Choose the amount of weight you want to use as assistance from the lat pull-down machine.
Kneel on the seat of the lat pull-down machine, facing away from the machine, and secure your feet under the rollers.
Grasp the bar of the lat pull-down machine and pull it down to behind your neck.
Flex your hips a little so that you lean forward a bit.
Flex your ankles so that your toes point up towards your shins.
Keeping your hips flexed a little and your ankles flexed, inhale as you allow your body to slowly and carefully fall forward, making sure to control the descent as much as possible with your hamstrings.
Exhale as you reverse the movement and pull your body back up to the starting position using your hamstrings.
Repeat for the prescribed number of repetitions.
Comments and tips
This exercise can be dangerous. To avoid falling forward and smashing your face on the floor, make sure that you use enough weight from the lat pull-down machine for assistance. If you fall forward, let go of the bar and catch your body with your arms.
Keeping your hips flexed a little ensures that your hamstrings remain stretched, which allows them to work more efficiently. This is also why the bench of a lying leg curl machine has an angle.
Keeping your ankles flexed allows your gastrocnemius to work as a synergist more effectively. If you do not flex your ankles, your gastrocnemius will be loose and therefore unable to make a decent contribution.
Use the assisted inverse leg curl with lat pull-down machine only when you do not have access to a leg curl machine.