Rucksack?

I imagine that regular use of a rucksack might spark off shoulder problems further down the line.
I witness children trooping along to the nearby primary school heaving a loaded rucksack on their backs and a carrier bag/sports holdall stuffed with the necessary 'stuff' for that day's lessons.
It can't be good for their physical health.

Good idea to use a rucksack. Holds quite a bit and less strain on arms/ shoulders than carrying bags

I use bags. The Costco ones are very big . Shopping trolleys provided by the stores mean you don’t have to actually carry anything, just wheel it to the car and unload then take the trolley back to the designated place in the car park. They don’t mind you using them here even if you don’t actually shop at that particular store. Probably if we lived right in the city they wouldn’t let you do that.

I had a wonderful shopping trolley which held a week's shopping and was very easy to use. I just held it behind me as I walked, you'd hardly notice it was there. Obviously can also be used for just a few items. Can easily be dragged up stairs. It was great.
Hoppa Shopping Trolley