Which muscle forms the floor of the popliteal fossa?

Which muscle forms the floor of the popliteal fossa?

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

Answer: (B)

The floor of the popliteal fossa is formed by the popliteus muscle. This slim muscle lies on the posterior aspect of the knee, running from the lateral femoral condyle to the posterior surface of the tibia and crossing the fossa obliquely. It effectively lines the floor of the space and even helps divide the fossa into two parts. The other muscles listed mainly shape the walls or boundaries of the fossa rather than its floor: gastrocnemius forms part of the superior boundary, semimembranosus contributes to a medial boundary, and plantaris is a small accessory muscle nearby.

The floor of the popliteal fossa is formed by the popliteus muscle. This slim muscle lies on the posterior aspect of the knee, running from the lateral femoral condyle to the posterior surface of the tibia and crossing the fossa obliquely. It effectively lines the floor of the space and even helps divide the fossa into two parts. The other muscles listed mainly shape the walls or boundaries of the fossa rather than its floor: gastrocnemius forms part of the superior boundary, semimembranosus contributes to a medial boundary, and plantaris is a small accessory muscle nearby.