By Roger Harrabin
BBC Radio 4 Today Programme
Top experts in bones and joints have warned that the government's public health policies concentrate too heavily on hearts and lungs.
Yoga is good for posture
They say more attention should be paid to the whole human frame.
Ministers plan new strategies to tackle obesity by increasing physical activity and to cut falls among old people.
But two leading rheumatologists told Today that both strategies ignored the need for flexibility and agility.
They said sitting slumped in a chair all day was not just bad for the heart and the weight, it also reduced the mobility of joints which greatly increased the likelihood of falling.
Having flexible joints had another benefit, too, they said - it made people feel better and happier in themselves.
Professor Rodney Graham, from University College London Hospitals, said the Department of Health under-emphasised the need to keep the musculo-skeletal system healthy.
"It is a neglected area, which needs attention," he said.
Professor Tony Woolf, from the Royal Cornwall Hospital, who is working with the World Health Organization on its project, 'The Decade of Bones and Joints', said one in four adults in Europe had a structural condition like back pain, rheumatism or arthritis that caused them problems.
He said: "It gets considered a normal part of ageing - something that normally happens.
"We always talk about pain being bearable - implying that we should put up with it - but we now know there are things we can do to prevent it or treat it more effectively."
He said people needed to keep up flexibility to stave off pain.
Professor Woolf said in Eastern cultures where people are more physically active and often sit on the floor rather than on chairs, there was anecdotal evidence that problems with joints were less common.
The author of a yoga book, Anton Simmha, has just returned from India.
The route of our problems?
He told Today that people there - especially children - appeared much more aware of their bodies than people in the UK, and enjoyed better posture, co-ordination, flexibility and balance.
He urged schools to encourage children to sit cross-legged in class whenever possible in order to retain their childhood flexibility keep their back muscles active.
He also wants teachers to offer exercises like stretching and yoga which encourage flexibility and parallel development of both sides of the body to counterbalance sports like football, tennis and cricket which encourage the body to develop out of line.
A big part of the problem in the West, he said, was the ubiquitous use of chairs.
"In the West, the chair does present a very serious problem. If you sit a lot, the muscles of the legs shorten so dramatically that it overloads the spine, causing everything from bad posture right through to more serious problems."
"If you sit on the floor, your muscles are working. The spine is working to align itself, making micro-adjustments to keep you erect. If you are sat in a chair, invariably you tend to slump."
Falls among elderly people cost the NHS almost £1bn a year. Ministers plan a drive to try to tackle the problem through practical measures such as making sure carpets are properly fixed.
Another possible measure may to encourage firms to buy desks which enable employees to work standing as well as sitting.
They are expensive, but Scandinavian countries reported a big improvement in back problems and RSI following their introduction.