The back-right passenger side door was opened by pulling on the outside handle after a hobbled passenger was cautioned that the door was going to slide open and moved a few inches away from the vehicle to allow for that. The door required more clearance than either of us anticipated. The passenger fell backwards either trying to avoid being hit by the door or by actually being hit by it, leading to a broken bone, hospitalization, cancellation of the pending surgery to address a pre-existing orthopedic issue, and many continuing expenses. I have not attempted to reproduce this accident (duh), and this is my first report of it. There were no warnings of which I am aware. The speed of door sliding open likely contributed to the accident, as did the required clearance from the vehicle.