I tore a ligament in my lower back at the end of October, ive been doing these sorts of exercises to get it somewhere near:
ive been doing the back extension slightly different to the above, doing more of a superman; http://www.bodybuilding.com/exercises/detail/view/name/superman
after advise from a physio, that i shouldnt be using my arms to put myself into the position during the stretch as its placing more strain on your lower back muscles.
i found these really helped aswell, really loosened it up;
a massage really helped as well......
started doing some really light deadlifts a couple of week ago and its on the up like, feeling better all the time.
my eclipse pod pack is pretty good whilst playing also, puts some pressure on all the right places.