The contact owns a 2021 Ford Explorer. The contact stated that after she had parked her vehicle and retrieved items out of the liftgate compartment; the vehicle began to roll back independently towards her. A witness alerted her that the vehicle was rolling towards her; the contact moved out of the way. She then opened her driver-side door as the vehicle proceeded to roll back; the contact was pinned in between the concrete post and the driver-side door as the vehicle eventually stopped. Witnesses assisted her and aided her away from the vehicle which bruised her left arm. The contact did not seek medical attention for the injury. The contact called the dealer and they offered no assistance. The contact then had the vehicle towed to a different dealer Lithia Ford Idaho Falls(980 W Broadway St, Idaho Falls, ID 83402) where the driver-side door was replaced. The manufacturer was also notified of the failure and she was given a case number. The cement post was damaged as a result of the failure. The police were called after the failure and a report was filed. The vehicle was repaired; however, the cause of the failure had yet to be determined. The failure mileage was approximately 4,500.