This was a statement from a collegiate volleyball player that I recently treated. She was home for the summer and was a very familiar patient. Our physical therapy clinic was where she would come for her knee pain when she was in high school. She has had knee problems for years and was using the summer to rest and rehab her knee. Landing from jumps was painful, and she also had pain after practice or a game. She did, indeed, have jumper’s knee or patellar tendinopathy, as it is known as in the medical field. Her knee pain did improve significantly with therapy. However, with the amount of volleyball she plays, I expect to see her next summer as well. To learn more about jumper’s knee, read on. Let’s start with anatomy!
The knee joint
The knee is the largest joint in the body. The knee is made up primarily by the tibiofemoral joint and patellofemoral joint. The tibiofemoral joint is what most of us think of as the knee. It is the joint made between the bottom of the femur (the thigh bone) and the top of the tibia (the larger lower leg bone). The patellofemoral joint is the joint made between the femur and the patella (the kneecap).
The quadriceps
The quadriceps are a group of 4 muscles on the front of the thigh. These are very large powerful muscles that activate to straighten the knee. They are extremely important in performing everyday activities such as squatting, walking, running, jumping, kicking, and many others. The 4 quadriceps muscles come together towards the bottom of the femur (the thigh bone) and form a common tendon called the quadriceps tendon. A tendon connects muscle to bone. The quadriceps tendon then attaches to the patella and the patella connects to the tibia (the shin bone) through the patellar tendon (which is actually a ligament). The patella acts as a pulley when the quadriceps contract to straighten the knee. This is known as the extensor mechanism.
What is tendinopathy?
Before delving into the patellar tendinopathy, let’s review tendons. A tendon is the connective tissue that attaches the muscle to the bone. The area where the tendon connects to the bone is more susceptible to irritation and injury because it’s limited blood supply.
Tendinopathy is a term used to encompass any issue with the tendon. This includes tendonitis and tendinosis. There is a difference between tendonitis and tendinosis. Many of the conditions that were previously thought to be tendonitis are actually tendinosis. However, because we do not necessarily know if the tendon has tendonitis or tendinosis, we refer to the condition as tendinopathy.
Tendons can get inflamed with a force that is too strong or quick. This tensile force on the tendon can cause micro-tears in the tendons. This is tendonitis. It is postulated that untreated tendonitis can become tendinosis. Tendonitis is an inflammatory condition and will respond to anti-inflammatory medication. It typically has a recovery period of 1-6 weeks.
Tendinosos is a degeneration of the tendon’s collagen proteins. This is hypothesized to occur after a period of untreated tendonitis. Collagen provides the tendon with durability and strength. Tendinosis is caused by chronic overload of the tendon without sufficient time to rest and heal. It does not have signs of acute inflammation and is not improved with anti-inflammatory medication such as ibuprofen. Early-stage tendinosis can heal within 6 to 10 weeks, but chronic stage can take 3 to 6 months. Tendinosis is probably more common than tendonitis, but the term tendonitis is often used to encompass both.
What is patellar tendinopathy?
Patellar tendinopathy is an overuse injury of the extensor mechanism of the knee. Micro-tearing occurs at the tendon and is not given sufficient time to heal. This micro-tearing is caused by accumulated stress on the quadriceps or patellar tendon from repetitive quadriceps activation. This includes repetitive activities like jumping, landing, cutting, acceleration, and deceleration. For this reason, patellar tendinopathy is also called “jumpers knee”.
The pain will most likely present at the inferior pole of the patella where it attaches to the patellar tendon. This is the area of the kneecap that is closest to the shin bone. Pain could also occur at the top of the patella where it attaches to the quadriceps tendon and at the area of the shin bone where the patellar tendon attaches. However, these two areas are much less common.
What are the symptoms of patellar tendinopathy?
There are several symptoms associated with patellar tendinopathy. These include:
- Pain in the front of the knee
- Pain at the bottom of the kneecap
- Pain after sport or activity
- Could progress to pain during activity if left untreated
- Pain with squatting
- Pain with descending stairs and/or landing from a jump
- Pain with prolonged sitting – also known as the “Movie Theater sign”
Who gets patellar tendinopathy?
Patellar tendinopathy typically occurs with a younger athletic population. The typical age of onset is around 15-30 years old and it is more common in men than women. It also occurs more often with certain sports. These sports include:
- Volleyball
- Basketball
- Long jump
- High jump
- Tennis
- Football
- Skiing
What are the risk factors for patellar tendinopathy?
There are several risk factors that are associated with patellar tendinopathy. These include:
- Hypermobility at the knee joint
- Tight hamstrings and quadriceps
- Previous knee injury or irritation
- Excessive training time and frequency
- Hardness of the ground where playing the sport or activity
Who should I see?
- Physical therapy – This would be my first stop. Physical therapy can help decrease pain and inflammation with techniques including manual therapy and dry needling. PT can evaluate and address abnormal joint mobility, muscle weakness, and flexibility. With patellar tendinopathy (especially if you have had it for a long time) it is important to slowly increase the load on the extensor mechanism. Your PT can help you add appropriate exercises at the appropriate time. This allows the quadriceps and the muscles around the hip and knee to strengthen while allowing the tendons to continue to heal. Your PT will also assess your training schedule and technique to prevent the problem from happening again.
- Orthopedic or sport medicine physician – An orthopedist might be necessary if the condition is not responding to physical therapy. Your physician can prescribe medication, give an injection, or order imaging if needed. Surgery is an option if your condition does not respond to any conservative treatment.
What can I do?
- Relative rest – Resting the area to decrease further pain and damage from occurring is one of the best ways to treat patellar tendinopathy. Basically, stay away from the activities that are causing pain. This gives the tendons time to rest and heal. You can perform non-irritating activities such as swimming or biking to maintain cardiovascular and muscle strength. Return to your sport slowly and under the supervision of a physical therapist once the pain has subsided.
- Ice – Ice can help decrease pain and swelling in the tendon. Ice the painful area for 15 to 20 minutes at a time. I would recommend using an ice pack several times per day if the pain is constant or is preventing you from participating in an activity. Ice immediately after activity.
- Soft tissue mobilization – Soft tissue mobilization helps release the quadriceps and decrease the stress on the tendon. Roll on a massage ball or trigger point roller on the painful area in the inner thigh. Spend a good 3 to 5 minutes rolling. Do not roll so hard that you bruise the area, but it should be a pretty painful sensation. Roll out the area no more than a few times a week. See the video below.
- Stretching – The hamstrings and quadriceps are typically tight with patellar tendinopathy. Decreasing tightness in the quadriceps can decrease the pull on the quadriceps and patellar tendons. See the video below for quadricep, hamstring, hip flexor, and calf stretching.
- Strengthen the muscles around the hip and knee – It is important to strengthen the muscles around the hip and knee. This includes your gluteal muscles and the hamstrings. It is also important to strengthen your core muscles. All these muscles will help take some of the load off the extensor mechanism. Using ankle weights can increase strength and difficulty.
- Strengthening the quadriceps – You will need to strengthen the quadriceps as well. This is to be slowly as to not place too much stress on the tendons too quickly. This is why having a physical therapist to guide you through the rehab process is essential. The first video is isometrics and some non-weightbearing exercises that can be done at the beginning of your healing process. The next video is more mid-stage strengthening and should only be performed when the pain has subsided significantly. There should be minimal soreness when performing the exercises and no pain afterwards. Using loop resistance bands, resistance bands and ankle weights can increase strength and difficulty of the exercises. See the videos below.
- Knee strap – A knee strap can help decrease the pull on the patellar tendon and decrease the pain and stress on the knee.
In review
- Patellar tendinopathy is an overuse injury of the extensor mechanism of the knee.
- Micro-tearing occurs at the tendon and is not given sufficient time to heal.
- This micro-tearing is caused by accumulated stress on the quadriceps or patellar tendon from quadriceps activation.
- Patellar tendinopathy is also called “jumpers knee”.
- Symptoms include:
- Pain at the base of the patella.
- Pain when landing from a jump.
- Pain when descending stairs.
- Typically occurs in athletes ages 15-30.
- More common in certain sports especially
- Volleyball
- Basketball
- Long jump
- High jump
- Usually treated with physical therapy.
- An orthopedist or sports medicine physician would be needed if not responding to physical therapy.
- There are things that you do to help:
- Relative rest
- Ice
- Rolling out the quadriceps
- Stretching
- Strengthening
- Knee strap
As always, If you have questions about the content of this post or any other musculoskeletal questions, please e-mail me.
Additional resources
https://www.physio-pedia.com/Patellar_Tendinopathy
https://www.ncbi.nlm.nih.gov/books/NBK532969/