Hi Ashley and Welcome to the Mattress UnderGround.
This is a common issue for several reasons. As you have discovered, couples with different sleep positions, weight disparities, and personal preferences often find out too late when things start to go awry. It is also becoming more of a common theme with certain legacy brands of mattresses typically after about the 9-15 month mark. This is unfortunate as it seems to be happening more often then one would expect.
The fact that you feel your hips sink further than expected might indicate that the mattress isn’t providing enough support in that area either. When the mattress is too soft in certain places, it can lead to misalignment throughout your spine, contributing to muscle aches, especially in the mid-back.
Since you mentioned using a pillow between your knees for alignment, that’s a great strategy, but it’s also important to make sure that the pillow is the right height for your body. If the pillow is too thick, it could push your legs too far apart, creating more strain in your lower back, which can sometimes translate to discomfort in your mid-back as well. Also, considering your sleep positions side sleeping and back sleeping, you may need a mattress that provides a better balance of support for your hips and shoulders while keeping your spine in a neutral alignment. If the mattress feels fine when you first lie down (which is common in a typical showroom setting) but causes discomfort after sleeping on it for hours(now you are in the real world and in at home environment), it may be starting to show signs of wear, or the initial support may not be enough for your needs. I was hinting at this in the initial paragraph.
Since your mattress is about six months old and you’re noticing sagging in the hip area, it’s likely that the mattress is losing some of its initial support, which could explain the mid-back pain you’re experiencing. Even though the mattress felt comfortable at first, sagging or uneven support can develop over time, leading to discomfort in different areas of the body.
If the mattress is not sagging when you get into bed the next night you attempt to sleep on it, you can try using a topper to modify the mattress for better mid back pain comfort, but with the mattress already 9 months old and this being a common issue with the S&F’s lately, the topper fix may not offer much longevity.
Since you visit the chiropractor on a regular basis, I am sure he would confirm your alignment issues and their connection to the mattress. Rick @BackScience tackles these issues all the time. I would suggest you reach out to him if he doesnt respond here first and speak with him about his backscience mattress with the lumbar flex option. Egh, I know this stinks, but thre is nothing worse than waking up with back pain every morning. Those middle back muscles are becoming sore and stiff, because of the lack of that lumbar support. Think of a pair of shoes, where your feet have a higher arch and the arch in the shoe is relatively flat. That places a lot of strain on your arch. You may try sleeping with a thin pillow under that area to see if that helps, then possible have a piece of curved polyfoam cut and placed under your side of the mattress under the mattress cover to see if that helps. Again, not a long term solution. A mattress needs the ability to support anything placed on top of it, whether it be a topper or a person trying to sleep.
Sometimes we dont realize what we have purchased when we jump into a new mattress, particularly with a short trial, then find out there is an issue when it is too late.
I think @BackScience may be able to help you here. Pehaps he can modify the lumbar flex to work in conjunction with your mattress and mattress cover.
Wishing you the best,
Maverick
