THEY
MAY LOOK FANCY AND SHINY IN THE
STORE,
BUT DEFECTIVE RUNNING SHOES CAN QUICKLY PUT A
PAIN IN YOUR STRIDE
Are
Your Shoes True?
An under inflated air pocket
can cause the runner to roll in and break the shoe down. The deformed left
shoe above led to a serious running injury.
by Bruce R. Wilk, PT., O.C.S.
As
runners and triathletes, we know we need top-notch running equipment we can
depend on, namely our athletic footwear. Triathletes also know the importance of
checking bike wheels to make sure they’re true because we know that a loose
spoke or slightly bent rim is likely to fail, ruin our performance and
potentially cause serious injury.
That
same reasoning applies to our running shoes. As runners, we must remember to
check if our shoes are straight and true. We know that when shoes are worn past
their lifespan, they lose their shock absorption and stabilization ability.
But
you may not realize that manufacturer defects such as crooked heel counters,
loosely glued midsoles and under-inflated shock-absorbing pockets can limit the
shoe’s ability to absorb shock and stabilize the foot, thus increasing chances
for injury even
when shoes are brand new!
Combine these manufacturer defects with excessive mileage and you’re an injury waiting to happen. It’s important to know what to look for in your own shoes to prevent injury and keep you running on all cylinders.
Rule Out
Other
Factors
If
unusual pain crops up, make sure there are no other factors causing your running
problems before blaming your shoes. Be sure you have a good stretching routine,
weekly mileage has been consistent and you incorporating appropriate cross
training. If everything seems in order and you’re suddenly been plagued by
injuries, it’s time to take a closer look at your shoes.
I
was made painfully aware of a problem with my own running shoes, a model I’d
faithfully used for nearly two trouble-free years. I injured my right foot
during the 1996 Florida Challenge Triathlon. Since I’m an experienced
triathlete and board certified orthopedic physical therapist, I’m very careful
to prepare properly before such a long triathlon. When I woke up the day after
that half Ironman and was unable to walk on my right foot due to heel pain, I
knew there was a mystery to solve.
While
carefully examining my racing shoes, I noticed the right shoe heel counter was
severely twisted inward, causing my foot to roll in. In turn, this over
stretched my arch, which led to plantar fascitis. I discovered the heel counter
was glued improperly. I hadn’t noticed the defect before the race, but rain at
the beginning of the run caused the wet shoes to stretch and the defect to
worsen. Even though I knew what to look for, I had overlooked the telltale signs
of a manufacturer’s defect in my shoes.
To understand more clearly why a defect or excessive mileage harm us, we must take a closer look at how most of us run. When we run, the foot absorbs three to five times our body weight with every heel strike. The gait cycle consists of a stance phase and a swing phase. Most, if not all, overuse injuries occur during the stance phase. The stance phase consists of heel strike, mid-stance and push-off.
At
heel strike, the foot initially contacts the ground in a supinated; i.e. locked
position. As the foot continues to contact the ground during mid-stance, it
pronates (rolls in) to absorb shock (body weight), and becomes a mobile adaptor
to the ground’s contour.
During
the push-off phase, the foot supinates (rolls out) again to become a rigid lever
and propels the body forward. In essence, the foot initially coils to absorb the
body’s weight then recoils to propel the body onto the other foot.
The
way we run varies considerably. A shoe that’s right for one person can give
another blisters, strained muscles or sore joints. Twenty years ago, buying
running shoes meant making sure you toe didn’t jam against the toe box.
Because today’s running shoes tend to be somewhat customized, it pays
to know your feet before you shop. To select the right shoe, you’ll need to
know something about your feet and how you run.
Know Your Feet
First,
find out if your arches are low, normal or high. Get your bare feet wet, then
step on and off a piece of cardboard placed on a hard floor. If your foot has a
low arch, nearly the entire bottom of the footprint will be on the floor and
very little or virtually no arch ‘indentation” will be visible. A
high
arch, on the other hand, will leave a very deep indentation as very little of
the arch touches the floor. It may appear c-shaped. Normal arch prints, as
you’d expect, fall somewhere between the low and high arch.
If
you’re like most people, each of your feet goes through the following motions
about 600 times per mile:
•
Lands on the outside back of the heel.
•
Rolls inward (pronation) and flattens out as you move forward, absorbing
much of the impact.
•
Rolls through the ball and rotates back outward (Supination).
•
Pushes off.
If
your foot excessively rolls in, you are a pronator. Athletes who have pronated
feet tend to roll inward throughout the lower extremity. They also tend to have
a more supple, shock-absorbing foot. The drawback to this type of foot is that
more power will be necessary during push off. You’ll know you’re a pronator
if your old shoes are deformed, tilting inward. The arch side
of
the midsole will be compressed. There will be extensive wear at the outside of
the heel and at the inside of the forefoot. You may have low arches. Athletes
with pronated feet need shoes, which emphasize control more than shock
absorption.
If
your foot excessively turns in (pigeon-toed), you are a supinator. Your feet do
not absorb shock well. You’re a supinator if an old pair of shoes tilts to the
outside. The outside of the midsole will be compressed and soles will be worn
along the outer edges. Your arches are probably high. The outside of your foot
needs to be supplied with more shock absorption by your shoe so you’ll need a
shoe to compensate for this.
After
you’ve determined your foot and running characteristics, seek a qualified
running shoe store and call on their expertise to put you in the right shoe.
They’ll know which shoes are recommended for pronators and supinators, as well
as which are best for high arches or flat feet.