People who experience pain in their knees when using the stairs may be displaying early symptoms of the most common type of arthritis, a new study has found.

Osteoarthritis (OA) is the most common type of arthritis. Symptoms include pain, stiffness and swelling in the joints and most Irish people over the age of 55 have evidence of the condition at some joint in their body.

The most common weight-bearing joint affected by the condition is the knee.

UK researchers set out to investigate which patient activities were first linked with knee pain, in an attempt to improve the early detection of the condition.

"At present we have little concept of ‘early' osteoarthritis and often only see people when they have significant longstanding pain and loss of function. This research is vital to understanding early symptoms of knee osteoarthritis," explained lead researcher, Prof Philip Conaghan, of the University of Leeds.

He and his colleagues looked at over 4,600 people who had, or were at high risk of developing, osteoarthritis. The participants completed surveys every year for up to seven years. This was done to keep track of the emergence of pain while undertaking different activities over a long period.

The researchers found that using stairs was the first weight-bearing task in which people noticed pain in their knees. This was followed by pain while walking, pain while standing, pain when sitting or lying down and lastly, pain when resting in bed.

"Knowing this will help us intervene earlier, perhaps leading to more effective ways of treating this very painful condition," Prof Conaghan said.

Details of these findings are published in the journal, Arthritis Care & Research.