Popliteus tendinitis is inflammation in the popliteus tendon, which extends from the outer surface of the bottom of the thighbone (femur) diagonally across the back of the knee to the top of the shinbone (tibia).
Popliteus tendinitis is very uncommon.
The popliteus tendon prevents the lower leg from twisting outward during running as well as helping to prevent forward movement of the femur on the tibia. Excessive running downhill tends to put excessive stress on this tendon.
Pain and soreness, particularly when running downhill, develop along the back and the side of the knee. Doctors make the diagnosis based on the person’s symptoms and physical examination findings.
Treatment includes rest, nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain, ice, and occasionally physical therapy. People should not run until the area is free of pain and then should limit their workouts and downhill running for at least 6 weeks. Bicycling is a good alternative exercise during healing.