Secure your legs at the end of the decline bench and lie down. Place arms cross-body on either side of your chest, keeping your elbows in. While pushing your back down in the bench, begin to roll your shoulders upward. Continue to push down with lower back as you contract your abdominals. Your shoulders should come up off the bench and and elbows should touch your quads. Pause briefly, then return to starting position. Repeat for all reps.