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

The option indicating Quadratus Lumborum is indeed not one of the hamstring muscles, making this the correct choice. The hamstring group consists of three primary muscles located at the back of the thigh: Semimembranosus, Semitendinosus, and Biceps Femoris. These muscles are responsible for knee flexion and hip extension, playing a crucial role in activities such as running and jumping.

On the other hand, the Quadratus Lumborum is a muscle located in the lower back, involved in stabilizing the pelvis and spine rather than in the functioning of the hamstring group. Its primary actions include lateral flexion of the spine and assisting in extension and stabilization of the lower back. Therefore, understanding the anatomical positions and functions of these muscles is vital for yoga practitioners and teachers, especially in alignment and in avoiding injuries during practice.