Health: Bend and extend - put an end to the pain: For those with back problems, yoga's ancient techniques may help where drugs and surgery have failed, writes Jacqui Brommell

Yoga often conjures up the image of a body twisted into knots - not the obvious cure for nagging back pain. But yoga 'therapy' has enabled Catherine Boon to resume an active life after 15 years of agonising back problems.

In 1989, 11 years after she had surgery to remove a ruptured disc, Ms Boon, a retired nurse, began suffering from pain in her right leg, caused by a trapped nerve in her spine. The following year, she underwent major back surgery to remove two more discs and fuse three vertebrae. It didn't help. 'The pain was there most of the time, and I had great difficulty walking, even though I was swimming frequently,' she says.

'The surgeon said he could carry out more surgery, but told me I'd be left with permanent backache.' Not surprisingly, Ms Boon declined the operation.

Three weeks of intensive physiotherapy in a rehabilitation unit provided some pain relief. But Ms Boon still felt more needed to be done. Last summer, she heard about the Yoga Biomedical Trust, which provides 'yoga therapy' for lower back pain.

The trust, a registered charity, was founded 10 years ago to promote scientific research into yoga for the treatment and prevention of medical problems. Last September, it set up the Yoga Therapy Centre at the Royal London Homoeopathic Hospital, which runs clinics for those suffering from asthma, diabetes and hypertension as well as back pain. It has a panel of international medical advisers and can, when necessary, refer patients to medical specialists.

Ms Boon's condition was assessed by one of the centre's certified yoga therapists. Because Ms Boon's medical history was complicated, she was also referred to the trust's private orthopaedic specialist to approve the therapy.

She then enrolled for six weekly yoga classes for back pain, each lasting about two hours. 'The exercises may seem gentle, but when I started I found them quite difficult,' she says. 'But with practice and determination I improved.' New patients, she says, are instructed to stop if they feel pain.

Ms Boon says that after completing the classes and practising at home, she noticed a gradual improvement in her back problem. Eight months on, with regular yoga practice, she suffers hardly any pain and feels stronger. 'I can now walk much farther - sometimes for an hour or two a day - which is tremendous after having been in agony just walking for five minutes.'

Yoga therapy for lower back pain is based on traditional yoga postures, or asanas, as well as deep relaxation and breathing exercises, but some of the classical movements are omitted or modified. 'A lot of techniques carried out in a normal yoga class would be positively dangerous for people with serious back problems,' says Dr Robin Monro, a non-medical research biochemist who is founder and and director of the trust. 'But there's no risk with yoga therapy - it's very gentle.'

The sequence of exercises was developed by Dayamurti Dongaonkar, Professor of Orthopaedics at Grant Medical College, Bombay, who teaches yoga in conjunction with conventional medicine. Professor Dongaonkar recently worked with British spinal specialists at Queen's Medical Centre, Nottingham, testing the benefits of yoga on lower back pain. Preliminary findings look promising, Dr Monro says.

Ms Boon's GP has been so impressed with her improvement that he has asked the trust if he can send other patients to the clinics. 'We would like to work with more patients' doctors,' Dr Monro says.

He would like to see yoga therapy available on the NHS. Studies show that people with lower back pain can benefit from yoga even when surgery, drugs and physiotherapy have failed.

Patients most likely to benefit are those with mild back pain, ligament or muscle strains and those who want to prevent a recurrence of past back problems. Patients who would not usually be recommended include those with prolapsed discs or arthritis.

Dr Monro warns: 'If you have a serious back problem, be careful what you do in general yoga classes.' The trust has trained about 25 yoga therapists who are now working in other parts of the country.

Central to any yoga practice is the health and strength of the spine. 'Forward bending, backward extending, twisting and sideways bending - yoga improves the flexibility of the spine, which in turn improves the circulation and keeps the cartilage healthy,' Dr Monro says. 'Yoga also helps to relieve chronic muscle tension that can 'lock' the spine. It builds up strength in the muscles that hold the spine in position.'

Yoga also has a relaxing psychological effect. 'Tension and anxiety can make back pain worse,' he says. 'Yoga is good for stress because it slows down the respiratory rate and heart rate, lowers blood pressure and reduces the levels of 'stress' hormones.'

Dr Monro says that regular practice of about 20 minutes a day can yield benefits in a few weeks, although severe conditions may need up to a year.

The Yoga Therapy Centre (at the Royal London Homoeopathic Hospital) 56-57 Great Ormond Street, London WClN 3HR (071-833 7267). Individual assessment costs pounds 30 and classes pounds 10 each. The centre can also provide details of trained yoga therapists in other parts of the country.

(Photograph omitted)