A painful form of arthritis in the foot affects one in six people over 50 - more than previously thought, research suggests.
Experts at Keele University's Arthritis Research UK Primary Care Centre studied more than 5,000 people with painful foot osteoarthritis.
The condition is caused by inflammation in and around the joints, damage to cartilage and swelling. People can suffer a range of symptoms including pain, stiffness and difficulty moving and often have osteoarthritis in other joints, such as hips or knees.
The study found that foot osteoarthritis affects more women than men, while those who have spent a lot of time in manual work are more likely to develop it.
Three quarters of people with the condition reported having difficulty with simple day-to-day activities such as walking, standing, housework and shopping.
Dr Edward Roddy, clinical senior lecturer in rheumatology at Keele University, said the research had focussed on "midfoot" joints, which previous studies have neglected to do.
He said a "substantial proportion of people" with painful foot osteoarthritis have the problem in this area, meaning there has been a previous underestimate in how common it is.
He added: "Foot osteoarthritis is a more common and disabling problem than we previously thought, making everyday tasks difficult and painful for people affected.
"While it's been known for decades that joints in the foot can be affected by osteoarthritis, much of the previous research has focussed on the hip and knee areas, and research into the foot has concentrated almost entirely on the 'bunion joint' at the base of the big toe.
"However, by looking at the whole foot and the impact on people's lives, it's clear the problem is more widespread than we anticipated.
"Doctors and other healthcare professionals should also be aware of osteoarthritis as a common cause of foot pain in this age group."
According to Arthritis Research UK, 7% of people aged 45 and over have sought treatment for osteoarthritis in the foot or ankle, including 9% of those aged 75 and over.
Professor Anthony Redmond, spokesman for the charity, said: "This is a very important study. We know that foot problems become more much common as we get older but the medical and healthcare community have been guilty in the past of dismissing this as just an inevitable part of ageing.
"The new study tells us that these problems in the midfoot involve some of the same processes that affect arthritic hips and knees: conditions that are taken much more seriously.
"We have long known about some forms of osteoarthritis in the feet such as bunions, which are a common type of osteoarthritic damage affecting the big toe joints and are taken much more seriously, with both non-surgical and surgical treatments widely employed.
"The study tells us that if we want to keep our over-50s active and healthy we should be similarly serious about 'arch' or midfoot pain."
He called for wider use of X-rays to check for signs of the condition.
He added: "While osteoarthritis does not yet have a miracle cure, the associated pain and disability are not inevitable and people with foot pain should be given genuine treatment options - something can always be done."Suggest a correction