I have a fairly long history of working with high-speed (i.e., slow-motion) video. As a graduate student, I did my dissertation research in a lab that specialized in locomotor and feeding biomechanics of animals, and to do these types of studies, the ability to film at very high frame rates (200 frames/second and up) was a must. However, the NAC cameras we used in those days priced easily in the 5-digit range (possibly even 6-digits), making the technology far too expensive for the average person wanting to play around with slow-motion video. Technology has come a long way in recent years, and cameras that can record at such high-frame rates have finally dropped into a price range where they are affordable to people not working in grant-funded academic research labs.

Let me start by describing what exactly I mean when I refer to high-speed video. Most home digital video cameras shoot at a frame rate of ~30 frames/second (fps), which means that they essentially are taking 30 still photographs per second, then playing them back in in sequence such that they appear to form a seamless video. It turns out that 30 fps is sufficient enough to prevent us from being able to detect the gaps between images with the naked eye when they are played back. However, if you were to slow down video taken with a regular camera (e.g., in a program like Virtualdub), you would notice a distinct “jumpiness” due to the gaps between images – the video would be far from smooth, and this is why you need a more capable camera when you wish to film fast action and play it back in slow motion.

My series of slow-motion running videos have sparked a lot of commentary on this blog, as well as a decent number of direct e-mails to me from readers (for an example, see this post looking at the effects of shoe type on footstrike). Most of these clips have been shot with a Casio Exilim EX-F1 digital camera. The EX-F1 is an amazing piece of electronics, and in terms of high-speed video capability, it does for about $1000 what historically could be done only by far more expensive cameras. The Casio Exilim EX-F1 does a lot more than just high-speed video (e.g., HD video at 1080i, 60 high-res stills in one second in high-speed burst mode, plus a lot more – you can read the full overview on Casio’s product page for the EX-F1), but that’s it’s primary use for me, it does it very well, and that’s what I’ll focus on here.

The Casio Exilim EX-F1 can shoot high-speed video at 300, 600, or 1200 frames/second. As you increase filming speed, however, you get a loss of resolution as follow: 512 x 384 (300 fps), 432 x 192 (600 fps), 336 x 96 (1200 fps). That being said, the 512 x 384 resolution is more than suitable for my purposes, both personal and academic. The EX-F1 also has a variable 30-300 fps mode that allows you to toggle the movie recording speed between 30 fps and 300 fps on the fly. This would allow you to switch between real-time and slow-motion as the need arises (think capturing a baseball player sliding into a base). Below is a sample slow-motion video of Ryan Hall running in the 2010 Boston Marathon recorded by two of my students at 300 fps on the EX-F1:

Ryan Hall – Boston Marathon 2010 from Runblogger on Vimeo.
Video clip of Ryan Hall running near mile 17 in the 2010 Boston Marathon. Filmed at 300 fps with a Casio Exilim EX-F1 digital camera. Video courtesy of https://runblogger.com.

You need a lot of light to get image clarity/quality with high-speed video cameras, and the EX-F1 is no exception. While shooting outside usually gives good results, I have to use halogen spotlights on subjects in my lab to get crisp images with this camera. In fact, the 1200 fps setting requires extremely well-lit conditions (and I mean very, very bright) to get a usable image. Below is an an indoor video of me running on a treadmill in my lab shot at 300 fps with the EX-F1 (be aware that there is some loss of quality when uploading to Vimeo):

Brooks Launch from Runblogger on Vimeo.
Slow motion video of treadmill running in Brooks Launch – mild heel strike here. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.

So, my experience so far with the Casio Exilim EX-F1 has been extremely positive, and for a small-college researcher like myself, it’s an affordable option that allows me to still do many of the things I did in graduate school at a large research institution. I’d say that If you have money to burn, or are in an academic or competitive athletic environment (e.g., biomechanics research), the Casio Exilim EX-F1 is a great choice for affordable high-speed video. As time allows, I’ll try to add some additional videos at 600 and 1200 fps for you to view, as well as one in HD.

Ryan Hall – Boston Marathon 2010 from Pete Larson on Vimeo.
Video clip of Ryan Hall running near mile 17 in the 2010 Boston Marathon. Courtesy of https://runblogger.com.

And here’s the same video slowed down even more:

Ryan Hall Super Slow Motion – 2010 Boston Marathon from Runblogger on Vimeo.

Video clip of Ryan Hall running near mile 17 in the 2010 Boston Marathon. This video was shot at 300 frames/second with a Casio Exilim EX-F1 digital camera, and then processed to play at a rate of 5 frames/second in Virtualdub. Courtesy of https://runblogger.com.

If you’re a fan of Ryan Hall, check out the great work he’s currently doing with the Hall Steps Foundation, whose goal is to fight worldwide poverty: http://thestepsfoundation.org/.

So here are my videos – they go in the following order – 1. stability shoe, 2. neutral racing shoe, 3. Vibram Fivefingers KSO, 4. barefoot:

Running in Asics Kayanos – Posterior View from Pete Larson on Vimeo.
Slow motion video of me running in Asics Kayanos, which are a high-end support/stability shoe. Looks like my feet are pronating quite a bit after footstrike despite the supposed stability features of the shoe (particularly pronounced on the left foot). Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of runblogger.com/.

Running in Nike Lunaracers – Posterior View from Pete Larson on Vimeo.
Slow motion video of me running in Nike Lunaracers, which are a neutral, lightweight racing shoe. Looks like my feet are pronating quite a bit after footstrike. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.

Running in Vibram Fivefingers – Posterior View from Pete Larson on Vimeo.
Slow motion video of me running in Vibram Fivefingers, which are a barefoot-like, lightweight, non-supportive shoe. Looks like my feet are pronating quite a bit after footstrike – more pronounced on left side. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.

Running Barefoot – Posterior View from Pete Larson on Vimeo.
Slow motion video of me running barefoot on a treadmill. Looks like my feet are pronating quite a bit after footstrike. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.

My interpretation of these videos is that I would probably be classified as an overpronator by anyone who does gait analysis on a regular basis (and so I was by the salesman at the local running store when I first started running regularly back in 2007). I also show striking asymmetry, with much more pronounced pronation on the left foot (I already knew this, and it’s confirmed by the wear patterns on my shoes). What’s surprising to me is that I don’t really see much of a difference among the videos in how much my feet pronate after hitting the ground – they roll inward in all of the them. Even in the stability shoes (Asics Kayanos), my feet still pronate to what seems like a similar degree as in the other shoes (or barefoot), they just do it inside the shoe. This makes me wonder what benefit stability shoes are actually providing – I’ll have to hit the scientific literature and check out what data we have on the topic.

I’ll finish by pointing out that despite my pronation issues, I’ve been wearing lightweight, neutral shoes and the Vibram Fivefingers almost exclusively since last May with no injuries, pains, or any other issues. I tend to think of pronation as a natural process, and am curious to get into the scientific literature a bit more and try to find data that actually links pronation to increased chance of injury. Unfortunately, a lot of that data is likely proprietary and held by shoe manufacturers, which is unfortunate since as an academic scientist I’m trained to think that if data isn’t openly published through peer-review, then it’s not of any value. I’ll be back to post more when I’m done with a bit of research.

Me: Available data indicate that most people are heel-strikers. Is it your belief that the presence of extensive heel cushion (i.e., a heel wedge/lift) essentially forces a heel strike in most people?

Ian’s response to this question was as follows:

“More accurately the data shows people running in traditional shoes are forced to engage the ground with heel of the shoe. Remove the heel and you remove the heel strike. Professor Daniel E. Lieberman from the Department of Human Evolutionary Biology at Harvard University has been studying running gait in humans and concluded that no one heel strikes naturally. He looked at (among other groups), people who have never worn shoes. Dr. Lieberman’s study should be appear shortly in a major scientific publication.“

Needless to say, I’m looking forward to seeing Dr. Lieberman’s forthcoming paper (I’ve previously written an extensive post about some of Lieberman’s earlier work), but in the interim I thought I’d contribute a little personal insight into Ian’s answer to this question. My interest in footstrike stems from a study I am conducting with my students looking at footstrike patterns in runners recorded during the recent Manchester City Marathon in Manchester, NH.  Regardless of what we find, we will be unable to tease apart the question of whether the footstrikes we observed are the “natural” gait of each runner or patterns that are induced by the shoes that they have on their feet.  To do this would require that we film each runner in shoes, and then barefoot under identical conditions.  While this is doable in a controlled laboratory situation, it is impossible to do this in a “real-world” racing situation.

Given this difficulty, I, along with one of my students, have decided to address this question in the simplest way possible – by looking at ourselves.  Although the sample size is very small, simple studies like this are great for hypothesis development, and hopefully this will serve as a springboard for more complex studies with larger samples in the future.

A quick word about Ryan, who is the student that I’m working with.  Like me, Ryan was an early reader of the book “Born to Run” by Christopher McDougall. Also like me, “Born to Run” heavily influenced Ryan’s thinking about footwear and its relation to running. Ryan is a Junior runner on the cross-country team at our college, and since early this year he has been running almost exclusively in Vibram Fivefingers, homemade huarache sandals, or barefoot. He has accumulated approximately 1500 miles in Vibrams (and if I’m not mistaken, all of those miles have been on only a single pair), and he has been known to run barefoot in temperatures down into the 30’s.  He’s worn his Vibrams so much that the cinching strap has worn off, and in its place he used a long strip of leather. Needless to say, although I have also put in some miles in Vibrams, Ryan is a far more dedicated minimalist runner than I.  Currently, he is a captain of our track club, and is averaging running about 50 miles per week.

Filming conditions were similar to those in my previous post on treadmill running in various shoe types (in fact, videos of me below were pulled from that post).  For each of us, videos show our footstrike in stability shoes (Brooks Adrenaline for me, Asics 2130’s for Ryan), Vibram Fivefingers KSO’s, and barefoot. All were recorded while running steadily at 7mph.

First me:

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/.

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/.

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/.

In me, what you can see is a progression from a clear heel-strike in the stability shoes with a big heel cushion to a more midfoot strike in Vibrams and in the unshod (barefoot) condition.

And now for Ryan:

Ryan – Asics 2130 from Pete Larson on Vimeo.
Slow motion video of treadmill running in Asics 2130’s – clear heel strike. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.

Ryan – Vibram Fivefingers KSO on Treadmill from Pete Larson on Vimeo.
Slow motion video of treadmill running in Vibram Fivefingers KSO’s – clear forefoot strike. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.

Ryan – Barefoot Running on Treadmill from Pete Larson on Vimeo.
Slow motion video of barefoot treadmill running – clearly a forefoot strike. Video shot at 300 frames-per-second with a Casio Exilim EX-F1 camera. Courtesy of https://runblogger.com/.

Ryan’s shift in footstrike between the Asics stability shoes and the Vibram/barefoot conditions is truly a thing to behold. He goes from being a harder heel striker than me in the Asics, to being a clear forefoot striker in the Vibram Fivefingers and when barefoot. This is all the more compelling given that he hadn’t run in the Asics for quite some time (he’s pretty much as exclusive a minimalist runner as you’ll find at this point), and simply putting them on resulted in a reversion back to the heel-striking condition. We were both pretty amazed this afternoon when we first watched the videos, and he even reported that his shins were tight after running just over a mile in the Asics. Seems his body may have re-adapted to the unshod condition (he generally doesn’t even wear regular shoes when walking around campus or going to class), and the shod condition now seemed to be putting his legs under greater stress. I’ll re-emphaisize that we are still only a sample of two, but the pattern here is clear enough to me that it warrants additional investigation.

So, for at least me and Ryan, when wearing shoes with a big, cushioned heel we are both heel-strikers, and when that heel is removed, we convert into a midfoot striker (me) and a forefoot striker (Ryan). If humans evolved to run without shoes, then the lack of a heel cushion would seem to be the more natural condition for our bodies, and it makes one wonder why the heel cushion is necessary. I still don’t believe that there are solid data that conclusively show that one type of footstrike is necessarily better than another from a performance or injury-prevention standpoint, but I firmly believe that our footwear choices heavily influence the type of footstrike that we adopt. I see it in myself, and I see it in my student. I also see it in children – my son is a midfoot striker when barefoot. Now I just need to get him on a treadmill in his mini Asics 2130’s (yes, he does have them!), and hope that they come out with Vibram Fivefingers in childrens sizes!

If you have any questions for either Ryan or I, feel free to leave a comment.

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!