The pain of walking on flat feet when you are a high-heel wearer
There must be something transforming about high-heel shoes that makes women want to wear them despite the killer heels’ notoriety. Plantarflexion, or the lifting of the heels by the ball of the foot through the action of the calf muscles, creates a more pronounced lordosis, or arching of the back. The result is a sexier, confident forward stance.
Researchers in a recent study looked into a condition where high-heel wearers find it uncomfortable, even painful, to walk flat-footed or to switch to flat shoes.
When high heels are being worn, calf muscles are placed in a shortened position. The researchers wondered if chronic or prolonged use of high heels causes structural and functional changes, such as shortening of the calf muscle tissue itself. To test this scenario, the research team studied 11 volunteers who had regularly worn 5-cm heels for two years or more and who felt uncomfortable walking flat-footed. They were compared with nine other women who did not wear high heels.
Using MRI to measure the size of the women’s calf muscles, the researchers found that there was no difference in the calf muscle volume of the two groups. The team then tested the muscle fiber length on ultrasound and saw that high-heel wearers did have 13 percent shorter muscle fibers than those who wore flat shoes. “This confirmed the hypothesis,” says author Marco Narici from Manchester Metropolitan University, “because when you place the muscle in a shorter position, the fibers become shorter.”
The researchers explained that with shortened fibers, the muscles would have to contract more if they were to shorten by the same length. Muscle insufficiency, or the inability to produce enough tension in the calves, prevents optimal function. This begs the question: Had the shortened muscle fibers made it difficult for high-heel wearers to walk efficiently?
The authors then looked at the Achilles tendon, which attaches the calf muscle to the heel bone. The MRI scan showed that the tendon was the same length in the two groups of women. However, they noticed that the tendons were thicker and stiffer among the high-heel wearers. They realized that the tendon thickened and stiffened to compensate for the insufficiency of the calf muscles, allowing optimal function as the high-heel wearers walk. This, however, causes pain or discomfort when walking on flat feet because the stiff tendon cannot stretch sufficiently in this position.
Would the scientists recommend that women kick the high-heels addiction? The lead author of the study published in the Journal of Experimental Biology said he is not advocating against fashion. “This is not intended to scare women off wearing heels, it’s just to make them aware that exercising and stretching their calf muscles can help.” He advises women to do stretching exercises to avoid developing any soreness.