An adjustable foundation and process includes a mattress support surfaceincluding a head and back section hingedly connected to an intermediatesection at oneend and a leg and foot section hingedly connected to the intermediate sectionat anotherend, wherein the intermediate section includes a first portion and a secondportion,wherein the first portion is hingedly connected to the head and back sectionand thesecond portion is hingedly connected to the leg and foot section. Theintermediate orseat section is configured to increase in length upon articulation of the headand backsection 18 and/or the leg and foot section 22 from a flat position or anincrease ininclination of any section. Likewise, the intermediate or seat section 20 isconfigured todecrease in length upon articulation of the head and back section 18 and/orthe leg andfoot section 22 from an inclined position to a flat position or a decrease inlength upondeclination of any section. By doing so, a prone user does not have to shifthis positionon the mattress in order to accommodate the inclination or declination.
