Running and Knee Arthritis – Once Again…
Gretchen Reynolds, a health and fitness columnist for the NY Times, recently (9/25/13) penned an article titled “Why don’t runners get knee arthritis?”
If you’ve followed this column, you know that this is a topic I have covered a few times in the past, in an attempt to provide runners with hard evidence to refute the persistent question/statement non-runners often lob at us: “Aren’t you afraid that all that pounding will lead to arthritis?” As I have shown in the past, numerous studies have again and again shown that there is no increased risk for developing arthritis of the knees or hips in those who engage in long-distance running for many years. Ms. Reynolds cites two more recent studies that once again show this to be the case.
Despite what appears to be this compelling evidence, a tour of the online comments from readers reveals an unrelenting skepticism on the part of many people. Typical comments seem to fall within two categories; (1) those who question these findings due to the fact that they know runners who have had joint replacements, and (2) those who are unconvinced because, after all, almost every runner they know has complained of knee pain at one time or another. After reading these remarks, the question I’m left with is – why does this myth persist?
With respect to the first group, it has to be pointed out that they are missing a crucial piece when they seem to be interpreting Ms.Reynolds’ article title, and the various study conclusions, as indicating that distance running in some way confers immunity from the development of knee or hip arthritis. This is, of course, not the case. A certain percentage of runners do in fact develop arthritic knees and/or hips, and some do go on to require joint replacements. But – and this is a big but – this percentage is not at a higher rate than the sedentary population. (Some investigators do propose that running may actually lower the risk, but this has not been conclusively proven.)
Based on this fact alone, there should therefore be no reason to blame this condition on the activity. To date, there has been no single cause of arthritis definitively identified (e.g., genetics, prior injury,abnormal mechanics, bacterium…), so those runners who do end up with the condition may just be victims of the same causes as anyone else.
With respect to the second category of skeptics – those who point to the high incidence of knee pain in runners – the problem is that their conclusions are based on a misunderstanding of knee anatomy.
The knee actually has two joints – one between the two long bones of the lower limb, the femur and tibia (thigh and shin bone), the one between the patella (knee cap) and the femur. The arthritis that possibly leads to a joint replacement involves the first joint, while the condition that most often causes knee pain in runners, known by various names such as Runner’s Knee, patellofemoral pain syndrome (PFPS), or chondromalacia patella, is found in the second. (See Articles #15, 16, 72, 89, and 103). While PFPS is the most common knee complaint among runners, it is not the type of arthritis that necessary progresses steadily, nor does it lead to joint replacement.
The point is, this is a very common problem and so it is not surprising that the non-running public combines two separate facts – runners often have knee pain and arthritis causes knee pain – into the one conclusion that runners are doomed to develop knee arthritis. But now that you know why this myth persists, you are well-armed with the information you’ll need at your next cocktail party or family reunion to explain to your obnoxious boss or uncle why running is not going to inevitably lead to your joints being replaced. And they will either be grateful for the tutorial or will walk away glassy-eyed, never to bother you again with this question.