WHILE CHANGING CUTTING EDGES ON A 988F LOADER EMPLOYEES WERE USING A ROUGH TERRAIN FORKLIFT TO MOVE THE EDGES. INJURED EMPLOYEE WAS ADJUSTING THE CUTTING EDGE ON TO THE FORKS AND PLACED HIS LE FT HAND ON THE TOP OF THE FORKLIFT BACK REST AS THE FFORKLIFT OPERATOR TILTED THE FORKS BACK, PINCHING THE EMPLOYEES FINGER BETWEEN THE BACK REST AND THE BOOM HEAD. FAILURE TO COMMUNICATE BET