Repetitive springing up and landing stresses the attachment of the patellar tendon.
What causes patellar tendinopathy?
This disorder is generally agreed to be an 'overuse' problem, with the tendon developing frequent small tears which it attempts to heal. Instead, the tendon develops a mushy ('mucoid') degeneration, which weakens it, causes local discomfort, and may predispose the tendon to rupture.
Confusion of names
The condition used to be called patellar 'tendinitis' or 'tendonitis'. The term '-itis' in medicine means 'inflammation' - a process of irritation, increased blood supply, and infiltration of the area with special inflammatory cells - but these features are not actually seen in patellar tendinitis. So there is a lot of medical literature suggesting that the condition no longer be called 'patellar tendinitis' but 'patellar tendinopathy' or 'patellar tendinosis' instead, implying a degenerative condition rather than an inflammatory one. For your research, you need to search using all of these keywords.
Forum discussions
- Knee tendinitis/tendinosis! help!
Loads of practical advice and empathy about patellar tendinitis.
Peer-reviewed papers
Quote:
"Patellar tendinopathy...has continued to challenge health care professionals...effective conservative intervention includes relative rest, addressing biomechanical issues, eccentric exercise, stretching, and movement retraining...TFM [Transverse friction massage] and counterforce bracing...have weak or little evidence to support their use...In the case of persistent tendon pain...injectables or surgery may be indicated."
Citation: Reinking MF. CURRENT CONCEPTS IN THE TREATMENT OF PATELLAR TENDINOPATHY. Int J Sports Phys Ther. 2016 Dec;11(6):854-866. PMID: 27904789; PMCID: PMC5095939.