When it comes to finding the best firm mattress for back pain, there are a few things to keep in mind. First, consider the type of mattress you currently have. If it is too soft, it may be causing or aggravating your back pain. Second, think about the size of the mattress. A too-small mattress can also lead to back pain, as it does not provide sufficient support for your spine. Finally, take into account your sleep position. If you typically sleep on your stomach or back, a firmer mattress may be best, as it will provide more support for your spine. Ultimately, the best firm mattress for back pain is the one that best meets your individual needs and preferences. We recommend the Loom and Leaf, as it has superior support in comparison to other memory foam mattresses on the market.