Overview
Patellar tendinopathy (jumper knee) is a painful, overuse-related condition affecting the patellar tendon, the thick band that connects the kneecap (patella) to the shin bone (tibia). It is most common in people who do jumping or repetitive knee-bending activities, but it can also occur with sudden increases in training, strength work, or running. The tendon tissue becomes irritated and less able to handle load, which is why pain and stiffness often build during activity and improve somewhat with rest. Over time, some people also notice weakness in the front of the thigh when pushing off or going up stairs.
Symptoms
Pain is usually felt at the lower front of the kneecap or just below it, and it may start during activity and worsen the longer you continue. Many people notice morning stiffness or discomfort when first standing after sitting for a while. Jumping, sprinting, squatting, kneeling, and going downstairs often aggravate symptoms, while rest or reduced loading may help temporarily. With ongoing overload, you may feel reduced power when extending the knee and may avoid activities that require explosive effort.
Causes
Patellar tendinopathy develops when the patellar tendon is repeatedly loaded beyond what it can tolerate during a period of training or activity. Over time, this repetitive stress leads to tendon micro-injury and failed healing, producing persistent pain and reduced tendon capacity. Sudden increases in jump frequency, resistance training volume, or high-impact work commonly trigger symptom onset.
Risk Factors
Risk is higher in athletes or active people involved in jumping sports such as basketball, volleyball, and track, especially during seasons with increased practice or competitions. Poor movement mechanics, limited knee and hip strength, and inflexible or tight muscles can increase tendon strain. Using improper technique or progressing jumping or weight training too quickly can also raise risk. Age-related tendon changes and body weight may contribute by lowering the tendon's tolerance to load.
Prevention
Reduce risk by increasing jump and high-impact training gradually and avoiding large week-to-week spikes in volume. Strengthen the legs and hips with a gradual, tendon-friendly program and focus on good squat and landing mechanics. Add flexibility and mobility work for the hips, thighs, and calves to support efficient movement. If pain begins, modify activity early and keep working through a structured rehab plan rather than pushing through worsening symptoms.
How the Diagnosis Is Evaluated
Clinicians typically start with a detailed history about activity level, jump frequency, training changes, and where the pain is located on the tendon. A physical exam often shows focal tenderness at the patellar tendon, pain with squatting or resisted knee extension, and sometimes reduced strength compared with the other side. Imaging is not always needed at first, but ultrasound or MRI may be used if symptoms persist, if the diagnosis is uncertain, or if there are concerns for a tendon tear or other knee problems.
Nonsurgical Treatment Options
Non-surgical care focuses on reducing painful overload while restoring tendon capacity and knee function. Physical therapy is the cornerstone and usually includes progressive loading such as eccentric or heavy-slow resistance exercises for the patellar tendon, along with quadriceps and hip strengthening. Activity modification helps by temporarily reducing jumping, deep knee bending, and high-impact work while maintaining overall conditioning. Pain control may include short-term NSAIDs if appropriate, ice after activity, and sometimes a patellar strap or supportive bracing to decrease strain during movement. In selected cases, a clinician may consider injections such as platelet rich plasma (PRP), and corticosteroid injections are sometimes discussed, though they are generally used cautiously in tendon problems and not as a primary long-term solution.
When to Seek Medical Attention
Seek prompt medical evaluation if you cannot bear weight, if there is sudden loss of knee function after a pop or major injury, or if the knee becomes rapidly swollen or very hot. Get urgent care if you have fever or severe redness around the knee, or if symptoms are worsening quickly despite activity reduction. Contact a clinician sooner if pain persists beyond several weeks, repeatedly returns, or significantly limits daily activities or sports participation.
Frequently Asked Questions
Most cases improve with consistent, non-surgical treatment such as progressive strengthening and activity modification.
Often you can stay active by reducing the painful activity and working with a clinician or physical therapist to use a tendon-tolerable exercise dose.
Not always, because early tendinopathy can be subtle; ultrasound or MRI is usually reserved for persistent symptoms or uncertainty about the diagnosis.
Next Steps
If your pain is localized to the patellar tendon and flares with jumping, squatting, or stairs, it is reasonable to start activity modification and begin a structured tendon-loading physical therapy plan. If symptoms are not improving after a few weeks, are getting worse, or you have concerning injury features, schedule an evaluation with a sports medicine clinician or physical therapist to confirm the diagnosis and tailor your rehab.