I too have a dicky back. Operation on L4 and L5 for a bulging disc before I turned 40!
I opened heaps of CT's and came up with a few ideas on how they could all be improved.
We opted for a hard floor camper (see sig below) because in the worst case scenario I'd need to pack it up, hitch it up and tow the darn thing without any assistance and for me, these were the easiest to close/open. The ones with the strap and handle I found were the hardest (sorry that brand) because I'm a sheila and 5'5" and the handle was much higher than I could reach on the 4WD version without a ladder. The easiest to operate (IMHO) were the AS or the KK for me, but we didn't try some of the other hardfloors on offer, as they didn't have things we liked, so haven't tried every brand out there.
Kit_e