Pretty much injury free after 15 years of lifting but the lower back is a constant problem.
I know getbig must have the cure, what are the secret stretches, exercises or sleeping styles to get rid of lower back pain?
For real? You are asking it here? Well, I think that you have already all good advises you can get, because there is only one real solution:
Nothing on this planet cannot help you more, than this excercise. Here in Finland they use this for therapy after back surgeries etc. and it is only know help for the lower back pain...but it need work, and some time..AND lots of reps, 20 -> 50 -> 100, so it means reasonable weights. And to avoid unbalance between abs and lower back, you need to do shitloads of abs also to maintain your posture. Not sit ups, but crunches etc. so you will avoid strenghten hip flexors too much.