The bicep femoris, or hamstring or thigh-bicep, runs up the back of the leg from the knee to the gluteus maximus, or buttocks. The hamstrings are responsible for bending of the knee and raising the foot for walking or running, much like the arm biceps bend the arm and raise the hand. The hamstring is probably one of the more neglected muscles in the legs as far as exercise routines are concerned, but it need not be. Incorporating a few easy exercises into the leg part of a routine will pay dividends in both body function and appearance.