If the shoe fits
According to Sammy Margo, a spokeswoman for the Chartered Society of Physiotherapists, any new shoe is potentially harmful.
"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. Instead, she suggests "easing yourself into a new shoe style" by wearing them for only half an hour at a time and then slowly building up.
This might not always be convenient, particularly if you're dying to wear your new shoes out on the town, but Margo stresses that the "slightest changes in heel height can trigger problems".
Flat shoe strain
Mike O'Neill, a spokesman for the Society of Chiropodists and Podiatrists, squashes the myth that heels are the only enemy by revealing that flats can "strain the Achilles tendon that runs from the back of the heel, and also the calf muscles in the back of the leg". Two weeks of wearing ill-fitting or uncomfortable flats is all it takes to develop an injury and associated pain.
"Flip-flop styles of sandals are even worse," O'Neill stresses, "[because] there is no support whatsoever for the heel." With no heel support and no shock absorbency, there is also the added risk of developing a painful heel condition known as plantar fasciitis .
Mix and match
To avoid painful foot problems, Margo suggests alternating your shoe styles from heel to flat, and also trainer to boot – and to avoid wearing the same pair of shoes day in, day out. And keep your muscles supple by doing a few calf stretches before, during and after long periods spent wearing flats.