What muscle group is referred to as the knee flexor muscles?

The knee flexor muscles are primarily identified as the hamstring muscles. These muscles are located at the back of the thigh and are responsible for bending the knee. The hamstrings consist of three main muscles: the biceps femoris, semitendinosus, and semimembranosus. When these muscles contract, they pull on the tibia and fibula, facilitating the flexion of the knee joint.

In contrast, the quadriceps, located at the front of the thigh, are involved in knee extension, working to straighten the leg. The iliopsoas plays a key role in hip flexion rather than knee movement, while the hip adductors are primarily involved in bringing the legs together, which does not impact knee flexion. Thus, the hamstrings are specifically designated as the knee flexors, making this the correct identification of the muscle group responsible for this action.