Outside magazine, January 1996
Close might be good enough in horseshoes, but a difference of as little as a quarter of an inch in leg length can set you up for a bad case of iliotibial band syndrome or trochanteric bursitis, particularly if you're a runner, getting a constant beating from feet to hips. And according to sports medicine specialist Dr. P. Z. Pearce, at least one in every ten people has legs of disparate lengths. "Your feet are the foundation for your body's frame," says Pearce. "A lopsided foundation will throw the entire building off; what often gives are the hips." If you suspect that a minor leg-length inequality stands between you and a pain-free iliotibial band, you might want to experiment with a heel lift, a simple felt or neoprene pad that fits into your shoe on the short side. Most drugstores sell them over the counter; try Spenco's Heel Cushion ($6-$7) or Sorbothane's Full Sole ($27).
If you're an overpronator--that is, if your feet tend to roll too much to the inside--you're a likely candidate for trochanteric bursitis. You should be running in so-called motion control shoes, to start with. And while you're still in a decent running-shoe store, a properly trained fitter will be able to tell, just by watching you walk, whether you need inserts. Pearce recommends the Spenco Orthotic ($25-$30), which you can put in boiling water and then mold to your foot.
If over-the-counter devices don't help, a sports-medicine specialist, podiatrist, or physical therapist can analyze your anatomy and gait and design custom orthotics. Unfortunately, you'll stride out of the professional's office with about $300 less in your pocket. But you'll also get many pain-free miles on your built-to-last prescription orthotics: Pearce has logged 20 marathons and seven Ironmans on his.