December 20, 2022

What is runner's knee?

Learn everything that there is about runner's knee.

In short

Patellofemoral pain syndrome, also known as runner's knee, is a common condition that affects the patellofemoral joint, which is the joint between the patella (knee cap) and the femur (thigh bone). It is characterized by pain that is typically located behind or around the knee cap and is often triggered by activities that put pressure on the joint, such as running, jumping, and climbing stairs.

Runner's knee is a common injury among runners, hence the name, but it can also affect people who are physically active in other ways. It is more prevalent in women than men, and research suggests that this may be due to differences in biomechanics. The incidence of runner's knee varies among different populations, with estimates ranging from 5.1% to 14.9% of adolescent amateur athletes developing the condition over a single season.

Runner's knee can be a frustrating and persistent condition, with recurrence rates estimated to be between 70% and 90%. Despite the effectiveness of exercise therapy in reducing the risk of recurrent knee pain, many patients do not seek additional care after a diagnosis of runner's knee.

The etiology of runner's knee is complex and varied, making it difficult to determine the best course of treatment for each individual. To help guide therapy, clinical practice guidelines for runner's knee propose a classification system that consists of four subcategories: patellofemoral malalignment, patellofemoral instability, patellofemoral osteoarthritis, and patellofemoral pain of unknown cause.

Causes for runner's knee

Patellofemoral malalignment refers to a misalignment of the patella within the patellofemoral joint. This can be caused by structural abnormalities in the bones or muscles, or by muscle imbalances that pull the patella out of its normal position. Patellofemoral instability occurs when the patella is not stable within the patellofemoral joint, often due to weak muscles or ligaments. Patellofemoral osteoarthritis is a form of degenerative joint disease that affects the patellofemoral joint. Finally, patellofemoral pain of unknown cause refers to cases where the cause of the pain is not clear and requires further investigation.

Treatments for runner's knee

Treatment for runner's knee often involves a combination of approaches, including exercises to improve strength and flexibility, changes to training and activity levels, and the use of pain management techniques such as ice and non-steroidal anti-inflammatory drugs (NSAIDs). Physical therapy can also be helpful in addressing underlying muscle imbalances and improving patellar tracking. In more severe cases, surgery may be necessary to correct structural abnormalities or repair damaged tissue.

Prevention for runner's knee

Prevention of runner's knee involves addressing any underlying risk factors, such as muscle imbalances or overtraining, and taking steps to protect the patellofemoral joint during physical activity. This may include using proper footwear, incorporating strength and flexibility training into your routine, and avoiding high-impact activities if you are prone to runner's knee.


In conclusion, runner's knee is a common and potentially persistent condition that affects the patellofemoral joint. It is more common in women and can be caused by a variety of factors, including structural abnormalities, muscle imbalances, and degenerative joint disease. Treatment typically involves a combination of exercises, changes to activity levels, and pain management techniques, and may include physical therapy and surgery in more severe cases. Preventing runner's knee involves addressing underlying risk factors and protecting the patellofemoral joint during physical activity.

Written and edited by Netic Team

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