I've had slipped discs and pinched nerves before in my lower lumbar spine... it's painful as hell, you can't sleep or even stand up without sharp pains all through your lower back/legs.
I went to a chiro for the pinched nerve - 3 adjustments later and I was pain free until 6 years later when I slipped the discs after a long (23+hr) flight. Went to another chiro for 1 visit (1 adjustment) and I was all set, no problems since and that was about 8 months ago.
They can do a lot in terms of adjusting and readjusting your body but using a chiro to market the brassage is the type of thing that gets them in serious trouble and gives them a really bad rep.