Seat assembly and support portion

A seat assembly, comprising:

• a support portion including:
• a first main portion;
• a second main portion disposed such that a gap is provided between the first main portion and the second main portion;
• a plurality of first extensions projecting from the first main portion away from the gap;
• and
• a plurality of second extensions projecting from the second main portion away from the gap;
• a seatback frame that does not include a wire suspension mat;
• wherein the first main portion and the second main portion are configured to extend along opposite sides of a spine of a user such that the gap is aligned with said spine;
• and
• the plurality of first extensions and the plurality of second extensions are connected to the seatback frame.

A support portion for a seat assembly, comprising:

• a first main portion;
• a second main portion disposed such that a gap is provided between the first main portion and the second main portion;
• a plurality of first extensions projecting from the first main portion away from the gap;
• and
• a plurality of second extensions projecting from the second main portion away from the gap;
• wherein the first main portion and the second main portion are configured to extend along opposite sides of a spine of a user such that the gap is aligned with said spine;
• the plurality of first extensions and the plurality of second extensions are configured for connection with a seatback frame;
• and
• the plurality of first extensions and the plurality of second extensions are configured to limit pressure on bone prominences of said user.