Aching feet:

But these days, we see a whole soccer teams of 16-year-old girls" complaining of the sort of foot pain when we used to see mostly in "older, fatter" people.

The culprits aren't the girls' soccer cleats or even the high heels they break out on prom night. Instead, it's their flip-flops — the flimsy, slip-on, toe-thonged sandals that girls and young women nationwide have adopted as their warm-weather, everyday shoe uniform.

"Flip-flops were never meant to be everyday shoes," "They were meant to wear from the locker room to the pool and back."

The problem, is that flip-flops offer little cushioning and no arch support, and they force their wearers into an unnatural, toe-gripping, foot-slapping gait.

Among the possible consequences:

•Sore arches and heels, which can progress to chronic conditions, including inflamed Achilles tendons and plantar fasciitis, inflammation of the connective tissue between the heel bone and the toes. Heel calluses (from the pounding). Hammer toes (from the gripping). •Irritation between the toes (from the toe thongs), which can lead to nasty fungal infections.

Of course, flip-flops aren't the only popular shoes that can hurt your feet. Pretty little ballet flats and sky-high wedges, if worn too often or in the wrong circumstances, can cause just as much pain as classic trouble-makers such as stiletto heels, experts say. Even sensible, low-heeled, wide-strapped sandals can harm your feet if you wear the same pair every day from June to September.

A few tips for making it through the summer with feet that look good and feel good, too:

•Spend most of your time in sturdy shoes that offer heel and arch support. "If you can take the sandal or ballet flat and twist it into a little ball, that's a sign that they can't take everyday wear and tear," Crane says.

•Stick to heels — or wedges — of 2 inches or less, except on special occasions. A wedge may feel more stable than a heel of the same height, but it can put just as much pressure on your feet, knees and hips.

•Wear the right shoes at the right time. "If you are going to be involved in a sport or walking all day, wear shoes that are made for that.

•Switch shoes daily, if possible, especially if you live in a humid climate. Even very comfortable, sensible shoes can grow fungus if they don't get a chance to dry.

•Buy shoes that fit and feel comfortable the first time you put them on. "The concept that you just have to break in a shoe is a fallacy. If the shoe is not comfortable, don't buy it," Anderson says.

•Put some sunscreen between those sandal straps. "People put it on their legs, completely forget their feet" and end up with badly burned feet..