By: Mak Mun San

Sporting trendy flip-flops might be a great fashion statement but a recent study has warned that they can be bad for you.

Researchers from Auburn University in Alabama studied the biomechanics of flip-flops and determined that wearing thong-style flip-flops can result in sore feet, ankles and legs.

This is because when people walk in flip-flops, they alter their gait, which can result in problems and pain from the foot up into the hips and lower back, the study said.

This view is echoed by Mr Adriaan Erasmus, principal podiatrist from the Department of Rehabilitation Medicine at National University Hospital.

He says that flip-flops should not be a person's primary footwear and people should avoid flip-flops or reduce the wearing time, especially if they have foot problems.

'When a person wears flip-flops, his toes need to grip them to prevent them from falling off,' he says.

'Flip-flops will not stay in one position underneath the feet when walking and this can cause the feet to slide off to the side, most often the inside edge.'

This changes the mechanics of the lower leg and stresses are transferred to other parts of the body, such as the knees, hips and lower back.

Mr Erasmus cautions that it is counter-productive for a person with foot injury to wear flip-flops since they put all these abnormal stresses on the legs and the injury cannot heal.

Diabetic patients are also advised not to wear flip-flops since they do not provide any protection to the high-risk diabetic foot, he says.

'The strap between the toes can cause friction and result in ulcerations,' he explains.

This article was first published in The Sunday Times on June 15, 2008.