Are flat shoes bad for you?

They do little for a woman's stature, but the gladiator sandals and flat pumps seen adorning the feet of Sienna Miller, Kate Moss and Carla Bruni of late must surely be better for feet and ankles than a skyscraper wedge. Apparently not. Foot experts warn that you face as many risks wearing flatties as you do teetering on heels.

Sammy Margo, a spokeswoman for the Chartered Society of Physiotherapists, says a period of transition is needed with any style of shoe. "Go straight from wearing trainers, which have incredible amounts of support for the arch and upper foot, or from high heels in the winter to flat pumps in the summer and you risk pain and strain," she says. "You need to ease yourself into a new shoe style, wearing them for half an hour at first, then building up."

According to Mike O'Neill, a spokesman for the Society of Chiropodists and Podiatrists, flat shoes can "strain the achilles tendon that runs from the back of the heel, and also the calf muscles in the back of the leg". Pain can develop after as little as two weeks.

With no shock absorbency and little heel support, there is the added risk of developing a painful heel condition called planta faciitis if you wear them constantly, according to Margo. "Flipflop styles of sandal are even worse as there is no support whatsoever for the heel," she says.

So, what to do? Her advice is to alternate your shoe style - from high to low, trainer to boot - and avoid wearing a particular pair day in, day out. Calf stretches before, during and after long periods of flattie-wear can help to keep muscles loose and less vulnerable to strain. "This is advice to be followed by men too," she says. "Slightest changes in heel height can trigger problems."

Perhaps Nicolas Sarkozy should rethink those stacked heels he's been seen in recently.