Which of the following is NOT one of the quadriceps muscles?

The sartorius is not one of the quadriceps muscles. The quadriceps group consists of four specific muscles that work together to extend the knee joint and play a key role in activities such as walking, running, and jumping. These four muscles are the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius.

The rectus femoris, which is one of the quadriceps, also plays a role in hip flexion since it spans across both the hip and knee joints. The vastus lateralis and vastus medialis are part of the quadriceps that specifically assist in knee extension but do not contribute to hip flexion. Each of these quadriceps muscles has a distinct location and function that differentiates them from other muscles surrounding the thigh.

In contrast, the sartorius is a long, thin muscle that runs from the hip down to the inner side of the knee. While it does contribute to hip flexion, knee flexion, and outward rotation of the thigh, it is not part of the quadriceps muscle group. Therefore, the sartorius stands apart from the quadriceps muscles and is the correct choice as it is not included in that specific set.

Understanding the classifications of muscles and their