Many things come into play, frequence of lifting and of course recovery all together.
One thing that helps my lower back is doing some good mornings after squats, i do 3 sets of 5 reps and i use about 50% of my squat max for the GM's.
If you are having back pain, i would take some time off any squating/deadlifting for a week or two and then come back light for a few weeks.
if you are like me, then squating heavy and deadlfting heavy in the same week is impossible. if i go heavy on squats, then my next dead lift workout is dynamic and based on speed. likewise, if my squat workout is light(speed), then my deadlifting that week will be ME and all singles. i keep squats and deads about 4 days apart and i could never make gains doing them on the same day.
I alternate like this.
Week 1 - Tues(Speed squats), Sat(ME Deadlifts)
Week 2 - Tues(Heavy squats), Sat(DE Deadlifts)
I'm not sure how your program is structured anymore, so let me know what split you are currently doing.
I actually took a week off of lifting completely last week, so I don't know why the lower back problem hit me this week. I don't remember injuring myself. But I think I'll take a week off of squats/deadlifts, and then start out light and get back into it.
My current routine is this:
Close Grip Bench 4-6 reps (alternate heavy and speed)
Military Press on Smith Machine 6-10 reps
Weighted Dips 6-10 reps
Rope tricep pulldown 8-12 reps
Deadlift 3,2,3 reps (alternate with speed deadlift)
Alternate wide grip/close grip weighted pullups 6-12 reps
DB or cable row 8-12 reps
BB Bench 3,2,3 reps (alternate with DB flat bench)
Incline DB Bench 6-10 reps
Cable flyes 8-12 reps
DB hammer curl 6-10 reps
preacher curl 8-12 reps
Squats (alt heavy/speed) 4-6 reps
Leg extension 15-20 reps
Leg curl 10-15 reps
seat and/or standing calf 10-15 reps
I'll probably put the good mornings in