Physiotherapist Rachel Marffy is limbering up to treat some of the tens of thousands of runners competing in this month's London Marathon.

Married mother-of-four Mrs Marffy, 44, of Aston Upthorpe, near Didcot, works as a physio at The Park Club Physiotherapy and Sports Injuries Clinic in Abingdon.

But on April 17, she will be inside one of the marathon's medical tents, treating a stream of blisters, sprains and strains.

"I'll probably never take part in the marathon, but when I saw an ad in a physio magazine for volunteers, I thought it would be a good way to make a contribution," she said.

"We expect to see a wide range of problems, including bruising, sprains, cramp and fatigue, and I expect there will be some pretty horrible blisters to deal with. "We could also see some stress fractures caused by running on asphalt for such a long distance and also dehydration, particularly if the weather is warm."

The physios work in teams. They are posted at 13 stations -- large marquees, tents and ambulances near the finish line.

Mrs Marffy said: "There are about 400 St John Ambulance personnel, specialist doctors and cadets, 50-100 sports medicine doctors, 100-140 physiotherapists and 50-70 podiatrists, all working together."

There is an elite tent near the finish line, three huge tents with intensive treatment units and also a secondary finish tent near Horse Guards Parade.