EMPLOYEE WAS PLACING A PALLET IN PLACE TO STACK BAGS. AS HE WAS DOING THIS A 50 LB BAG FELL FROMTHE ROLLERS TO THE FLOOR, WHEN HE PICKED UP THE BAG, HE FELT SOMETHING POP IN HIS BACK. THE E.R. DOC SAID HE HAD MUSCLE SPASMS. THE DR GAVE HIM PRESCRIPTION FOR PAIN AND INSTRUCTED HIM NOT TO LIFT BEN SCOOP FOR ONE DAY.