Which muscle extends the knee?

Which muscle extends the knee?

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

Answer: (A)

Knee extension is produced by the quadriceps femoris group, which straighten the leg by pulling on the patellar tendon to rotate the tibia at the knee joint. Among the muscles listed, vastus lateralis is one of these knee-extending fibers. It sits on the outer side of the thigh and, when it contracts with the other vasti, helps straighten the knee. It doesn’t cross the hip joint, so it acts primarily as a knee extensor. Rectus femoris also extends the knee, but it crosses the hip and can flex the hip as well, which is why it isn’t as purely a knee-extending muscle. The vastus medialis and vastus intermedius also extend the knee, but the given correct example highlights vastus lateralis as a representative knee extensor.

Knee extension is produced by the quadriceps femoris group, which straighten the leg by pulling on the patellar tendon to rotate the tibia at the knee joint. Among the muscles listed, vastus lateralis is one of these knee-extending fibers. It sits on the outer side of the thigh and, when it contracts with the other vasti, helps straighten the knee. It doesn’t cross the hip joint, so it acts primarily as a knee extensor.

Rectus femoris also extends the knee, but it crosses the hip and can flex the hip as well, which is why it isn’t as purely a knee-extending muscle. The vastus medialis and vastus intermedius also extend the knee, but the given correct example highlights vastus lateralis as a representative knee extensor.