%0 Journal Article %T Medium firm mattresses reduced pain related disability more than firm mattresses in chronic, non-specific low back pain %D 2004 %R 10.1136/ebm.9.4.119 %J Evidence Based Medicine %P 119-119 %V 9 %N 4 %U https://ebm.bmj.com/content/ebmed/9/4/119.full.pdf