KANSAS
CITY, Mo. — The style of your running shoes isn’t just
making a fashion statement. It may be controlling the way you
run and setting you up for injuries down the road.
That’s
what researchers at the University of Kansas Hospital found
when they put a dozen high school athletes through their paces
on a treadmill.
When the
teens ran barefoot or in flat-soled racing shoes, they
generally landed on the front halves of their feet, the
researchers say. But when the young athletes put on
standard-issue running shoes with thick, cushioned heels, they
instantly switched to a radically different gait, striking the
treadmills with their heels.
Although
there is no direct evidence that landing on your heels when
you run leads to long-term injury, some experts say that
running this way may over time increases wear and tear to
knees and hips.
"It
may be more natural to land on your forefoot. It’s
uncomfortable to land on your heel," said Scott Mullen, a
University of Kansas sports medicine specialist who
co-authored the study. "But there’s something in the
makeup of the (cushioned) shoe that promotes that kind of heel
strike."
Mullen
presented his findings last month in Chicago at the annual
meeting of the American Academy of Orthopaedic Surgeons. The
study will be published in the Journal of Pediatric
Orthopaedics.
Mullen,
a marathoner and triathlete, put the teens on a treadmill to
add some perspective to the growing reaction among runners
against thick-heeled shoes. In fact, the relative merits of
different shoe soles have become a regular topic of debate in
recent years.
Barefoot
running or running in "minimalistic" shoes with as
little as a third of an inch between the sole of the foot and
the ground has become popular as a more "natural"
way to run. The idea was promoted by the 2009 best-selling
book "Born to Run," about the Tarahumara Indians of
Mexico, who run for hundreds of miles without injury wearing
thin-soled sandals.
The
injury-prevention message has also been fueled by some
research findings, including a Harvard study from 2010 that
looked at runners in Kenya. The researchers found that even on
hard surfaces, barefoot runners who landed on their forefeet
gave their bodies less of a jolt than did runners who wore
shoes and landed on their heels.
Shoe
companies, which had been adding padding to their products
since the first modern running shoes were developed in the
1970s, changed course. They have come out with a variety of
shoes that minimize the difference in the thickness of the
heel and sole of the shoe.
"We’ve
seen a shift in the consumer wanting this and asking for
it," said Jane Tompkins, the manager of Garry Gribble’s
Running Sports, a store at Ward Parkway Center for serious
runners. "It’s more mainstream thinking now. Lose the
heel and be a midfoot striker."
Mullen
wanted to see how the different kinds of shoes affected young
athletes who hadn’t settled on a running style.
His
subjects were six boys and six girls ranging in age from 13 to
18 who were recruited from local track teams. They took turns
on a treadmill that was surrounded by 12 infrared cameras
recording motion in three dimensions from markers attached to
their feet, ankles and knees.
Each did
short runs at different speeds going barefoot, wearing the
conventional cushioned-heel running shoes most of them used
for training or wearing racing flats with little or no heel
elevation.
In the
cushioned shoes, the runners landed on their heels about 70
percent of the time. But in track flats, they hit heel-first
less than 35 percent of the time, and barefoot just 30 percent
of the time.
"Simply
by changing their footwear, the runners’ foot strike would
change," Mullen said. "When they ran in the
cushioned heel of an average running shoe — even when
running a five-minute mile — the athletes landed on their
heel first."
Sam
Toby, a senior at Blue Valley Northwest High School, regularly
trains in minimalist Vibram FiveFingers shoes with flat soles
and individual toes. He has gotten used to striking the ground
with the front of his foot.
"I
find it tends to be easier on my legs," he said.
"You build up muscle in your foot. It’s a natural shock
absorber."
But when
he put on regular running shoes for the study, he found his
heels hitting the treadmill first.
"When
you run with a two-inch block on your heel, you naturally hit
with the heel," said Toby, whose father, Bruce Toby,
heads the orthopedics department at KU Hospital and
co-authored the study.
Young
athletes who are still developing their running styles may
want to start out with minimalistic shoes as a way to lessen
their risk of injuries over the long term, Mullen said.
Although
no studies have tied particular running styles to greater risk
of injuries, heel-strike running does put more stress on hips
and knees, he said.
"I
certainly think it’s a reasonable conclusion that if you
decreased the forces when running it would be for the
better," he said.
But
older, seasoned runners who’ve been running in comfy,
cushioned shoes for some time shouldn’t make a quick switch
to minimalistic.
"I
don’t know if there’s a point where you can’t change,
but you need to work on it slowly," Mullen said.
"Pay very close attention to what your body is telling
you, the aches and pains. We have seen patients with stress
fractures because they threw their regular shoes aside too
fast. It’s worth considering, but it may not be for
everyone."