Hi MMT2014,
Welcome to the Mattress Forum!.
Just for the sake of clarification … the specific design of a mattress and how suitable it is for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) will have much more to do with how a mattress affects back pain (either positively or negatively) than the type of materials that are inside it. There is no specific material that is better or worse for back pain than any other.
Almost everything that could be an issue has probably come up as an issue on the forum and the weight of latex is certainly no exception and has come up in various contexts (making the bed, moving the mattress, or assembling a component latex mattress). It would depend to some degree on the type of latex (Talalay is lighter than Dunlop and softer layers are lighter than firmer layers) and on whether your mattress had only “some” latex layers or was “all” latex. Some types of memory foam for example are heavier than some types of latex but memory foam is only used in upper layers and latex can be used in any layer of a mattress. It would probably also depend on how much room and access you have around the mattress or to the bottom of a mattress (for example whether the latex mattress sits inside a bedframe with solid sides or sits on top of a bedframe) and how much you need to bend over or lift up the mattress to make the bed vs tucking the sheets underneath with minimal lifting. There are also some aids that can be helpful such as the Bed Made EZ here.
When you are in the store testing mattresses then you can “simulate” making the bed to see whether it would be an issue for you.
You’ve probably seen this but just in case you haven’t … the better options and possibilities I’m aware of in the Dallas area (subject to the guidelines here) are listed in post #4 here.
Phoenix