Knee tendinitis: patellar and pes anserine
Knee tendinitis is irritation of a tendon from overuse. The most common types are patellar tendinitis (front of the knee) and pes anserine tendinitis (inner side, below the joint).
Educational information prepared by Dr. Belinda Martínez, physician and surgeon. Last updated: October 3, 2026. It does not replace an assessment by a doctor.
Patellar tendinitis ("jumper's knee")
It affects the tendon that joins the kneecap to the tibia. It is common in sports with repeated jumps and sprints, such as basketball or volleyball.
- Pain just below the kneecap that increases when jumping, running or climbing stairs.
- Tenderness when pressing on the area.
- In advanced stages, pain even when walking or sitting.
Pes anserine tendinitis
The "pes anserine" is the spot on the inner side of the knee, below the joint, where three tendons attach. It can become inflamed from overuse, excess weight, knee osteoarthritis or certain repeated movements.
- Pain on the inner side of the knee, a few centimeters below the joint.
- Worse when climbing stairs, getting up from a chair or walking.
- Pain when pressing on the area; sometimes mild swelling.
How they are diagnosed
The exam is usually enough: the pain is reproduced by pressing on the tendon. Ultrasound shows thickening or inflammation, and MRI is reserved for unclear cases or when another associated injury is suspected.
What helps relieve them
- Reducing the load that causes the pain, without stopping movement completely.
- Progressive strengthening exercises for the tendon and the thigh and hip muscles.
- Ice during acute pain and medications only as prescribed by a doctor.
- Weight control and appropriate footwear.
- Adjusting technique and training progression.
Tendinitis tends to improve with rehabilitation, although it can take weeks or months. If it does not improve, the doctor considers other options.
When to see a doctor
Seek medical care soon if you have any of these signs:
- Sudden, severe pain with a feeling that "something snapped".
- Pain that does not improve with rest and rehabilitation after several weeks.
- Swelling, redness and warmth in the area, with fever.
Frequently asked questions
How long does knee tendinitis last?
It depends on the tendon and how quickly the load is reduced. It can improve in a few weeks or take months if it becomes chronic.
Can it be confused with osteoarthritis?
They can look alike and sometimes coexist. Tendinitis hurts at a specific point on the tendon; osteoarthritis usually hurts inside the joint. The exam and imaging help tell them apart.
Is it a good idea to immobilize the knee?
A short rest can help at first, but prolonged immobilization weakens the muscle. It is generally better to keep controlled movement and strengthen.
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Dr. Belinda Martínez reviews your case at her office in Guadalajara. The assessment is free of charge and does not commit you to any treatment.
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This content is informational and educational; it is not a diagnosis or a treatment recommendation. If you have any symptoms, consult a health professional.