best exercise for wrecking the lower back, your doctor will thank you.
only if you try to move weight your not ready for oryour lower backed is not proper trained. someone with good form and posture with good strong lower back spinal erectors will only get stronger from these excercises, most people that wreck lower backs never had a proper trainer foundation and tried to make too big of jumps in weights. people that put time in and did things the right proper way from the beginning would be exempt from this.
smart athletes dont get injured through training much, maybe a nick or ding here and there, most docs get training injuries from weekend warriors,half wits or wannabes
power cleans and deady's are the best for back.