EE STATED THAT HE HAD PARKED THE NO. 8 COAL HAULER THAT HE WAS OPERATING TO HELP A COWORKER CHANGE THE BATTERIES ON HIS COAL HAULER. WHILE WALKING BACK TO HIS COAL HAULER, EE STEPPED ON A FLY PAD THAT WAS LYING IN THE WALKWAY & SLIPPPED & FELL AGAINST THE BATTERY OF THE COAL HAULER. HE HIT HIS UPPER CHEST ON THE CORNER OF THE BATTERY. DID NOT START MISSING WORK UNTIL 3/17/06.