Popliteus tendinitis is inflammation in the popliteus tendon, which extends from the outer surface of the bottom of the femur diagonally across the posterior knee to the medial superior 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 posterolateral knee. Diagnosis is by physical examination. The patient sits with the involved extremity in a cross-legged position (ie, the hip flexed, abducted, and externally rotated and the knee flexed with the leg crossed over the opposite extremity). The examiner then palpates the posterior lateral corner for tenderness. The differential diagnosis of reported posterior knee pain should always include intra-articular pathology, such as a posterior horn tear of the meniscus.
Treatment includes rest, NSAIDs, ice, and occasionally physical therapy. Patients should not run until the area is free of pain and then should limit their workouts and downhill running for at least 6 wk. Bicycling is a good alternative exercise during healing.