I have a compressed disc in my lower back and things that have really helped:
1) I check my posture multiple times a day (ie: when I'm walking I think about how my posture is. They say to pretend like your a puppet and someone is pulling a string from above your head)
2) Deadlifts: I dont go heavy, I think I do 3 sets of 10 at 120-140 lbs....thats not heavy. But check your form.
3)Work your core, it does most of the work pertaining to posture.
4) Orthotics: I have heel seats in all my work shoes.