What is the Biceps Femoris?
The biceps femoris is one of the main muscles on the back of your thigh, and it’s part of a group of muscles called the hamstrings. You have a biceps femoris on each leg, running from the pelvis and the femur (thigh bone) down to the outside of the knee, where it attaches near the head of the fibula (a smaller bone of the lower leg). It has two parts, often called a long head and a short head. The long head crosses both the hip and the knee, while the short head only crosses the knee.