High Heels Hurt Feet Even When Off

(July 19, 2010) - When it comes to shoes, some women will go through just about anything for a pair of Jimmy Choo's. But what effect does wearing high heels have on our bodies? Clinicians have known for a long time that if you hold a limb in a shortened position over an extended period, the muscles shorten. High-heeled shoes push our heels up, which made researchers wonder whether wearing heels on a regular basis could shorten our calf muscles.

According to lead researcher Marco Narici, there was some anecdotal evidence that something changed because secretaries in the 1950s complained about discomfort when they took their heels off and walked flat-footed. "I thought it was an experiment which was inadvertently being done by women. What we could do was test high heel wearers to see if we could find some changes in the calf muscle," says Narici

The researchers collected volunteers ranging in age from 20 to 50 years who had regularly worn 2 inch high heels for 2 years or more. They attracted 80 recruits, which they whittled down to a final group of 11 who felt uncomfortable walking without their heels. Then they recruited a second group of women who did not wear high heels.

The researchers next used ultrasound (Read about "Ultrasound Imaging") to measure the muscle fiber length in the women's calf muscles, and this time they did see a difference. The high heel wearers' muscle fibers were 13 percent shorter than those of the women who wore flat shoes. The team next turned their attention to the tendons that attach the calf muscle to the heel. (Read about "Feet, Ankles & Legs") Scanning with MRI, the team could see that the Achilles' tendon of the high heel fans were much thicker and stiffer than the flat shoe wearers'. Narici and his team realized that by thickening and stiffening, the Achilles' tendon compensates for the shortened muscle fibers in the calf muscle, allowing the fashion addicts' calf muscles to function optimally as they walk, but causing discomfort when walking on flat feet because the tendon cannot stretch sufficiently.