PRODUCTION TRUCK DRIVER PULLED AWAY FROM THE #59 SHOVEL AFTER BEING LOADED WITH ROCK OR TACONITE. HE EXPERIENCED BACK PAIN AS HE DROVE AWAY FROM THE SHOVEL. INITIAL REPORTS WERE THAT THE AREA WAS BUMPY, BUT UPON INSPECTION NO CORRECTIVE ACTION WAS REQUIRED. TRUCK SUSPENSION AND SEATS WERE O.K. DRIVER SAYS A SUDDEN SWITCH IN DIRECTION CAUSED THE INJURY.