The physiotherapist to The Royals tackles bad back Britain

"We need controversy and new approaches as there has been a stagnation of ideas," she explained in a lilting Australian accent.

"I've been in the back business for 30 years and I could see we were in a wilderness and that common sense had gone out the window."

Sarah Key has treated hundreds of patients and developed her own theory as to why backs break down.

She believes the spine becomes dehydrated and can begin to deteriorate if we are sedentary for too long.

"The spine is an elongated concertina of many bricks sitting on top of each other," the 57-year-old explained.

"The 'bricks' should pull apart and compress – this lubricates the discs and keeps the spine flexible. Bending gives the discs a drink."

But with more of us sitting at our desks all day, back pain is on the increase.

"Eventually the bones come together causing pain as they rub. Discs can start to wear out and even cause arthritis," she said.

She believes that MRI scans, which show differences in water content between body tissues, supports her theory. She also has the powerful backing of her most famous client, the Prince of Wales.

The future king of England wrote a glowing foreword to her latest book 'Back Sufferers' Bible'.

"I find Sarah Key's makes sense in what to many is a pretty incomprehensible subject," he wrote.

"It is such a help to have it explained so one can actually understand what is going on."

The Prince describes himself as one of her "willing guinea pigs" and vouches for the effectiveness of Sarah Key's exercises.

For your chance to win a copy of Sarah Key's book enter our competition below

Sarah rejects conventional advice that those with bad backs should take to their beds and lie still. In fact, she says, they should be doing the opposite. After a short period of rest they should be bending and moving their spine and this principle underpins her method.

In this way she believes back breakdown can be prevented and that recovery is possible at any stage.

"I would say touch your toes as often as you can," Sarah advised.

"If you can't reach your toes just walk down your legs as far as you can and hang there for a moment. You should unfurl your spine gradually. Your discs are always sinking and by doing this it's like you are plumping up the pillows.

"Ten per cent of fluid is lost from your spine in the first two hours of sitting so try and touch your toes first thing in the morning."

Building up a strong retaining stomach wall can also help.

"Instead of doing sit-ups you should do the reverse so bring your knees up to your chin," Sarah recommended.

"Also Yoga and Tai Chi work very well but I think Pilates can over exercise the tummy.

"And when sitting at a computer the key is don't sit slumped. Pull everything upwards but avoid sitting bolt up straight as you need to allow your spine to keep it's natural S bend - to help this place a pillow in the hollow of your back and relax onto it."

Sarah is now teaching her method to physiotherapists in London and has released the second edition of The Back Sufferers' Bible.

"Prince Charles was the one who convinced me to teach my method to others," she said.

"I'm so glad I listened to him."

WIN A COPY OF SARAH KEY'S BOOK

We have 15 copies of Sarah Key's The Back Sufferer's Bible to give away.

For your chance to win simply answer the following question...

What does Sarah Key advise you to do to limber up your spine?

A: Bend down to touch your toes

B: Sit as upright as you can

C: Do lots of vigorous exercise

Think you know the answer? Click here to enter

The winners will be picked on Monday 19th November at 4pm.

Sarah Key holds a 'Back in a week' course for back pain sufferers in Cornwall twice a year. For more information visit www.sarahkey.com