Which muscle extends the knee and is the lateral quadriceps muscle?

Which muscle extends the knee and is the lateral quadriceps muscle?

• A. Vastus Lateralis
• B. Rectus Femoris
• C. Vastus Medialis
• D. Vastus Intermedius

Answer: (A)

Knee extension is produced by the quadriceps femoris group. The muscle on the outside of the thigh—the lateral quadriceps—is vastus lateralis. It extends the knee by contracting to straighten the leg, pulling on the patella through the quadriceps tendon and transmitting force via the patellar ligament to the tibia. Its position on the lateral side distinguishes it from the others: vastus medialis is on the medial side, vastus intermedius lies deep between them, and rectus femoris is more anterior and crosses the hip to assist hip flexion. So the muscle that both extends the knee and is the lateral one is vastus lateralis.

Knee extension is produced by the quadriceps femoris group. The muscle on the outside of the thigh—the lateral quadriceps—is vastus lateralis. It extends the knee by contracting to straighten the leg, pulling on the patella through the quadriceps tendon and transmitting force via the patellar ligament to the tibia. Its position on the lateral side distinguishes it from the others: vastus medialis is on the medial side, vastus intermedius lies deep between them, and rectus femoris is more anterior and crosses the hip to assist hip flexion. So the muscle that both extends the knee and is the lateral one is vastus lateralis.