EE STATED HE WAS HELPING CO-WORKERS SET TIMBERS ALONG THE NO.1 UNIT CONVEYOR BELT, A TIMBER WAS LAYING ON THE MINE FLOOR, STUCK IN THE MUD. WHENHE ATTEMPTED TO LIFT THE TIMBER FROM THE MUD, HE EXPERIENCED SHARP PAIN TO HIS LOWER RT. BACK. THE PAIN WORSENED OVER THE NEXT FEW DAYS, HE STARTED LOOSING SCHEDULED WORK DAYS ON 1-7-02.