Pelvic and lumbar support system

1. A pelvic support apparatus for a seat having a seat back and a seat pan, the pelvic support apparatus comprising:

a frame positioned within the seat back;

a pelvic support member coupled with the frame adjacent a bottom of the seat back and a rear of the seat pan, the pelvic support member movable between a first, retracted position, and a second, extended position that provides support to a pelvic area of a person seated in the seat from behind the pelvic area, the pelvic support member having first and second lateral support portions operable to provide support to the pelvic area, each lateral support portion spaced from a central axis of the seat back; and

a guide member coupled with the frame and the pelvic support member to guide movement of the pelvic support member relative to the frame, the guide member including an arcuate surface engaging an arcuate portion of the pelvic support member such that the pelvic support member is movable along an arcuate path between the first and second positions;

wherein the pelvic support member does not include any portion aligned with the central axis and that provides support to the pelvic area, thereby preventing direct pressure from being applied to the person's sacrum or coccyx.

2. The pelvic support apparatus of claim 1 , wherein the pelvic support member is formed from a rod having a generally constant cross-sectional shape.

3. The pelvic support apparatus of claim 1 , wherein the lateral support portions are substantially J-shaped.

4. The pelvic support apparatus of claim 1 , further comprising a lumbar support member coupled to the frame in the seat back, movable between a first, retracted position, and a second, extended position that provides support to the person's lumbar area, and operable with the pelvic support member such that the pelvic support member and the lumber support member both move from the respective first positions to the respective second positions synchronously.

5. The pelvic support apparatus of claim 4 , wherein a single actuator controls the synchronous movement of both the pelvic support member and the lumbar support member.

6. The pelvic support apparatus of claim 1 , wherein the movement of the pelvic support member along the arcuate path provides an upward and forwardly-arching movement of the pelvic support member relative to the pelvic area of the person seated in the seat.

7. The pelvic support apparatus of claim 1 , further comprising a flexible sheet positioned adjacent the lateral support portions of the pelvic support member to distribute pressure on the pelvic area of the person seated in the seat.

8. A pelvic support apparatus for a seat having a seat back and a seat pan, the pelvic support apparatus comprising:

a frame positioned within the seat back;

a pelvic support member coupled with the frame adjacent a bottom of the seat back and a rear of the seat pan, the pelvic support member movable between a first, retracted position, and a second, extended position that provides support to a pelvic area of a person seated in the seat from behind the pelvic area, the pelvic support member having first and second lateral support portions operable to provide support to the pelvic area, each lateral support portion spaced from a central axis of the seat back;

a guide member coupled with the frame and the pelvic support member to guide movement of the pelvic support member relative to the frame, the guide member including an arcuate surface engaging an arcuate portion of the pelvic support member such that the pelvic support member is movable along an arcuate path between the first and second positions; and

an actuator and a biasing member coupled to the pelvic support member, the actuator and biasing member cooperating to permit movement of the pelvic support member between the first position and the second position.

9. The pelvic support apparatus of claim 8 , wherein the actuator controls an actuator cable and the biasing member includes a spring.

10. A combined lumbar and pelvic support apparatus for a seat having a seat back and a seat pan, the support apparatus comprising:

a frame positioned within the seat back;

a lumbar support member coupled with the frame and movable between a first, retracted position, and a second, extended position that provides support to a lumbar area of a person seated in the seat;

a pelvic support member coupled with the frame adjacent a bottom of the seat back and a rear of the seat pan, the pelvic support member movable between a first, retracted position, and a second, extended position that provides support to a pelvic area of the person seated in the seat, the pelvic support member having first and second lateral support portions operable to provide support to the pelvic area, each lateral support portion spaced from a central axis of the seat back; and

a guide member coupled with the frame and the pelvic support member to guide movement of the pelvic support member relative to the frame, the guide member including an arcuate surface engaging an arcuate portion of the pelvic support member such that the pelvic support member is movable along an arcuate path between the first and second positions.

11. The combined lumbar and pelvic support apparatus of claim 10 , wherein the lumbar support member and the pelvic support member are synchronously operable to move together between the respective first and second positions.

12. The combined lumbar and pelvic support apparatus of claim 11 , wherein a single actuator controls the synchronous movement of both the pelvic support member and the lumbar support member.

13. The combined lumbar and pelvic support apparatus of claim 10 , wherein the lumbar support member and the pelvic support member are independently operable to move between the respective first and second positions.

14. The combined lumbar and pelvic support apparatus of claim 13 , wherein a first actuator controls the movement of the pelvic support member and a second actuator controls the movement of the lumbar support member.

15. The combined lumbar and pelvic support apparatus of claim 10 , wherein the pelvic support member does not include any portion aligned with the central axis and that provides support to the pelvic area, thereby preventing direct pressure from being applied to the person's sacrum or coccyx.

16. The combined lumbar and pelvic support apparatus of claim 10 , wherein the pelvic support member is formed from a rod having a generally constant cross-sectional shape.

17. The combined lumbar and pelvic support apparatus of claim 10 , wherein the lateral support portions are substantially J-shaped.

18. The combined lumbar and pelvic support apparatus of claim 10 , wherein the movement of the pelvic support member along the arcuate path provides an upward and forwardly-arching movement of the pelvic support member relative to the pelvic area of the person seated in the seat.

19. The combined lumbar and pelvic support apparatus of claim 10 , further comprising a flexible sheet positioned adjacent the lateral support portions of the pelvic support member to distribute pressure on the pelvic area of the person seated in the seat.