Hamstring curls is performed using a machine, but it is an effective way to work on your hamstrings only. Most people are only conscious on their upper body and fail to realize the importance of working on your leg strength can do. For instance, people’s back pain would not be as severe if their hamstrings were stronger and more flexible. The hamstrings help pick up the slack for your lower back in your everyday activities. For the hamstring curl, it is pretty self explanatory to see what to do based on the picture below. Do not overdo this workout, because by injuring your hamstrings you will be sidelined for a long time and will not be able to focus on your fitness.