What is the name of the muscle located in the upper leg?

The muscle located in the upper leg is indeed called the Bicep Femoris. This muscle is one of the hamstring group, which is situated at the back of the thigh and plays a crucial role in movements such as bending the knee and extending the hip. The Bicep Femoris is comprised of two parts: the long head and the short head, both working together to facilitate movement and provide stability to the leg.

Understanding the function and location of various muscles is essential for yoga teachers, as it allows them to guide students in optimizing their poses and avoiding injuries. The other muscles mentioned, such as Pectoralis Major, which is located in the chest, Gastrocnemius, which is part of the calf muscle, and Erector Spinae, which runs along the spine, are not situated in the upper leg and therefore do not fulfill the requirements of the question.