This assumption goes against the personal experience of multiple runners who have made the switch to maximalist shoes and report drastic reduction in injuries.

completely agree. Even when the cushion begins to wane, I feel a lot more pain

Wtf they used a stability shoe with a 4mm drop, compared to a 12mm drop neutral shoe? ...I stopped reading.

This study mirrors results from a 1960 military study on over 40,000 boot camp cadets. Besides assessing incident of injury, they also did force impact studies, and found that with more cushioning came higher impact loads on the legs.
In my own N=1 “study”, at 63 years old this year I finally decided why not at least try barefoot running. For this I did not actually run barefoot, I used a “shoe” from a company named Skinners (http://www.skinners.cc). These shoes are mistaken as socks by most people, as is it essentially what they are, except with a very thin protective material on the bottom- glass, etc cannot cut through. My first run I was very skeptical, and cautious, starting very slowly. It felt much better than expected, and I gradually increased my pace, and within about 1/4 mile was running my normal training pace. It felt great! I limited the run to 1.5 miles, and continued to do this for a full week. Over this week, my feet got noticeably stronger, and I enjoyed running in Skinners much more than my regular mix of conventional neutral shoes.
I have now been doing this for almost 2 months, am up to 45 miles a week in my build up period, and my feet, legs, knees, and back have never felt better.
Before starting this experiment I never thought I could run without some form of cushioning. I am glad I tried, for me, running without cushion is definitely better.
I doubt this would work out for everyone, but I do think everyone should give it a try and find out :-)

This personal experience goes against the personal experience of multiple runners who have made the switch to maximalist shoes and report drastic reduction in injuries.

---

***

Why would either drop or stability alter ground contact forces?

IDK if these results are relevant to current shoes, clearly it's interesting given that Hoka seemed at that time to lay claim to being a max cushioning shoe. IIRC these shoes were out around 2012 or 2013. if I had to bet I'd bet on 2013.

The Conquest was a shitty shoe (my opinion ymmv) and isn't being made any more. The Ghost 6 is vastly different than the Ghost 11 that is the current edition. The ghost drop has grown 1.5mm to 12mm, maybe that would have some impact (no pun intended) on results if you redid the study.

IDK if we can extrapolate these results to today's foams that Hoka and Brooks use. They are vastly different foams today.

Would the results change with the Ghost vs the Pegasus? Or Asics Cumulus and/or Nimbus from that era or that era vs today's era? Are current shoes better? Worse? Lots of questions in my mind. I do love me some running shoes though and thought this was interesting research for sure.

---

Brian Stover USAT LII
Accelerate3 Coaching
Insta

pretty sure the Ghost 6 was <12mm drop.

10 I think although for some reason I think 10.5mm


ETA: There isn't a ton, if any research to support one drop over the other as being a benefit.

---

Brian Stover USAT LII
Accelerate3 Coaching
Insta

Both drop and stability add unwanted variables to the study, which is just trying to establish a relationship between force and the incidence of injury. Especially considering that those are both, in themselves, things people alter to try and avoid injury makes it seem like a bad study setup.

This choice of shoe is interesting, because I was always under the assumption that a big part of the “minimalist” movement was having a shoe with little to no drop.

Causative or coincidental? (Same can be said for me, except I have tried BOTH, and had a strong bias to cushioned). Try yourself, over a reasonable period of time, and then comment :-)

Pretty established in the running medicine/rehab world that all the latest shoe company "technology" and "innovation" isn't going to reduce running related injuries and most of their claims aren't true. Runners run, shoes are simply tools. Runners will get injured in all types of shoes.

---

CB
Physical Therapist/Endurance Coach
http://www.cadencept.net

Did you mean 'isn't going to reduce running related injuries' or 'isn't going to eliminate running related injuries'?

Logically this makes complete sense. You can have the spring in the body that stores and releases or you can just dissipate it all in a soft shoe with a stiff leg (vs gradually eccentrically contract and release on push off). One way of looking at this is skip rope for 10 minutes in hard shoes on a hard floor or soft shoes on the same floor and report back on which shoes you perform better in. I think if we do this experiment, we'll have zero benefit skipping rope in soft shoes since the proprioception with the ground is lost (thus the stiff leg).

In practice there is a tradeoff between running on hard ground with zero padding and running in highly cushioned shoes and losing proprioception. Its actually interesting watching people running from the swim to the bike tranition in bare feet vs their final 1km during a tri. Most people seem to have better form out of the swim and have more spring in their legs vs at the end of the race in shoes. But, of course there is more fatigue. But watching Frodo or Gomez or Brownlee running after the swim or end of run and its exactly the same form.

This claim ('runners are continuing to get injured as steady rates') is brought up a lot, but I haven't been able to find a source that controls for shifting demographics (older population, fatter population, etc). The paper makes a similar claim, but only cites a 3 decade old review. Any works regarding recent trends?

I think that's a really good point? What is even the metric for injury rate in a population? Injuries per mile, per year?

Can someone put the 41N impact difference in perspective for me? Not sure why they don't mention the total impacts rather than the differences. The way I figure it it's a pretty small proportion of the total impact force for the 75kg +/- 6kg runners they used isn't it? Isn't 3 x force as a peak on landing a typical approximation? So am I right in thinking it's 41N difference in a overall figure of about 2250N? So 2% ish? Or did I get that completely wrong?

 
Extract 1 : "Each subject had sports experience (team sports, running), several years of training and ran with a heel striking pattern."

So... running with heel striking pattern, mostly used to higher drop shoes probably, don't need forefoot cushion, then expected to adapt quickly to lower drop shoes with high mid-foot cushion they don't need... smell like bullshit...


Extract 2 : "at the slow speed in MAX shoes, runners applied 38 N less force on the ground than in CON shoes, whereas at the fast speed, the force was 41 N greater in MAX shoes (Fig. 3e)."

But... the title concentrate on "increased effort with Max"... smell like bullshit again


So, let's take heel striker, lets give them a shoe adapted to their gait (Ghost), and another not at all (Conquest), eliminate the speed range you want, get a clunky conclusion on there other speed range, and affirm this increased force (which might be linked to the inadaptation of the shoe to runner gait, but who care) will deliver more injuries... any proof ? No, just say it.


OK... do this study with cohort of half heel striker, half mid foot striker, with 2 reasonably adapted shoes, and really test correlation between forces and injuries, and we can talk.

Sample size of 12, eh?

If this wasn't Nature I'd completely dismiss it but man, *Nature*. Even though its Scientific Reports, hard to ignore.

I seriously can't believe this paper made Nature. I'm actually kinda in shock about it. The paper seems perfectly fine, but has enough small sample size, small choice of shoe type limiters that it can be justifiably judged as a small-case study, not an overarching paradigm-producing shift in the field. And the conclusion isn't some shockingly unexpected finding - this kind of research result has been suggested for years (decades) now.

This is honestly the type of research I thought may have made it to a high school science fair, performed by an aspiring high school student with an interest in running, who goes and does a summer research project with a legit human physiology lab. This doesn't mean I'm discounting the research - it seems solidly performed, yet is seriously limited in scope, and is so far from what I'd expect from a typical Nature paper that I'm pretty aghast at that being in there.

FWIW: https://www.nature.com/...es/referees#criteria


But yeah, even by that minimized bar I'm amazed that its worth publishing.

Ok - I see that I missed that this is in Nature "SCIENTIFIC REPORTS", which apparently is a VERY different standard than for the original Nature paper. (I"ve been out of original science long enough that this offshoot wasn't around when I was doing it!)

I googled 'impact factor' for each paper:
Nature (the original): 41.8 (higher is better)
Nature Scientific Reports: 4.6

So we shouldn't judge this as a paper published in the prestigious giant Nature, but as a much smaller scale paper on the scale with most small-journal findings. By that criteria, I'm less surprised, but I don't like how confusing these journals (have intentionally made it) by sharing the name so closely.

My 2 cents:

These results should not be surprising and have been reported in other studies changing footwear or removing it for that matter don't produce anticipated results. The main issue is they are not allowing for habituation/adaptation to the change in attenuation mechanics...

We are creatures of habit and often when "healthy" runners are first placed in maximalist shoes (or shoes that attenuate more force) we will seek mechanics based on sensory adaptation i.e. we drive into cushion shoe (increased stiffness) to match legacy sensory feedback.

This often changes when placing symptomatic runners e.g. knee pain/back pain into these shoes as they have guarded mechanics and the additional attenuation has an immediate effect, or overtime a healthy runner will adapt to new mechanics from footwear.

Yeah,

1) let's give a "heel strikers only" cohort a clunky low drop high forefoot cushion shoe not adapted to their stride / gait
2) let's ignore results for the 2 speed range are opposite, considering only one of them
3) let's affirm that more force give more injury... despite this is not proven, can come from lower angles, or...

May be the test protocol is OK, for evaluating the forces.

But the cohort is not : heel strikers only
The shoes are not (especially given heel strikers only) : why not NB1400V6 vs Vaporfly ? Same drop, different cushion.
They kind of ignore half of the results (lower speed)
They affirm a correlation not proven

Totally biased claimed results, from biased cohort, shoes, speed selection, and final claims...

Bullshit ^4

This study is made with a cohort of peoples 100% heel strikers (extract presented in post 17).

So it would make sense if the shoes used were, for example :
- a 10mm drop racing flat : NB 1400, or other similar
versus
- a 10mm drop cushion shoe : Vaporfly, or Glycerin, or...

Then, the result would be significant, in term of force.

Then correlation between force and injury would still to be established.

For example, in the Vaporfly study (the serious one, not the NYT bullshit study, with margin error much higher than result delta) :
https://link.springer.com/...07/s40279-017-0811-2

comparing exactly that (racing flat vs high cushion)
the increased leg stiffness with cushioned shoe is not attributed to higher forces in muscles, tendon, ... but to lesser knee angle.

So, increased leg stiffness with less muscular effort... with 2 consequences :
1) more efficient : 4% versus racing flat
2) less fatigue and injury

If you run a marathon with Vaporfly instead of flat, legs feel better at the end, and injury rate is lower... if you are not a pronator, because if you are VF will destroy you. Not a matter of cushion, then, matter of stability. Life is complex.

This study show nothing. Biased cohort, biased shoes, biased speed selection, clickbait like title announcing things not proved.

Well... it show that bullshit is easy.