One reason minimalist running shoes, which are barefoot-like shoes that a have very thin sole
or even running barefoot, one reason these running conditions have been producing a data-trend in
the research for doing a better job at encouraging more optimal mechanical arrangements that are good
for impact protection and better landing stability is because there’s simply less mechanical
interference between the foot and the ground that the foot has to wrestle with as compared with
running in shoes that have thick and very soft squishy cushioning. In fact, running in really
thick, soft cushioned running shoes may almost surely cause landings to be harder on the ground
and may cause irregular movement patterns of the foot, like overpronation, which means the back of
the foot shifts into straining, extreme positions during the touchdown and stance phases of running.
Proving true of this is a 2015 study in the journal Footwear Science which is linked down
below the video in the description box, found that the thicker and softer the underfoot
materials of a shoe when running, the more the foot was forced to pronate or shift around,
the greater the maximum vertical loading rate which means the greater the downward force of the
foot with the ground, the higher the force-time integral which means there was more loading that
lasted longer on the foot and leg, and last but not least, the longer the ground-contact
time duration which means the foot spent more time on the ground. All of these metrics are
well-known to increase the risk of injury because higher-than-normal levels of vertical loading
that persists long in duration could result in excessive impact that the muscles can't absorb.
As for increased ground-contact time of the foot, it’s been linked to injury because the
longer the foot spends interacting on the ground when running, the more time there may be for the
foot to shift into extreme, straining positions which is partly why there was excessively forced
pronation of the foot in the runners who ran in thick, soft cushioned running shoes. To account
for why soft, thick underfoot cushioning produced these negative, injurious interactions during
running, the researchers concluded that it wasn’t so much the thicker the underfoot cushioning
that was all that problematic, rather it was the softer the cushioning that resulted in a prolonged
compression duration of the soft cushioning from the foot during the stance phase of running.
In other words, the foot spent an unusual prolonged time pushing through all the soft,
compressible material to reach the ground during the stance phase of running. What’s
worse is the runners were unaware that they were actually striking harder on the ground,
and this is something called “perceptual illusion” which is a term coined by Dr. Steven Robbins
who’s done a lot of pioneering work on barefoot vs shod or shoe running and how some running
shoes can actually be a mechanical interference that may push foot strike and leg swing mechanics
outside a greater distance, outside its natural ranges and may cause you to land
too hard on the ground without even knowing it. His paper on that entitled “ “Athletic Footwear:
unsafe due to perceptual illusions ” explains more on all that and is linked down below
the video in the description box as well. Getting back to the study, running in softer cushioned
running shoes was compared to running in firmer cushioned running shoes which was associated
with less rapid overpronation and more controlled landing stability. These metrics are consistent
with other studies that have investigated the impact and mechanical metrics in barefoot
runners and minimalist runners of which most of these studies have found the same basic conclusion
in that barefoot and minimalist runners consistently showed more controlled pronation,
stronger footstep stability and landed with much less collisional impact and
downward force as compared with runners in thickly cushioned, conventional running shoes
of which these runners consistently produced more all-around force components acting across
the foot and leg which may also result in greater muscle response to counteract excessive pronation
and impact production. In keeping with this, one false assumption is that the thicker and softer
a running shoe, the more impact it will absorb, and the more safe you will run, but in reality,
several studies over the past few decades have found that soft, thick cushioned running shoes
are one of the biggest stressors or risk factors that cause excessive pronation and excessive
impact production that the cushioning of the shoe can’t absorb and the muscles and tendons
of the leg can’t absorb either, and is one of the countless reasons an overwhelming majority
of runners get hurt. That said, if you want to break the flow of high impact and achieve sturdier
landing stability in a sustainable way, it’s best to try minimalist running shoes, or even better,
running barefoot because these running conditions actually improves the neuro-muscular and reflexive
movement coordination through the increases in ground-feel whereas the thicker and softer
the underfoot cushioning when running, the more impact-intensive, the more mechanically reckless,
and therefore the more injury prone you may be. That said, if you prefer to run in shoes with
cushioning, aim for a cushioned shoe that feels more firm, just like how the ground feels when you
run barefoot or in minimalist shoes, the ground feels firm, not pillowy, and it’s that firmess
is what delivers more natural-like stimulus for enhanced neuromuscular and reflexive responses
in landing control and leg swing mechanics that may help reduce harmful impact loads. And, this
could be one of the reasons that the Nike Vapor Fly, or CheaterFly as many call it, hasn’t caused
a lot of injuries as was expected given how ridiculously thickly cushioned these shoes are,
however the underfoot sensation of these shoes is very firm, not pillowly or plush in the least,
and it’s the firmness in feel that could be partly what’s stopping these runners in these
shoes from getting hurt. So essentially, the take home message is thick underfoot cushioning
that is overly soft and very compressible may be counterproductive because the consistent
consequences of higher-than-normal-impact levels and abnormal pronation that these
shoes seem to bring about as compared with firmer cushioned running shoes, minimalist running shoes,
or running barefoot ~ underfoot substrates that have a firmess feel at the underfoot, are more
consistently on record for producing results that seem to make running more safe. I hope you’ve
enjoyed this video. If you did, feel free to hit the thumbs up and the subscribe button if you
haven’t already where you will stay more informed on forefoot running vs heel strike running
as well as the benefits of barefoot and minimalist running. Thank you so
much for listening and watching. Have fun out there on the roads and trials. Bye for now.