EMPLOYEES WERE TRYING TO LOCATE A WATER LEAK ON THE MINER. THEY PULLED THE CENTRAL PIN BETWEEN 2OFF SIDE RUB RAILS & PUSHED THE SHORT RAIL BACK TO GAIN ACCESS TO THE WATER FILTER. REASSEMBLING THE MINER, THEY WERE PUSHING THE METAL COVER IN.WHILE SEATED ON THE MINE FLOOR W/BACKS AGAINST THE RIB & FEET AGAINST THE COVER, THE INJURED PLACED HIS FOOT UNDER THE RAIL & IT FELL ON L FOOT