EE WAS CUTTING CONVEYER FLIGHT OF #12 MINER JUST PRIOR TO THIS INCIDENT. HE WAS IN THE PROCESS OF GETTING OFF THE MINER TO GET A CABLE TO PULL A BROKEN PIECE OF CONVEYER CHAIN OUT OF THE MINE R. AS HE STEPPED DOWN OFF THE MINER HE MISSED THE RUB RAIL, FELL FORWARD AND TRIED TO CATCH HIMSELF WITH HIS HANDS. HE HIT HIS LEFT HAND ON A PIECE OF BROKEN CONVEYER FLIGHT FRACTURED ARM.