This is an exercise that directly tagets the lower back. Primary muscle used in this exercise is the lower back. Secondary muscles used in this exercise are the upper back and hamstrings.
This exercise is very similar to a reverse sit-up. To perform weighted hyper extensions mount the machine with your ankles pushing down on the pads. Your waistline should be just under where the padded section ends on the machine. Bend forward at the waist and rise back up to your starting position utilising only your lower back muscles.
Bend down to around a 70 degree angle and come back up all the way until your back is straight. Repeat the process.