Runners commonly experience several different types of knee injuries. If your knee throbs when you run -- and resting for several days doesn't help -- you'll likely need to see your physician. You may have an injury to a tendon or even a stress fracture. If that's the case, you'll need treatment before you can run safely again. Since it can be difficult to differentiate between these conditions based on your symptoms alone, you'll need to see your physician for testing and a diagnosis.
Runner's Knee
Patellofemoral pain syndrome, or "runner's knee," presents as pain directly behind your kneecap, and results from a heavy running routine or other overuse of your knee. If you have runner's knee, you'll probably feel more throbbing when you run downhill or go down a set of stairs. In addition, you may sometimes hear a grinding or popping noise in the affected knee, and it may swell up. Treatment of runner's knee involves basic first-aid steps such as ice packs, over-the-counter pain killers and joint elevation. Your physician may recommend you wear a custom knee brace for better support.
Bursitis
Bursitis caused by running also can cause pain behind your kneecap. It involves inflammation of the bursa, a small lubricating sac in your knee. Again, you can blame overuse of your knees through aggressive training, especially downhill. If you have knee bursitis, you can treat it with ice and pain medication. If the pain fails to subside, talk to your doctor about getting an injection of steroids and anesthetic directly into your knee, which should offer quick relief.
Tendon Injury
An injury to your hamstring muscle or one of its tendons actually can result in knee pain when you run, according to Ithaca College. If you normally fail to warm up properly by stretching, you might be more susceptible to this type of injury, which will make your knee painful to extend fully; if that's one of your symptoms, your physician may order an MRI to confirm the diagnosis. If you have a tear in a tendon, you'll need to rest for six weeks or more before returning to running.
Stress Fracture
Runners -- especially female runners -- run a greater risk for stress fractures of the bones in their knees, legs and feet, according to New York University Medical Center. It's difficult or impossible to tell from your symptoms whether you've actually got one of these hairline cracks in your bones. To provide a firm diagnosis, you'll need X-rays. Some forms of stress fractures require aggressive treatment to avoid further damage, while others may simply warrant conservative treatment involving rest and cold packs. Your doctor can advise you on the best treatment, but unfortunately, you probably won't be able to run for at least two months.
References
- Columbia University Medical Center; Patellofemoral Syndrome; Pierre Rouzier, M.D.; 2003
- Ithaca College; Posterior Knee Pain and Its Causes; Julie Muche, M.D.; March 2004
- Hospital for Special Surgery; Goosefoot (Pes Anserine) Bursitis; September 2000
- NYU Medical Center; Stress Fractures and Knee Injuries in Runners; Anne Hoch, et al.; 2005
