The back seat driver's side door shut with such impact as to amputate the finger from an adult. Vehicle was parked on incline when front driver's side door shut, the back door also shut. There were no safety features to protect fingers from the hinge side of back door. The force of the door slamming and lack of any space between the hinge side of the door and its frame caused my middle finger from the top knuckle up to be cut off completely thus amputated from hand.