Methods
Twenty-seven healthy subjects allocated to sequences A and B with different intervention order were laid in supine and lateral positions on a cardboard bed without a mattress, bubble wrap, or air mattress: the mattress-body contact pressure and contour areas were measured, and subjective firmness and comfort during these conditions were also investigated using the visual analog scale (VAS). Acquired data were analyzed using a linear mixed-effects model and Bonferroni’s 