Causes 

There are three main types of runner’s knee: iliotibial band syndrome (ITBS), patellofemoral pain syndrome (PFPS), and medial tibial stress syndrome (MTSS). ITBS is caused by friction between the iliotibial band—a thick band of tissue that runs outside your thigh—and the bones in your lower leg. This friction results in inflammation and pain in the affected area. ITBS is most common in long-distance runners and those who run on hilly terrain. 

PFPS occurs when the kneecap (patella) rubs against the thighbone (femur). This rubbing can happen for several reasons, including incorrect kneecap alignment or a change in training routine (such as increasing mileage too quickly). PFPS is most common in women due to their naturally wider hips which result in a higher angle between the kneecap and thighbone. This higher angle puts more pressure on the kneecap when running. MTSS is caused by overuse of the shinbone (tibia) and surrounding muscles and tendons. This overuse leads to microtears in these tissues, which results in pain and inflammation. MTSS is common among long-distance runners because they put a lot of mileage on their legs every week. 

Symptoms 

The symptoms of runner’s knee depend on which type you have. However, all types generally result in pain around the knee joint that gets worse with activity (such as running) and improves with rest. For ITBS specifically, you might also feel pain on the outside of your knee or hip when going up or down stairs or when sitting with your knees bent for long periods. For PFPS specifically, you might notice that your pain gets worse when going up or down hills or after sitting for extended periods with bent knees (such as at a movie theater). MTSS typically results in shin pain that worsens with activity but might also cause swelling in the affected area. 

Treatment 

The best way to treat runner’s knee is to rest until the pain goes away completely. You should also ice your knee for 20 minutes at a time, several times per day, to reduce inflammation. For ITBS specifically, you can also try foam rolling or stretching your iliotibial band to loosen it up and reduce friction between it and your leg bones when running. For PFPS specifically, you should focus on strengthening your quadriceps muscles (located at the front of your thigh) to take pressure off your kneecap when running. And for MTSS specifically, you should focus on stretching your calf muscles (located at the back of your lower leg) to ease tension on your shinbone when running.  

Prevention 

The best way to prevent runner’s knee is to cross-train with other activities such as swimming or biking so that you’re not putting excessive mileage on your legs every week. You should also warm up before running and cool down afterward by stretching all major muscle groups in your legs.      

Conclusion 

Runner’s knee is a catch-all term for any pain around the knee joint while running. There are three main types of runner’s knee: iliotibial band syndrome (ITBS), patellofemoral pain syndrome (PFPS), and medial tibial stress syndrome (MTSS). Each type has different causes but similar symptoms, including pain around the affected area that worsens with activity and improves with rest.  

Treatment options include resting until the pain goes away completely, icing your knee several times per day, foam rolling or stretching if you have ITBS, Quadriceps exercises if you have PFPS, and Calf stretches if you have MTSS. You can also prevent runner’s knee by cross-training with other activities warming up before running and cooling down afterward by stretching.