I hurt my back a long time ago doing smith machine squats...(didn't realize at the time how much of a bind it was putting my lower back in) I eventually recovered after a little time off and staying away from squats in general...But now it seems like every time I do free squats or hacks I get a nasty lactic acid burn in my lower back, which will be gone before I leave the gym that day...but I did deadlifts for the first time in a while this past week (I LOVE deads) and I've had that same burning sensation all week long...like picking up my room and dumb shit like that...I guess it's safe to assume that I shouldn't deadlift anymore....but what advice can anyone offer me?? Has anyone else experienced this before or know what it is?? Should I take this lightly or exercise extreme caution in the future??