Final answer:
The Vastus medialis is not a hamstring muscle but part of the quadriceps group, which extends the knee, while the hamstrings flex the knee.
Step-by-step explanation:
The muscle that is not one of the hamstring muscles listed is the Vastus medialis. The hamstrings are located in the posterior compartment of the thigh and consist of three main muscles: the Biceps femoris, Semitendinosus, and Semimembranosus. These muscles primarily function to flex the knee. In contrast, the Vastus medialis is part of the quadriceps femoris group, located in the anterior compartment of the thigh, and functions to extend the knee. Thus, the Vastus medialis does not belong to the hamstring group. Additionally, a non-existent muscle name like extensor minimus longus, presented in an educational example, does not make sense as it is not found in anatomical nomenclature.