The condition is most often seen in athletes in sports that involve a lot of jumping and therefore place heavy demands on the knee extensor muscles at the front of the thigh. Hence the name jumper's knee.
The medical term for the condition is patellar tendinopathy. Tendinopathy is an umbrella term for painful conditions in tendons. Unfortunately, tendinopathy and tendonitis are still used interchangeably, even though it has been found that it is very rarely a matter of inflammation. Instead, we see degenerative changes as a result of overload. Part of the tendon changes in structure and in its ability to handle load. For that reason, pain can occur. Anyone can get tendinopathies in the tendons of the body, but when it comes to jumper's knee specifically, it is by far most common among young adult athletes.
Do I have jumper's knee?
Jumper's knee is characterised by load-related pain just below the kneecap, which means that the more you load the tendon, the greater the pain. Jumping will be particularly painful, but other activities such as squats or climbing stairs can also cause pain. Pain at the start is common before the tendon "warms up" and the pain may disappear. If the activity continues, the pain often returns more strongly so that you are forced to stop, or you will often feel that the tendon has been provoked afterwards.
It is usually also painful to touch the spot directly below the kneecap, especially after the tendon has been provoked by activity.
Jumper's knee differs slightly from other tendinopathies, as it seems that a lot of force is needed to produce the condition. This is probably the reason the condition is seen more often in high-level athletes, as this often means larger training volumes and more powerful athletes who expose the tendon to greater forces. The condition is also much more common in men than in women. Greater forces among male athletes are probably one of the explanations for this.
How is the diagnosis made?
If you have pain similar to that described above, it is a good idea to see a healthcare professional to get the right diagnosis. Jumper's knee is a clinical diagnosis, which means that it is usually made based on a conversation and a clinical examination. A practitioner will often test whether pressure on a specific point in the tendon is painful, and whether it is painful when heavy demands are placed on the muscles at the front of the thigh. A typical test is a single-leg squat on a decline board, as this will often reproduce your symptoms.
The condition is characterised by structural changes in the tendon tissue, and an ultrasound examination can help to confirm or rule out the diagnosis. Since several conditions can cause similar pain, it is also important to consider whether you fit into the group in which we see the condition most commonly. If you are, for example, a 35-year-old woman who does not take part in regular demanding activity, it is probably unlikely that you have this condition, even though the symptoms can be relatively similar.
How does jumper's knee develop?
Jumper's knee occurs after overload of the patellar tendon, often as a result of a lot of jumping and other activity that places heavy demands on the knee extensors. The condition can develop during a period in which training volume has increased considerably. Or in periods when other factors mean that the amount of load you can recover from is reduced. There are few risk factors that we can say with certainty make you more likely to get jumper's knee, but those that seem to be associated with a greater chance of getting the condition include:
- A larger amount of activity or training increases the risk of doing a little too much, a little too often and a little too quickly.
- Higher body weight places greater load on the tendon during activities that already expose the tendon to large forces.
- The more powerful you are and the higher you can jump, the more likely it is that you will develop the condition. It is conceivable that this is due both to the fact that becoming good at jumping requires a lot of jump training, and to the fact that those who can jump high are able to produce more force, which loads the tendon more.
How is jumper's knee treated?
When we treat jumper's knee, we first aim for pain reduction, and the first thing we do is often to reduce the total load on the tendon. This can mean removing provoking activity and reducing training volume in general. Beyond this, isometric exercise has been shown to potentially have a pain-relieving effect in jumper's knee. This can be particularly useful if the tendon is so irritated that other exercise becomes difficult.
Furthermore, the most important part of treating jumper's knee is probably progressively heavier strength training for the knee extensors, as well as generally exposing the tendon to gradually more and more load. A painful tendon can often be loaded heavily as long as we move slowly. You can therefore start with a tempo where you take 3 seconds on the way down and 3 seconds on the way up in the exercises. Over time, we want to gradually move towards a more relevant tempo that is closer to your sport or to life in general. Pain during exercise is not dangerous, but it should not get worse afterwards or the day after exercise. The level of pain afterwards tells you whether the training was tolerated or whether it was a bit too much.
Exercise and load management are by far the most important forms of treatment for jumper's knee. Shockwave therapy has, however, been shown to potentially have an effect on the condition. Most likely by modulating the pain, which can make it possible to do the exercise that we know has an effect.
In rare cases, the condition has been treated with surgery. In that case, part of the "diseased" tendon tissue is removed, either via keyhole surgery or by opening up to the tendon. Surgical treatment does not have a particularly well-documented effect and is used only in exceptional cases.
Does it take a long time?
Tendinopathies in general are conditions that can take a very long time to treat. Tendon tissue has a long healing time, and the usual estimate is a minimum of 3-6 months before you can expect a large improvement. Many people, however, are troubled for much longer, and it is not unusual to have the condition for many years. Being consistent with the rehabilitation over a long period, as well as managing to avoid regular flare-ups, is probably important.
Our practitioners have good expertise in jumper's knee and tendinopathies in general. Get in touch if you need treatment or guidance.
References:
- Theodorou, A., Komnos, G. & Hantes, M. Patellar tendinopathy: an overview of prevalence, risk factors, screening, diagnosis, treatment and prevention. Arch Orthop Trauma Surg 143, 6695–6705 (2023). https://doi.org/10.1007/s00402-023-04998-5
- Cummings, K., Skinner, L. & Cushman, D.M. Patellar Tendinopathy in Athletes. Curr Phys Med Rehabil Rep 7, 227–236 (2019). https://doi.org/10.1007/s40141-019-00232-9
- Lian OB, Engebretsen L, Bahr R. Prevalence of jumper’s knee among elite athletes from different sports: a cross-sectional study. Am J Sports Med. 2005 Apr;33(4):561-7. doi: 10.1177/0363546504270454. Epub 2005 Feb 8. PMID: 15722279.
- Pavlova AV, Shim JSC, Moss R, et al Effect of resistance exercise dose components for tendinopathy management: a systematic review with meta-analysis British Journal of Sports Medicine 2023; 57: 1327-1334.
- Vang C, Niznik A. The Effectiveness of Isometric Contractions Compared With Isotonic Contractions in Reducing Pain For In-Season Athletes With Patellar Tendinopathy. J Sport Rehabil. 2020 Oct 12;30(3):512-515. doi: 10.1123/jsr.2019-0376. PMID: 33049706.
- van Ark M, Cook JL, Docking SI, Zwerver J, Gaida JE, van den Akker-Scheek I, Rio E. Do isometric and isotonic exercise programs reduce pain in athletes with patellar tendinopathy in-season? A randomised clinical trial. J Sci Med Sport. 2016 Sep;19(9):702-6. doi: 10.1016/j.jsams.2015.11.006. Epub 2015 Dec 7. PMID: 26707957.