Which muscle is the deepest in the popliteal space?

• A. Popliteus
• B. Plantaris
• C. Soleus
• D. Gastrocnemius

Answer: (A)

The deepest muscle in the popliteal space is the popliteus. It lies on the floor of the popliteal fossa, tucked between the femur and tibia, and is covered by the more superficial muscles around it. It runs from the lateral femoral condyle to the posterior surface of the tibia, placing it deep within the fossa compared with the other muscles in the area. The popliteus also has the important function of unlocking the knee by rotating the femur on the tibia when the leg is bearing weight. The other muscles—plantaris, soleus, and gastrocnemius—sit more superficially or along the sides of the fossa, so they aren’t deepest.