What causes soreness and pain in the tendons of the popliteal fossa (the area behind the knee)?

The popliteal fossa—the anatomical region located at the back of the knee—is commonly referred to as the “knee pit.” Pain in this area can arise from various causes, broadly categorized into the following four points.

1. Prolonged maintenance of a single posture—such as standing or sitting for extended periods—can lead to popliteal fossa pain, often resulting from injury to the fascia and associated musculature. In such cases, patients are advised to avoid prolonged sitting or standing.

2. In patients with osteoarthritis, involvement of surrounding soft tissues may cause pain in the posterior aspect of the knee (i.e., the popliteal fossa). Diagnosis is typically confirmed via X-ray imaging. If the posterior horn of the meniscus is damaged, pain in the popliteal fossa commonly occurs during knee flexion or squatting; magnetic resonance imaging (MRI) is required for definitive evaluation.

3. Some patients experience popliteal fossa pain due to a cyst in this region. As the cyst enlarges, it may compress adjacent arteries and subcutaneous nerves, thereby causing pain. In such cases, further evaluation of the cyst’s nature is essential. Smaller cysts may resolve spontaneously or with therapeutic massage, whereas larger cysts—particularly those exhibiting progressive enlargement—typically require surgical excision. Pain usually subsides once the cyst is removed.

4. Popliteal fossa pain may also result from deep vein thrombosis (DVT). Anticoagulant and vasodilatory therapies are indicated, and patients should remain on bed rest during treatment to help alleviate pain.