How to Identify the Biceps Femoris

The biceps femoris is a muscle on the back of the thigh that forms part of the hamstring group and is opposed by the quadriceps. This large muscle is important in bodybuilding and is primarily trained with leg curls. The following steps will aid in your search for information about identifying this muscle.

Instructions

Difficulty: Challenging

1. Read up on Latin roots to know that "biceps" means "two-headed" and "femoris" means "thigh." This muscle has two heads, although the shorter one is occasionally absent.
2. Examine the biceps femoris to see that it flexes the knee (mainly the short head) and laterally rotates the thigh when flexed at the knee and the long head extends the hip.
3. Observe how the biceps femoris originates from the ischial tuberosity for the long head and the lateral lip of linea aspera and the lateral intermuscular septum for the short head.
4. Look at the insertion of the biceps femoris into the head of the fibula and possibly to the lateral tibial condyle. A slip also may pass to the gastronemius in some individuals.
5. Research the nervous system to know that the nerve for the biceps femoris is the tibial nerve from the fifth lumbar and first two sacral nerves for the long head and the common peroneal nerve from the fifth lumbar and first sacral nerves for the short head.
6. Study the circulatory system to know that the blood supply for the biceps femoris is the perforating branches of the profunda femoris and the inferior gluteal artery.