Runner’s knee? Jumper’s knee? What is it?

Pain at the front of the knee is a common complaint, especially amongst people who are physically active or involved in sport. However, there are several structures at the front of the knee that can be the cause of pain, and it can sometimes be difficult to differentiate between these causes. Two of the most common culprits are the patellofemoral joint and the patella tendon. This blog post will help you to understand the differences between these two common sources of pain, and to understand what treatment options are available. 

Patellofemoral joint pain:

Patellofemoral joint pain is one of the most common causes of pain at the front of the knee, with annual prevalence rates in the general population reported to be as high as 22% (1).  Patellofemoral joint pain describes pain around or under the patella (kneecap). It is commonly described as a dull, achey pain, which may sometimes seem to move or spread around the front of the knee (2). Pain usually worsens with activity, particularly movements such as squatting, stair-climbing or running (2). Occasionally people will describe an ache around the kneecap when sitting with the knee bent for prolonged periods, especially if the pain has become more severe. 

Taping of the patellofemoral joint can often be helpful to reduce pain, allow you to continue some activity and start your rehab. Strengthening exercises are crucial, and it is important that these are individualised to target any specific weaknesses or imbalances you may have. Your physiotherapist can assist in determining the best strengthening exercises to suit your needs.

Patellar tendinopathy:

Patellar tendinopathy describes localised pain within the patella tendon, just below the kneecap (3). It is most common in young, jumping athletes, such as basketball or volleyball players (4). It is twice as common in men compared to women (4). In comparison to patellofemoral joint pain, patellar tendon pain remains incredibly localised and does not move or spread. People with patellar tendinopathy should be able to point with one finger to the exact location of their pain and this should always remain consistent. The movements that aggravate the patellar tendon also differ slightly from those that are problematic for those with patellofemoral joint pain. Faster, more explosive movements such as jumping, hopping and fast changes of direction are often described as being the most painful. Patellar tendinopathy rehabilitation requires a structured strength program, targeting many of the major muscle groups in the legs. Your physiotherapist will be able to assist in designing a program to help you reach your goals.

References:

1.         Smith BE, Selfe J, Thacker D, Hendrick P, Bateman M, Moffatt F, et al. Incidence and prevalence of patellofemoral pain: a systematic review and meta-analysis. PloS one. 2018;13(1):e0190892.

2.         Crossley KM, van Middelkoop M, Barton CJ, Culvenor AG. Rethinking patellofemoral pain: prevention, management and long-term consequences. Best Practice & Research Clinical Rheumatology. 2019;33(1):48-65.

3.         Scott A, Squier K, Alfredson H, Bahr R, Cook JL, Coombes B, et al. Icon 2019: international scientific tendinopathy symposium consensus: clinical terminology. British journal of sports medicine. 2020;54(5):260-2.

4.         Lian ØB, Engebretsen L, Bahr R. Prevalence of jumper's knee among elite athletes from different sports: a cross-sectional study. The American journal of sports medicine. 2005;33(4):561-7.