EE REPORTED: HE & A COWORKER USING SHIELD HAULERS WERE TRANSPORTING A COAL FEEDER FROM A WORKING SECTION TO THE PORTAL ALONG THE MINE SUPPLY ENTRY. THE FEEDER SLID OFF THE VICTIM'S SHIELD HAUL ER FORKS, THIS ALLOWED THE MACHINE TO BOUNCE CAUSING HIS HEAD TO STRIKE THE TOP OF THE SHIELD HAULER CANOPY ROOF. HE IS EXPERIENCING PAIN & STIFFNESS TO HIS NECK.