5NW SECTION OUTBY FEEDER IN #6 ENTRY. EMPLOYEE GETTING OUT OF SCOOP (OPERATORS COMPARTMENT), NO CANOPY, HE STOOD UP & HIS FOOT SLIPPED ON MUD & OIL ON THE DECK & HE FELL BACKWARDS. HIS BACK HIT CORNER OF SCOOP AS HE FELL OUT OF THE DECK. POSSIBLE LOWER BACK INJURIES.