EE WAS EXITING A SCOOP CAR. HIS FOOTING SLIPPED ON A LOOSE ROCK ON THE MINE FLOOR AND HE HIT HIS ANKLE ON THE FRAME OF THE SCOOP CAR BEHIND THE SEAT. THERE WAS NOT DAMAGE OR IMPARIMENT TO THE MINING OPERATION OR TO THE EQUIPMENT. THE INJURY DID NOT INVOLVE ANY ASPECT OF COMPLIANCE, JOB SKILLS, PROFICIENCY, TRAINING, ATTITUDE OR PROTECTIVE ITEMS OR DEVICES FOR PROTECTION ON THE MAC