Compared to high heels, they don't look remotely hazardous. But flip-flop wearers would do well to think twice before slipping on a pair.

　　The National Health Service spends £40 million a year treating injuries caused by wearing the casual footwear.

　　More than 200,000 people visit their general practitioner or even end up in hospital every year after suffering falls or developing long-term problems.

　　Once worn only at the beach, flip-flops have become the regular summer footwear of choice for many, with one in five women owning at least one pair.

　　But experts are warning of the dangers of prolonged use, such as the risk of shin splints and joint pains.

　　They say flip-flops force people to change the way they walk so that when taking a stride they put pressure on the outside of their foot, rather than their heel, causing long-term damage.

　　And there is also the risk of serious injury from tripping over.

　　Frequent complaints include twisted ankles, but some have broken their arms or wrists after falling because their flip-flops caught on uneven ground.

　　Many also suffer aching toes as they constantly scrunch them up to grip the thong, while there is also the danger of the odd stubbed toe.

　　Flip-flops are one of the most popular shoes among women, with 15 million wearing them a day in summer, according to shoe firm MBT which obtained the figures.

　　Mike O'Neill, spokesman for the Society of Chiropodists and Podiatrists, warned of the damage done by wearers forced to adapt how they walk.

　　He said: 'They land on the outside and then roll the foot inwards putting all the pressure on the big toe. This constant rolling puts pressure on the ankle joint causing it to weaken.

　　'The lack of support of the flip-flop also causes pain in the tendons on the inside of the foot and lower leg. It can also lead to shin splints.'

　　And if you're not used to wearing them, they can cause blisters, he added.

　　Medics say flip-flops are just as bad for the feet as stilettos but cause far more damage as they are worn for longer periods of time.

　　Emma Supple, consultant podiatrist for the MBT, said: 'Flip-flops are universally popular. They are easy to put on and easy to wear but women do need to be mindful that prolonged wearing on hard flat surfaces can cause considerable foot and leg problems.'

　　She encouraged women to wear sensible shoes to help recover from summertime injuries.（来源：中国日报英语点津）