Knee osteoarthritis is one of the major causes of mobility limitations in older age. However, walking a lot may protect against damages, according to US physicians. As they write in a study published in «Arthritis Care & Research», walking at least 6,000 steps per day is necessary to minimise the risk.

Researchers at Boston University (Massachusetts) measured the number of steps taken by 1,788 persons with, or at risk of, knee osteoarthritis over a period of seven days. Two years later, the functional limitations were measured.

When the study participants walked less than 6,000 steps per day, specific mobility problems were more likely. Per additional 1,000 steps, the incidence of functional limitations decreased by 16 to 18 per cent.

«Walking is an inexpensive activity and despite the common popular goal of walking 10,000 steps per day, our study finds only 6,000 steps are necessary to realize benefits», said study author Daniel White. He recommended people with, or at risk of, knee osteoarthritis to walk at least 3,000 steps daily and to gradually increase this number to 6,000 to minimise the risk of functional limitations.