Romanian Dead Lifts (RDL)-

Single Leg Dumbbell RDL's-

Hamstrings

The function of the hamstrings is to curl the leg at the knee joint similarly to the bicep with the arms.  The bulk of this muscle is in the Biceps Femoris which consists of a long and short head.  Parallel to this but closer to the central line of the body is the Semiteninosus and then there is the Semimembranosus which lies just above the back side of the knee.