Set-up: Begin by lying face down on a lightly cushioned surface.
Movement: Engaging your hamstrings, raise the heel of your working leg behind you towards your butt while providing resistance using your other leg. Return slowly to the start position maintaining tension in your working hamstring. Maintain stability in your back throughout the movement and do not flail.
Repetitions: Perform all prescribed reps on one side, then on the other. This counts as one set.
Assists: If you have trouble providing resistance with your off leg, remove it from the exercise and focus on the contraction in the working leg.