And, by the way, I love your slow motion videos of running.  These have been a very helpful resource for me and for the podiatry students/residents that I teach on the biomechanics of running.  Excellent!!

Cheers,

Kevin

It sounds like a decent shoe (though the heel seems a little high for a “minimal” offering). I’d definitely be open to giving them an honest shot, but I’m not sure how to get you my info without putting it out there for everyone (not that I don’t trust Pete or the readers of his awesome blog).
Thanks for bringing this topic to the forefront of your upcoming meetings. I hope that Asics will truly consider bringing a minimal shoe lineup to shoe store shelves soon. Maybe the success of other minimalist shoes such as Vibram’s Fivefingers line, Saucony’s Kinvaras, and the Merrell Barefoot shoes (just to name a few) will encourage the executives at Asics to green light more minimalist shoe development.
I think we’ve all agreed that there is definitely room for improvement in the shoe industry starting with education and honest/open discussion (which we appear to be doing here).
It would be great to have lots of variety offered by EVERY manufacturer, but I understand that there is a substantial cost and risk involved in such a venture. In my opinion though it is well worth the cost & effort for every shoe company to have innovative shoes that span the most “minimal” to the utter “maximal” shoe choices.
After all, if everyone with their differing biomechanics and personal preferences can find their own “perfect” shoe offered by their favorite manufacturer (we all have favorites), then the shoe industry will make their money while helping runners stay healthy and happy. Then maybe we can decrease the injury rate of runners, get more and more people running, reverse the obesity epidemic, and achieve world peace! I went a little too far there, but you guys know what I mean.

Amazingly well referenced and thoughful response. Here is my reply posted to Zero Drop.

Running colleagues,This is good thoughful discussion and glad we are having it. Lets keep it educational, scientifically skeptical (this is debate), and provide the BEST evidence we have when little exists.  And as CR and JD suggest…design the study.
Here is a database of resources and articles on the topic from our website
http://trtreads.org/Articles_O…
Jason Robillard also has dug into the literature.
http://www.runnersworld.com/co…
For an experienced N or 1 take my story.  Horrible injuries like most runners including multiple surguries in a competitive running career. 
Now do almost all my running barefeet on pavement and grass surfaces.  Use shoes for races and longer and quicker road work.  i truly believe like Ken Bob does that it is almost impossible to hurt yourself running barefeet on hard surface if you use your brain.  you self regulate in a way you cannot when in shoes. you land soft and if something shows even the slightest discomfort you stop.  i’ve never seen a kid running around and playing voluntarily in summer in bare feet have an overuse injury.  We are teaching the STYLE of bare foot running.  I presented this video and some teaching techniques at the AMAA Sports Med Symposium at Boston Marathon this year.  Dan Lieberman and Irene Davis had tons of science.  Ran 2:37:00 at age 44 in shoes.  Sweet bare foot one hour recovery on day after…amazing how i was post race sore before the barefoot run and afterwards this hit the reset button and felt great.
http://youtu.be/kpnhKcvbsMM
out for a morning bare foot run now after some coffee.
Respectfully,
Mark Cucuzzella MD

In regards to the 10 degrees dorsiflexion “requirement” noted, yes, that is what Novacheck notes in his review article on running biomechanics, (likely describing heelstrikers). In the running assessments I perform in our clinic, certainly this is all over the map, sometimes closer to neutral as you noted in your summary. Mid and late stance dorsiflexion and triplanar motion is really more interesting, as it doesn’t always reflect the same amount of limited passive dorsiflexion that was measured passively – yes, I know that some of this is due to triplanar motion at the subtalar articulations, but not all of that is explaining the increases in dorsiflexion during loading. This is true of those runners whether barefoot or shod during video analysis.

I really take with a grain of salt the measurements of heel-toe drop – given the varying densities of midsole components and the distribution of forces during loading throughout stance, a runner may well be compressing portions of their midsole to a greater depth than others – the breakdown patterns evident in a worn training shoe evidence this. Add in outsole wear over the life of a shoe, and any accurate representation of this after the first 100 or sole miles is probably wishful thinking. I do think that as a generalization, that a runner functions better with less rather than more heel lift  and with less rather than more midsole. Certainly, the information from looking at balance dysfunctions in older adults suggest that the risk for falls is higher in those with thick, cushioned midsole shoes (without taking into consideration the issues we see with neuropathy  in some of those individuals).

You did well to note the problems of assessing foot strength via arch height vs. MR – we really don’t have very accurate ways to assess foot “strength” nor do we measure rearfoot motion well (with the rather primitive tool of trying to bisect the calcaneus as a reference point). These measures of motion become more complicated when one is shod, even with slow motion video analysis – its very difficult to assess forefoot/rearfoot motion that occurs inside of a shoe when running. Its more laughable that a clerk in a running shoe store believes that they have a handle on assessing foot mechanics with a few-second observation of running gait (whether filmed or eyeballed) – there’s so much that happens during a running stance that isn’t apparent until one has the ability to control the variables and get a proper slow motion video, and that’s not also taking into consideration the combined mechanics at the hip/pelvis, trunk and knee. In my situation of assessing runners, performing video and assessing the other issues (strength/flexibility/foot mechanics/posture and trunk stability), the video assessment that takes probably 10-15 minutes to film (treadmill and road, training and race pace, barefoot and shod) takes anywhere from 2-4 hours to break down and summarize in a way that’s meaningful and understandable for the runner involved – thank goodness for Dartfish.

Anyway, thanks again – keep up the good work!

Kent Kurfman, PT,DPT,OCS,MTC

Kevin,

To answer your question, yes, some stores do refuse to sell certain shoes to
their customers. I have no idea how frequently it happens, but it does
happen. In fact, was just having a conversation with a PT who does gait
analysis. He did a full eval of a patient and then sent them to a store with
a tailored list of shoes to try. Store refused to sell the patient any of
the shoes, presumably because they did not sync with their fitting policy.
Maybe this is rare, maybe it’s not, but when stores will even ignore advice
from expert medical professionals because they are so tied to a certain
fitting protocol, there is a problem. Like it or not, fitting based on
degree of pronation and the belief that prnoation is evil is still the norm
rather than the exception. I was told that I needed stability shoes solely
on the basis of a clerk watching me run across a store in my socks – I
suppose they must have had a bionic eyeball. Even more sadly, once told by a
store that they need a certain type of shoe, many runners are terrified to
ever try somthing else, even when what they are using isn’t working. It took
a long time before I worked up the guts to try a racing flat – I was told I
needed stability, and that’s what I always bought. At that time, I didn’t
know any of the literature – I was ignorant, and believed everything the
college kid at the store told me. In addition to increased variety of shoe
choice, research on best practices for shoe fitting, and better education of
store owners are very much needed.

As for flats, I don’t dispute that specialty running stores carry them –
they do. My point was that the beginnning or recreational runner often goes
to their local sporting goods store or a mall to buy their shoes. They’re
not going to find flats at those places. Some specialty running stores are
very open minded, and do a great job working with their customers. Others
are locked into a rigid fitting protocol and don’t deviate. What’s more,
customers get wowed by having their gait filmed, or when they step on those
fancy pressure mats and get a colorful photo of their foot. Is the average
runner going to argue when they are told by a computer analysis of arch type
that X shoe is perfect for their foot? Most don’t even know about
biomechanics, and just want to be able to run.

My take would be that you are lucky to have a good store in Sacramento,
others may not be so lucky. I hear from them all of the time.

Pete

Dave,

I feel your pain. I am in search of some shoes that are more lower profile and just finding a size 14 is enough of an accomplishment. But add in the fact that I am a EE and it doesn’t help. I will say that New Balance MT101s (one of Pete’s favorite shoes) have a great fit and a wider than normal toe box. Oh I have them in size 14 also. They are more geared for trail running, but I have on occasion used them on the road. you may want to give them a try (they are also pretty cheap).

My speculation is that there is no danger in forefoot striking with heel-lifted shoes. But if you do, why have heel-lifted shoes? Heel-lift is there for you to heelstrike on hard surfaces, and support that. With forefoot or midfoot strike there is no need to pad the heel, so you’re just shuffling along unnecessary dead weight. But I see people do it, and the main reason is that there are not zero drop running shoes or even racing flats to buy, you need special interest and travel to the major cities to get a minimalist running shoe.

Indeed there will be a transitional injury risk when moving to zero drop, since if forefoot striking in heel-lifted shoes plantar flex will be exaggerated, and as always with heel-lift your achilles tendon and calf will not be ready for high volumes of zero drop right away.

Great article again.  Very well thought and researched.  I just wanted to comment on the changes that might occur in the rate of loading with forefoot and barefoot running. I think I have a different take on the research.  You cite the research suggesting that it is the rate of loading that is the important variable that is linked with injury.  From my take on the literature (which may be wrong) both Lieberman and Squadrone found no difference in the RATE of loading when running barefoot with a forefoot strike and when running in shoes with a heel strike.  The only difference that occurs is when you run barefoot and continue to heel strike. It is in this subgroup of people who have a higher rate of loading.  Running in shoes while heel striking appears to attentuate this high rate of loading similar to running barefoot with a heel strike.  The impact transient is still there with the shoes but the rate is comparable with a forefoot barefoot strike. This is well illustrated in the Lieberman paper.  I wrote a quick article here about this exact topic (http://thebodymechanic.ca/2011…  ).

As for the Williams and McClay (2000) study that you cite that suggests that a converted forefoot strike reduces impact loading when compared with a rearfoot strike the authors of this paper never compared these two groups.  They only did a stats analysis on forefoot strikers and converted forefoot strikers.  They just had old data and graphs from rearfoot strikers that they put in the paper for visual comparison. I can send the paper if you like.

I hope I am not coming off as an ass here. I’m just being a little picky.  This by no means takes away from your post – I just wanted to comment on the rate of loading but still support everything else you wrote.

Thanks,

Greg
http://www.thebodymechanic.ca
 

Simon,

Let’s be fair here: “…I think that we’ve now pretty much established that
it’s good to have the heel raised in shoes. About 12mm is a good thing
biomechanically, because you’re in a more efficient position.” Your words
from an interview here:
http://www.sneakerfreaker.com/… .
Do we have published, peer reviewed research showing that a 12mm heel lift
is more efficient than alternatives?

Granted, you go on to correctly state that it hasn’t been settled, but
forgive people for being confused:

*You mentioned before about a 12mm heel height being ideal? Why is that the
standard?
*Well, that’s a very interesting question because it hasn’t been settled on
at all. With ASICS we’ve always worked on a 10mm gradient. That’s the
difference between the height of the forefoot and the height of the rear
foot, so if you’ve got a cushion type shoe it might be 24mm and 14mm off the
ground. A racing flat might be slimmer at 10mm and 20mm. We’ve done a lot of
research on this and we understand that it actually puts your foot in a
mechanically better position, makes it more stable, takes a load off the
Achilles tendon… so there’s a lot of positives. There’s a lot of myths and
all that sort of crap and the problem is that every time you add a little
raise, people are going to say ‘oh but you’re removing the foot from the
ground therefore you’re going to make it more unstable and you’re more
likely to sprain an ankle’, which is complete nonsense. That’s
scientifically unsustainable. There’s no evidence to say that happens at
all.*

I’d love to see the research you mention, and it frustrates me that research
like this does not get published in peer reviewed journals.

And as for the 10mm gradient, the numbers published on the Running Warehouse
page show many popular Asics shoes to be 12mm differential:

Kinsei – 38mm, 26mm
Nimbus – 34mm, 22mm
Cumulus – 34mm, 22mm
Kayano – 32mm, 20mm

*Some are less – Speedstar, Hyperspeed, Piranha, etc.

I also happen to have two pairs of older 2100 series that my wife used to
wear (2120 and 2130), and measuring with C-calipers yields around 32mm, 18mm
(with insoles in).

Are these numbers incorrect?

For someone who wears shoes with differentials like these, going to a
flatter shoe is a big change, and does feel strange and carries risks for
sure. But as someone who has been wearing flatter running shoes for 2 years,
and who now wears mostly zero drop shoes to work (Vivobarefoot Aquas), I can
tell you that putting on my old pair of Saucony Guides makes me feel like
I’m standing on a steep downhill grade. My feet are now really good at
sensing small differences in heel height, because I have re-adapted them to
know what it’s like to be flat most of the time. I did this initially simply
out of curiosity to see what would happen, and I do still run in higher drop
shoes from time to time (rarely ever anything more than 9mm or so
differential). I’m an experiment of one, but I can attest that small
differences in midsole construction are noticeable.

Pete
*
*

Greg,

Yes, I’m aware of the distinctions you mention, which is why I didn’t
include Lieberman or Squadrone when discussing loading rate, just impact
peak. My point was that there is conflicting data out there, which I have
openly discussed in previous posts. I do have the Williams paper as well,
and they used a comparison with the rearfoot strike group to generate their
hypotheses. It was not a part of the paper per se, but the differences were
discussed and were a basis for the study design.

The data on loading rate and injury are muddy to be sure, and there are
papers pointing both ways. My point again is that it is not so cut and dry
as some make it seem.

Pete

Kevin,

Thanks for your thoughtful response, I agree with most of what you say here.
One point I would make is that I view racing flats as one subcategory of
what many refer to now as minimalist shoes. Yes, racing flats have been
around for a long time, but for most of that time the average runner would
never see them in a typical shoe store. For example, in April of this year I
went to my local Dick’s Sporting Goods store and counted 90+ pairs of
running shoes on the wall (men’s and women’s). Not a single pair of racing
flats, not even a cross country shoe. Every single pair was what we might
refer to as a PECH shoe to use RIchards et al., 1998 terminiology. So,
though racing flats have been around the average runner would rarely if ever
have been exposed to them. Furthermore, most shoe companies and specialty
stores would typicaly only recommend them to what they call “efficient
runners” and only for racing or short distances. Some stores would refuse to
sell them to recreational runners. What we are now seeing is broader use of
shoes similar to racing flats (or even less), with some runners using them
for all of their training with seemingly positive results. We are also
seeing broader usage of barefoot running as a training tool, much as it has
been used by competitive runners for many years. I don’t run barefoot much
at all, but on occasion will do so to cool down after a track workout or on
a treadmill to work on form and strengthening.

In my opinion, racing flats have a limitation in the they are often narrow
and often stiff in the sole. These features might be positive on race day,
but I’m not so sure they are positive in an everyday trainer (maybe they
are, I don’t know). There are some exceptions – the Mizuno Universe comes to
mind, but there are some flats that I could barely even squeeze my foot into
(e.g., the Nike Waffle Racer). What is different now is we are seeing more
shoes with features like a wide toebox, greater flexibility, anatomical
lasts, etc. There are many features that can be varied in a minimalist shoe
beyond just sole thickness and heel height.

I view variability in choice to be what we should all be aiming for, and
like you, I advocate variability in shoe use if you can handle it. As you
have said, different shoes stress the body in different ways, and mixing
things up might help to avoid stressing tissues in the same way on every
run. I’d be quite happy with 3-4 shoes – a cushioned shoe like a Saucony
Kinvara, a racing flat, a barefoot-style shoe like a Vibram for form work
and strengthening workouts, and a trail shoe. You might be interested in
this post I wrote on overuse injuries and rotating shoes as I think we think
very similarly on this topic:
https://runblogger.com/2010…

Again, thanks for chiming in.

Cheers,
Pete