Barefoot in the park.

there is a prominent reliance on corrective shoes and orthotics to counter various foot and ankle problems in the running population (see "Which Way Do Your Ankles Curve?" on page five). However useful this approach may be, it downplays the notion that over time, it's possible to do more than compensate for a foot problem or undesirable gait. Studies of surprisingly injury-free populations that routinely go barefoot have repeatedly shown that it's possible to strengthen and train your foot to naturally behave.

When it comes to foot problems shoes are there to help, but they can also act as enablers. By constantly wearing shoes, our culture has created a weaker foot that relies on artificial support to maintain its integrity.

A study at the Department of Movement and Sport Sciences at the University of Ghent in Belgium found that barefoot runners create a softer landing and quickly learn to avoid a heel-first strike method, which is not the ideal way to spread ground reaction forces over the entire sole. They also found that barefoot runners employed a significantly higher leg stiffness during landing.

In another study of ankle coordination, subjects ran either in a hard shoe, a soft shoe or unshod. No significant differences in coordination were found between the two shoe conditions. However, significant differences in ankle coordinative strategies existed between the shoe conditions and the barefoot condition.

These adaptive strategies contribute to better running economy and protect against injury. When the foot allows excessive forces to travel upward, many knee, hip and back injuries can result. In a third study of 17 recreational runners, the researchers attribute this increased load deflection to sensory feedback from the bottom of the foot, and somewhat boldly conclude that, "The sensory insulation inherent in the modern running shoe appears responsible for the high injury frequency associated with running."

If you want good running economy and strong, injury-free feet, training barefoot can help. You will learn to spread your toes and use them for a stronger push-off; your arch will depress and expand more effectively, allowing you to absorb shock and then propel forward; and your support structures will be strengthened. In addition to improved landing technique, barefoot running results in a more conditioned and flexible version of the muscle spanning the arch. It simply helps make this muscle stronger and more impervious to impact.

To safely get the most out of barefoot running, remember to start gradually. First increase the frequency with which you walk around the house barefoot. You will overstress your Achilles tendon and plantar fascia if you just jump out there barefoot right away. You might want to try sprinter spikes, road racing flats or wrestling shoes as an intermediate step. Another way to ease into barefoot running is to perform plantar and arch strengthening exercises: learn to pick up marbles with your toes and try ankle flexes while sitting at your desk at work. At www.barefootscience.com, you can find insoles designed to strengthen your foot by simulating the movement patterns in barefoot walking and running.

Once you're ready to go barefoot, you can attempt running on a track or a grass playing field. These environments may be harboring glass shards or other hazards, however. It's a good idea to inspect your running surface carefully first. Nike now manufactures a shoe designed to mimic barefoot running which could help put an end to these hazards (www.nike.com/nikefree).

Another idea is to run on the beach if possible. It can be easier to spot litter, and the beach provides the ideal training scenario: a low-impact workout with a high energy cost. One study tested beach running at various speeds and reported the aerobic energy cost of running on dry beach sand as one and a half times greater than running on grass. At the fastest speed, there was an almost four times greater anaerobic energy cost (as measured by lactate accumulation) for running barefoot on sand than for running barefoot on grass. Note that soft sand may be too unstable a surface for running if you're not used to it. Without proper prior conditioning, you may strain your ankle, plantar fascia or knee--work up to this type of training gradually and carefully.

Begin with easy jogging on the balls of your feet and gradually increase to full stride. As you run, you'll find your form adapting to absorb impact.

Working out like this once or more a week can train your lower extremities to run the way nature intended, which is a vital component of keeping injury-free.

(J. Am. Podiatr. Med. Assoc., 2004, Vol. 94, No. 1, pp. 53-58; J. Sci. Med. Sport, 2001, Vol. 4, No. 4, pp. 416-430; Explosive Running by Michael Yessis, PhD, 2000, Contemporary Books, pp. 121-126; J. Biomech., 2000, Vol. 33, No. 3, pp. 269-278; Sports Med., 1998 Vol. 26, No. 1, pp. 59-61; Med. Sci. Sports Exerc., 1987, Vol. 19, No. 2, pp. 148-156)