An occupant support structure for supporting an occupant includes an orientation adjustable torso section, a lower body section, and a control system. The lower body section includes a heel region subsection which supports the heel region of an occupant of the occupant support. The control system is adapted to A) cause the heel region subsection to temporarily substantially disengage from the heel region of the occupant in response to a change of angular orientation of the torso section which begins at a time to, and B) cause the heel region subsection to subsequently re-engage with the heel region of the occupant, the re-engagement occurring at a time tB which is later than to.
