Gurney - photos in the nineteenth century took a long time (up to 7 minutes) so necks & bodies were supported. People rest their arms on tables & chair arms, & lean on walls etc. Mothers squatted behind the chair baby was sitting in, while the photographer waved a toy.

Pinterest even has category for 'The Posing Stand - For helping LIVE people hold still! And another for Post Mortem photography!

google search 19th century photography long exposures neck supports check out the Images, also the related searches like Victorian post mortem photography!