A 45-year-old ex-serviceman has found that the physically active life he has led for the past 25 years has left him with chronic low back pain. X-rays show some excessive wear and tear in his lumbar vertebral joints but an MRI scan demonstrates that there is no significant pressure on his spinal cord. He finds his troubles are most annoying at nights when the discomfort keeps him awake.

The joints of all mammals other than the whale and sloth wear out. The speed with which this happens depends on what is required of the joint. Those, for example, of a farm worker, miner or soldier will show degenerative changes earlier than the same joints in the city solicitor or country parson. Heavy demands on a joint, such as those experienced by many athletes, may also prove destructive and cause early or excessive degenerative wear. A liability to osteoarthritic troubles also often has a genetic link. It has been found that a grindingly hard life in some families produces early severe osteoarthritis whereas in other families its members may get away with it.

Whatever treatment has been recommended for the reader's osteoarthritic spine, one of the simplest ways of helping it is to find the right mattress. Recent technological advances have led to the production, by Nasa's suppliers, of suitable padding called Tempur, a material that protects astronauts during re-entry into the Earth's atmosphere. It has been utilised to make mattresses and pillows. The material is open-celled, temperature-sensitive and supports the sleeper's pressure points by evenly distributing body weight. The mattress, pillow or padding moulds to the sleeper's exact shape and position. This gives the whole body support. The manufacturer claims that this leads to a quieter, less disturbed sleep as the pressure of even the heaviest patient is redistributed from time to time without the tossing and turning that characterises a suffering sleeper.

Does it work? I have now slept on one for the past couple of months and, to my surprise, after the first week or two, found that it lived up to its hype and has made sleeping more comfortable.