Latex mattress confusion!

[phoenix]

Hi lenc,

Welcome to the Mattress Forum!

Thanks for providing this very informative site.

You’re very welcome.

I wonder if you can help me work out what is going on regarding a recent purchase of a latex mattress? I just bought my first latex mattress after years of sleeping on futons and pocket sprung mattresses. I am quite small (5 foot two), female and quite thin (around 8 stone in weight) but muscular.

For those of us across the pond, that would be about 112 pounds at a BMI of 20.5. While I can’t diagnose mattress comfort issues online, as there are far too many personal variables involved and I can’t feel what you feel, I certainly can do my best to provide you with some general guidelines that might prove useful.

The latex mattress, from a reputable UK supplier, was a 6-inch solid piece of natural Dunlop latex with 7 comfort zones, described as ‘firm’ (80kg per cubic metre) and I hoped it would be suitable for me as someone who mainly sleeps on my back and having enjoyed using a futon mattress in the past.

You certainly chose a good quality and durable material. An 80 kg/M3 mattress core would translated to about a 5 lb/ft3 density. While ILDs can vary a bit, this would generally be in the uppers 20s / lower 30s for an ILD, which most manufacturers consider a “medium firm”. Of course, terminology isn’t standardized, so this information would be more for comparison purposes.

When the mattress arrived it felt like a rock at first and quite uncomfortable but after a few nights I was sleeping quite well on my back without disturbance from my husband (who sleeps on anything) but, on waking in the morning, I noticed that the surface was so firm that I couldn’t really spend much time lying on my side. It also didn’t have the comfy feel I expected (even my futon had a softer surface) so I wondered if, considering my light weight, I should really have gone for the ‘medium’ mattress instead.

It sounds as if after a few nights you began to adjust to the new mattress and sleeping surface. There will always be what I term a “period of retrogression” where you adjust to your new mattress and lose some of your learned alignment from our old sleeping surface, and your mattress will also adjust a bit to you. What you describe seems to be that your alignment was fine (as evidenced by you “sleeping quite well”) but then you express a desire for a bit of extra surface plushness, which would be normal when sleeping more upon your side as compared to your back.

I exchanged the firm mattress for a medium (also 6 inches of Dunlop latex with 7 comfort zones, but this time 70kg per cubic metre) expecting that it would be similar to the firm but just a bit softer. Well! How wrong I was! Where the firm mattress was solid and unmoving, the medium feels quite squashy and bouncy

A 70 kg/M3 would translate to about 4.4 lb / ft3, which most manufacturers would consider in an upper teen – low 20 ILD range, which would generally be called plush. While this would certainly be softer feeling overall than your past choice, you’d also be sacrificing some support by choosing such a plush product.

To learn 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”.

Of course the ideal would be to have both suitable support/alignment and comfort/pressure relief in a mattress (especially in this kind of much higher budget range), but if you have to choose one over the other then I would choose support/alignment. There is some great information in this PHD thesis by Vincent+Verhaer (who is one of a group of researchers that I greatly respect) about the importance of good spinal alignment that clearly indicates that for healthy individuals it has the single biggest effect on the depth and quality of sleep and recovery for healthy individuals. Having proper alignment doesn’t necessarily mean that a mattress needs to feel hard like a board, and in your situation you certainly would want some surface comfort along with this deep support.

The first couple of nights it felt really comfortable and my back sank into it what seemed just enough, although I noticed I was waking up several times in the night. On subsequent nights I started to have difficulty dropping off to sleep on my back, feeling hip and shoulder pressure that was quite uncomfortable. Now, after 7 nights, I can hardly sleep at all on my back or my side as I seem to be held at uncomfortable angles with pressure on shoulder and hip joints and, on waking, my hips are very painful and my shoulders feel almost pushed out of joint and similarly painful. Now, I am completely baffled because, if this mattress is pushing on my joints like this presumably it is too firm? Then how did I escape having pain when I was sleeping perched on top of the even firmer mattress? If anyone could explain then I would be very grateful!

I can’t explain exactly what is happening to you, but your current mattress is not as “supportive” as your first mattress, and we know this by the difference in the density of the foam being less in your current mattress. However, a softer mattress can sometimes feel “firmer” because it allows certain areas of your body to sink in more deeply (sometimes too much), placing pressure on other areas of your body that have to bear this additional mass, resulting in a feeling of more “pressure”, which many people relate as being too “firm”. Also, the zoning of this mattress can be playing into your feelings as well and with the less dense mattress it might not be supportive enough for you in certain areas. What you seem to be describing with feeling like you’re being “pushed out of joint” is common for those sleeping upon a product that doesn’t have enough deep down support.

Your first mattress seems to have provided you with a good natural alignment, and a compromise might have been to add 1"-2" of a bit of softer latex on top for when sleeping on your side, but not so much that it would negatively impact your alignment when sleeping upon your back. When you are looking for a softer surface comfort (as you initially stated for sleeping upon your side) changes made to the uppermost layers of a mattress will have the most noticeable and dramatic impact. Changing to the softer latex core did provide an initial softer feel, but it also seems to have negatively impacted your alignment.

All of this is my best “theory at a distance”, but I help it, along with the information I linked, is assistive to you.

Phoenix