We live in a casual age, at least when it comes to footwear. Visit just about any college campus in the United States and, when the weather is warm, you'll see many students wearing flip-flopsthe flimsy, thong sandals that once upon a time were meant only for the shower and pool.

Students wear flip-flops because they're comfortable. Plus, they're easy to slip on when you wake up at noon and realize you're late for that geology final. But what many daily flip-flop wearers may not know is that the sandals are also really bad for feet.

According to podiatrists, those soft, spongy sandals provide no arch support and cause the foot to roll inward. And, because the only thing keeping flip-flops on feet is that little rubber thong, you end up gripping them mainly with the toes.

So wearing flip-flops is even worse than going barefoot, which is bad. Shoes and socks were invented for a reasonthey protect the feet from wear and tear, provide support, and reduce stress on tendons and ligaments. All the stress placed on flip- flop-clad feet can result in plantar fasciitis, a painful swelling of a ligament running across the bottom of the feet and into the heel.

Flip-flops are still fine for the beach and hanging out by the pool. But wearing them to get around campus, or town, is risky foot business.