The question was posed as to whether a particular bag design works well, or what should be improved, for arm amputees. As we know, this blog is a technical right below elbow amputee issues blog and that is what I can offer.
I do have a backpack that I use often, but as it is it has zippers. The problem with all these zippers is that for me to be able to close them (or even open them) I need to give the zipper a bit of a pull, or stabilization, so it can glide in a straight way. That is also a problem with the backpack. So for places where I cannot foreseeably put the bag down and for situations where I cannot have enough time for this, the backpack is not as convenient.
I have a few sports bags with zippers that are even less convenient. And I have one bag for swimming equipment, fins, kickboard and so on, that closes with a cord that goes around its opening. Without any video demo - trust me, these are not convenient a bit at least in terms of handling their lids or closing and opening mechanism.
The bags that I use most frequently are Freitag bags. The classic models they had before the thing got out of hand are Dexter, Dragnet, Top Cat and (only availabe used, not made any more) Rex. I inherited about three and got some more via online auctions, and as they are regarded as a fashion item here, they are sold as much as they are bought. So they are good value, as they are made carefully and with sturdy materials, and if you can get a used one that is not so hip at the moment they are affordable and last long.
The simple cut of this Freitag bag makes it extremely easy for me to also take things out or put things in when there is no place where I can put the bag on.
So I can handle the bag very well while standing and also, pay or handle wallet or cell phone during that process.
So without getting too upset about the choice of bags there is or is not, that is the type of bag I use most often, for work, for trips, or to go grocery shopping.