Hi Ana,
Thanks for adding a bit more detail about your sleeping experience on both mattresses. It’s good to know that the foundation is sturdy and does not bend under the weight of the mattress when you sleep on it. You noted that there is up to 1/2" a height differential between slats. This may account for some of the pressure points you are experiencing resulting in “numbness and tingling” and the burning sensation when sleeping on your side so you may want to try to sleep in an area where there is no slat elevation at all to see if it makes a difference. The surface of the foundation needs to be totally flat.
I’d, also make sure that you reevaluate your pillow to ensure that it is providing a decent alignment to keep your cervical/upper thoracic region in a relatively neutral arrangement. Improper pillow thickness is a common cause for shoulder issues, especially with a new mattress.
Next, you may wish to continue to reevaluate how you are sleeping upon your side and the location of your arms, as this can also make a large difference in shoulder pain, regardless of mattress types. You can try while sleeping on your side to, fold your arms across your chest (like what is commonly depicted on an Egyptian sarcophagus). if sleeping upon your right side, your right arm would be crossed over your chest, with the elbow pointing down toward your waist area and your hand closer to your left shoulder. Doing so abducts your shoulder girdle and takes some of the pressure off of your shoulder joint. Also, consider placing a thicker pillow in front of you and place your free arm (in his case, the left arm) atop this pillow to help support it in a more neutral position and take the pressure off of both shoulders. I know that you need to keep your arm sideways while nursing the baby but I’d try to shift to the position I described as soon as possible and bring your arm close to the body to see how this works out.
As far as the support/comfort balance … It appears from your experiments, that you need something that is not quite as frim as the Avocado to help relieve the pressure points when sleeping on your side but not quite as soft as My Green Mattress that is not supportive enough and causes you lower back pains when sleeping on your back. Generally, you cannot fix a mattress that is too soft by adding another layer (especially a softer one) as you did by adding the 2" soft Dunlop with your MGM mattress. This most likely caused you to sink in too far and compromised your neutral spinal alignment.
You are correct that in the case of the Avocado mattress, as a side sleeper, typically you’d need a bit more pressure point relief to accommodate the wider dimensional variances between the shoulders and the hips and the waist. There’s a bit more about different sleeping positions here. You did well to add the softer 2" Dunlop layer and while it still “did not feel good” I am not clear if this discomfort was for side sleeping, back sleeping or both.
You also described sleeping in what I call a “pretzel” position with certain parts of the body twisted which may complicate things further. Protecting your baby while sleeping and nursing is also a background modifier of your posture. All of these have overlapping effects and you’d need a high level of confidence that you have identified the real problem (which may be compounded}. Some people can “react” to symptoms that were only there for a couple of days and make quick random changes. Then “react” again to new symptoms and this can quickly become so complex that they become lost in the details and nothing seems to work because changes are happening so quickly that the body doesn’t have time to catch up and it’s never clear which change is producing what symptom (the symptoms can happen sometime after the change). The suggestion is really just a matter of making certain that what you are seeing and feeling is an accurate predictor of your long term experience and to take into account the many factors that I tried to point out that are unknown or hidden rather than just the ones that are known. In many cases when something appears “suddenly” … I am very cautious and like to rule out other possible causes that may not be so obvious.
One of these for example is that the position you are “assessing” is not quite the same as the position that you sleep in for part or most of the night that is causing the “symptom”. Just as one example … if you bring up your knees into a more fetal position this could change the profile compared to side sleeping in a more straight position. Sometimes a slight shift in one part of the body can produce a flatter surface under that area which changes how far some parts will sink in. In other words … it’s just a matter of prudence and the level of confidence you have that you have “nailed” the most likely cause which is not always as obvious as it seems. Time tends to “average out” all the potential causes including the ones that are known and are more obvious and the ones that may not be as visible or obvious.
All in all, you are making good progress. You just need to pinpoint with a little more clarity where the issue resides and any factor that may contribute to it before you decide your next step.
Phoenix
would you please respond to my long reply? Maybe i replied to myself and that’s why it didn’t inform you…
