Which muscle is known for its role in extension of the knee?

The quadriceps femoris is the primary muscle responsible for extending the knee. This muscle group consists of four individual heads: the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. When these muscles contract, they work together to extend the knee joint, which is essential for actions such as standing up, walking, running, and jumping.

The function of the quadriceps in knee extension is critical in various activities that require the leg to be straightened from a bent position. For example, during the last phase of a squat or when kicking a ball, the quadriceps generate the power needed to complete these movements effectively.

In contrast, other listed muscles have different roles; the hamstrings primarily function to flex the knee and extend the hip, the sartorius assists in flexing, abducting, and laterally rotating the hip while also helping with knee flexion, and the popliteus has a role in knee stabilization and facilitating flexion rather than extension.