THE TRUCK WAS IN PARK AND TURNED ON AND NOT MOVING ON A FLAT SURFACE IN A PARKING GARAGE WITHOUT THE EMERGENCY BRAKE ENGAGED. AS I ATTEMPTED TO GET INTO THE VEHICLE IT STARTED TO ROLL. I AM 4'11 AND THE TRUCK DID NOT HAVE A STEP. I ATTEMPTED TO CLIMB INTO THE VEHICLE TWICE AND ON THE SECOND TIME I FELL TO THE GROUND AND INJURED MY LEFT KNEE AS I COULD NOT GET PROPER FOOTING TO GET INTO THE TRUCK. MY HUSBAND WAS ABLE TO STOP THE TRUCK FROM THE PASSENGER SIDE BY GETTING HIS FOOT TO THE BREAK AS THE SHIFT KNOB WOULD NOT WORK. *****THIS IS A TRUCK THAT WAS RENTED FROM BUDGET RENTAL CAR******