Daniel Lieberman, PhD, professor of Human Evolutionary Biology at
Harvard University, caused a stir within the media and running community when
the study, Foot Strike Patterns and Collision Forces in Habitually Barefoot
Versus Shod Runners, was published. Lieberman, lead author, and his
colleagues investigated how runners generate impact caused by the foot
colliding with the ground prior to the invention of the modern shoe. Though the
study was initially intended to investigate general footfall patterns, it has
created a controversy regarding what people believe is implied about barefoot
running.
Hypothesis
According to the study, most American runners who habitually use running
shoes generally rearfoot strike, in part because the shoes they use facilitate
this kind of landing and they are designed and equipped to slow down the rate
of loading of the high impact forces that rearfoot striking generates.
Habitually barefoot and minimally shod runners predominantly forefoot or
midfoot strike, according to the study. The study explained the biomechanics of
why there is no discernable impact transient when you run with a forefoot or
midfoot strike.
“Evidence that barefoot and minimally shod runners avoid rearfoot
strikes with high impact collisions may have public health implications,”
the authors wrote in the study.
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| © 2010 iStockphoto.com/Willie B. Thomas |
The authors hypothesize that always rearfoot striking was uncommon
before the invention of the modern shoe. Rearfoot strikes generate a larger
impact transient force than forefoot and midfoot striking. Barefoot and
minimally shod running may reduce the risk of injury because they generate much
lower collision forces. Lieberman emphasized in the study that this is merely a
hypothesis that still needs to be properly tested.
“Although there are anecdotal reports of reduced injuries in
barefoot populations, controlled prospective studies are needed to test the
hypothesis that individuals who do not predominantly rear-foot strike either
barefoot or in minimal footwear, as the foot apparently evolved to do, have
reduced injury rates,” Lieberman and colleagues wrote in the study.
Points to consider
The important point to consider, according to Lieberman, is not whether
barefoot running is better than shod running, but whether runners should be
fore-foot striking, mid-foot striking or rear-foot striking.
Kevin Kirby, DPM, MS, associate professor at the Department of Applied
Biomechanics for the California School of Podiatric Medicine at Samuel Merritt
University thinks those involved in the heated debate are missing the point.
“It is a different type of running,” Kirby explained to
O&P Business News. “Running barefoot, you tend to run on
the fore-foot and have a shorter stride. The runner is more at risk of Achilles
tendon problems as well as metatarsalgia. You will not have as much risk at
developing heel pain because you are not landing on the heel.”
Lieberman agreed that people who switch to fore-foot striking without
adequate training are at a greater risk of developing Achilles tendonitis. But
he questioned the claim that barefoot running could lead to metatarsalgia by
pointing out that the lack of an impact transient during fore-foot striking
leads to extremely low magnitudes and rates of metatarsal loading, comparable
to those that occur during toe-off in either kind of running. He contends that
if the rates of loading are lower and the magnitudes of loading are lower, then
it would be highly unlikely that you would sustain metatarsal problems by
fore-foot striking, which, as pointed out in the study is predominately
performed by habitually barefoot and minimally shod runners.
Growing trend
While most would consider the barefoot running movement a growing trend,
Kirby explained that barefoot running is only growing online, where there are
numerous websites and blogs dedicated to the movement. Kirby contends that the
movement online has not translated to the tracks and pavement of the outdoors.
“It is a virtual movement,” he said. “People are talking
about it, but not actually doing it.”
Lieberman disagreed with Kirby, citing the current production and
marketing of minimal shoes by major shoe companies geared toward runners.
What if a habitually shod runner came into Kirby’s office armed
with clinical research that suggested barefoot running was the healthier choice
and wanted to make the switch?
“As a health professional, I could not ethically recommend it
because there is too much risk of catastrophic injury,” Kirby explained.
“But, if they were to run barefoot, I would advise them to start out slow
and on a safe surface. If you have been running with shoes your entire life, as
most people have, you are not going to be able to go out on the asphalt and run
five miles without getting blisters or abrasions. You must toughen your feet
up. You should find a nice park with soft grass or maybe sand on a beach.”
Because there is no appreciable impact transient when barefoot running,
some of the best surfaces on which to run are smooth hard roads or tennis
courts, Lieberman argued. He noted that by minimum estimates, more than 30% of
shod runners get repetitive stress injuries.
Kirby also recommended alternating running barefoot one day, followed by
shod running the next day to decrease the risk of injuries.
“It could be helpful for someone who is running a lot of miles who
needed variety,” Kirby said. “Especially for marathon runners or
athletes on a cross country team because when you are running that many miles,
you need a daily change in the stresses acting on your feet and legs in order
to decrease the risk of injury. But someone who is a beginner at running? I
would never tell them to run barefoot.”
Lieberman and Kirby both agree that the study has sparked a major debate
among the passionate running community. The study garnered enough interest to
likely yield additional studies that will either raise more questions or
provide more answers.
“I think the definitive research has not been done yet,” he
said. “At least the debate is generating enough interest for people to
want to do the research to find out what is going on.” — by
Anthony Calabro
For more information:
Lieberman DE, Venkadesan M, Werbel WA, et al. Foot strike patterns
and collision forces in habitually barefoot versus shod runners.
Nature. 2010;463: 531-535.
Barefoot running is a good training tool and is a means to strengthen
the leg and foot. But in reality, we are in a shod world and we have been
raised as shod individuals.
I tell my customers that minimal shoes that lower the foot to the ground
and provide less support, are a great way to train yourself. I emphasize to
them that it is a training tool as opposed to a training shoe. What we see as a
problem is that people are using them as a training shoe and then go out and
run six miles and they end up with injury because of the lack of cushioning and
support. I think it is a great idea for training purposes to try to strengthen
the muscles, but people just use them the wrong way.
For efficient runners who have great flexibility and progress into
minimals slowly, it can be a great means of improving your lower leg
functioning. For overweight beginners who have abnormal biomechanics and need
that support, the technologies we have in running shoes allow them to
participate in a sport that they normally would not be able to take part in.
— Jamie Dick, CPed, PT
Abingdon Therapy
Services and secretary, Pedorthic Footwear Association
Barefoot running is a hot topic with many runners asking questions and
experimenting. The majority of my patients are runners and we discuss the topic
at length. As a strengthening tool and training technique, barefoot workouts
are beneficial for persons with reasonably good biomechanics. The injuries I
have seen result from runners reading about barefoot running and trying it
without proper coaching.
A person with bad mechanics will not do well without a shoe. If we ran
from childhood without shoes the intrinsic muscles might be strong enough to
tolerate the lack of a shoe. We have been in shoes from a very young age and
therefore we do require the control a shoe provides.
Again, I will state that strengthening the foot with the barefoot
forefoot technique could be beneficial for some but the majority of runners do
not have the mechanics to make the transition without injury.
— Dane LaFontsee, CPed
President, Pedorthic
Footwear Association
