Can you say overpronation?
A simple guide for identifying your foot biomechanics and the best shoes for you.

To select the best show for you, it's important that you know your foot biomechanics.  Are you a normal pronator?  An overpronator?  An underpronator?  Your foot biomechanics are important because they can determine the type of shoe you should buy: a stability shoe, a motion-control shoe, or a cushioned shoe.

For many runners, these terms and the assessment of the foot biomechanics present a baffling dilemma.  We're here to make it easier.

The absolute best way to determine your foot biomechanics is to have a shoe expert or podiatrist observe you (or, even better, videotape you) while you're running on a treadmill.  Of course, you might not have this opportunity.  Second choice: Have a veteran runner observe you while you run on a track or smooth road.

Here's the do-it-yourself method.  Stand in front of a full length, on-the-floor mirror, and compare your lower legs and feet to these three illustrations.  If your legs and feet look like Figure A, you're an overpronator.  If they look like Figure B, you're a normal pronator.  If they look like Figure C, you're an underpronator.

Here are some additional explainations:

Overpronators (Figure A):
Your feet are splayed outward in a manner often termed "duck feet".  You probably have low arches.  When you're running, your arch collapses to absorb the impact shock, and your feet roll inward excessively (overpronate), sending force waves up your legs to your knees and beyond.

Best shoes for you: Stability shoes of motion-control shoes.  They will reduce the inward roll of your feet, and thus the stresses on your legs.

Normal Pronators (Figure B):
Your ankles and feet maintain the vertical line of the lower leg.  Your feet pronate, but not excessively.  This is the most common foot type.  Now you just have to determine if you have rigid or highly flexible feet. 

To do this, measure your foot length by putting a ruler on the floor, and place your foot on the ruler with no weight on the foot (sit in a chair).  Then stand up, put all your weight on the ruler, and measure your foot length again.  If the length of your foot doesn't change, you have rigid feet; if the length increases by 1/8 of an inch or less, you have normal foot flexibility; if the length increases by more than 1/8 of an inch, you have highly flexible feet. 

Best shoes for you: If you have rigid feet, cushioned shoes.  If you have normal feet, choose stability shoes.  If you have highly flexible feet, choose stability or motion-control shoes.

Underpronators (Figure C):
Your feet are turned in (pigeon-footed), and you probably have high arches.  You most likely have rigid feet that don't pronate inward as much as you run, which decreases shock absorption.

Result: You need extra cushioning to absorb the impact shock of each running stride.  (Note: This is the least common foot type.)

Best shoes for you: Highly cushioned shoes with single-density midsoles.