Having just had surgery on my back I can not stress enough a proper "back healthy" seating position. Knees not above your hips, back at a slight angle not to upright and a lumbar support. Dubai Physio sells a good one and you can pop it in the microwave to heat it up as well.
On another note, for those Bus guys going over to the Boeing take a look at the new FOM now call OM-A section on fleet transfers. It looks like the 6 months on type prior to the upgrade has know become 12 months!!