It's long been known that wearing killer heels may look good but is bad for your health, but new research shows switching back into flats at the weekend could be just as dangerous.
Australian scientists recruited two groups of young women - the first had worn heels at least 5cm high for 40 hours a week for at least two years. The second nearly always wore flat shoes.
The heel-wearers walked differently, even when they went barefoot and when they switched back to flats.
The findings, in the Journal of Applied Physiology this month, show heel-wearers move with shorter, more forceful strides and their feet are perpetually in a flexed, toes-pointed position, even barefoot.
Researcher Dr Neil Cronin said this shortened the fibres in the calf muscles and put greater mechanical strain on the muscles, meaning heel-wearers needed more energy than those in flats.
Dr Cronin said the large muscle strains that occurred when walking in heels could increase the likelihood of strain injuries, including when the woman changed to flat shoes or exercised in running shoes.
It's bad news for anyone with weekend fashion sense inspired by Hollywood, where stars such as Gwyneth Paltrow are regularly seen tottering on spikes as high as seven inches.
Paltrow's passion for heels reached new heights in 2008, when she flaunted a pair of $900 Giuseppe Zanotti stilettos dubbed "limo shoes" because only those with chauffeurs to drive them around can wear them.
Podiatry New Zealand president Bruce Baxter said it was no secret that women who wore heels could suffer problems.
"We've always known it but to have this evidence is great," he said. "There's no doubt that the high heel shoe wearer who chooses to run is at far more risk of Achilles problems and other secondary issues."
Mr Baxter said of lot of the patients he saw were middle-aged corporate women who exercised at the weekend.
"It's a hard job at the best of times to tell a well-dressed women that she's putting herself at risk - I've even had women say to me, 'Well look, I'll cut my running down,' rather than compromise their fashion ideals."
He advises women wanting to put fashion first to opt for heels that have platforms at the front, to reduce the extreme height between the front of the foot and heel, and stretch well before they train in flat shoes.
ACC figures show 503 high heel-related injuries in the 2010/11 year, and 521 the previous year.
Confidence and poise come with height of fashion
Hannah McQueen says the risks of heels aren't enough to make her give them up.
"I love them, I think they make you stand a lot better, they give you really good posture."
Ms McQueen, who works in an upmarket Auckland shoe shop, says she wears heels most working days - partly because of her job but mostly because of the way they make her look and feel.
"They just make you feel a lot better, more confident ... They make you look taller, they just make the whole outfit look better."
The 22-year-old owns about 20 pairs of shoes and tends to buy about five or six new pairs every six months.
Her stilettos are usually reserved for "going out to town, weddings or parties", while wedges and thicker heels are common at work.
Her tallest heels are orange and 15cm high - but she claims they are not as uncomfortable as they might sound.
"I wore them all day at work and by the end of the day they were a bit sore, but probably no more than wearing flats because we have got a concrete floor.
"It doesn't particularly worry me because I feel I'm still young and I alternate the shoes I wear. I don't wear them every single day of the week."By Elizabeth Binning | Email Elizabeth