Which muscles are included in the quadriceps group?

The quadriceps group is comprised of four primary muscles located at the front of the thigh, essential for various movements, particularly those involving knee extension. The correct option includes vastus medialis, vastus lateralis, vastus intermedius, and rectus femoris.

Vastus medialis and vastus lateralis are two of the three vastus muscles that play a significant role in stabilizing the patella and enabling smooth knee motion. Vastus intermedius lies beneath the rectus femoris and contributes to the overall strength of the quadriceps. Rectus femoris is unique among the quadriceps as it also helps in hip flexion, making it essential for activities that involve both the knee and hip joint.

In contrast, the other options included muscles that do not belong to the quadriceps group, such as the sartorius and adductor longus, which serve different functions. The hamstrings and gluteus maximus, while important for posterior chain movements, are also not part of the quadriceps. Understanding these distinctions is crucial for anyone studying anatomy and training principles in physical fitness.