“The pressure (or pounding) of each stride helps harden the bones and improves bone density. That pressure will also strengthen and improve flexibility of the joint because the ligaments and muscles that support the knees are reinforced by the stresses of running, improving the knees’ mechanics.”
Dr. Edith Cullen, musculoskeletal and sports medicine specialist with OSMC
Question From your editor: I have been running for 18 years. Hardly a year has gone by when someone didn’t warm me: “Running is bad for your knees.” Well thanks, I say, and kindly add that actually, I had bad knees before I started running. In fact, I couldn’t run a block without shooting pain in my knees. But I do wonder, is that really true, or just my imagination?
Answer Dr. Edith Cullen, a musculoskeletal and sports medicine specialist with OSMC, agreed (with several asterisks) that there was some truth to my statement. She pointed out the good and the bad of how running affects the knees. Perhaps most importantly for RPM readers, she also stressed the need to protect our knees in order to keep running a constructive activity for the body. Below, Dr. Cullen gives us her medical point of view and research insights on the impact running has on our knees.
Running encourages weight loss. And weight loss takes pounds and pressure off the knees exponentially. Walking increases the pressure on the knees four to five times the person’s weight and running is almost twice that of walking. So, every pound lost will mean exponential pressure off the knees. Lose the weight with proper diet and more gentle cardio activity before you take up running. No need to start out behind.
Running does have protective value. The pressure (or pounding) of each stride helps harden the bones and improves bone density. It will also strengthen and improve flexibility of the joint because the ligaments and muscles that support the knees are reinforced by the stresses of running, improving the knees’ mechanics.
The good news for cartilage for those of us too far in to quit: The compressive motion of running helps bring more nutrient-feeding synovial fluid to the knees. We must keep in mind, however, that the line of how many miles before the cartilage begins to break down is difficult to draw and varies by genetics, previous injuries and many other factors.
Current studies indicate jogging or running itself will not cause arthritis. In fact, one study found that when people who were at risk of developing arthritis began a moderate running program, the health of their cartilage improved, while the cartilage of similar people who didn’t start running did not improve.
In general, there is medical consensus that “moderate” running will not ruin already healthy knees and, that when protective measures are practiced, the knees may very well strengthen.
And the word “moderate” means marathon-distance running and training will most likely take a toll on your knees. The prescription is for short distances, running two and four miles regularly vs. continued long runs. Remember, genetics, previous injuries, running gait and extra pounds all weigh in on each runner’s equation.
If you already have arthritis with bone-on-bone contact and no cartilage in your knee, running will make it worse.
Knees take the toll for about 48 percent of injuries in the running world. Anterior knee aspect injuries lead the way—20 percent in men and 10 percent higher in women due to female hip alignment issues.
If you have a knee replacement, you should be done with running. You want the joint to last and the more you pound, the faster that joint wears out.
Clearly, there are people who have been running and training for marathons their entire lives with few issues. (Alas, they are the lucky ones!) Listen to your body. If you are a runner who is constantly battling injuries, you may not have to quit, but you do need to start protecting more.
If you are going to run, protect your knees. You know the requirements, but do you practice them all, or choose the most convenient elements? Use Dr. Cullen’s below advice as a checklist (not a menu) to keep risk of injury to your knees—and all lower extremities—at the lowest odds.