not forward lean. If you lean forward, you tend to run faster and that sends you forward on the belt.
There are excellent (medical) treadmills available from companies like Woodway that compensate for the lack of real world forces, but these cost around $20,000. Alternatively you can use a waist belt and bungee tethered to a solid object behind you. This is difficult to calibrate, but is inexpensive and effective.
It is worth noting that you need to frame head to toe when filming to capture all changes in gait. The legs are only part of the kinematic chain, and head, torso and arm position are also important. Ideally one shoots from the front, back, side and overhead.
For many people adapting (or more accurately re-learning) to run with their natural gait (e.g. barefoot style), their muscle firing patterns take time to overcome. This is basically breaking habit, and why people often still heel strike as they retrain their physiology. Think of any habit (golf swing, shooting hoops, snow skiing, etc.) and how long it takes to re-train to avoid a bad habit. Running is the same, only you probably have millions of steps not thousands of (ball) shots establishing the habit.
Ian Adamson
MS Sports Medicine
BS Bio-mechanical Engineering
Dir. Research & Education
Newton Running
Thanks for the response Ian. You make an excellent point about
allowing time for adaptation to occur. People all too often want
change to happen instantly, but it takes time. Too many people push
too hard and wind up getting hurt. It needs to be thought of as a long
term processs of relearning – it doesn’t happen overnight.
Incidentally, this is a big flaw in many academic studies that compare
metabolic efficiency between gaits. You can’t just ask a heel striker
to run forefoot on the spot and make a comparison – I wouldn’t expect
anything other than that they would be less efficient.
Pete
On Wednesday, January 26, 2011, Disqus