This might be a silly question, but I honestly don’t know. I’ve been suffering knee pain usually after seven or so miles of running. Based on the location of the pain and feedback I’ve received online, it seems likely that it might be runner’s knee. I’ve been trying to strengthen all the muscles that attach to the knee. I was wondering if there is some kind of joint supplement that would help someone with runner’s knee as well? Or would supplements not really apply for something like runner’s knee?
Thank you for this question; I do not think there is a category of silly questions when it comes to health.
“Runner’s knee” is another name for patellofemoral pain syndrome, which translates in plain language to kneecap pain. The kneecap is a sesamoid bone located within the tendon that connects the quadriceps muscle to the lower leg bone, or tibia. It functions to improve the forces through the tendon as it crosses the joint and to protect the tendon from wear and tear.
When properly aligned, it slides in a groove on the end of the femur as the knee bends. Although it is nicknamed runner’s knee, patellofemoral pain occurs in athletes from nearly every sport and in non-athletes who stress the knee in their daily activities.
From my perspective, patellofemoral pain is most often a result of abnormal mechanics caused by problems up- or downstream from the knee, forcing the patella to bump against the femoral groove. A good analogy to explain this is of a train car: the patella is like a train on the femoral groove railway track.
A longstanding explanation for runner’s knee is weakness in the quadriceps (the vastus medialis), and while that may contribute to the pain, it is not the usual culprit. Vastus medialis weakness was thought to cause the kneecap to drift into the “rails,” putting pressure on the edge of the kneecap and causing pain. Many professionals recommended strengthening the vastus medialis to keep the kneecap aligned in the centre of the femoral groove.
But more likely, the cause is the track moving under the train, putting pressure on the edge of the kneecap. This occurs when the pelvic muscles controlling the femur are not strong enough to keep the femur from rotating inward during the weight-bearing phase of your running gait. As the femur rotates inward, the patella strikes the edge of the groove causing pressure - and pain. By strengthening the external rotators of the hip, you can help hold the femur in the proper position while you run, which should allow your knee to heal.
Why seven miles for you, and three, or 15 miles for others? This probably has to do with the strength it takes to keep your knee aligned through the entire run. To get to seven miles and beyond without pain, you will need to strengthen your external rotators and core so your muscles can endure the loads of longer distance running.
I would suggest you keep your mileage below the pain threshold and meet with a physiotherapist who can make sure your pelvis is properly aligned and guide you through a strengthening program to improve the mechanics of your patellofemoral joint. This investment in kinetic chain evaluation and core strengthening will pay off with long term dividends of pain-free running.