Hamstring workouts

Leg curls primarily stress the hamstrings with minimal emphasis on the calves.  If using a lying leg curl machine, lie face down with your knees comfortably at the edge of the pad.  You may need to adjust the machine depending on your height.  Pull the roller pads upward toward the glutes and hold momentarily.  Then slowly lower the legs to the original position and repeat.  You may find it useful to grab the edge of the pad or any handle bars to stabilize yourself during the movement.  Also, try to keep the hips snug against the pad rather than using a rocking motion to lift which takes some of the emphasis off the hamstrings.  

Note on stiff-leg deadlifts-While I see numerous individuals perform this movement in the gym, years ago I suffered a serious back injury from this exercise so I cannot recommend it.