Knee pain that suddenly strikes while enjoying sports or concentrating on training. The most troublesome of these is ``jumper's knee.'' This article provides a comprehensive explanation of the causes of jumper's knee, the latest treatments, and effective preventive measures.
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What is jumper's knee?
Jumper's knee is medically referred to as ``patellar tendonitis'' and ``quadriceps enthesitis.''
It is a disease that causes inflammation and degeneration of the quadriceps tendon above the kneecap (patella) or the patellar tendon below.
It is often seen in sports that involve a lot of jumping, such as volleyball and basketball, hence the name "jumper's knee." However, people who don't jump can also develop the disease, so you need to be careful.
jumper's knee symptoms
The most noticeable symptom of jumper's knee is pain.
In daily life, you may experience pain when the muscles in the front of your knee contract when you stand up, or you may experience pain above or below your knee when going down stairs.
Pain may also be caused by crouching down or placing your knees on the floor, which puts pressure on the inflamed area.
When playing sports, it is easy to experience pain when taking off or landing from a jump, and the pain increases as you continue to jump.
Pain may also occur when sprinting, stopping, or changing direction. If the pain becomes frequent or severe, muscle performance may become insufficient or movement may be restricted, which may affect overall performance.
In the early stages, the pain remains localized, but as the inflammation becomes stronger, the pain may feel like it has spread and swelling may occur.
Causes of jumper's knee
The main cause of jumper's knee is excessive stress and repeated stress on the quadriceps and patellar tendons.
In addition, the risk of developing the disease is strongly related to the following factors:
Landing form issues
If you land in an inappropriate position, such as landing in an almost straight position without bending your knees or ankles too much, the shock absorption will be insufficient and this will put a sudden load on the patellar tendon.
Additionally, landing without leaning your upper body too far forward also increases the load on your knees. This is because a moderate forward lean has the effect of dispersing the impact. Similarly, a form that causes your knees to fall inward when you land also puts stress on the patellar tendon.
However, during sports, it is expected that you will land in a variety of positions, and of course there will be situations where you are forced to land in an unstable position. Of course, if you simply do a lot of jump training, the probability of developing jumper's knee increases, but if you consider that the burden of being forced to land in such an unstable position is greater. That's fine.
muscular imbalances
An imbalance in the strength of the quadriceps and knee flexors (hamstrings) has been shown to place excessive stress on the patellar tendon.
It has also been reported that cases where the muscle strength ratio is not appropriate, especially when the quadriceps muscles are excessively strong and the hamstrings are relatively weak, can easily damage the patellar tendon and increase the risk of jumper's knee by 1.5 to 2 times. Please be careful.
Also, among the quadriceps femoris muscles, if the vastus medialis is relatively weak and the vastus lateralis is strong, the movement of the patella will be uneven and the load on the patellar tendon will increase. The risk of developing jumper's knee is also high if the muscle activity on the inside of the thigh is decreased.
Furthermore, it is clear that when core muscles such as abdominal muscles and back muscles are weak, posture control during jumping and landing becomes insufficient, resulting in increased stress on the knees and a higher risk of developing jumper's knee. It has become.
low muscle flexibility
It has been found that when the flexibility of the quadriceps and hamstrings is low, stress is easily placed on the patellar tendon.
Poor quadriceps flexibility limits the flexibility of the patella and increases the incidence of jumper's knee. Additionally, tight hamstrings make it difficult to exert muscle strength properly, making it easier for the knee to overextend when jumping, which has also been shown to increase the strain on the patellar tendon when landing.
Anatomical effects (high/low patella position)
If the patella, known as the kneecap, is located higher than it should be, the patellar tendon is more likely to be pulled, causing damage to the patellar tendon, while if it is located lower, the quadriceps tendon is more likely to be pulled. , which can put extra stress on the quadriceps tendon.
Additionally, increasing the number of jump training sessions or rapidly increasing the amount of exercise may increase the risk of developing jumper's knee.
Diagnosis of jumper's knee
During the interview, you will be asked about the degree of pain and when it occurs, as well as your medical history and exercise history. We will also examine your knee condition and range of motion.
You may also be asked to perform the following specific tests for jumper's knee.
Special tests for jumper's knee
- Patellar tendon compression test: Press the patellar tendon with the knee extended and evaluate the pain.
- Squat test: Check pain during squat movements
- Single-leg jump test: Evaluate pain and function when jumping on one leg
We also perform X-ray examinations, ultrasound examinations, MRI examinations, etc. as necessary.
Severity classification
Based on the diagnostic results, we classify the severity of jumper's knee. The Blazina classification and Roels classification are commonly used and are divided into four stages:
Classification of Blazina
- Grade 1: Pain only after exercise
- Grade 2: Pain during exercise, but does not affect performance
- Grade 3: Pain during exercise, affecting performance
- Grade 4: Complete rupture of the tendon
Roels classification
Blazina's classification is further subdivided into 5 levels.
Stage 1: Pain after exercise
Stage 2: Pain during warm-up (no pain during exercise)
Stage 3: Pain during and after exercise
Stage 4: Pain with decreased performance during exercise
Stage 5: Pain in daily life
jumper's knee treatment
Treatment for jumper's knee varies depending on the severity of the symptoms, but conservative treatment is often selected as the initial treatment.
RICE treatment
Effective for acute symptom management. This is done to calm down inflammation.
- Rest: Avoid excessive stress and do not worsen symptoms
- Ice: Ice for 15-20 minutes several times a day to suppress inflammation.
- Compression: Apply light pressure with an elastic bandage to reduce swelling.
- Elevation: Elevate the knees above the heart to help reduce swelling
physical therapy
Electrical therapy is used to reduce inflammation and promote tissue repair.
Ultrasound therapy provides deep tissue heating and massage effects. Low frequency therapy can reduce pain and relax muscles.
One form of physical therapy is to cool the affected area with ice packs to reduce swelling and relieve pain.
drug therapy
Analgesics may be prescribed if needed, and drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs) may be used to control inflammation and pain.
In some cases, hyaluronic acid injections can increase the lubricity within the joints and suppress inflammation.
regenerative medicine
It is often selected when conventional treatments are ineffective. This is the latest treatment method that is attracting attention as it allows for fundamental treatment in the case of sports injuries without surgery.
PRP (platelet rich plasma) therapy
Platelets extracted from the patient's own blood are concentrated and injected into the injured area. Promotes tissue repair through the action of growth factors.
Autologous fat-derived stem cell treatment
This is a treatment method that promotes repair and tissue regeneration by extracting stem cells from the patient's own fat tissue and administering them to the injured tendon.
surgery
Selected when more extensive treatment is required. We perform repairs and reconstructions of the patellar tendon, excision of degenerated parts, and adhesiolysis.
Measures you can take yourself
Here are some things to keep in mind in your daily life and when playing sports.
Adjust your landing form
It is necessary to learn the correct form. Pay particular attention to your posture when landing.
- Bend your knees slightly when landing to absorb the impact
- Be careful not to let your knees slide inward.
- Land on the whole sole of your foot
Practice with these things in mind on a daily basis. It is also effective to check your form by video recording. Receiving form guidance from a professional trainer may also be an effective measure.
Consider using appropriate insoles to improve foot alignment. It can reduce the burden on your knees.
balance muscle strength
Rather than just strengthening specific muscles, try to balance your quadriceps and knee flexors, and also strengthen your core strength at the same time.
Don't forget to stretch
Stretching has the effect of promoting blood flow and speeding up muscle recovery, and allows the muscles to respond more easily to sudden changes in movement, reducing the risk of injuries such as jumper's knee. Incorporate it into your daily routine to increase muscle flexibility.
Some simple stretches include:
- Quadriceps stretch: While standing, bend one leg back and bring your heel toward your butt.
- Hamstring stretch: While sitting, stretch your legs and lean your upper body forward.
- Calf stretch: Place your hands on the wall, extend your back legs and place your heels on the floor.
etc. Try to hold each stretch for at least 15 seconds. If you stretch for less than that, your muscles won't respond and the stretch will be meaningless. Ideally, you should stretch every day. It would be even better if you could use it as a warm-up before training or as a cool-down after training.
If you have pain above or below your knees
If you are already experiencing symptoms similar to jumper's knee, the RICE treatment described in the treatment section is effective. However, there are times when you can't rest while playing sports. In that case, it might be a good idea to just do the icing.
summary
Jumper's knee is a condition that can be improved with proper treatment. However, there are limits to self-diagnosis and self-treatment. While referring to the information in this article, if your symptoms persist or if you are concerned, we recommend that you consult a specialist without hesitation. Early detection and treatment are the keys to maintaining knee health. Even if you don't feel it is urgent, you should be able to find the best treatment for your current situation in order to prevent knee pain in the long term and live a healthy life. In order to enjoy comfortable exercise in the future and to enjoy sports safely, be sure to seek support from a specialist.