EE HAD BEEN LOADED WITH MUD BY THE 1800 HITACHI SHOVEL. HE WAS STARTING OUT THE RAMP WHEN THE MUD TRANSFERRED TO THE BACK OF THE BED. THIS CAUSED THE 777 TO RAISE IN THE FRONT. WHEN THE TRUCK CAME DOWN, THE SUDDEN STOP CAUSED HIS HEAD TO WHIP FORWARD & STRIKE THE STEERING WHEEL (10 SUTURES REQUIRED).