EMPLOYEE WAS OPERATING SHUTTLE CAR HAULING COAL FROM MINER TO FEEDER WHILE HE WAS WAITING TO BE LOADED A PIECE OF COAL FELL STRIKING EMPLOYEE IN FOREARM. THERE WAS NO IMPAIRMENT IN MINING OPER ATIONS OR EQUIPMENT. EMPLOYEE WAS ADVISED TO KEEP UNDER PROTECTIVE CANOPY AT ALL TIMES WHEN POSSIBLE.