Why do you want to sit straight?
http://www.officeteam.co.uk/2013/06/21/proof-that-slouching-is-officially-better-for-your-back/
Get a comfy reclining couch.
This is the new ergonomic way to work on pc/laptop apparently.
My back isn't all that great from many years behind the pc. Reclined on my home theater seating is most comfortable to me for tv and gaming.







