A shoe that can help posture and back problems - and give you a workout while you walk? Harriet Griffey explains

For postal worker Kath Welch, her chronic back pain was beginning to affect not only her life, but also her ability to work. Through a combination of bad posture and occupational hazards, she began to experience recurrent problems with sciatica and, in a job that demanded the daily activity of her delivering letters on foot, it was becoming increasingly difficult for her to work, leading to increasing periods off sick. And at the age of only 36 this incapacitation was both frustrating and depressing.

"It was beginning to make me feel like a 60-year-old. But then a friend recommended that I should get a pair of shoes that had recently been introduced in the UK [they have been available in continental Europe for years] called MBTs. And I have to say that when I first tried them on, I thought I'd never be able to walk in them as their design made me feel completely unbalanced. But after 10 minutes it felt brilliant."

Paradoxically, the effectiveness of the shoes lies in the creation of this imbalance. The Swiss engineer Karl Muller, who suffered from back, knee and Achilles-tendon problems, designed the shoes because he'd noticed that the pain was worse when he walked in shoes rather than bare feet. It was Muller's observation that those people who walk barefoot over long distances on uneven surfaces - like the Masai people of East Africa - rarely suffered from back or joint problems. Hence the naming of the shoes "Masai Barefoot Technology", or MBTs as they have become known. And there was evidence that the posture of people who walked in this way was both strong and upright. Back and joint problems were unknown.

It seemed that walking in a way that forced the body to be more active, automatically mobilised those muscles that improved posture. And not only that, but this was activated immediately after the way of walking was changed. Extensive research and development with a team of orthopaedic doctors and physiotherapists led to the creation of a range of MBT shoes.

"For me, the shoes provided the missing part of the jigsaw," says registered osteopath Bronwyn Stevens. "What the shoes do is reinforce what I am trying to do to get a body to relearn. They are fantastic for rehabilitation after injury. And because they force you to walk in a more dynamic way, the whole posture of the body is improved."

No wonder then, that these shoes are beloved of pilates teachers, Alexander technique teachers, chiropractors and osteopaths alike. And in Europe they are beloved of orthopaedic doctors and physiotherapists, with countless medical studies paying testament to their effectiveness, and many Swiss medical insurance companies now refund part of their costs.

Both the Austrian and Canadian national ski teams, and athletes from boxers to footballers are happy to testify to the ways in which they have benefited from wearing and training in MBTs.

Historically both Dr Scholls and Birkenstocks started out as health shoes, but a revolution in design has found them re-established as fashion accessories thanks to the high-profile support of stars such as Gwyneth Paltrow. MBTs don't have quite the same glamour. They come as ultra-plain trainers in black or white, chunky sports sandals and sensible black lace-ups. However, it's my guess that, with new designs on the way, these could catch on.

Effectively MBT shoes change the surface on which we walk from a flat, hard one to a soft, uneven one. This creation of an uneven surface on which to walk, forces us constantly to maintain our balance. And because of this, any exercise becomes immediately more effective. It has been calculated that not only do you exercise more efficiently in these shoes, you get greater effect in less time - a 10-minute walk or jog in MBTs is equivalent to 30 minutes in ordinary shoes. Active muscles become strong muscles, which can then act as shock absorbers, so joints are better protected. This is how our bodies were originally designed to work but - because we wear shoes and walk on hard, flat surfaces - they can't.

The foot is designed for walking in a way that naturally activates the deep muscles in the legs, and the girdle of transverse abdominal muscles designed to support the lower back to protect the upper. Without this strength and support, excessive strain is placed on the upper body.

Anecdotal evidence of the shoes helping with problems as diverse as multiple sclerosis, diabetes, inflammatory and degenerative problems such as arthritis and osteoporosis, and post-natal recovery is now being more closely researched. This is no surprise to Stevens. "A lack of core strength, an unsupported spine and compression of the internal organs means that the lungs, stomach, liver, spleen, kidneys and gut are all restricted from functioning properly.

For Kath Welch the shoes were a godsend. "Although I still have problems, they are definitely improving. But what I'm really pleased about is that, following treatment, there is something I can do to help continue the improvement - and prevent problems in the future."

Bronwyn Stevens runs a practice in North London and can be contacted via www.mbt@body-matters.biz or 07973 419660; MBT shoes UK: 020-7684 4632; www.mbt-uk.com