Hi backman,
It certainly can be yes. “Symptoms” that you experience on a mattress are related to time and either adjusting to a new mattress or to sleeping out of alignment or muscles that are too tense but all of these may not cause “symptoms” over a shorter period of time even though the body can start to “complain” if they happen over longer periods of time. There is more about the normal break in and adjustment period and some other suggestions that may also be helpful in post #2 here. The “normal” break in and adjustment period takes a few weeks but for some people it can take a little longer or shorter and it can also depend on how different a new mattress is from the one you are used to sleeping on.
It’s very possible that your body has “adapted” to sleeping out of alignment and some muscles and ligaments have stretched and some have shortened so it may take some time for your muscles to loosen and for your “muscle memory” to get used to sleeping in better alignment. Stiffness is usually related to muscles that are too tense for too long (trying to compensate for a different sleeping position to what you are used to or that isn’t in a neutral alignment). If you tightly squeeze a finger with your other hand for a minute or two for example and then try to open your hand you will see that your muscles have become stiff in the closed position and it’s difficult to open your hand. Another example is some people that have ongoing stiffness or tension in various parts of their body because of poor posture and muscle tension when they are awake (such as sitting at a computer for too long) or from a lack of flexibility that comes from a lack of movement or exercise where the muscles and joints become stiffer and are “locked in” to a narrow range of movement and lose their natural flexibility.
If your symptoms are in the lower back or pelvic area then it’s usually connected to either how much your pelvis is sinking in (Primary support) or to whether the mattress is “filling in the gaps” in the small of your back (secondary support). There is more about primary and secondary support and their relationship to pressure relief in post #4 here and in post #2 here
The post you linked was about mattress protectors, mattress pads, and toppers so I’m not sure if it was the one you meant to link but there is also more about “learned” sleeping positions in post #7 here that may have been the one you meant. There is also more information in post #2 here about the more common symptoms that people may experience on a mattress and some of the more common reasons that can cause them. Most symptoms have a “most common reason” but they can also be connected to other reasons as well so for example lower back pain can be connected to a mattress that is too soft and “allows” the pelvis to sink down too far but it can also be connected to a mattress that is too firm and doesn’t fill in and support the small of the back or causes “twisting” of the spine which can also lead to stiffness and pain if you are out of alignment for long enough so it can take some detective work to decide on the types of changes that may help alleviate your specific “symptoms”.
Yes … sleeping posture and alignment on a mattress has much more to do with the specific design of a mattress (including the thickness and firmness of the layers and how they interact together) and whether it provides you with good primary and secondary support along with good pressure relief than it does with the type of materials that are in it. Any type of material or combination of materials can be used to manufacture a mattress that is suitable for a particular person in terms of PPP. There are hundreds of very different mattresses in each mattress category and regardless of the type of mattress … some of them would work well for some people while others in the same category won’t work well at all even though the basic materials are the same. The choice of materials in other words is a preference rather than being “better or worse” for backs or for alignment. Every type of material also has better quality and more durable versions and lower quality and less durable versions so outside of choosing a mattress that is a good match in terms of PPP … it’s also important to choose the more durable versions of the materials that you prefer.
Some memory foam mattresses that work very well for some people would be completely unsuitable for others to sleep on even if they have a similar body type or sleeping position or have similar issues. The same is true of every other type or category of mattress such as innersprings, latex or hybrids.
Other than some of the other suggestions (such as checking your foundation or support system or any mattress pad or protector you are using or making sure your pillow is suitable) the best thing to do for the first few weeks if possible is usually nothing at all so that you have time to adjust to a new mattress and the mattress has a chance to break in a little bit as well.
Phoenix