Hi MD,
When someone has pre-existing back issues then the “rules” of mattress selection are still the same (focusing on PPP or Pressure relief, Posture and alignment, and Personal preferences) but alignment becomes even more important than it would be with someone that has no back issues and a little wider range of tolerance that would work for them. In most cases … even the firmest mattresses have some soft foam in them to relieve pressure but the comfort layers will tend to be thinner so that the feel of the firmer support layers will “come through” more.
There was a belief many years ago that firmer is better for back issues and some people still hold on to this belief but this is now known to not be accurate (firmness doesn’t always provide the necessary alignment) and a mattress that is too firm can also result in back issues because it may not provide the neutral alignment and support that is needed (and is even more important with back issues). Firmer deep support layers are important in these cases (to prevent the heavier areas of the body from sinking in too far) but secondary support which can “fill in” the gaps in body profile in different positions and help maintain the natural curvature of the more recessed areas or inward curves of the spine is also important and for this you need some softer foam on the top of the mattress.
I also believe that free movement on a mattress is also a good idea because a mattress that tends to “hold you” in position (such as many memory foam mattresses) where it is more difficult to change position (which is a vital part of healthy sleeping) can also lead to “jerky” position changes and risk aggravating back issues.
Post #11 here provides some tips about how to test for alignment and for him … testing specifically for alignment (rather than just going by subjective perceptions of firmness) may be a very good idea. If he goes by these suggestions he may need enough soft foam on the top of the mattress (and still have firm support) that will provide his lighter wife with the pressure relief she needs.
In these cases when there is the added complication of two different comfort preferences, body types, and sleeping positions there are really 3 ways to deal with this.
The first and worst is compromise where both of the people won’t really have what they want.
The second is through different types of layering. Heavier people will sink in deeper into a mattress than lighter people so if the top few inches are softer and then the layers underneath this are firmer, then the heavier person will feel more of the firmness of the lower layers (they will “go through” the upper layers more) while the lighter person will feel more of the softness of the upper layers. There are many variations of layering softness and thickness that can be used to provide both with what they need and prefer. This is the reason that some mattresses feel firm to some but soft to another.
The third method would be a side to side split layering where each side of the mattress can be layered differently to accommodate each person. This is more commonly available in a King Size but some manufacturers make this available is queen as well. I know that R&S can provide this in their Brooklyn Bedding mattresses in King Size and some of the others in the Salt Lake City list may as well.
Sometimes it can be important to let go of preconceptions like “firmer is better” not because they are completely wrong but because they may only deal with part of the story.
I certainly agree with this opinion. There is more of my thoughts about airbeds in this article and they are not nearly as “automatically” adaptable to different sleeping positions as other types of support systems or layers and they tend to have worse value than many other alternatives as well.
Hope this helps provide some general guidelines and ideas about what to look for and what may work for both of them.
Phoenix