Abstract: A lumbar support assembly (2) comprises a support arrangement (3) which may have the form of a wire framework with two side wires (4) and a plurality of transverse wires (6). A Bowden cable arrangement (10) with a single Bowden cable is attached by two plate clips (15, 17) to the two side wires (4). A first end portion (13) of the wire (12) of the Bowden cable arrangement (10) is anchored to a front edge of a seat frame (1), while a second end portion (14) of the wire (12) is coupled to an actuator (20) for adjusting the tension of the Bowden cable. The lumbar support assembly (2) thus requires only one single Bowden cable to arch the lumbar support assembly at least in a lumbar region and to adjust the degree of lumbar support accordingly.

Abstract: A seat back unit connected to a seat of a chair comprises a main frame having vertical and horizontal sections. A first hinge portion is disposed on a top end of the vertical section, and a resting seat with an embedded concave portion is fixed to a middle segment of the vertical section. Connection projections are disposed on a junction between the vertical and horizontal sections. A supporting member has one end formed with a second hinge portion, and the other end formed with a crossing portion embedded into the embedded concave portion. A backrest member is composed of vertical and transversal curved sections. The vertical arch section has third and fourth hinge portions corresponding to the first and second hinge portions, respectively. A herringbone-shaped structure composed of the vertical arch section and the transversal curved sections conforms to the profile variation of the human body.

Abstract: The back of a wheelchair user is independently supported along and about three mutually perpendicular axes. Two elongated adjustment arms are pivotally connected to extension arms which telescope into opposite ends of a hollow connecting tube. The support positions along and about the three axes is achieved by pivoting the arms and the connected relationships of a back shell and cushion to the connecting tube, while the adjustment arms remain pivotally connected to the wheelchair and the extension arms are telescopically retained in the connecting tube.

Abstract: A number of variations of loose fill (1) cushions having at least one stabilizer (3) to keep an internal lumbar support (2) in the proper position and alignment. Additionally, some embodiments are shown with a fin 4 above the lumbar support to provide further alignment stability.

Abstract: A chair having a seat rotatably attached to a tilt spring portion of a tilt mechanism such that the tilt spring is activated by movement of the seat. A backrest and/or the seat can be rotatably connected to the tilt mechanism by parallel arm arrangements which permit the seat and backrest to tilt relative to each other. A tilt limiter can have a magnetic member which facilitates full movement of the tilt limiter between free and locked positions, and which creates an audible indication of full movement of the tilt limiter. The seat/backrest can be made from a flexible mesh material secured to a rigid overmolding which surrounds and is attached to an inner frame of the seat/backrest wherein an outer surface of the overmolding forms an outer surface of the seat/backrest frame and attachment of the overmolding causes the inner frame to stretch the mesh to a final condition.

Abstract: Disclosed is a seat element (1) for a seat system, which extends substantially across an entire zone of a backrest and/or a seat area of a seat in a mounted state. Said seat element (1) comprises devices (12-21) for receiving functional elements in order to provide additional seat functions. Such a modular seat system makes it possible to create in a simple manner different fittings of a seat, especially a vehicle seat.

Abstract: A power lift lumbar support system for a furniture member includes a lumbar pad. A scissoring portion is rotatably connected to the lumbar pad and moves the lumbar pad between a fully retracted and a fully extended position. A lumbar actuation portion is connected to the scissoring portion and drives the scissoring portion using a powered actuator to displace the lumbar pad. A carrier support rod has first and second carriers slidably disposed on the carrier support rod. The scissoring portion is connected to each of the first and second carriers. Displacement of the first and second carriers toward each other operates through the scissoring portion to displace the lumbar pad away from the carrier support rod and toward the fully extended position.

Abstract: A movable seating arrangement includes a seat pan, a back support rigidly connected with the seat pan, and a seat member slidably mounted to the seat pan. The seat member can be moved from a retracted position proximate the back support to an extended position displaced forward of the upright position, without movement of the back support. In certain embodiments, a lumbar support is mounted to the back support, and motion of the seat member to its extended position causes a mid portion of the lumbar support to flex forward from a flattened position.

Abstract: An adjusting device for a lumbar support comprises a pair of spaced guide members, an adjusting member coupled to the pair of guide members, and a drive mechanism for effecting an adjustment of the lumbar support. The adjusting member is displaceable along the pair of guide members and configured such that the lumbar support is adjusted when the adjusting member is displaced. The drive mechanism comprises a motor, which is provided on the adjusting member so as to be displaceable along the guide members jointly with the adjusting member. The motor may be coupled to a shaft having a structured exterior surface, the drive mechanism being configured to effect a relative displacement between the adjusting member and the shaft.

Abstract: A pelvic support apparatus for a seat having a seat back and a seat pan includes a frame positioned within the seat back and 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 is 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. The pelvic support member has 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.

Abstract: The invention relates to a movement device for mounting in a support device and a support device which entails that at least one part of the device actively moves in a continuous, predetermined fashion. The pattern of the movement occurs independently of the movement of the user. The movements entail that the muscles of the user are continuously activated changing the muscle strain of the user, which entails that the user does not get tired and sore as quickly as usually. The invention further relates to a support device, such as a bed or a chair comprising such a movement device.

Abstract: A vehicle seat feature to provide additional legroom for feet or legs of a rear-facing child in a safety carseat installed in a vehicle seat, by utilizing a bounded cavity or the like in the vehicle seat backrest, which is accessible from the front side of the backrest by feet or legs of a rear-facing child. Such a cavity may in some embodiments be deployable and made available by removing or repositioning a barrier object or the like, which when restored may in effect constitute part of an otherwise normally functional backrest.

Abstract: A seating structure includes a backrest member having an upper edge, opposite side edges and a lower edge. The backrest member has a forwardly facing convex shape formed along a vertical centerline thereof between the upper and lower edges. The lower edge has a forwardly facing concave shape. The lower edge has outer portions positioned forwardly of an entirety of the upper edge.

Abstract: A vehicle seat comprises a rectangular-shaped seat back frame having right and left side frames; a headrest for supporting a head of a seat occupant that is installed within the vehicle seat; a rear-end collision detector mounted to the seat back frame at a position behind the seat occupant, wherein the rear-end collision detector detects rearward movement of the seat occupant and moves rearward; a link member that supports the rear-end collision detector with the seat back frame therethrough; and a biasing member that biases the link member; wherein: the rear-end collision detector acts such that the rearward movement of the rear-end collision detector reduces a distance between a head of the seat occupant and the headrest, and a lower end portion of the biasing member is coupled to a rear portion of the side frame and disposed posterior to the rear-end collision detector.

Abstract: A lumbar assembly has a wireframe for attachment to a frame of a vehicle seat. The wire frame has first and second spaced apart side members. First and second flexible lumbar support bands are each mounted to a wire frame side member, and each have a lateral portion extending inboard with a guide member. The guide members of the first and second lumbar support bands cooperate so that the lumbar support bands are adjusted in a fore and aft direction by translating the lateral portions relative to each other along the guide members.

Abstract: A vehicle seat and head restraint assembly is disclosed in which the configuration of the seat back is automatically adjusted as the position of the head rest is changed. Upon lowering the head restraint, a forwardly directed face of the seat back is urged outward to thereby decrease a torso angle associate with the seat assembly. Additional versions are described in which the torso angle is decreased by raising the head rest. And, versions are described in which horizontal or pivotal movement of the head restraint causes movement of a forward face of the seat back.

Abstract: A seat having a plurality of defined zones for supporting the human anatomy. The zoned seating can also include one or more recoil shields that can be one piece, multiple pieces, or can itself comprise multiple sections that correspond with the multiple zones or individual zones. The seating can also include inserts to assist in supporting or isolating certain desired portions of the human anatomy. The seating includes both seat back structures and seat pan structures, with each including a zoned configuration designed to support and stabilize specific structures of the human anatomy in a defined manner. The zones can separate independent and defined zones that are designed to be separate and act as individual anatomical support areas that collectively support, cradle and permit the human anatomy to be supported in a comfortable manner. It is preferred that the zones act and operate independently from one another.

Abstract: An apparatus for sitting, including: a keystone assembly which connects various parts of the apparatus; a back that provides support for at least a person's back or shoulders; a floating lumbar support, which provides support for a person's lower back, attached to the keystone assembly; a seat that can adjust between a forward tilted and reclined position; a plurality of rollers, disposed on the keystone assembly, on which the seat rests; a central column, attached to the keystone assembly, on which the seat can spin; and a lower torsion spring connected to the seat and disposed on the keystone assembly allowing controlled movement of the seat.

Abstract: A four way lumbar support for an automobile seat includes a wire array, a fixed frame, and a basculating arm. When in its extended position, the basculating arm exerts pressure on the wire array thus providing lumbar support to the seat occupant at that point. A system of cables and sliding connections allows the basculating arm to slide along the fixed frame so that the lumbar support may be provided at different heights within the seat.

Abstract: A lumbar support seat is disclosed for supporting lumbar vertebra portion, which stably supports the lumbar vertebra portion and the pelvis portion so as to maintain proper posture and comfortable sitting. The lumbar support seat includes a seat main body having an upper central portion that is curvedly indented so as to correspond to the shape of pelvis portion; a lumbar supporting die including fixing frames fixed at the upper portion of the rear end of the seat main body, and a base plate for supporting lumbar vertebra portion. The pelvis portion is supported via the seat main body and the lumbar vertebra portion is stably supported via the lumbar supporting die. The lumbar support seat helps a user to sit with proper and comfortable posture.

Abstract: A vehicle seat comprises a square-frame-shaped seatback frame including a pair of side frames, a seat spring (32A, 32B) mounted between the side frames, a single plate-shaped flexible cushion plate (31) mounted on its back face to the seat spring, a seatback cushion provided in front of the cushion plate, a single plate-shaped flexible auxiliary plate (40) provided between the seatback cushion and the cushion plate and mounted on the cushion plate. The cushion plate has a vertically extending rib (36) with which the lower portion of the auxiliary plate comes in contact.

Abstract: An adjusting device for a lumbar support comprises a pair of spaced guide members, an adjusting member coupled to the pair of guide members, and a drive mechanism for effecting an adjustment of the lumbar support. The adjusting member is displaceable along the pair of guide members and configured such that the lumbar support is adjusted when the adjusting member is displaced. The drive mechanism comprises a motor, which is provided on the adjusting member so as to be displaceable along the guide members jointly with the adjusting member. The motor may be coupled to a shaft having a structured exterior surface, the drive mechanism being configured to effect a relative displacement between the adjusting member and the shaft.

Abstract: An actuating element for a lordosis supporting device driven by a traction rope and a lordosis supporting element in a vehicle seat are provided. The actuating device includes a deflecting element that is mounted on a frame such that it is pivotable about an actuating shaft and includes a rope guiding element that is arranged with the fastening point and the deflecting element in such a way that a rope portion leading toward the deflecting element and a rope portion leading away from the deflecting element are guided approximately parallel in a starting position. In preferred embodiments, a fixed end of the traction rope is fastened to the frame at a fastening point and a free end of the traction rope is guided at least partially around the deflecting element for actuating the device.

Abstract: In order to provide a lumbar support apparatus whose position can be adjusted by a simple structure and which can softly support a lumbar vertebra portion of a sitting person, a lumbar support apparatus of a chair according to the present invention is configured by two lumbar support members 10 which are separated into left and right parts, each of the lumbar support members 10 includes a lumbar support portion 11 supporting the lumbar vertebra portion and a stay portion 12 supporting the lumbar support portion, and an end portion of the lumbar support stay portion 12 is rotatably connected and attached to a back frame 2 via a rotation shaft 14, so that the position of the lumbar support portion 11 in the height direction can be adjusted by moving the same such that its distal end side is moved in a circular manner about the rotation shaft 14.

Abstract: A lumbar supporting device for a vehicle, may include an actuator, a lumbar plate slidably mounted to a seat back frame of the vehicle, and having a lumbar support part, wherein the lumbar support part is formed between upper and lower ends of the lumbar plate, and a driving unit coupled to the actuator and pulling both upper and lower portions of the lumbar plate together towards the lumbar support part, using power transmitted from the actuator.

Abstract: A lumbar support for a chair includes a member having a first portion separated from a second portion via a slit formed in the member and a slider mechanism. The slider mechanism has a slider that is moveable from a first position to a second position. The first and second portions of the member are attached to each other when the slider is at the second position via the slider. The first and second portions of the member are unattached at the second position when the slider is moved from the second position to the first position.

Abstract: A backrest frame 5 is provided with a cushion plate 31 of one substantially square plate form positioned behind the waist from the upper part of the back of a vehicle seat occupant, movably back and forth by way of a plurality of upper and lower parallel seat springs, one end of either one of a pair of right and left seat springs 34B of the plurality of upper and lower parallel seat springs is connected to a pair of lower link mechanisms 35 provided rotatably on the backrest frame 5, and a rear end collision sensor 40 is formed by the cushion plate 31 between the seat springs 34B for moving a headrest 4 forward, and a coupling part 39 of the other end of the seat spring 34B is directly attached to the lower link mechanism 35.

Abstract: An office chair is provided having a back assembly which is configured to provide supplemental support to the back of a chair occupant in addition to the support provided by the primary support surface of the chair back. The chair back includes a lumbar support unit having a lumbar support pad wherein asymmetric support is provided to the left and right halves of the lumbar pad. As such, the asymmetric support loads are independently adjustable to more comfortably support a chair occupant. The chair back also includes a pelvic support pad which is disposed vertically adjacent to the lumbar support.

Abstract: An adjustable lumbar support assembly for a chair includes a base, a lumbar support, and an angle adjustment assembly. The base is formed at a lower end of the backrest of the chair. Bar sections bilaterally formed at a lower end of the lumbar support are positioned across the base. The angle adjustment assembly is connected with one bar section of the lumbar support and the base. To tilt the lumbar support forward or backward, a pulling rod is pulled backward to bring the lumbar support into a free state where projections on corresponding surfaces of a positioning element and a moving element mounted around the pulling rod are pressed against each other to allow manual adjustment of the lumbar support for optimal support. When the pulling rod is pushed back, the lumbar support enters a locked state where the positioning element and the moving element are in projection-recess engagement.

Abstract: An apparatus for sitting, including: a keystone assembly which connects various parts of the apparatus; a back that provides support for at least a person's back or shoulders; a floating lumbar support, which provides support for a person's lower back, attached to the keystone assembly; a seat that can adjust between a forward tilted and reclined position; a plurality of rollers, disposed on the keystone assembly, on which the seat rests; a central column, attached to the keystone assembly, on which the seat can spin; and a lower torsion spring connected to the seat and disposed on the keystone assembly allowing controlled movement of the seat.

Abstract: A power seat adjustment assembly comprising an active material actuator, adapted for use when a resting load is present within the seat, and configured to reduce actuator demand, and therefore actuator size and/or rating, by modifying the load to augment performance.

Abstract: A resilient lower-back supporting device capable of vertical adjustment along with a backrest of a chair includes a resilient supporting unit pivotally connected between a lower end of the height-adjustable backrest and a supporting element. Configured for resilient extension and retraction, the resilient supporting unit includes an outer supporting rod and an inner supporting rod inserted therein. The two supporting rods are pulled toward each other by a spring provided therebetween. Besides, a spring is provided at an outer end of each supporting rod to bias the resilient supporting unit and the backrest toward a predetermined direction. With the backrest being vertically adjustable, and with the resilient support provided by a lower-back supporting portion at the lower end of the backrest, people of different heights are ergonomically supported especially on the lower back while sitting in the chair and are protected from back pain attributable to a prolonged sitting posture.

Abstract: A lumbar support mechanism includes a damper having one end supported by the inside of a seat back and the other end capable of extension and contraction. Seesaw links are provided with each having one end connected to the other end and capable of extension and contraction. An intermediate portion is supported at a swing fulcrum by the seat back with the other end extending in the width direction of the seat back, and swung around the swing fulcrum. Pantograph links are connected to the respective seesaw links and are movable up and down in the back and forth direction in conjunction with the swing of the corresponding seesaw links. The lock-release lever is operated to release the lock mechanism of the damper. The extension and contraction force of the damper is transmitted to the pantograph links via the corresponding seesaw links with the pantograph links shifting the pad provided in the seat back.

Abstract: A vehicle seat comprises a cushion plate mounted on upper and lower seat springs, a seat cushion provided on a front side of the cushion plate, an auxiliary plate provided between the seat cushion and the cushion plate for pushing out the seat cushion forward. The cushion plate includes an upper plate located higher than the lower seat spring and a lower plate located lower than the lower seat spring. The lower plate has such elastic force that when the lower plate receives, through the seat back cushion, pressure from a person properly seated on the seat, the lower plate can move backward by a greater distance than the distance of rearward movement of the lower seat spring.

Abstract: A vehicle seat comprises a synthetic resin cushion plate (31) attached to a back frame (3) by way of seat springs (32) so as to be movable forward or backward, a single elastic auxiliary plate (40) attached to the cushion plate (31) so as to be movable forward or backward relative to the cushion plate (31), a specific section of the auxiliary plate (40) formed as a push-out section (70) protruding forward when a distance between an upper edge and a lower edge of the auxiliary plate (40) is shortened by moving the lower edge upward. Elasticity of the auxiliary plate (40) supporting the body of the seated passenger is adjusted by moving the auxiliary plate (40) near the push-out section (70) forward or backward. The push-out section (70) has a corrugated part (71) formed from a sideways projection that projects forward or/and backward as viewed from a side.

Abstract: An occupant lumbar support system for a furniture member includes a belt member having a longitudinally elastically flexible first portion having opposite first and second ends and a longitudinally inelastic second portion. The first portion is connected to the second portion at the first and second ends. The second portion when spaced freely away from the first portion except at the first and second ends defines a belt member free state. The second portion has opposed first and second connecting ends extending freely away from the first and second ends. First and second tensioning members are each connected to one of the first and second connecting ends whereby operation of the first and second tensioning members longitudinally elastically stretches the first portion until the second portion moves into substantially continuous contact with the first portion between the first and second ends defining a belt member aggressive state.

Abstract: Lumbar support for a seat backrest, comprising a support basket (10) extending in the longitudinal direction of the seat backrest, a frame (12) to which the support basket (10) is mounted and an adjustment device (11) which changes the position of the support basket relative to the frame, the adjustment device including a plurality of adjustment members (60) some of which are movable with respect to one another.

Abstract: An office chair (1) comprising a seat (2) and a backrest (3), wherein the backrest (3) includes a lumbar support (4), which is adjustable between an inactive position in which it follows the general shape of the backrest (3), and a fully active position in which it is curved outwards forwardly from the backrest (3) in order to support the lumbar back portion of a person seated on the seat (2) of the chair (1).

Abstract: A suspension assembly of a vehicle seat may include a lumbar plate disposed within an edge of a seat back frame, and an elastic wire section connecting the edge of the seat back frame with a side of the lumbar plate, wherein the elastic wire section includes a first elastic wire, opposite ends of which may be connected to one edge of the seat back frame and at least a portion thereof may be supported by one side of the lumbar plate, and a second elastic wire, opposite ends of which may be connected to the other edge of the seat back frame and at least a portion thereof may be supported by the other side of the lumbar plate.

Abstract: A lumbar support assembly (2) comprises a support arrangement (3) which may have the form of a wire framework with two side wires (4) and a plurality of transverse wires (6). A Bowden cable arrangement (10) with a single Bowden cable is attached by two plate clips (15, 17) to the two side wires (4). A first end portion (13) of the wire (12) of the Bowden cable arrangement (10) is anchored to a front edge of a seat frame (1), while a second end portion (14) of the wire (12) is coupled to an actuator (20) for adjusting the tension of the Bowden cable. The lumbar support assembly (2) thus requires only one single Bowden cable to arch the lumbar support assembly at least in a lumbar region and to adjust the degree of lumbar support accordingly.

Abstract: An ergonomical seat assembly for supporting a seated human body in correct posture to maintain proper and healthy spine, hip, and pelvic alignment. The seat assembly includes a back panel for supporting the back of a user in an upright sitting position and side support members for engaging the sides of the user's torso. Included is a lumbar support member for engaging the lower back of the user just above the hips. The back panel is secured to a base panel upon which is arranged hip support members for engaging the seated user's hips. Together the elements of the seat assembly maintain proper and healthy posture of a seated user and comfortable long or short term seating.

Abstract: A lumbar support for a vehicle backrest has a resting element with a front surface shaped for supporting an area of the back of a user; the resting element is connected to a frame of the backrest via elastic elements, which are bistable for allowing the resting element to click from an advanced position to a rearward position when a thrust against the front surface exceeds a given threshold.

Abstract: A lumbar system for use in a seat includes a frame having a first side and a second side substantially opposite the first side, a pump mounted to the second side of the frame and operable to pressurize air, and a control module mounted to the second side of the frame. The control module is in communication with the pump to receive pressurized air. The lumbar system also includes a plurality of air cells mounted to the first side of the frame. Each of the plurality of air cells individually communicates with the control module to receive variable amounts of pressurized air provided by the pump such that each air cell is independently inflatable. The frame, the pump, the control module, and the plurality of air cells are installable in the seat as a single unit by coupling the frame to the seat.

Abstract: A chair having a seat and a back rest comprises a fluid-containing cushion in the back rest that provides passive automatically adjustable support for the user's lumbar region. The cushion can comprise one or more fluid-containing chambers encompassing the areas of the user's upper back and lumbar regions. As the user leans backs, fluid is forced from the regions adjacent the upper back down to the lumbar region to provide enhanced lumbar support to the user.

Abstract: A cushion-less passenger seat. The passenger seat includes spaced left and right spreaders, each having a front and rear leg with top and bottom ends and a seating surface fanned from a flexible bottom diaphragm attached to and extending between the left and right spreaders. The passenger seat also includes a lumbar support having lower and upper sections and front and back sides formed from a flexible diaphragm. The lower section of the lumbar support is attached to and between the left and right spreaders. The lumbar support upper section extends upwardly above the seat's rear legs and seating surface.

Abstract: A multi-way adjustment device, in particular a two-way adjustment device, is proposed for a seat component, which is suitable in particular for the seat-back width adjustment of a seat. The multi-way adjustment device comprises an adjustment part (7) adjustably mounted relative to a mounting plate a (1), which when moved in a first adjustment direction (A) requires less energy expenditure than when moved in a second adjustment direction (B). In order to compensate this, there are provided mechanical energy accumulation means (5), which takes up mechanical energy when the movement is in the first adjustment direction (A), in order to release this when the movement is in the second adjustment direction (B) and thus to assist the movement of the adjustment part (7) in the second adjustment direction (B).

Abstract: A task chair with a chair base, a pivoting mechanism housing supported by the chair base, a non-pivoting seat bottom, and a pivoting seat back coupled to the pivoting mechanism housing. The seat bottom can have a rigid seat pan that underlies a flexible seat insert and a seat cushion. The seat pan, the seat insert, and the seat cushion can be matingly engaged. A seat back frame can retain a panel of elastomeric material, and lumbar supports can be slidably retained by the seat back frame. The lumbar supports can be flexible to adjust to contoured support rails and can be fixed at selected locations along the rails. The lumbar supports can have non-symmetrical, contoured surfaces and shapes and can be nondestructively removable and exchangeable. Adjustable arm structures with upper and lower arm members can be raised and lowered by operation of an actuation trigger.

Abstract: A vehicle seat comprises a rectangular-shaped seat back frame having right and left side frames; a flexible plate member provided between the right and left side frames; a seat back cushion provided in front of the flexible plate member; a mechanism for pushing the seat back cushion to a front direction by forwardly protruding the flexible plate member that results from the flexible plate member being bent; a headrest for supporting a head of a seat occupant, wherein the headrest is forwardly movably connected to the right and left side frames via right and left link members; and a rear-end collision detecting plate disposed at a portion of the seat back frame behind the seat occupant, wherein the rear-end collision detecting plate detects rearward movement of the seat occupant.

Abstract: A vehicle seat comprises a rectangular-shaped seat back frame having right and left side frames; a flexible plate member provided between the right and left side frames; a seat back cushion provided in front of the flexible plate member; a mechanism for pushing the seat back cushion to a front direction by forwardly protruding the flexible plate member that results from the flexible plate member being bent; a headrest for supporting a head of a seat occupant, wherein the headrest is forwardly movably connected to the right and left side frames via right and left link members; and a rear-end collision detecting plate disposed at a portion of the seat back frame behind the seat occupant, wherein the rear-end collision detecting plate detects rearward movement of the seat occupant.

Abstract: A cushion for a chair includes a cushion body (20) having a mediate position provided with a convex waist support portion (21), an upper end provided with an inclined backrest support portion (22) and a lower end provided with a concave resting portion (24). Thus, the backrest support portion and the waist support portion of the cushion body are designed to fit the user's back and waist ergonomically so that the cushion body can support the user's back and waist smoothly and exactly. In addition, the upper buffering space (202) and the lower buffering space (201) of the cushion body provide a buffering effect to allow deformation of the cushion body so as to regulate the user's seating posture and to provide a comfortable sensation to the user.