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Knee Pain

Patellar Tendonitis (Jumper’s Knee)

Minute Read


Posted 12 months ago


Last updated: 29/11/2022


by James McCormack

Patella tendonitis is more commonly known as Jumper’s knee, it is a condition of pain in the patellar tendon at the front of the knee. The tendon attaches the quadriceps muscle to the front of the shin bone, the tibial tuberosity. The tendon becomes painful when it is injured, or in a state of disrepair. This can occur from trauma, or if it has been overused without sufficient recovery. Patellar tendon pain can occur in one or both knees. The location of pain is normally at the end of the patella tendon where it attaches to the bone, insertional patellar tendonitis, and occasionally in the middle part of the tendon, a mid-portion patellar tendonitis.

When a tendon is a state of disrepair, it develops a greater number of new blood vessels and nerve endings within its structure. This is what can cause the tendon to be more sensitive or painful, and to feel warm or hot. Typically, there will be no swelling of the knee with patellar tendonitis but often the tendon can become thickened, and this can appear or feel like a lump or bump in the tendon. This is caused by an increase in water within the tissue. This is due to a different protein that is produced is this state of disrepair that attracts more water, as it is more hydrophilic.


The most common symptom is pain in the tendon at the front of the knee between the patella and the top of the shin bone. Often this pain will be described as an ache or soreness, as the condition develops pain can feel sharper and more severe. There is a common patter that can be seen with tendon pain, that it may hurt more on starting an activity, and as the muscle and tendon warm up pain can reduce.

In addition to pain, tightness in the quadriceps muscle and stiffness to bend and straighten the knee are common. Similarly to pain, this can improve with movement. Typically, stiffness will be more significant first thing in the morning or after long periods of being sedentary. The tightness felt in the quadriceps muscle can often cause the knee to click, or a popping sensation. As discussed above, swelling and bruising is not associated with tendonitis, but the tendon specifically might feel thicker.

When irritable the tendon can be painful with any use, it is common for it to hurt to walk, and movements such as descending stairs, squatting, lunging and especially jumping can be very painful. Pinching or compressing the tendon will increase pain, so kneeling or bending the knee fully can also be a problem.

Causes of Patellar Tendonitis

Patellar tendonitis is also known as jumper’s knee, as it is common in athletes of jumping sports, such as basketball, netball, gymnastics, jump rope etc. But it is not exclusive to jumping sports. It can also present in people who do not do these sports but do repetitive and powerful knee bending and straightening actions, such as runners. The patella tendon is also stressed when the knee bends over the foot with weight such as, hiking or trail running especially going downhill, tennis players lunging forwards for a ball, weight lifting in the gym squatting or deadlifting, and many other occasions.

Photo of basketball player with Patella tendonitis

Tendonitis can be an acute or degenerative condition. Acute tendonitis might be triggered by trauma, such as a fall or a direct blow to the tendon, or a sudden change if the load that the tendon usually takes. Such as taking up a new sport and overdoing it in the first few days of excitement. This can occur in a wider range of ages.

The degenerative condition is more common in over 35-40year olds and is a gradual build-up of stress over a more prolonged period of time. As we age our tendons become less flexible and are less able to tolerate stress. Therefore, any changes to training or increase of load to the tendon need to be done more gradually than when younger. You can read more about patellar tendonitis and sport here.

Muscular imbalances, especially weakness in the quadriceps can increase the risk of developing tendonitis as it represents poor conditioning of the muscle-tendon unit. Therefore, it will have a low tolerance for load. And the other end of the spectrum, if the quadriceps is overly dominant it will also be at risk of degeneration. It is common for the quadriceps to be very well developed and the cycling saddle height it set too low this can cause the angle of knee bend to be great and the action of the quadriceps to dominate. This can trigger patellar tendonitis from cycling.

It is rare for tendonitis to develop out of nowhere, and usually with careful questioning and reflection mechanism of injury or contributing factors towards its development will be found.

Diagnosis of Patellar Tendonitis

A thorough history of activity and symptoms will be taken by the health care professional, who from experience will be able to identify patterns to narrow down the issue to a few differential diagnoses and this will guide the physical examination. Ruling out possible causes of these symptoms is just as important as ruling in the correct diagnosis. It is important to keep an open mind, in order to avoid missing things

While there isn’t one specific orthopedic test to conclusively diagnose patellar tendonitis it can be diagnosed with a cluster of different tests and movements. During the examination, with a patellar tendonitis, pinching or compressing the tendon will increase pain. Especially palpation around the tip of the shin bone where the tendon attaches. Using the quadriceps to straighten the knee, especially with additional resistance will typically provoke pain, and some movements will be used in the assessment, each stressing the tendon more until the pain is felt. It may start with sitting and straightening the knee, progress to a single leg squat, and finally a jump or hop if the previous movements were pain-free.


Radiology is helpful to confirm diagnosis, but is still not a conclusive on its own, without the relevant finding of a physical examination. Ultrasound is a useful tool to look at the health of the tendon. Ultrasound images can show tendinopathic changes such as greater number of new blood vessels or nerve, areas of inflammation or small tears. Similarly, but at a greater cost MRI can be sensitive diagnostic tool for patellar tendonitis. With MRI findings showing inflammation and thickening, calcification in the tendon or development of bone spurs. X-ray is not sufficiently sensitive to show tendinopathic changes, however if a bone spur or significant calcification were present this would appear on an x-ray scan.

Physiotherapy with James McCormack

This is not medical advice. We recommend a consultation with a medical professional such as James McCormack. He offers Online Physiotherapy Appointments for £45.

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