I’ve been sleeping on the soft SleepOnLatex mattress for a couple weeks now. I’m liking it much more than both my BeautyRest plush pillowtop and my BME (old version) soft mattresses that I had prior. I have less pressure points in my hips and shoulders than I did on the BeautyRest and I don’t have any lower back issues like I did with the soft BME mattress. However, I have been waking up with a numb arm (I sleep on my side) almost every morning. Is this normal with the break in process? About how long should I give it before deciding that this is an issue with the firmness of the mattress?
Hi sretodd,
It sounds as if the alignment of this mattress agrees with you more than your previous choices, so that’s a good thing. While I can’t diagnose why your arms are feeling numb, I can provide some insight and possible things to investigate.
Technically, limbs “going numb” are usually caused by a lack of pressure point relief.
Each person has a range of tolerance for both pressure relief and alignment (the two main functions of a mattress) and there are many methods that are part of mattress theory and design to deal with both of these and how they interact so that both are within the range of what someone needs and prefers in their mattress. While pressure is never relieved down to “zero” … as long as it is within the tolerance of the individual both in terms of their perception and comfort and in terms of any restriction of the capillaries and blood flow in the areas of the “bony prominences” then different types of mattress construction and materials can achieve both the pressure relief and alignment that someone needs yes. There’s lots more information about this in the “mattresses” section of the site and in the more detailed information at the end of this post that describes how and why different materials and types of construction can be used to achieve both.
There is little consensus information about pressure relief … even in a hospital setting that deals with treatment of pressure ulcers and there is a great deal of information that needs further research. Technically, to qualify as a “pressure reducing support surface”, a mattress needs to reduce pressure to below 32 mmHg (also called a Torr) on “most bony prominences most of the time”. Bony prominences are the bones and joints in each sleeping position that protrude and have less tissue between them and the surface. To qualify as a “pressure relieving support surface” pressure needs to be reduced to below 32 mmHg (Torr) on “all bony prominences all of the time”. This is also not quite accurate as fixed numbers like this are not considered to be completely accurate or valid anymore as research continues.
So if you can create just enough “sinking in” to distribute pressure points over a wide enough surface area around the body prominences using comfort layers (and the upper surface of the middle layers if necessary) of various types and which will deal with the support needs of the recessed areas of the lumbar, then the only remaining issues are issues of alignment. This is controlled by the middle and deeper layers of the mattress and they need to prevent or “stop” any further sinking down of the heavier areas than are necessary (hips and pelvis primarily) to prevent them from sinking in further than necessary for pressure relief which could put the spine out of its natural range of good alignment.
In other words … the upper layers are about “allowing” enough sinking in to create the mattress cradle which is a larger area of surface contact with the mattress to relieve pressure and support the recessed areas of the spine. The deeper layers are about controlling any further compression than necessary for pressure relief to “hold up” the heavier parts of the body and keep the spine in its range of natural alignment. The amount of sinking allowed by lower layers has less effect on pressure relief in other words (in most types of mattress construction) but controls alignment. This is why when people change the firmness of upper layers to solve support issues or the lower layers to solve pressure relief issues they will often create new issues and may not solve the issue they are trying to “fix”.
Arms falling asleep often indicate a comfort layer that needs to be softer or thicker. The next most common reason is probably a pillow issue (likely needing a thicker or firmer pillow) which could also affect pressure on the shoulders. Of course the initial break in or adjustment period is also a possibility but this would generally lead to gradual improvement over time … particularly if you walked on the mattress to speed it up. The challenge of course is to figure out which it is so that any fine tuning or refinements can change things in the right direction. Sometimes people are sleeping better throughout the night and repositioning less often on their new mattress, and this is the cause of pressure build up.
The links contained in post #11 here provide quite a bit of good information about diagnosing possible reasons for should joint pain.
There is also more information in post #2 here that talks about the various symptoms that people may experience on a mattress and some of the reasons that can cause them that can help with the detective work or trial and error that may be necessary to identify the types of changes that may be helpful.
Hopefully that information is helpful to you.
Phoenix
Are you sure that it is the mattress and not the pillow? I am a side sleeper and used to have arm numbness problem. I switched to a down pillow and it has never happened once since.
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Hi slockthomas,
Welcome to the Mattress Forum! 
I’m glad that you were able to fix your arm numbness problems with a proper pillow - thanks for sharing your success story. Checking for pillow thickness was one of the items I mentioned in my reply post to sretodd in one of the last paragraphs of the reply. It is an important part of alignment in the cervical/upper thoracic region.
Phoenix
Thank you both for your help. I made some adjustments to my pillows and it hasn’t helped. I also had to make a change to my slat system (still using bowed slats but had to get more secure ones from IKEA, the Lonset system, as opposed to the system that came with my Living Spaces bed that was not supportive enough for my all latex mattress.) However, I’m probably experiencing more numbness than before with this new base support.
I went to one of the retailers recommended here, European Sleepworks, who were awesome and super helpful but unfortunately their mattresses were out of my price range. I think at this point I have two options:
- add a latex topper, however I’m not sure how many inches I should add and whether I should put more dunlop or a talalay layer on top.
- try the Dreamfoam Eurotop latex hybrid which is quite thicker than my current mattress at 12"
The Dreamfoam solution is less expensive overall, but of all the beds I’ve tried the SleepOnLatex is the closest to what I’ve been looking for in terms of support.
Thanks for the help!
Hi sretodd,
If you do end up selecting a topper, there is some information here about guidelines for picking out a thickness, along with the posts it links to. What you’re describing can be common when someone needs a bit more plushness on the upper surface of their mattress, and when you’ve already found a mattress that meets your satisfaction for support/alignment, a topper can be a logical next step.
Phoenix
Thanks for the quick reply! Unfortunately that link doesn’t seem to work for me to read more about the toppers.
Question about toppers: I’m considering buying a latex topper from SleepOnLatex.
Seeing as though my mattress has (I think) a 24ILD core and a 2" 20ILD topper, would adding an additional 2" 20ILD soft topper from SleepOnLatex would be helpful? The rep at European Sleepworks thought that perhaps the issue was simply that the mattress was too thin for me and not necessarily too firm, but I’m not sure that adding another 2" of the same material would help my situation. Thanks again for your help!
Hi sretodd,
I’m sorry about that incorrect link. I pasted back into the same thread by accident. It has been corrected and should work for you now.
You’d want to contact Sleep on Latex to find out what the density (using Dunlop they would most likely provide that to you versus ILD) of the layers are in your mattress. I’m guessing you have the 9" version, as you mentioned the 2" upper part, which is not included in their 7" version.
It’s not necessarily the issue of your mattress not being “thick enough” (you can create a 6" thick latex mattress that is as soft as a cloud), but more than likely the need for your upper “comfort cradle” to allow for a bit more conformation, which in this case could be accomplished through the addition of a bit more plush latex. As your alignment characteristics are good, I would not make changes to the base mattress, but instead to the top-of-bed comfort layers. A softer topper (such as something in the 20 ILD range) certainly could be a good alternative.
I would also phone Sleep on Latex and also ask them their opinion, as they would be the most knowledgeable group about their own product.
Phoenix
I would add that Sleep on Latex has been one of the most helpful and responsive sellers that I’ve had the opportunity to work with. Even when contacting them with multiple questions about their topper covers they have been very courteous and prompt in their replies, always welcoming their further support if I had any other questions or issues.
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