Is running bad for your knees?
One of the most common questions I get in the office is whether or not running and other physical activities and sports are inherently bad for knees. In one sense, it is a completely logical conclusion. Repetitive impact to the bones and articular cartilage of the knee would seem to have detrimental effects long term and potentially lead to arthritis of the knee. But is there definitive evidence that physical activity is harmful to the knee?
In the March 2011 issue of Medicine & Science in Sports & Exercise, the official journal of the American College of Sports Medicine, Donna M. Urquhart et al. present their results of a literature review to try to answer that question. They performed a thorough computer search for studies examining physical activity and evidence of cartilage damage. They found 28 studies that they felt were well designed and demonstrated evidence as to whether physical activity was related, positively or negatively, to radiographic signs (x-rays or MRI’s) of cartilage damage and/or arthritis.
Notice the bone spur under the inside of the patella (knee cap) of the left knee (the knee on the right side of the image).
I have always felt that the benefits of physical activity (cardiovascular fitness, weight loss, mental health, etc.) far outweigh the risks to bones and joints. I would argue that even if arthritis of the knee develops, we have treatments for it. Overall health, to me at least, is more important than possibly needing a hip or knee replacement later in life.
Notice how the cartilage is frayed on the entire surface of the femur. This study suggests that physical activity does not lead to this arthritis of the knee.
I will say that while I am excited that sports medicine physicians will be able to tell patients about the potential benefits of physical activity to articular cartilage of the knee, I think we have a long way to go to make definitive conclusions. The problem with these research studies is that there are a lot of variables such as weight, prior injuries, and surgeries. I would tell patients with known cartilage damage to the knee or prior injuries or surgeries to check with their orthopaedic surgeon and find out if running is potentially harmful. In those patients, adding non-impact activities (swimming, biking, using an elliptical trainer, etc.) can be mixed in with 2 or 3 days of running to improve health while still protecting the knee.
Running bad for your knees?
Podcast: Play in new window | Download
Click here for full episodes or subscribe on iTunes.
Feel free to leave your comments. To all the runners out there – are you excited about these findings? Did you even worry about damaging your knees with running? Share your thoughts!
C. David Geier Jr., M.D.
6 Comments
I am a 52 year old female and have been recently told by my doctor that I have lost cartilage and that I should not do any exercises except swimming and bicycling. I am now confused because this article indicates that there may not be a connection between running and lose of cartilage. Should I exercise (running, walking, etc.) or not?
Running may or may not cause cartilage damage in healthy knees with no structural damage. In knees with ligament, meniscal, or cartilage damage, the repetitive impact could be harmful over time. Now one could argue that the benefits of exercise outweighs any potential joint wear and tear, but switching at least some exercise to lower impact activity (bike, elliptical, etc.) is probably a good idea in people with cartilage damage (arthritis).
I wonder about the correlation vs. causation argument with this statement: “more active patients had fewer cartilage defects in their knees.” Is this because activity protects the knees, or because patients with cartilage damage are less active as a result of their injuries?
Great observation! I don’t think that there is an easy answer. There are many variables in play. Yes, someone with cartilage damage might have pain that keeps her from running, but that isn’t a guarantee. I have a patient with absolutely no articular cartilage on the femoral condyles or patellar throughout the knee and yet runs marathons and completes triathlons. We know that activity and motion can be good for articular cartilage, maybe by moving the synovial fluid through the knee, and that inactivity and immobilization can be bad for it. Whether someone with significant damage should perform a repetitive impact sport like running instead of one with less impact, such as biking or sing an elliptical trainer is also up for debate. Thanks!
I am a pediatrician and run or jog 20 miles a week. I have early OA of right knee and if I run fast and with bigger strides I get anterior knee pain, tenderness and a small swelling just above the patella. My right knee pains at rest though pain is bearable and does not require anti inflammatories. Kindly let me know if I should continue my running routine together with hamstring stretching and quadriceps strenghthening exercises.
Thank you sir.
I can’t really give you specific advice, but in general I rarely advise people that they must stop running. A good program of home exercise or formal physical therapy can be very beneficial for patellofemoral pain.