Hi Srehn,
It seems that the foundation is not the issue … so that means focusing on other possibilities.
I think the answer is somewhere inside this …
For most people … 32 ILD would be somewhat firm and there may not be enough pressure relief on wider lighter shoulders to allow them to sink in enough. When this happens … there is a tendency to either change position or to “twist” the shoulders to distribute pressure from the shoulders to the chest which can lead to twisting of the spine … and back pain. Sometimes people will put their arm under their head to change the shape and surface area of the shoulders and distribute pressure onto the rib cage. Same thing can happen with the hips if there is too much pressure there and the body tries to “twist” (move the top leg forward) to relieve pressure. All of these are more common with people who tend to “shift” towards the stomach position rather than the back position. This can be aggravated if the ILD of the mattress under the hips isn’t firm enough to “hold them up” and they are sinking in too far which can aggravate the twist. This can result in a half stomach half side sleeping position which is twisted in some fashion. The odd thing is that this can mean the mattress is both too firm on top (for pressure relief) and too soft (usually under the hips in the deeper layers for best alignment).
A topper can correct the “too firm on top” symptoms of pressure on the shoulders or the hips for side sleepers and relieve the tendency to “twist” towards your stomach as much. A pillow that is suitable for the sleeping position (holds the head up high enough when sleeping on the side) can also help. If the underlying pelvis support is too soft … then some form of zoning in the topper can also make a slight difference although zoned toppers are harder to find than zoned support cores or innersprings and don’t make as much difference in alignment. There are also more creative “zoning” solutions such as those that Catherine is trying in the later posts in this thread.
The lumbar gap (hand under the waist) would generally only be a problem if the mattress is even firmer and you are not sinking in enough in the hips to fill in the gap which doesn’t seem to be an issue here even though it is still worth checking.
In a single layer mattress such as yours (with only a very thin polyfoam comfort layer) … talalay is often not as “effective” as Dunlop latex because it doesn’t have the same sag factor (rate of firmness increase as you sink deeper) as Dunlop so it doesn’t have the same ability to be both soft enough on top and firm enough underneath without increasingly firm layers.
Does any of this seem to apply to what you are experiencing or your “typical” changes or shifts in sleeping positions?
Phoenix