My crookneck was caused by trauma, being pecked on the head. I posted the question here and got the answer from dhlunicorn: http://dlhunicorn.conforums.com/index.cgi?board=casestudiesemergencies&action=display&num=1160927052
I was able to do everything except giving it the predisone. I gave it...
the only time I saw any of my chickens walk backwards is when one of my month old chicks got crook neck. Its head was turned 180 degrees and when it was startled it would just keep backing up till in got in to a corner.
We cured her crookneck and everything is alright and she is walking forward...