pressure relief encourages good blow flow - get this from thicker or softer comfort layers
firmer upper layers give freedom of movement to move freely (your forth point)
I want both!
it seems pressure relief is not possible if its too firm- so maybe this is just kind of binary extreme??
so i can get pressure relief blood flow with a firm, but not too firm, mattress?
Hi ducksmack,
The short answer is yes.
Your question is a quite broad question, and a complete answer is beyond the scope of this forum and the time it would take to answer it completely, so I’ll attempt to stay with general statements.
First of all, each person has their own definition of what is “too soft” or “too firm”, and there is no consensus of such (nor could there ever be), as there are far too many individual variations between individuals and sleeping styles and how that all interacts with the various layering combinations available in a mattress. Nothing can replace you own personal testing in determining what would work best for your own particular situation.
Surface layers will provide the most noticeable difference in comfort, and latex and memory foam in the upper layers of the mattress tend to be two very good products at pressure point relief. Of course, they are part of a complete mattress system so they work in conjunction with the rest of the mattress componentry. There is more about some of the general differences between memory foam and latex in post #2 here. Some people tend to prefer the faster response and more resilient and “on the mattress” feel of latex and some prefer the slower response and more “in the mattress” feel of memory foam and some people may prefer some combination of both of them but the only way to know which one you tend to prefer in general terms will be based on your own careful testing in a store or your own personal experience when you sleep on them.
The compression of each layer (mainly controlled by thickness, firmness, compression modulus, hysteresis, and position along with a few other specs) are what creates the pressure relieving cradle of a mattress in the top layers which re-distributes weight and pressure on the bony prominences and pressure points of the body while the resistance to further compression of the deeper layers is what “stops” the heavier parts of the body from sinking down too far and putting the spine and joints out of their natural alignment. The balance between the opposing needs of pressure relief and spinal alignment is the main factor behind all mattress design and theory and why different mattresses match the body types and sleeping positions and preferences of different people … or don’t.
For more about pressure relief and support, there is more about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel”.
For a very detailed explanation of pressure point relief and “softness”, see post #1 here.
The ability to be able to reposition is related to pressure point relief, but it is not an “either/or” situation.
Latex has a lower hysteresis (how much energy is absorbed) and conversely a higher resilience (how much energy it returns) than polyfoam and memory foam so there are also factors that can make latex feel firm, yet still soft, in the upper layers of a mattress, which can make it easier to reposition while still having a relatively “plush” level of comfort. Because of its unique qualities and ability to take on the shape of the person on it (point elasticity) it can feel softer and firmer at the same time and some will feel it as one or the other depending on what they are more sensitive to, their body type, sleeping position, and how they sink into the mattress. True high resiliency polyfoam (above 2.5 lb) can also have similar characteristics.
Additionally, all the layers of a mattress actually compress simultaneously not sequentially and they will each compress to different percentages of their thickness depending on their position on the mattress, the firmness of each layer, the compression modulus of the material, the thickness of each layer, and the compression force that they are exposed to (which depends on the weight of the part of the body in contact with the mattress and the surface area that is bearing that weight which is constantly changing as you sink into the mattress more or change sleep positions).
So, you could have a very plush surface comfort, even using memory foam, that would have you feel as if you were “in” the mattress more, but if the layers beneath the memory foam were more resilient and using a different material and the memory foam layer wasn’t overly thick, you might still be able to reposition easily.
But repositioning is very personal to an individual and depends upon one’s level of strength, fitness, flexibility, mobility, and the sleeping positions that are being rotated to - all of this is independent of the mattress you choose to sleep upon. And how these variable coordinate with any mattress you choose can only be determined by again personally testing a product and attempting to relocate from one area to another.
I know these answers are rather broad, but short of your own personal testing it’s the best I can provide.
I hope the information here and what I linked to is helpful to you.
Phoenix
this is GREAT!
Thanks Phoenix
Hi ducksmack,
I’m glad you found the information helpful. You’re welcome.
Phoenix