Popliteus

Description

Centered on the posterior knee, the popliteus lies deep in the popliteal fossa as a flat triangular muscle running inferomedially from the lateral femoral condyle to the posterior surface of the tibia, superior to the soleal line. Lateral to it, the fibular head and proximal fibula define the posterolateral corner, while the tibia forms the medial boundary of the proximal leg. A slender plantaris belly arises just superior and lateral to the lateral femoral condyle and continues distally as a long tendon coursing between gastrocnemius and soleus toward the calcaneal (Achilles) tendon. Bony landmarks at the knee and the distal tibia and fibula at the ankle frame the full length of the posterior compartment. Popliteus matters because it controls tibial rotation and helps “unlock” the knee from terminal extension, a small motion that becomes clinically obvious when the posterolateral corner is injured. Its tendon traverses the lateral capsule near the lateral meniscus and the arcuate complex, so edema or tearing can accompany lateral meniscal pathology and ligamentous injury patterns after varus stress. Plantaris often enters the differential when patients describe acute medial calf pain; rupture at the musculotendinous junction is a classic cause of tennis leg and can mimic deep venous thrombosis on presentation. Small muscle. Common problem. Use this artwork for teaching posterior knee anatomy in gross anatomy, kinesiology, and orthopedic modules, or for illustrating posterolateral corner repair, arthroscopic lateral meniscus discussions, and radiology correlation when explaining MRI findings around the popliteus hiatus and plantaris tendon. It also fits rehabilitation handouts that contrast deep rotators of the tibia with the superficial triceps surae complex. Anatomical accuracy verified by SciePro's Medical Advisory Board.