Sarah Jessica Parker -- once the poster child for the sensual power that is a towering pair of Manolo Blahnik pumps -- said recently that high heels have ruined her feet."For 10 or so years, I literally ran in heels," Parker told Net-a-Porter magazine in an interview published earlier this month. "I worked 18-hour days and never took them off. I wore beautiful shoes, some better made than others, and never complained." Then, on the set of her 2011 movie, I Don't Know How She Does It, Parker slipped while wearing a pair of cheap shoes with plastic soles and twisted an ankle."I went to a foot doctor," Parker continued, "and he said, 'Your foot does things it shouldn't be able to do. That bone there. ... You've created that bone. It doesn't belong there.'"According to a 2003 survey by the American Podiatric Medical Association, 42 percent of women wear uncomfortable shoes because they are stylish, 31 percent wear high heels to work even though they're uncomfortable, and 73 percent admitted to having had a shoe-related foot problem.Doctors say wearing heels higher than 2 inches can cause knee and back pain, shorten tendons, exacerbate arthritis, and create all sorts of other problems.But in 2011 women in the U.S. spent $38.5 billion on shoes, according to published reports. More than half of those sales were for heels over 3 inches high."High-heel shoes contribute to my practice," says Dr. Paul Fortin, an orthopedic surgeon who is head of foot and ankle services for Beaumont Health System in Michigan. "I have a lot of patients coming to see me with problems."High heels elongate our legs -- pointy-toe pumps do a better job than round toes -- and make us look taller and slimmer.Men think women look great in high heels.Even Fortin, who encourages his patients to consider high heels a privilege that should be exercised only on special occasions that don't require a lot of walking, says, "I like the way it looks."If the shoe fits ... another might notBuy the correct size. Shoe sizes depend on manufacturer.High heels increase the risk of foot problems and put most of the body weight on the ball of your foot.Platform heels help distribute weight more evenly. So do wedges.