Shape-changing support, such as for seating

摘要

A back construction for a seating unit includes a plastic back shell having a flexible lumbar region and configured to support a seated user's torso, and a lumbar adjustment mechanism in the form of a pleated bladder attached to a face of the flexible shell so that when the pleated bladder expands in a thickness direction and simultaneously shortens in a vertical/longitudinal direction, the back panel is flexed to a different more curved shape in its lumbar region. The lumbar adjustment device can be removably or permanently attached to the back shell, and the back shell can be pivotally attached to a rigid back support at one or more locations.