Walking reduces the risk of mobility problems in people with knee osteoarthritis, a new study suggests.

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.

Previous research suggests that knee OA is a leading cause of functional limitation among older people. This means that many struggle to do everyday activities such as walking and climbing stairs.

"Our study examines if more walking equates with better functioning, and if so, how much daily walking is needed to minimise risk of developing problems with mobility in people with knee OA," noted researchers from Sargent College at Boston University in the US.

They measured the daily steps taken by almost 1,800 people who either had knee OA, or were at risk of developing the condition. The participants were followed up two years later.

The study found that walking reduced the risk of functional limitation among the participants. In fact, walking an extra 1,000 steps every day was associated with a 16-18% reduction in risk.

The threshold was found to be 6,000 steps daily. In other words, walking 6,000 or more steps every day offered the greatest benefit to those with knee OA.

The researchers emphasised that walking is an ‘inexpensive activity'.

"Despite the common popular goal of walking 10,000 steps per day, our study finds only 6,000 steps are necessary to realise benefits. We encourage those with or at risk of knee OA to walk at least 3,000 or more steps each day, and ultimately progress to 6,000 steps daily to minimise the risk of developing difficulty with mobility," they said.

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