EE WAS ASSIGNED DUTIES OF OPERATING A COAL TRUCK. HIS NORMAL JOB HAS BEEN OPERATING DRAGLINE FORTHE PAST SEVERAL YEARS. HE OPERATED COAL TRUCK STARTING THE WEEK OF JUNE 17 AND HIS BACK STARTED BOTHERING HIM. ON JUNE 28 HE RAN A TRUCK THAT WAS RECENTLY RETROFITTED TO HAUL LARGER LOADS. HE SAID IT WAS ROUGHER RIDING AND PRODUCED A SIDE-TO-SIDE MOTION. HIS BACK WAS VERY PAINFUL SAW DR