Knee pain is common among runners and is not something to ignore.

Runner’s Knee: What Causes It, How to Prevent It?

The most common serious running injury, Runner’s Knee is an aching pain in and under the kneecap caused by irritation of the joint. As suggested by its official name, patellofemoral pain syndrome (PFPS), the problem develops when the patella (kneecap) doesn’t track correctly in the groove at the top of the femur (thigh bone), causing inflammation.

Are You at Risk?

Despite its nickname, PFPS can happen to anyone as a result of a sport or activity that involves jumping, lunging, or putting pressure on the knee. Long bouts of sitting are also hard on the knees. Runner’s Knee tends to strike those who are more mobile, so in this case being loose or stretched isn’t necessarily a good thing. In my experience, many runners over-stretch their quads, which can contribute to this problem. I see PFPS most often among very mobile, flexible women.

Overpronation also makes you more at risk, which in turn can be a sign of other problems such as weak hips. If your hips are weak, you often can’t plant the foot in the proper position, so your thighs are adducting, enhancing pronation. Weak quads and glutes are also a risk.

How Does It Happen?

You may be training too hard or going for too much distance. A lot of times runners ignore pain, thinking it will go away, but running through it lets the damage progress. It’s important for runners to understand a little bit about anatomy and biomechanics and pay attention to what’s happening in their bodies.

What Signals Should You Watch Out For?

Pain or swelling, but you can’t just assess what happens when you’re out on a run, you also need to assess that evening, and the next day, as twinges of pain may happen later. You might notice your knees hurt when you sit for a long time.

What To Do When Your Knees Hurt?

Ice is the best treatment right after a run, especially if you notice signs of redness or swelling. Heat is better for longterm degenerative changes. If you feel like you pushed too hard, take it easy the following day. Sometimes people feel like they have to make it up if they cut back on a workout, but if you’re doing any work at all you won’t lose what you’ve gained that fast.

Yoga is a nice alternative to add some flexibility; I find that guys benefit more from yoga since they tend to be less flexible than the ladies. Bicycling is good for building quads, which support your knees.

Tips for Protecting Your Knees

  • Avoid Steep Downhills. Typically you’re going to have more difficulty going downhill, so rerouting your runs around steep hills may help, or you can step sideways down the hills to take the pressure off. You might try interval training using hills that aren’t so steep.
  • Strengthen Supporting Muscles. Do exercises to build up quads, glutes and hamstrings. with exercises like lateral side steps and squats. It’s also important to stretch your hip flexors.
  • Support Your Knees. Athletic tape is worth a try; there are many techniques and a physical therapist can help you make the right choices. Sometimes I put the softer tape on, then layer the harder tape on top to double it up. Elasticized braces may ease pressure but if you have to consistently rely on those, you need to reconsider the distance you’re running.
  • Try the Stairmaster. If you find uphill running less painful, try simulating hills on a treadmill. Uphill running strengthens your glutes, which can help control movement in the hips and thighs, preventing the knees from turning inward.

Final Takeaway: When one area is weak or hurting, there’s a tendency to compensate by putting pressure on another area, which can lead to further injury. When your knees hurt, you’re going to try to make up with your quads and calves. Somebody’s going to do the work. That’s why it’s important to vary your workouts and add other sports. You need to work on strength and flexibility in all areas.

Brian Soo is a senior physical therapist at the Kaiser Permanente San Francisco Medical Center who works inpatient, outpatient, and in sports medicine.  A recreational runner for many years, Brian also bicycles, plays racquetball, and most importantly, paddles on a 20-person Dragon Boat team that competes internationally and practices three times a week. He also enjoys active video games and believes they can be an excellent complement to an overall fitness regime.