What is it?
A shoe inspired by the African Masai tribe's traditional curved sandals. They're marketed as cellulite-busters and are said to strengthen core muscles by making them 'the natural shock absorbers they were designed to be'. Instead of a traditional flat heel, the Masai Barefoot Technology (MBT) shoes' rolling sole forces you to balance and straighten, creating a more upright gait. They were created by Swiss engineer Karl Muller, who got relief from knee and back pain only when walking without shoes on soft earth. During 10 years' research, Muller found that joint pain was minimal among the Masai, who walk long distances barefoot. The basic premise of MBT is not unlike that of Pilates.
How does it feel?
Initially, as if you're trying to stand upright on a plank balanced on top of a ball. The middle of the foot needs to find the apex of the shoe. Roll forward, back and then forward again, stopping just before the toes start to descend. This is the correct position. The idea is that the curve makes the shoe unbalanced, requiring more effort from the core and leg muscles. The shoes don't feel particularly comfortable at first, but a snug fit and gentle rocking motion mean they're increasingly enjoyable on long walks. The muscles at the back of the thighs feel as if they're working harder.
How do they work?
'It's not clinically proven,' says MBT director, personal coach and yoga teacher Joshua Isaac Smith. 'But they're shown to activate the gluteus muscles more.' The ideal way to walk in MBT shoes is with shorter steps and arms swinging slightly from front to back, rather than in long motions as when you're in a hurry. 'My feeling is that this shoe can change people's posture,' he says. 'I'd recommend it to people who have alignment issues.' Physicians have been quoted as saying the shoes can strengthen gluteus muscles (which, if weak, can cause back pain). MBT shoes have been classed as a medical device by the European Commission, and health insurers in Switzerland and Britain refund a major part of the cost. 'The theory behind it is good,' says chiropodist and podiatrist Karlyn Harfoot. 'I haven't used them, but I know that people who have say they're good. But it's horses for courses. Because they're pre-fabricated, they'll be good for some people, but not others.'