Running away from knee arthritis

If you ask someone if they want to significantly reduce their chances of developing knee arthritis in their lifetime, the answer is usually a resounding yes. However you may be surprised to learn that running can be one of the best ways to keep your knees in optimal condition. That’s right, despite the common misconception that running will ruin your knees, the available evidence actually indicates quite the opposite.

A large number of studies have demonstrated a reduced incidence of knee osteoarthritis (OA) in regular runners compared to the general population. Osteoarthritis is a degenerative joint disease that affects the joint cartilage and can also be considered natural wear and tear of the joint. In one long-term study out of Stanford University , researchers have been monitoring 45 runners and 53 non-runners for signs of knee OA since 1984. The latest results, published in the American Journal of Preventative Medicine show that 32 per cent of participants who are non-runners developed increased signs of knee OA compared to only 20 per cent of participants in the running group.

One possible issue with this and other studies is something called selection bias – perhaps the runners studied are a particular sub-group of the population that are not prone to damaging their knees while running and therefore drawn to the sport. A recent multi-centre study by a team in the USA called the Osteoarthritis Initiative has attempted to address this by intentionally recruiting their subjects from the general community rather than from an elite running background. They concluded that “non-elite running at any time in life does not appear detrimental and may be protective of OA”.

One key factor that is thought to reduce knee OA in runners is their, on average, lower body mass index (another great reason to run!) Osteoarthritis Initiave study accounted for this, demonstrating that in two people with the same BMI, the runner would be less likely to develop knee OA than the non-runner.

Now knowing all this is still not to say that running is for absolutely everyone and there are, indeed, some people for whom running may be detrimental. Your physiotherapist is well placed to advise you on an individual basis. However, next time you are sitting around the dinner table and that non-runner asks you if you’re concerned about the damage running may be doing to your knees you can re-assure both them and yourself that along with the multitude of other benefits from running the opposite in fact may be the case!