Back raises are a good way to target your erectors
without bringing your glutes and hip extensors into
play.
Secure your feet and place your body so that
your navel is in the center of the pad. Your knees
should be bent and by pushing your feet, you lock your
body against the padded bench. Round your upper body
down as far as you can go and extend back up.
Do not
hyperextend your back by arching past a neutral spine
position, as this can place too much strain on it.
Weight can be added by holding a bar behind the neck,
holding weight in front of the body or by attaching
bands.