Credit: Matti Paavonen/Wikimedia
SYDNEY: High heel wearers are physically different to other women - the shoes have shortened their muscles and thickened their tendons, making it excruciating to walk in flat shoes, scientists reported.
After many years of use, high heels shorten the length of the fibres in women's calf muscles, according to Marco Narici from Manchester Metropolitan University in England. But the Achilles tendon, which attaches the calf muscle to the heel bone, does not lengthen to compensate.
It's this combination that results in pain if the high heel wearer tries to walk in flat shoes, he reported in the Journal of Experimental Biology.
Heels can improve a woman's sex life
This is one more in a litany of problems affecting a high heel wearer's posture, back, hips, knees, ankles and feet.
But, in a strange twist, in 2008 Italian urologist Maria Cerruto discovered that the posture of a woman standing in high heels was the optimum position for their pelvic floor muscle, helping to strengthen it and ultimately leading to an improved sex life.
In this study, Narici recruited 11 volunteers who live in Manchester who have regularly worn five-centimetre-high heels for more than two years, and complained about discomfort when wearing flat shoes. He also recruited volunteers who regularly wore flat shoes.
Muscles fibres 13% shorter
The volunteers had the volume of their calf muscles measured with an MRI scan but there was no significant difference between the high heel wearers and the flats wearers.
The volunteers then had the length of their muscle fibres measured using an ultrasound and found that the muscle fibres of high heel wearers were 13% shorter than the flats wearers.
When muscles are held in a shorter position for long periods of times the muscle fibres become shorter. This occurs in people who are bed ridden or astronauts who spend long periods of time in space.
Achilles tendon thicker by 7%
Narici then measured the length of the volunteers Achilles tendon, and found it was thicker by about 7% and stiffer than that of the flats wearers. "The decrease in fibre length and increase in tendon stiffness seem to compensate each other, that is to say one effect counterbalances the other," says Narici.
Narici describes his results as "a sort of natural adaptation to an imposed 'unnatural' foot position."
The changes are not permanent and high heel wearers can lengthen their shortened calf muscles by engaging in calf strengthening and stretching exercises everyday, according to the researchers.
Matthew Triggs from the Podiatry Clinic at Queensland University of Technology in Brisbane, says "this is an interesting study".
He said this is more evidence that if you are going to wear high heels regularly then you need to look after you foot health.
