I pullled my lower back sometime around jan-mar of 06 when doing deads. I got back to my room, laid down and couldnt get back up for a while. Well, after about 3 weeks i tried deads again and i went up in weight ;-) But thats not the point of my story...its that i still do deads and my back still hurts sometimes, especially after doing weighted pullups. But i guess its just the price you pay?