Excess heel height can also increase pronation, especially in shoes
with heels that are thicker than about 1 inch. Too much heel height
can also causes the entire body to move abnormally.
A significant problem with thicker heels and soles is foot strike.
The natural running gait results in mid- to forefoot strike, depending
on how fast the pace. But the thick soles used in today’s running
shoes, for example, forces you to land on your heels — this is not nat-
ural and a significant mechanical stress. Try running barefoot, and no
matter how slow or fast you go it will be almost impossible to land on
your heel. (Landing on the heel is a normal walkinggait.)
In general, shoes with more cushioning are also likely to produce
excessive pronation, a falling inward of the foot’s inner, medial arch.
This is especially true of shoes with added soft midsole material.
Many shoe-support systems, including orthotics, can interfere with
the normal functioning of the medial arch, the most important of
three main arches in the foot. I have only on rare occasions recom-
mended orthotics, and only for a short time while the cause of the
problem was being corrected.
Sorbothane and similar materials commonly used in exercise shoes
and after-market insoles can also be counter-productive. While tests on
machines demonstrate Sorbothane’s great energy-absorbing abilities, a
study on humans shows that insoles made of this material actually
increase leg stress by 26 percent, enough to cause stress fractures.
Beware: The muscles of your foot and leg, especially the calf mus-
cles, have adapted to the thickness of your shoe. If you suddenly
change your shoe style by wearing flatter shoes, your muscles may
have to re-adjust their length. This may take a couple of weeks, dur-
ing which you may experience some calf discomfort.
Sizing Up Your Shoes
A significant number of people are wearing everyday, dress or exer-
cise shoes that are too small. In addition to foot problems, this can
cause pain or dysfunction in the ankle, leg, knee, hip, low back, and
at times as high up as the neck or TMJ (jaw) joint. And most often, the
feet don’t even hurt. A study done in my clinic over an 18-month peri-
od found 52 percent of all athletes were training in shoes that were too
small. Once the problem was diagnosed, these patients usually
required a change from one-half to one-and-one-half sizes larger.
SPORTS SHOES: THE DANGER UNDERFOOT • 229