Runner’s knee is one of the most common sports injuries in runners’ population (both recreational and professional long distance athletes), also called chondromalatia patellae.
The knee is a very complex joint. It involves articulation between tibia (calf bone), femur (thigh bone) and patella (knee cap or kneepan). But, when we speak of the runner’s knee, it’s important to mention two other important structures you must know about to understand this injury: quadriceps (above the patella) and patellar tendon (beneath the patella).
Causes of injury
When the knee joint functions normally, while running patella smoothly slides up and down without touching the femur. Sometimes not everything is perfect and inner side of patella painfully scratches the femur causing its inner cartilage to become uneven. There are different reasons for these pathological events. One of most common is weakness of medial (inner) part of quadriceps – vastus medialis, which is most important for regular patellar movement – the part that supports its central stabilization. With some runners activation of vastus medialis happens only in the last third of the extension (extended leg). When the medial part of quadriceps is too weak, there is no patellar stabilization – it moves laterally too much causing damage to the inner surface. Also, overdeveloped lateral (outer) part of quadriceps, usually found in runners with weak medial part of quadriceps, can be a predisposition for said injury. Foot pronation (inverting the foot inwards) also leads to patellar instability.
Other risk factors are:
- wide pelvis (women)
- X legs (genu valgum)
- high position of patella
- worn out shoes
- over training
- too much running uphill
Most important symptom is pain. It is usually experienced in the patella or near it, especially along its inner part or under it. Pain can be felt after long periods of sitting with bent knees (movie theatre sign), which gradually disappears when we start walking and maximizes when squatting. Running downhill can also be one of the causes.
I’d like to emphasize that pain in the knee doesn’t necessarily mean runner’s knee. Other possible reasons include ligament and meniscus injuries, osteoarthritis, iliotibial syndrome, but this is not the point of this article. So, if you’re not sure about the cause of knee pain, it’s best to visit your physician.
Next important sign is crepitating (scratching) we hear during movement of the knee joint. Some cases involve swelling of knee joint, which gets worse while moving, and better while resting.
- Stop running, take non-steroid anti-inflammatory medication for 5 to 7 days, apply ice under the patella in periods of ten minutes (wait for cold skin to get warmer before applying the ice again, so the tissue doesn’t get damaged). I don’t advise applying ice longer than three days.
- Avoid carrying heavy loads.
- Strengthen your quadriceps, but only when it’s pain-free
There are different exercises for strength of quadriceps, especially its medial part, but one of them is especially advisable after the pain stops: lie down and place a pillow under your knees. Strain your quadriceps by pushing the pillow down by your knee. Repeat this 20 times, in 10 series per day. Any exercises involving squats are not allowed, because this is the worst possible position for patella. Also, I would like to mention that you should simultaneously do stretching exercises for gluteal muscles, iliotibial tendon, hamstrings, calves, and Achilles tendon. .
Full recovery can be expected in 4 to 6 weeks. After that you can return to running, but gradually.
If self-help doesn’t work, then after two or three weeks seek help with your doctor. He will diagnose your problem, and in cooperation with consulting specialist (orthopedist or physiatrist) he will try to help you. As possibility of therapy I would mention wearing ortoses, physical therapy, and even surgery as a final possibility.
Without specific quadriceps strengthening exercises for achieving better muscle balance, and strict performing of stretching exercises there will be no permanent solution and the problem will arise again. In other words, a reason for injury must be found and removed.
According to my experience with patients and talks with runners before and after races – you are not following the treatment! This doesn’t apply to everyone, but is true for most. If you really want to get better, you must rest. Any activity causing pain in the knee, which is most often running, walking up or down the stairs etc, leads to further irritation of cartilage underneath the patella. You must give the body a chance to get better. Many runners think only of the next race, and this injury is only something that will vanish by itself in a few days. If that’s the way you think, you have a problem that only you can solve, because your thoughts must be focused on healing that takes at least a couple of weeks. Without full recovery there is no real racing.
Coming back into running has to be gradual and carefully planned. Listen to warning signals from your body. Don’t focus exclusively on measuring your heart rate and kilometers ran. Running is very beneficial for cardiovascular system and lungs, but if muscle or skeleton systems get damaged, you must consider the possibility that you’re overdoing it. So every warning sign should be thought about. It’s the only way to prevent the injury. If you’re already injured, you must rest. Otherwise, your body won’t be able to keep up.