Marsha Harmon can understand why most people don't think they need to take a class in walking. Racquetball may not be second nature; golf is not a normal, developmental step; but walking is something that just comes naturally. Don't you just put one foot in front of the other and start moving?

But the skill of walking - not strolling, but the kind of walking that doubles as exercise - is not necessarily as obvious as it would seem, says Harmon. Often she sees people, out for their daily constitutional, who are walking in ways that are potentially injurious.Harmon, a spirited walker herself, will be teaching a Walking Clinic from 10:30 a.m. to 12:30 p.m. May 13 at St. Ambrose Catholic Church, 1975 S. 23rd East. The clinic, sponsored by the Holy Cross Hospital Wellness Center, is open to all ages.

For the $20 registration fee students will receive two 30-minute tapes of walking music (at tempos conducive to warm-up, maximum heart rate and cool-down), plus a map of suggested walking sites, including mileage and altitude-change information.

The clinic will also include warm-up and stretching exercises, walking shoe information and a one-on-one evaluation of walking styles.

You need to find the gait, stride and shoes that are right for you, says Harmon, who notes that:

-Done improperly for long periods, an incorrect gait can lead to damaged joints and shin splints. Walking down hills requires a specific gait.

-Walking with several other people is not always the best way to exercise, since it may be hard to find a whole group of people who can walk at the same stride. Walkers may end up moving at a speed that does their cardiovascular system no benefit.

-Swinging your arms in pendulum fashion is not the best way to walk either. Instead she suggests bending the elbows and keeping the arms close to the body. Instead of walking in an upright fashion, she recommends, lean into the walk.

-Not all shoes are created equal. Some don't provide enough support and can result in joint pain.

-Race walking is not for everyone. It requires a lot of control in the hips and muscle strength in the thighs, says Harmon.