Are Shoes Really To Blame For Running Injuries?
The injury
rate in running is high. No one knows exactly how high, but whatever the
exact number is, it’s a greater number than is seen in virtually any
other form of exercise.
This unfortunate discrepancy was pointed out in a 1998 study
involving triathletes, who, of course, do a lot of swimming, cycling and
running. Researchers from Straffordshire University in England found
that among elite triathletes, 62.1 percent of injuries suffered during a
five-year period were caused by running, 34.5 percent by cycling and
only 3.4 percent by swimming.
Among mid-level triathletes, the numbers were 64.3 percent, 25.0
percent and 10.7 percent. And among recreational triathletes there was a
bit of a shift toward swimming, with a breakdown of 58.7 percent
running injuries, 15.9 percent cycling injuries and 15.4 percent
swimming injuries.
Why is the injury rate so much higher in running than in swimming and
cycling? The traditional explanation is that running causes more
injuries because it is a high-impact activity, whereas swimming and
cycling are non-impact activities. But in Born to Run, journalist
Christopher McDougall popularized a provocative alternative explanation
first proposed by Steven Robbins in the 1980s: that modern running shoes
inflate the injury rate in running by promoting unnatural stride
mechanics that place undue strain on the tissues of the lower
extremities.
For all the evidence adduced in support of this argument, it remains
fundamentally unproven, for one simple reason: only a formal,
prospective study comparing the injury rates in shod and unshod runners
showing a significantly higher injury rate in shod runners could prove
it, and that study has not been done.
For my part, based on the evidence currently available, I do believe
that running shoes became generally overbuilt in the 1980s and remain so
today. Runners are generally more likely to get injured in overbuilt
running shoes than in more minimal shoes, although the limited
historical data on injury rates suggests that the injury rate in running
did not increase between immediately before the era of overbuilt
footwear and today. However, I believe it’s absurd to suggest that
running shoes are entirely to blame—or even mostly to blame—for the high
injury rate in running.
To blame it all on shoes, you must overlook other factors that are
more than plausible contributors to running’s high injury rate, namely
(in shorthand): body weight, sedentariness, hard surfaces, and
popularity. Let’s take a closer look at each of these factors.
Body Weight
A study conducted a few years ago under the auspices of USA Track
& Field garnered a lot of attention because it found that stretching
had no effect on the injury rate in a large population of runners. But
another very interesting finding in that study was almost completely
overlooked. One of the very few factors that did correlate with injury
risk in this study was body weight. Simply put, the heavier a runner
was, the more likely it was that he or she would get hurt.
As everyone knows, we’ve gotten a lot fatter over the past 30
years—runners included. Undoubtedly, this is one contributing factor in
the high rate of injury observed in running today.
Sedentariness
The Tarahumara Indians of Mexico have been idealized as a kind of
prelapsarian perfect people who run the way humans were meant to run,
who run like all humans supposedly used to run and who never get
injured. Chris McDougall believes that the reason for the apparent low
running injury rate among the Tarahumara is their minimalist footwear.
I’m not so sure.
I think a much more important difference between the Tarahumara and
Joe American Marathoner is that the former are highly active outside of
running in diverse ways, whereas Joe American Marathoner runs 45 minutes
a day and sits on his bum or lies prostrate the other 23 hours and 15
minutes.
Being active in diverse ways outside of running actually encourages
healthier running. An active lifestyle outside of running helps prevent
most of the muscular and postural imbalances that are so common in our
society and that contribute to injuries because of reduced joint
stability.
Ultramarathon man Dean Karnazes told me in an interview that a recent
game of tennis left him so sore the next day he could hardly get out of
bed. All of that unaccustomed lateral motion on the court challenged
muscles that Dean never uses in 100 miles a week of running. Those
unassuming little muscles in the ankles, lower legs, groin and hips
could help us run healthier if, like the Tarahumara, we did use them
sufficiently in other activities to render them strong enough to play a
role in stabilizing our joints during running.
Hard Surfaces
Another key difference between the Tarahumara and us is that the
former run on dirt, whereas we run mostly on pavement. I believe the
fact that the Tarahumara run on surfaces soft enough to permit
comfortable running in minimalist footwear is more important than the
fact that they wear such footwear. In other words, I believe that
pavement is a bigger problem than our shoes, and that we would get
injured just as often in huarache sandals on pavement as we do in our
running shoes.
This is all speculation, because injury rates on different surfaces
have never been formally compared. A few years ago there was a message
board thread on letsrun.com concerning personal experiences in injury
rates during periods of running mostly on dirt compared to periods of
running mostly on the roads. It was completely one-sided. Virtually
every runner who had a basis for comparison and who volunteered his
experience said he ran much healthier when running mostly off-road.
Popularity
Yet another key difference between the Tarahumara and ourselves is
that they are a unique population of running specialists, whereas we are
not. There is no evidence to support this dewy notion that today’s
Tarahumara are the last vestiges of a lifestyle that was once universal
to humanity.
Long-distance running was probably never a population-wide practice
in early human societies as it is among the Tarahumara. Rather, it was
the province of a select few specialists. Consequently, the genetic
underpinnings of the gift for long-distance running were never terribly
widespread in most human cultures from our very beginnings until today.
The practice of long-distance running is more widespread in our
culture today than it has been for centuries. As we know, participation
in running has increased tremendously over the past three decades. Most
of that growth has come from the bottom, as it were, with millions of
slower, non-competitive types flooding into the sport.
I’ve been a part of the running scene since the early 1980s, and I
can tell you this transformation has been striking to witness. When my
dad was running road races back in the day, those events were filled
with runners—relatively fast men and women (mostly men) who ran
primarily because they were good at it. They were running specialists.
Today, the starting corrals are dominated by what we might call
non-runners who run. They are not running specialists.
Which is great. However, the same genetic package that gives a person
the ability to run relatively fast over long distances also gives a
person the capacity to run a lot without breaking down. Naturally gifted
runners get hurt much less often on a per-mile basis than less gifted
runners. Therefore, the high injury rate seen in running today is
certainly due in part to the fact that, as whole, today’s running
population is less “born to run” than yesteryear’s.
Back To Tradition
If weight, sedentariness, hard surfaces and popularity all contribute
to running injuries in our society today, how much blame is left for
overbuilt running shoes?
Let’s be real: running’s high-impact nature is indeed the true reason
the injury rate in running is so high. Footwear characteristics do
affect the amount of impact the body absorbs during running and how that
impact is absorbed, but it does not change the fundamental high-impact
nature of the activity. Thus, if you fall for the seductive idea that
running shoes are entirely to blame for all running injuries and that
getting rid of your shoes will enable you to run infinite distances
without injuries forevermore, you’re bound to be disappointed.
If you really want to reduce your injury risk as much as possible, by
all means, consider your footwear, but also lose weight (if necessary),
switch to soft surfaces and do stuff besides running to strengthen
those stabilizing muscles.
