Leg curls work your hamstrings (back of thigh).They can be done on machines which come in different styles. You may be limited by what is available to you.
It is most important to do this exercise slowly.
Allow the exercise to have a full range of motion.
Pause in the contracted position.
Lying Leg Curls
Lie face down on a leg curl machine and hook your legs under the roller pad.
Stretch out your legs with the pad resting on the back of your ankles.
Grasp the handles under the bench.
Curl your legs up to fully contract the hamstring.
Stay flat on the bench. Keep your butt down.
Briefly hold the contraction.
Slowly lower the pad to its original position.
Remember not to swing the weights into position and always use the full range of motion.
If you would like to intensify the burn in your hamstring try pointing your toes during this lift.
Seated Leg Curls
Sit down on the seated curl machine.
Place your ankles on top of the padded roller.
Hold handles for support.
Curl your legs down to the full range of motion.
Briefly hold the contraction.
Return your legs to the starting position without allowing the weight to swing them up. Be slow and deliberate.
Remember to always exhale during the contraction.
This exercise can also be performed with manual resistance like a dumbbell.