The pes anserine (or anserinus) bursa is located on the medial side of the knee at the proximal tibia where the pes anserine complex of medial tendons (sartorius, gracilis, and semitendinosus) insert. The function of the pes anserine bursa is to provide cushioning to these tendons during activity. Patients with pes anserine bursitis, like patients with medial collateral ligament (MCL) sprain, will have medial-sided knee pain. The pain is more often insidious in onset, and there is often no history of trauma; this is in contrast to an MCL sprain, in which there often is a history of distinct trauma. Patients with pes anserine bursitis will report a history of overuse, commonly in sports such as breaststroke swimming or with repeated kicking of ball. Both of these activities place repeated strain on the medial knee tendons and can result in bursitis. Occasionally, a history of direct trauma to the area may be reported.

There is tenderness to palpation at the proximal medial tibia, at the attachment of the pes anserine tendons. This is different from the medial joint line tenderness common with medial meniscus tears.

Patients with pes anserinus bursitis will not demonstrate any radiographic abnormalities, and plain x-ray stress views of the knee will also be normal.

Patients with pes anserinus bursitis often have resolution of their symptoms; however, it occasionally becomes a chronic problem.