Patellar tendonitis or tendinopathy

Terms associated with patellar tendinopathy

• Patellar Tendinopathy
• Patellar tendinopathy
• Jumper's knee, the English term for "jumper's knee"
• Jumper's knee: a term that can also refer to a problem with the tendon located above the kneecap
• Note the distinction: quadriceps tendinopathy affects the tendon above the kneecap, rather than the one below it

What is the difference between tendinitis and tendinopathy?

Tendinitis refers to inflammation of a tendon, while tendinopathy refers to persistent pain in a tendon that limits activity when the tendon is in use. A tendon is a strong cord that transmits force from a muscle to a bone. The term “tendinopathy” alone does not specify the specific changes in the tissue. Read the consensus on these terms. Certain inflammatory processes may contribute to tendinopathy, even in the absence of the classic signs of recent inflammation¹.

A 1999 review primarily described structural changes in painful tendons in athletes, without the cells typically associated with recent inflammation². These observations do not rule out all inflammatory processes. They explain why the term “tendinopathy” is used to describe the condition without presuming its exact mechanism.

In practice, your program depends mainly on your symptoms and your abilities. Physical therapy primarily uses progressive exercises and adjusts the amount of stress placed on the tendon. The evaluation also identifies areas that can be addressed, such as weakness or limited mobility.

What is patellar tendinopathy?

Patellar tendinopathy is persistent pain in the tendon located beneath the kneecap, which limits activities that put stress on the knee. The patella is the small bone at the front of the knee; the tibia is the large bone at the front of the lower leg. The patellar tendon connects them and transmits the force from the quadriceps—the group of muscles at the front of the thigh—to straighten the knee.

Anatomy of the Patellar Tendon

The patellar tendon is often about 4 to 5 cm long, though this varies from person to person. It attaches to the lower part of the patella and extends to the tibial tuberosity, the bony bump you can feel below the^{knee.³, ⁴} A large portion of its fibers attaches to the front of the patella, in its lower part.

When the quadriceps contracts, the force is transmitted through the patellar tendon to extend the leg⁵. This mechanism is essential for walking, running, jumping, and climbing stairs.

Difference Between the Patellar and Quadriceps Tendons

The quadriceps tendon is located just above the kneecap, connecting the quadriceps muscle to the kneecap. The patellar tendon, on the other hand, is below the kneecap and connects it to the shin bone. Both can become irritated, but patellar tendinopathy (below the kneecap) is more common in athletes.

The term “jumper’s knee” can refer to a problem with either the quadriceps tendon or the patellar tendon. These tendons have different attachments and functions. It’s important to specify which one is causing pain in order to tailor the exercise program⁶.

Who is affected?

Patellar tendinopathy is common in jumping sports. Among elite athletes, it primarily affects volleyball and^{basketball players⁷, ⁸}. It also occurs in recreational athletes. Sports that involve repeated jumping pose the highest risk, hence the nickname "jumper's knee."

What are the causes of patellar tendinopathy?

Patellar tendinopathy is associated with repeated stress on the tendon, particularly from jumping, but its exact cause remains incompletely understood. The tendon can adapt to training; the amount of exertion, movements, and recovery may all be factors to consider in^{the evaluation⁹, ¹⁰}. These factors do not constitute a single, proven cause in every individual.

Training Overload

A rapid increase in activity warrants consideration when pain occurs. A review found an association with a higher training volume, but data on specific risk factors remain limited or contradictory¹¹. In healthy young men, twelve weeks of exercise altered the way the tendon deforms under force¹⁰. This study demonstrates the tendon’s ability to adapt; it does not establish a rate of progression that would prevent injury.

Examples of changes in activity to discuss:

• Getting Back into Running After Winter Without Making Progress
• Start an intensive program of squats—those exercises where you bend your knees to lower yourself
• Increasing the frequency or intensity of workouts
• Going on a mountain hike without preparation

Strength, flexibility, and movement patterns

A physical therapist can assess your strength, flexibility, and movement patterns. Some of these factors are associated with tendinopathy, but it is not known for certain whether they cause the problem¹¹. The evaluation may include:

• Gluteal Muscle Strength
• Flexibility in the quadriceps and hamstrings, the muscles at the back of the thigh
• The ability to flex the ankle by lifting the foot upward
• The inward movement of the knee during a motion

An ankle that bends less upward—a movement known as dorsiflexion—has been linked to the onset of this problem in young basketball players who were followed for one year. This association does not prove that the ankle is the cause of every case of^tendon pain12^{, 11}.

Movements that put strain on the tendon

In a study of 20 healthy adults, single-leg jumps, changes of direction while running, and single-leg squats with the heel elevated placed significant stress on the tendon. Lunges—a step forward with the knees bent—and stepping down from a stair generally placed less stress on it¹³. This helps in choosing a progression, without classifying these movements as dangerous in and of themselves.

• Jumps and landings (volleyball, basketball)
• Deep squats with weight
• Lunges
• Going down hills or stairs
• Sprints and changes of direction

What are the symptoms of patellar tendinopathy?

Patellar tendinopathy causes localized pain at the tip of the kneecap or just below it. The pain gets worse with activities that put stress on the tendon.

Typical location

The pain is located precisely:

• At the lower tip of the kneecap (inferior pole)
• Just below the kneecap, on the tendon itself
• Pain above the kneecap is more likely related to the quadriceps tendon and must be distinguished from

You can often reproduce the pain by pressing on this area.

How Pain Changes During Activities

Pain may occur after physical activity or at the start of exertion, subside during exertion, and then return afterward. It may also make it difficult to climb stairs or sit for long periods. These situations do not necessarily occur in that order. Improvement is still possible even when the pain has persisted for a long time.

Activities that increase pain

• Doing a squat or a lunge
• Going up or down stairs
• Running, especially downhill
• Jumping and landing
• Sitting for a long time with your knee bent
• Getting up from a chair

How is patellar tendinopathy diagnosed?

The diagnosis of patellar tendinopathy is based on your description of your symptoms and an examination of your range of motion, strength, and areas^{of pain .¹⁴, ¹⁵} Imaging is not routinely performed. An ultrasound uses sound waves inaudible to the human ear to visualize the tendon; an MRI creates images using a magnetic field. These tests can be helpful when the diagnosis remains uncertain.

Pain in the front of the knee can have more than one cause. Some knee problems cause symptoms very similar to those of the patellar tendon.¹⁶ The purpose of the evaluation is precisely to determine the source of the pain before choosing a treatment.

Knee Examination and Evaluation

Your physiotherapist will assess:

• The precise location of the pain
• Movements that reproduce your symptoms
• Quadriceps strength and flexibility
• Ankle mobility
• How the hip, knee, and ankle move together

Tests that help identify the problem

Two tests are particularly useful:

Incline squat: A squat performed on a surface inclined at 25 degrees increases tension on the patellar tendon. Pain at the tip of the patella is a sign of tendinopathy that should be interpreted in conjunction with other^{findings.¹⁷, ¹⁸, ¹⁴}

Pressure on the tendon: Direct pressure on the lower tip of the patella often reproduces the characteristic pain, which can help pinpoint the problem; however, this sign must be interpreted in conjunction with the symptoms and other tests, as mild tenderness may be normal in athletes^{who are pain-free.¹⁹, ²⁰}

Imaging

An X-ray mainly shows the bones. It may be normal, but it can also reveal calcium deposits near the tendon or help identify other causes of pain. An X-ray alone is not enough to explain your symptoms.

An ultrasound may reveal a thickened tendon or a different texture.²¹ Such changes may also be present without pain. The choice between MRI and ultrasound depends on the clinical presentation, particularly if the diagnosis remains uncertain or if expected improvements^{do not occur22, 15}.

What are the risk factors for patellar tendinopathy?

High training volume is associated with patellar tendinopathy, and jumping sports are among the most commonly affected. The evidence linking muscle stiffness and improper training progression to this condition remains limited and does not support classifying them as major risk factors¹¹.

Studies are investigating whether the way people move can help predict injuries. Among recreational female runners, greater braking force with each step was associated with more running injuries²³. This study did not focus solely on the patellar tendon and does not prove that correcting this factor alone prevents patellar tendinopathy.

Program Elements to Be Reviewed

• The amount of training and the rate at which it increases
• Flexibility of the quadriceps and the muscles at the back of the thigh
• Gluteal Muscle Strength
• Ankle mobility
• Jumping and Landing Techniques, Based on the Difficulties Observed
• The running surface and your comfort; its hardness is not, on its own, an established risk factor

Age, Sex, and Medical History

• Males: In a review of several studies, the proportion of people affected was slightly higher among men than among women, but the data do not allow for a definitive conclusion regarding a difference between the sexes⁷
• Age: Patellar tendinopathy affects adolescents and adult athletes; in a review of several studies, the proportion of people affected was higher among athletes aged 18 and older than among younger athletes⁷.
• A previous episode of patellar tendinopathy, which should be noted during the evaluation

When should you seek medical attention for patellar tendon pain?

Pain in the patellar tendon warrants a medical consultation if it persists, limits your activities, or makes it difficult to return to sports. A physical therapist can assess these issues and recommend a tailored treatment plan. However, certain symptoms require urgent medical attention, as described below.

Signs that warrant a consultation

See a doctor if the pain does not improve, limits your daily activities, prevents you from exercising at your usual level, or occurs while you are resting or at night.

Seek urgent medical attention if the pain is severe, if you cannot move your knee or put weight on it, if your knee is severely swollen or deformed, or if it locks up, gives out, or clicks painfully. A high fever or feelings of heat, cold, or chills, along with a red or warm knee, also require urgent medical attention. Read about the signs that require prompt evaluation.

After a popping sound or an injury, sudden difficulty straightening the knee may indicate a tendon tear and should be evaluated promptly. Read about the signs of a patellar tendon tear.

Direct Access

In Quebec, you can see a physical therapist directly without a doctor's referral. If your condition requires additional tests, your physical therapist will refer you to the appropriate professional.

If you also experience pain in other areas of the knee, such as pain behind the knee or on the sides, please mention it during your assessment.

How does physical therapy treat patellar tendinopathy?

Physical therapy treats patellar tendinopathy through progressive strengthening and adjustments to athletic and daily activities. Guidelines recommend starting with exercises, even though confidence in estimates of their effectiveness remains limited¹⁵. A review of twelve studies reports improvements in pain, strength, and functional ability that may persist after the program ends²⁴.

Comprehensive assessment

Your physiotherapist will assess:

• Your sports and training history
• Your ankle, knee, and hip mobility
• The strength of your quadriceps, glutes, and calf muscles
• Your squat and jumping technique, if relevant
• Movements or actions that could contribute to the difficulties

Progressive exercise program

Strengthening exercises form the basis of^{treatment15, 25}. A progression can combine the following four steps. The choice, order, and difficulty should be tailored to your symptoms; this is not a one-size-fits-all protocol.

An isometric contraction involves working the muscle while holding a position. A study of six volleyball players observed an immediate reduction in pain that persisted 45 minutes after these contractions. Another study involving 21 participants found a slight immediate reduction in pain, similar whether the contractions were static or involved movements against resistance, with no clear sustained effect at 45^{minutes.²⁶, ²⁷} Holding a partial squat for an appropriate amount of time may be an option, depending on your tolerance.

You can do squats, push a platform with your legs on a leg press machine, or extend your knee against resistance. The movement should be slow, and the range of motion should be adjusted to what you can handle.

You gradually increase the weights and the difficulty of the exercises, depending on your tolerance.

You're practicing jumps, landings, and movements that require you to generate force quickly as you prepare to return to sports.

Adjusting Daily and Athletic Activities

Adjusting the amount and intensity of your exercise allows you to stay active while the tendon heals. You should reduce the duration or frequency of your workouts depending on how your knee responds. Avoid movements that cause severe pain for a while. Stick to activities you can tolerate well, such as swimming, biking, or walking. Then gradually reintroduce the problematic activities.

Complementary Techniques

Depending on your assessment, your physiotherapist may also use:

• Manual therapy—that is, guided movements using the hands—to help improve limited mobility when an evaluation warrants it
• Taping, or the use of adhesive tape, can make certain movements more comfortable when resuming physical activity. In a trial involving 97 athletes, taping reduced pain in the short term compared to no taping, but showed no clear advantage over a control group that used a different type of tape. Read the study on taping
• Advice on equipment and technique

What exercises can you do at home for patellar tendinopathy?

At home, you can perform quadriceps contractions, modified squats, and other progressive exercises tailored to your^{tolerance level²⁴, ²⁸}. The sets, repetitions, and durations listed below are examples to be adjusted—not a program to follow in its entirety from the start. Agree on an acceptable level of pain with your physical therapist and also monitor your response after each session. Reduce the intensity if the pain exceeds this threshold or remains more severe the next day. Stop immediately if you experience sudden or severe pain, and have the urgent symptoms described above evaluated.

Isometric exercises (initial phase)

• Sit with your leg straight and supported
• Tense the front of your thigh by gently pressing the back of your knee against the support
• You can aim for 45 seconds, five times, with breaks, if that length of time works for you; start with a shorter duration if necessary
• See if this exercise makes your knee feel better; immediate relief varies depending on the person and the exercise

Isometric wall squat. Slide your back down the wall until your knees are bent at a comfortable angle. Hold the position, then release. Adjust the angle to stay comfortable. Repeat as tolerated.

Strengthening Exercises (Intermediate Phase)

• Use a stable, non-slip ramp with a support to help you maintain your balance. The height of 2 to 3 inches given as an example should be adjusted; avoid using a book or a board that might slip.
• Lower yourself slowly over 3 seconds
• Rise back up over 3 seconds
• 3 sets of 15 repetitions

• Light to moderate load
• Slow and controlled movement
• 3 sets of 15 repetitions

To step down from a small step, place the leg you want to work on a stable step. Slowly lower the other foot toward the floor, then bring it back up. Use the handrail for balance, and adjust the height and number of repetitions according to your tolerance.

Complementary Stretches

• Stand with your feet firmly planted on the ground, and bring your foot behind you if you can do so comfortably
• Keep your knees together
• Hold for 30-45 seconds

• Sitting, with one leg extended forward
• Lean forward while keeping your back straight
• Hold for 30-45 seconds

Can you treat patellar tendonitis on your own?

You can temporarily reduce activities that are very painful, continue with movements you can tolerate, and try gentle stretches. A cold pack wrapped in a cloth can provide relief for up to 20 minutes at a time. It’s important to gradually resume your exercises. A program that’s too difficult or not rigorous enough may not meet your needs; an evaluation can help tailor it to your needs.

The physical therapist adjusts the intensity of the exercises to gradually build up the tendon’s tolerance. The evaluation aims to identify the likely cause of the symptoms, check for signs that require medical attention, and help select appropriate exercises. It does not guarantee that a single cause will be identified with certainty.

Assessment and follow-up can help you use the program at home and adjust it based on your progress. Home exercises have also been shown to be beneficial in studies; the best approach to follow-up depends on your needs.

How long does it take to recover from patellar tendinopathy?

Recovery from patellar tendinopathy often takes several months, with a recommended strengthening program lasting at least twelve weeks. This guideline is intended to help plan and reassess treatment, not to guarantee a specific recovery date. If progress is insufficient, the diagnosis and treatment plan should be reevaluated. Read the treatment guide.

In a trial involving 76 athletes, nearly all of whom had been experiencing symptoms for more than six weeks, two home exercise programs improved pain levels and functional ability. At 24 weeks, the progressive program had improved scores by an average of 28 points on a 100-point questionnaire, compared with 18 points for the slow-descent exercises; the adjusted difference between the groups was 9 points. The desired return to sports at the previous level was achieved by 43% versus 27% of the participants followed, with no statistically significant difference. Read the study by Breda and colleagues. These favorable results do not imply the same timeline for every individual.

Factors That Can Aid Recovery

• See a doctor if the pain persists or interferes with your daily activities
• Follow the program regularly and let us know what's preventing you from sticking to it
• Adjust the amount of force based on the knee's response
• Address the issues related to strength, mobility, or movement identified during the evaluation

• Symptoms that persist without improvement
• Continuing activities that cause severe pain
• Difficulty doing the exercises regularly
• Returning to sport too quickly

Return to sport

Returning to sports is a step-by-step process. The physical therapist will assess the strength of both legs, your ability to jump and perform sports-specific movements, how your knee responds, and your confidence level. Symptoms must remain within the agreed-upon limits and should not worsen as the sessions progress.

Resuming activity at a pace that exceeds what your knee can handle may cause your symptoms to flare up again. Work with your physical therapist to adjust your activity level rather than relying solely on a schedule.

Studies have investigated whether differences between the two legs can predict injury. The results vary widely depending on the tests, sports, and individuals. A difference in strength, power, or balance can help in choosing exercises, but correcting it does not guarantee that an injury will be prevented²⁹.

How to prevent recurrence?

To minimize the risk of recurrence, you can continue with strengthening exercises, gradually increase the intensity of your workouts, and monitor how your knee responds. These habits support a gradual return to physical activity, though they do not guarantee that pain will not return.

• Continue doing strength-training exercises on a regular basis.
• Increase your training volume in small increments from one week to the next, adjusting based on how your knee feels the next day
• Warm up adequately before intense activities
• Vary your activities so you don't constantly repeat the same movements
• Maintain comfortable flexibility in the muscles at the front and back of the thigh

Reduce intensity if you notice:

• Pain that gradually increases over several days
• Morning stiffness that persists long after waking up
• Pain that does not return to its usual level before the next session
• Decreased performance

If your knee pain persists despite these adjustments, see a doctor. It's better to take action early than to wait for the problem to get worse.

If you are a runner, the prevention principles are similar to those for shin splints or Achilles tendinopathy: gradual progression and regular strengthening.

References

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