Runner’s Knee
With "Runner's Knee", you need to strengthen the quad muscles in the front thigh.
Runner's Knee typically hits beginning runners or runners who have started up again after a lay off and is caused primarily by the quads being weak relative to the hamstring (back thigh). This causes the knee cap to not track properly in its groove which causes pain in the front of the knee under and adjacent to the knee cap (patella). The pain is caused by a temporary softening of the articular cartilage that lines the backside of the patella and/or the articular cartilage on the trochlea section of the femur (leg bone) that the patella glides across. The softening will reverse itself and heal provided you don’t try to train thought it. If you train through this for many months you can do permanent damage to the articular cartilage. This is rare as usually the pain and/or frustration is too great and the runner stops in time. However, beware of the risk of permanent damage if you try to train through it for many months.
You need to ice to get rid of any inflammation under the patella (which is usually not visible except in severe cases). Just because you can’t see any doesn’t mean it is not there and you need to ice to get rid of inflammation so it can heal.
You have to strengthen the quads, specifically the VMO muscle in the quad, which is the tear drop shaped muscle that attaches at the top inside of the knee. A strong VMO will pull the patella medially (toward the inside) and keep it into the groove.
Squats are the by far the best way to strengthen it, followed by leg presses followed by leg extensions and least effective is straight leg raises. However, leg extensions tend to hurt too much if you already have "Runner's Knee" so you should NEVER do leg extensions when you have Runner’s Knee.
First try squats with no weight. Stand with feet about shoulder width apart, with feet pointed slightly outward. Put your hands on your hips and squat down until your upper thigh is parallel to the ground. Keep your back as straight as possible. Do 1 set of 10 reps. Do it twice a day. If it hurts, vary your foot position until it feels most comfortable. Every day add a few more reps until you get up to 50 reps. Gradually your VMO will get stronger and the knee cap will track better over a few weeks and the pain will gradually go away.
If pain is too much and changing foot positions doesn't help you will have to try some of the alternate exercises (leg press or straight leg raises). Some people wait too long to address the problem and by then the only exercise they can tolerate is straight leg raises. If that is the case, do straight leg raises with foot pointed slightly outward to stress the VMO muscle.
There are 3 other things that will help and you should do.
1) Stretch the hamstring. When hamstrings are too tight they can cause the patella to track laterally (to the outside) and out of the groove. Stretching hamstrings will help.
2) Stretch the IT band. The IT band partially attaches to the patella and if too tight will pull the patella laterally (to the outside) and out of the groove. Stretching the IT will stop that excessive lateral pull.
3) Stretch the patella towards the inside (medially). Sit with both your legs straight. Place both thumbs on the lateral side (outside) of the patella, one thumb on the top of the outside and the other thumb on the bottom of the outside. Push the patella medially (towards the inside) and hold for 5 seconds. Repeat several times. Don’t push it laterally (to the outside or it will make it worse).
You may have a little pain at first doing the squats.
If the pain is really severe you can’t do squats or leg presses you might have to start out with the “baby” quad exercises such as quad sets, straight leg lifts, you can progress to the squats with no weight. The squats strengthen at least 10 times faster than other exercises so if you can do them without much discomfort you definitely want to do squats.