A vehicle seat for use by an occupant in a vehicle, for example an
automobile. The vehicle seat comprises a seat base (12) coupled to a
support structure (6) of the vehicle. A back frame (40) including side
members (41, 43), the back frame further includes a second transverse
member (46) coupled to the first and second side members, wherein the
side members each have a lower end pivotably coupled to the seat base. A
compliant back (60) is operably connected at an upper end to the second
transverse member (46) and operably connected at a lower portion
proximate the lower ends of the side members, and may include a biasing
mechanism. The seat may also include a tuberosity pivot (54) coupled to
the back frame (40) and the seat base (12), which pivot may be motorized.