There is perhaps no injury more associated with running than the aptly named "runner's knee." This affliction, also known by its scientific name, patellofemoral pain syndrome (PFPS), strikes most runners at some point in their careers. It is characterized by a dull, aching pain on the top and front of the kneecap (aka- the patella).
This pain can be felt during running, kneeling, walking upstairs or even just sitting for a long period of time. While the pain is often not extreme in the initial stages of injury, it can grow over time and hamper not only your ability to run, but also cause everyday activities to be quite painful.
Runner's knee is typically an overuse injury and its causes are wide ranging. A muscular imbalance in the hips or legs is one common source of patellofemoral pain. If, for example, a hip is weak and its range of motion is limited, the quadricep would have to do extra work to compensate for the hip's weakness. The over-worked quad might then tug on the patella, causing an onset of runner's knee.
Another cause of PFPS could be a malalignment in the lower extremities. A physical examination by a medical professional is the most effective way to determine the cause of your specific injury.
Even though runner's knee is quite prevalent, most cases are minor and can be cured without the use of surgery. If you begin experiencing pain on the front of the kneecap, it is important to reduce mileage or stop running entirely to keep symptoms from worsening. Instead of running, swim or bike for a few days. If you catch the injury early enough often several days of cross-training will fix the problem.
Also, begin a regiment of icing the knee as well as taking anti-inflammatory medications such as ibuprofen (be sure to follow the label's instructions regarding dosage). Finally, seeing a physical therapist who can work with you to strengthen any muscular imbalances is important to cure runner's knee as well as to prevent a reoccurrence in the future.
Often, cases of PFPS require you to strengthen your quads and hips. For more info about hip strength, check out this article.
Runner's knee can be frustrating, but know that you will get through this struggle and be back running pain free before you know it!