WO2005041721A2

WO2005041721A2 - Synergistic body positioning and dynamic support system

Info

Publication number: WO2005041721A2
Application number: PCT/US2004/036605
Authority: WO
Inventors: Alan Tholkes; Duwayne Dandurand; Jack Hockenberry
Original assignee: Healthpostures, Llc
Priority date: 2003-11-03
Filing date: 2004-11-03
Publication date: 2005-05-12
Also published as: WO2005041721A3

Abstract

A body positioning system and an integrated system for positioning a user’s body vis-à-vis a work surface is herein described. The body positioning system includes a carriage upon which is mounted a seat assembly. The seat assembly rotates a seat bottom and a seat back between a sitting position and a standing position to position the user. A knee brace is provided on the carriage to retain the user on the seat. Arm rests travel with the seat back and maintain a selected spatial and angular orientation therewith.

Description

SYNERGISTIC BODY POSITIONING AND DYNAMIC SUPPORT SYSTEM BACKGROUND OF THE INVENTION

The present invention generally relates to a body positioner that may be used alone or in conjunction with an adjustable task station.

DESCRIPTION OF RELATED ART Several medical studies have shown that prolonged static postures in any of the natural configurations such as, for example, sitting and standing cause discomfort, pain and ultimately injury. Further, the upper limbs, which include the shoulder, arm, forearm and hand, must be positioned to provide stability and to gain mobility. Because any slight injury to the upper limb is further aggravated by repeated motion of the hand and arm muscles, it is important to provide comfortable positioning and support to the upper limb at all postures related to a task seating workstation. Accordingly, there is a need for a body positioning system capable of providing fluidic and timely transposition of a user into various preferred, proper and wholesome postural configurations, maintaining comfortable ergonomic ranges to a task seating workstation at all postures and enhancing health and productivity relative to a defined space- volume envelope of the positioning system, that can be integrated and positioned in concert with a multi-positionable workstation.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a view of the integrated workstation system comprising the body positioning system and the multi-positionable work stand; Fig. 2 is a side elevation of the integrated workstation system of Fig. 1 in an upright position; Fig. 3 is an isometric view of the integrated workstation system of Fig. 1 in a seated position; Fig. 4 is a side elevation of the integrated workstation system of Fig. 1 in a seated position; Fig. 5 is a side view of the body positioning system in a seated position; Fig. 6 is back view of the body positioning system in a seated position; Fig. 7 is a front view of the body positioning system in a seated position; Fig. 8 is an isometric view of the body positioning system in a seated position; Fig. 9 is a side view of the body positioning system of Fig. 8 in a seated position, without a movable cowl covering; Fig. 10 is a top view of the body positioning system wherein the seat has been removed; Fig. 11 is a top view of the body positioning system in a seated position; Fig. 12 is a cross section of the body positioning system of Fig. 11 taken along cutting lines 12-12 and wherein the knee brace is in its forward position; Fig. 13 is a top view of the body positioning system in an upright position; Fig. 14 is a cross section of the body positioning system of Fig 13 taken along cutting lines 14-14 and wherein the knee brace is in its rearward position; Fig. 15 is a side view of the body positioning system in an upright position, without the moveable cowl covering; Fig. 16 is a close-up view of an arm rest of the body positioning system; Fig. 17 is a close-up cross-sectional view of a seat back angle adjusting mechanism of the body positioning system; Fig. 18 is a side view of the multi-positionable work stand of Fig. 1 shown in a lower position; Fig. 19 is a cross section of the multi-positionable work stand of Fig. 18; Fig. 20 is a side view of the multi-positionable work stand of Fig. 1 shown in an upper position; and, Fig. 21 is a cross section of the multi-positionable work stand of Fig. 20. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is able to accommodate the various shifts in weight and pressure normally encountered by the body when an individual changes from one posture to another. More particularly, the invention mimics ergonomically desirable postural silhouettes to proactively support and position the user in the healthiest posture, such that body weight and pressure are distributed to eliminate undue discomfort, pain, fatigue, and muscular and skeletal strain. With reference to Figs. 1 and 2, the body positioning system 100 is shown in relation to a multi-positionable work stand 200. In one embodiment, and as shown herein, work stand 200 is a computer work stand that is supported on an office desk 202 or the like (not shown). Body positioning system 100 is arranged with respect to the work stand 200 to permit a user (not shown) in the body positioning system 100, to use a desktop computer and/or monitor 201 and a keyboard 203 supported on the work stand 200. In some embodiments, other devices, structures, or tools may be supported on a suitably adapted work station 200 in lieu of a computer 201. Note that body positioning system 100 may be used independent of work station 200. In Figs. 1 and 2, the body positioning system 100 and work station 200 are shown in their upright positions. In Figs. 3 and 4, the body positioning system 100 and work station 200 are shown in their lower or sitting positions. In most embodiments, the body positioning system 100 and work station 200 are adapted for continuous adjustment between the upright and sitting positions illustrated in Figs. 1-4. In one embodiment, the body positioning system 100 and work station 200 are adapted to provide a user with a selection of discrete and dynamic orthopedically correct postures based on a coordinated, accurate and repeatable orientation of body positioning system 100 and work stand 200. More specifically, a plurality of basic discrete postures including a reclined seated posture, a reclined neutral or breath-easy posture, and a reclined standing posture may be proactively implemented by appropriate adjustment of the mechanisms of the body positioning system 100, which are described in more detail below. Furthermore, these postures may be implemented to address the user of the body positioning system 100 to the work stand 200 in an ergonomically correct manner. These and other discrete postures are a distinct part of a full range of dynamic hybrid postures continuously shiftable and adjustable to prevent injury, discomfort and fatigue while enhancing health and comfort. Particularly, positioning system 100 is a synergistic bio-mechanical system designed to accommodate and become synergistic with an optimal postural orientation of the human body ranging from a conventional seated posture, to a seated position with a full body stretch option, to a lean-stand with the full body in a substantially vertical posture. Body positioning system 100 includes a carriage 111 having a main structural member 112 that extends forward from a seat post 114 to a knee brace 116. Legs 118 extend laterally from a rear end of the structural member 112 to maintain the carriage 111 in a desired orientation, preferably parallel to the surface on which the body positioning system 100 rests. The distal end of legs 118 may be provided with a non-skid 'foot' (not shown) or with a rotatable caster 120 that allows the body positioning system 100 to be moved around on a supporting surface. Casters 120 may be locking or freely rotatable as desired. Other types of wheels or 'feet' may be provided in lieu of casters 120 as needed. Coupled to a front end of the structural member 112 is a foot support 122. The foot support 122 has an angled surface 124 upon which a user of the body positioning system 100 may rest his or her feet. In one embodiment, the angled surface 124 of the foot support 122 is fixed. However, in other embodiments, the foot support 122 may be adapted to allow the angled surface 124 to be rotated with respect to a user, thereby accommodating the user's postural needs. Wheels or casters 121 may be provided on the foot support 122 to facilitate the movement of the body positioning system 100. Knee brace column 126 is rotatively pinned to foot support 122 at joint 123 such that knee pad 128 may be rotated toward and away from a user seated in the body positioning system 100. Fig. 12 illustrates the knee brace column 126 rotated fully forward and Fig. 14 illustrates the knee brace column 126 rotated fully rearward. In the pictured embodiment, the knee brace column 126 is of a fixed height. However, it is to be understood that in alternate embodiments, the knee brace column may be provided with a telescopic length adjustment mechanism (not shown) of a type known in the art to allow for the adjustment of the length of the knee brace column 126. Alternatively, the kneepad 128 may be fixed to the knee brace column 126 at various heights to adjust the position thereof with respect to a user. Similarly, the kneepad 128 may be fixedly or rotatively secured to the knee brace column 126 to further facilitate the accommodation of the body positioning system 100 to a user's postural needs. Figs. 12 and 14 illustrate one embodiment of a mechanism 130 for adjusting the angular position of the knee brace column 126. A proximal end 132 of the knee brace column 126 extends below joint 123 that rotatively secures the column 126 to the foot support 122, preferably through an aperture or slot 134 in the foot support 12. A spring biased cylinder 136 is rotatively coupled between the proximal end 132 of column 126 and the undersurface of the carriage 111 , in the illustrated embodiment, structural member 112. The retraction of a shaft of the cylinder 136 causes the column 126 to rotate around the joint 123 as shown in Fig. 12. Extension of a shaft of the cylinder 136 causes the column 126 to rotate around the joint 123 as shown in Fig. 14. In one embodiment, the cylinder 136 is a spring biased pneumatic cylinder that allows for dynamic adjustment of the angular position of the column 126. While a pneumatic cylinder 136 may be able to adjust the position of the column 126, movement of the column typically requires the application of motive force by the user, except where the provision of a return spring (not shown) in the cylinder allows for adjustment. In another embodiment, the cylinder 136 may be a hydraulic cylinder or an electrically operated actuator that can apply motive force to the column 126 to positively and dynamically adjust the angular position of thereof. In yet another embodiment, a positive stop mechanism (not shown) may be provided to positively locate the column 126 in one of a number of discrete angular positions. Such a positive stop mechanism may include a clevis pin inserted through mating bores (not shown) in the proximal end 132 of column 126 and the foot rest 122 or the like. As shown in Figs. 12 and 14, a button 138 or similar control may be provided on carriage 112 to control the length of cylinder 136. In the embodiment that includes a pneumatic cylinder 136, depressing button 138 will allow the shaft of the cylinder to move freely, the action of a return spring notwithstanding. In this manner, the length of the cylinder 136 and the angular position of the column 126 may be modified. Referring again to Figs. 1 - 4, the basic structure of the seat assembly 140 of the body positioning system 100 may be seen. The seat assembly 140 supports and guides a seat bottom 142 and a seat back 144 in being positioned at, and moved between, the upright position of the body positioning system 100 and its sitting position. A parallel four-bar linkage 146 is rotatively coupled to seat post 114, thereby allowing the seat assembly 140 of the body positioning system 100 to rotate with respect to the carriage 111. In one embodiment, the seat post 114 includes a height adjustment mechanism 115 that is coupled to the structural member 112. The height adjustment mechanism 115 is in one embodiment a pneumatic cylinder such as that illustrated in Fig. 12 that facilitates raising and lowering the seat assembly 140. In another embodiment, the height adjustment mechanism 115 may be a screw device or the like. The parallel linkage 146 maintains the attitude of the seat back 144 with respect to the surface on which the body positioning system 100 rests as the seat assembly 140 is moved between its upright and sitting positions. Arm rests 111 are coupled to the parallel linkage 146 as shown in Fig. 16. The parallel linkage is most clearly seen in Figs. 9 and 15. The parallel linkage 146 includes a cantilever arm 152 that is coupled to the top of seat post 114. In one embodiment, the cantilever arm 152 will rotate about seat post 114 and may be raised and lowered by a height adjustment mechanism 115b, where so provided. In another embodiment, the cantilever arm 152 is fixed. The distal end of the cantilever arm 152 is curved or angled upward to form the forwardmost link of the parallel linkage 146. Note that the parallel linkage 146 has a right and a left side that are substantially the same. Accordingly, for the sake of brevity and clarity, only the side of the parallel linkage shown in the drawings will be described. An upper link 152 and a lower link 156 are rotatively pinned to the cantilever arm 152 by pin joints 158 and 160, respectively. The upper and lower links 152 and 156 are also rotatively pinned to a seat back support 162 by pin joints 164 and 167, respectively, the distances between the pin joints 158, 160 and 164, 167 being substantially the same. Note also that the lengths of the upper and lower links 152 and 154 are substantially the same when measured between their respective pin joints. The function of the parallel linkage 146 is such that as the links 152 and 154 rotate upward from their sitting position as shown in Fig. 9, the seat back support 162 maintains its attitude with respect to the surface on which the body positioning system 100 rests. Note also that the cantilever arm 152 extends away from the seat post 114 toward the front edge of the seat bottom 142. This moves the center of gravity of the seat assembly 140 forward upon the carriage 111 and reduces the footprint of the body positioning system 100. In one embodiment, the upper links 152 are secured to the cantilever arm 152 and seat back support 162 on an exterior surface thereof whereas the lower links 154 are secured to the cantilever arm 152 and seat back support 162 on an inside surface thereof. This arrangement allows the parallel linkage 146 to collapse into a more compact volume, thereby streamlining the seat assembly 140. A cylinder 166 is provided within the parallel linkage 146 to raise and lower the linkage and hence, the entire seat assembly 140. The cylinder 166 is coupled between a bracket 153 that is rotatively pinned at 155 to the cantilever arm 152 and a bracket 176 secured to and between the upper links 154 such that an increase in the length of the cylinder 166 raises the seat back support 162 as shown in Fig. 15 and a decrease in length of the cylinder 166 lowers the seat back support 162 as shown in Fig. 9. In one embodiment, a first end 168 of cylinder 166 is coupled to the cantilever arm 152 relatively near joints 158 and 160 and a second end 170 of the cylinder 166 is coupled to a bracket 176 secured between upper links 154 relatively near to joints 164 and 167. In this embodiment, the cylinder 166 is generally horizontal when the seat assembly 140 is in a sitting position. By moving the ends 168 and 170 of cylinder 166 nearer to the respective joints 158, 160 and 164, 167, the vertical height required to accommodate the cylinder 166 is minimized and the parallel linkage 146 may collapse to a more compact volume when the seat assembly 140 is in its sitting position as seen in Fig. 9. In a particular embodiment, the distance between joint 155 and the point at which the cylinder 166 is coupled to bracket 176 is approximately 10 %" when the seat assembly 140 is in a sitting position and approximately 14" when the seat assembly 140 is in an upright position. In one embodiment, one or more damping mechanisms 174 may be coupled between the cantilever arm 152 and seat back support 162. The damping mechanisms 174 act to ensure that sudden movements in the seat assembly 140 are avoided or at least minimized, as rapid movement of the seat assembly 140 may damage the body positioning system 100 and /or destabilize the user thereof, potentially resulting in an injury. The damping mechanisms 174 are in one embodiment a pneumatic cylinder and in another embodiment, a hydraulic cylinder. Other suitable mechanisms familiar to those skilled in the arm may also be used. The damping mechanisms 174 allow for the free rotation of the parallel linkage 146, but damp out sudden movements and high accelerations to provide a smooth adjustment of the body positioning system 100. In one embodiment, the cylinder 166 is a simple, passive pneumatic cylinder of a type commonly used in office seating to raise and lower the seat. In another embodiment, the cylinder 166 may be a hydraulic cylinder capable of actively modifying the angular adjustment of the parallel linkage 146. A hydraulic cylinder 166 adapted for positively modifying the angular arrangement of the seat assembly 140 is provided with a manually or electrically actuated pump that provides the pressure needed to extend the shaft of a hydraulic cylinder so as to modify the angular arrangement of the parallel linkage 146 as described above. In other embodiments, any powered, extensible actuator means, such as an electrically actuated screw-type linear actuator, may be used to modify and maintain the angular arrangement of the parallel linkage 146. A movable cowl 172 (see Fig. 1) is provided to screen the parallel linkage 146, cylinder 166, and damping mechanisms 174 from view and from ready access during use. An upper cowl 173a is coupled flanges 155 that extend laterally from upper links 154. A lower cowl 173b is coupled to and may be telescopically received within the upper cowl 173a. Where the seat assembly 140 is in its upright position as seen in Fig. 1, the cowl 172 is fully extended. Where the seat assembly 140 is in a sitting position, as shown in Fig. 4, the cowl 172 is telescoped. The seat back 144 of the body positioning system 100 is slidably secured to a seat member 180 that is itself rotatably coupled to the seat back support 162 by a back bracket 182. Seat member 180 is received in a channel 184 formed in the back of the seat back 144. In one embodiment, the channel 184 is disposed within a spaced defined by the cushion of the seat back 144 and a shroud 186. The shroud 186 may be removable from the seat back 144 or apertures (not shown) may be formed through the shroud 186 so that access to the channel 184 may be had. A detent locking mechanism may be provided between the seat member 180 and the channel 186. In another embodiment, a set-screw or the like may be provided to control the relative position of the seat back 144 with respect to the seat member 180. Referring to Fig. 17, the back bracket 182 is secured to a proximal end of the seat member 180 by means of a weld or a suitable fastener. The back bracket 182 is rotatively pinned at joint 188 to seat back support 162 such that the seat back 144 may rotated toward or away from the seat bottom 142. An extendable member 189 is coupled between the back bracket 182 and the seat back support 162. The extendable member 189 may be a screw device or a pneumatically operated device that through extension and retraction controls the angle of the seat back 144 with respect to the seat bottom 142 by changing the position of the back bracket 182 with respect to the seat back support 162. Arm rests 110 are coupled to the seat assembly 140 by arm member 190 as seen in Fig. 16. Arm member 190 is preferably welded directly to the seat back support 162 to securely support the arm rests 110 and to maintain a desired orientation of the arm rests 110 with respect to the seat back 144. In other embodiments, the arm member 190 may be removably attached to the seat back support 162 as by threaded fastener or pipe clamp. In one embodiment, the arm member 190 is a unitary structure while in other embodiments, the arm member 190 is made up of one or more sections that fit together in a typically male-female tubular connection of a type known to those skilled in the art. The extreme ends of the arm member 190 are generally positioned along the sides of the seat bottom 142 where the seat assembly 140 is in its sitting position, though it is to be understood that other positions are considered to be within the scope of the present invention. Arm brackets 192 are received over the extreme ends of the arm member 190. Arm members 192 include telescopic posts 194 to which are secured arm pads 196. The telescopic posts 194 function in known manner and may include a detent mechanism (not shown) to modify the height of the arm pads 196. In one embodiment, arm pads 196 are rotatively secured to the top of telescopic posts 194 such that the pads 196 may be rotated toward and away from a user. Arm member 192 may further include controls 198 for modifying the attitude and orientation of the body positioning system 100. As seen in Fig. 16, one embodiment of controls 198 includes a trigger 198a that is coupled to an adjustment mechanism, such as for example, cylinder 166 by means of a connector such as a push-pull cable or the like. It is to be understood that controls for the various adjustment mechanism of the body positioning system 100 may be provided directly on those adjustment mechanisms, or may be located remotely, illustrated in Fig. 16. Referring next to Figs. 1-4 and Figs. 18-21, the structure and function of the work station 200 will be described. As seen in Fig. 18, the work station 200 is essentially a parallel four bar linkage 208 having a first work surface 210 coupled thereto. One or more additional work surfaces may also be coupled to the work station 200. In one embodiment, a second work surface 209 that is an adjustable keyboard tray is also coupled to the linkage 208. Linkage 208 includes a bottom member 211 that rests on a surface 202 to support the work station 200. The bottom member 211 is essentially a channel having a flat bottom 212 and upturned sides 214. Sides 214 have a projection 216 extending upwardly from rear portion thereof. In one embodiment bottom member 211 has non-skid feet 218 applied to its bottom to prevent the work station 200 from moving during use or adjustment. Upper arms 220 are pinned to the projections 214 of their respective sides 214 by joints 222. Lower arms 224 are pinned to the projections 214 of the their respective sides 214 by joints 226. Arms 220 and 224 are freely rotatable about joints 222 and 226. Arms 220 and 224 are rotatably coupled to top link 228 by joints 230 and 232, respectively. First work surface 210 is coupled to the top link 228 as is the second work surface 209. Rotation of the arms 220 and 224 away from bottom member 211 raises the top link 228 from the lower position shown in Fig. 18 to the upper position shown in Fig. 20. The parallel linkage 208 ensures that the first work surface 210 retains its initial attitude with respect to the bottom member 211 between and at its upper and lower positions. Figs. 19 and 21 are cross-sectional views of the work station 200 that shows the location of a cylinder 230 that is coupled between the bottom member 211 and the top link 228. Where the length of the cylinder 230 is at a minimum, the work station 200 is in its lower position as seen in Fig. 18. Where the length of the cylinder is increased, the work station 200 is in its upper position as shown in Fig. 20. Damping mechanisms (not shown) may in some embodiments be coupled between the bottom member 211 and the top link 228 to smooth the movement of the linkage 208 and to prevent sudden movements that might overbalance or shift office equipment resting on the work station 200. Note that in one embodiment, the cylinder 230 is a passive, spring biased pneumatic cylinder that will maintain the first work surface 210 in a chosen position. The use of a passive device such as the described pneumatic cylinder requires the user of the work station 200 to provide motive force to modify the location of the first or upper work surface 210. In another embodiment, a single or double acting pneumatic or hydraulic cylinder with an external, electric or manual pump/control may be provided to positively change the position of the upper work surface 210. In yet another embodiment, an electrically actuated screw-type linear actuator may be used in lieu of cylinder 230. In operation, the body positioning system 200 supports a user in a dynamically modifiable and ergonomically correct position with respect to the work station 200 or with respect to another work surface 202. The user is seated on the seat bottoml42 with the user's back against the seat back 144. The user's feet are placed on foot rest 124. Because the body positioning system 100 is movable on its casters or wheels 120 and/or 121 and the knee brace 116 is typically lower than a standard work surface, the body positioning system 100 may be used as a standard office chair with the seat bottom and seat back 142 and 144 positioned in a sitting position. Note that the angle and vertical position of the seat back 144 may be modified using the extendable member 189 and channel 186. Where a user desires to change the attitude of the body positioning system 100 to a more upright position, the knee brace 116 is rotated toward the user's knees until the knee pad 128 contacts the user's knees. The cylinder 130 may then be actuated to release the seat assembly 140 from its current position. Where the cylinder 130 acts passively, the user will raise or lower his or her weight off or onto the seat bottom 142 and the spring biased cylinder will move the seat assembly into a desirable attitude. Where the cylinder 130 is an active device, actuation of a control by the user will raise or lower the seat assembly 140 to a desired position. The parallel linkage 146 allows the seat bottom 142 and seat back to rise to an upright or elevated position while maintaining the attitude of the seat back 144 with respect to a surface upon which the body positioning system 100 is positioned. As the arm rests 110 are secured to the seat back support 162, they too maintain the same attitude with respect to the surface of on which the body positioning system 100 is supported. Note that the arm rests 110 may be raised or lowered as needed and may also be rotated toward or away from the user. Once a desirable position is achieved, the user may raise or lower the work station 200 to ensure that the work surfaces 210 and/or 212 are in an ergonomic position with respect to the user when seated in the body positioning system 100. Note that work surface 212, in the illustrated embodiment a keyboard tray, may be further modified in its height, angle, and projection in manners known to those in the art. Furthermore, the work surface 212 may include auxiliary work surfaces 213 for supporting additional tools, computer mice, etc. Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention in its broader aspects and, therefore, the aim in the appended claims is to cover such changes and modifications as fall within the scope and spirit of the invention.

Claims

CLAIMSWhat is claimed is:

1. A body positioning system comprising: a carriage for supporting the body positioning system upon a surface; a seat assembly rotatably coupled to the carriage having a seat bottom and a seat back secured to a parallel linkage, the seat assembly being moveable such that the bottom and back of the seat assembly will support a user of the body positioning system at and between sitting and upright positions; a knee brace rotatably coupled to the carriage and oriented for rotation toward and away from the seat assembly; and, a pair of arm rests mounted on an arm member that is coupled to the seat assembly such that the arm rests rotate with and maintains substantially the same attitude with respect to the seat back during movement of the seat assembly.

2. The body positioning system of claim 1 wherein the knee brace further comprises: a knee pad coupled to a shaft, the shaft being passed through an aperture in the carriage, the shaft being rotatively pinned to the carriage for rotation within the aperture; and, an adjustment mechanism coupled between the carriage and the shaft of the knee brace to effect the rotation of the knee brace toward and away from the seat assembly.

3. The body positioning system of claim 2 wherein the adjustment mechanism is coupled to an underside of the carriage and to a portion of the shaft of the knee brace that is on an opposing side of the shaft beyond the location at which the shaft is rotatively pinned to the carriage.

4. The body positioning system of claim 2 wherein the adjustment mechanism is a cylinder having an extendable shaft.

5. The body positioning system of claim 1 wherein the seat assembly further comprises a cylinder having an extendable shaft received therein.

6. The body positioning system of claim 1 wherein the seat assembly is coupled to the carriage by an extendable seat post that comprises an adjustment mechanism constructed and arranged to modify the length of the seat post.

7. The body positioning system of claim 1 wherein the parallel linkage comprises at least one upper link and at least one lower link, the upper and lower links being rotatively coupled to a cantilever arm at a first end thereof and to a seat back support at a second end thereof, rotation of the upper and lower links from a lower position to an upright position resulting in the rotation of the seat back support from a lower position to an upright position, the angular orientation of the seat back support with respect to the surface on which the carriage rests remaining substantially the same at and between the lower and upright positions.

8. The body positioning system of claim 7 wherein the at least one upper link and at least one lower link define substantially the same distance between the locations at which their respective ends are coupled to the cantilever arm and the seat back support, the distance between the locations at which the respective upper and lower links are coupled to the cantilever arm and the seat back support also being substantially the same.

9. The body positioning system of claim 7 further comprising an extendable adjustment mechanism coupled between the cantilever arm and the at least one upper link such that the extendable adjustment mechanism is generally aligned with the at least one upper and lower links.

10. The body positioning system of claim 9 wherein the distance between where the extendable adjustment mechanism is coupled to the cantilever arm and to the upper link is approximately 10³Λ" when the seat assembly is in a sitting position and approximately 14" when the seat assembly is in an upright position.

11. The body positioning system of claim 7 wherein the arm member is fixed to the seat back support.

12. The body positioning system of claim 7 wherein the seat bottom is fixed to the at least one upper link of the parallel linkage.

13. The body positioning system of claim 7 wherein the cantilever arm extends away from an axis of the seat post and wherein the distance between the seat post and the location at which the upper and lower links are joined to the cantilever arm is sufficient to bring the center of gravity of a user seated on the seat bottom adjacent to an axis of the seat post.

14. The body positioning system of claim 1 further comprising a back bracket rotatively coupled to the parallel linkage, an extendable adjuster being coupled between the back bracket and the parallel linkage such that modifying the length of the extendable adjuster rotates the back bracket with respect to the parallel linkage, the back bracket having secured there to a seat member to which is secured the seat back.

15. The body positioning system of claim 9 wherein the wherein the arm rests further comprise a trigger control coupled to the extendable adjustment mechanism by a push/pull cable.

16. An integrated system comprising: a body positioning system comprising: a carriage for supporting the body positioning system upon a surface; a seat assembly rotatably coupled to the carriage having a seat bottom and a seat back secured to a parallel linkage, the seat assembly being moveable such that the bottom and back of the seat assembly will support a user of the body positioning system at and between sitting and upright positions; a knee brace rotatably coupled to the carriage and oriented for rotation toward and away from the seat assembly; and, a pair of arm rests mounted on an arm member that is coupled to the seat assembly such that the arm rests rotate with and maintains substantially the same attitude with respect to the seat back during movement of the seat assembly; and, a work station positioned adjacent the body positioning system, the work station comprising: a base having a bottom and upstanding sides; an upper link and a lower link rotatively coupled to the sides of the base; a work surface having a pair of flanges, each flange mounted on an opposing side of the work surface, the upper and lower link being rotatively coupled to the flanges of the work surface; the upper and lower links being substantially the same length as measured between the locations at which they are respectively coupled to the base and the work surface, the distance between the respective links at their points of connection to the base and work surface being substantially the same; and, an extendable adjustment mechanism for rotating the upper and lower links between a lower position and an upper position, the angular orientation of the work surface with respect to the base remaining substantially the same at and between the lower and upper positions thereof.

17. The integrated system of claim 16 wherein the upper and lower links of the work station are constructed and arranged to telescopically collapse together when the upper and lower links are rotated to their lower position.

18. The integrated system of claim 16 wherein the work station further comprises one or more auxiliary work holders coupled to the work surface.

19. The integrated system of claim 18 wherein at least one of the auxiliary work holders is a keyboard tray.

20. The integrated system of claim 16 wherein the knee brace further comprises: a knee pad coupled to a shaft, the shaft being passed through an aperture in the carriage, the shaft being rotatively pinned to the carriage for rotation within the aperture; and, an adjustment mechanism coupled between the carriage and the shaft of the knee brace to effect the rotation of the knee brace toward and away from the seat assembly.

21. The integrated system of claim 20 wherein the adjustment mechanism is coupled to an underside of the carriage and to a portion of the shaft of the knee brace that is on an opposing side of the shaft beyond the location at which the shaft is rotatively pinned to the carriage.

22. The integrated system of claim 16 wherein the parallel linkage comprises at least one upper link and at least one lower link, the upper and lower links being rotatively coupled to a cantilever arm at a first end thereof and to a seat back support at a second end thereof, rotation of the upper and lower links from a lower position to an upright position resulting in the rotation of the seat back support from a lower position to an upright position, the angular orientation of the seat back support with respect to the surface on which the carriage rests remaining substantially the same at and between the lower and upright positions.

23. The integrated system of claim 22 further comprising an extendable adjustment mechanism coupled between the cantilever arm and the at least one upper link such that the extendable adjustment mechanism is generally aligned with the at least one upper and lower links.

24. The integrated system of claim 23 wherein the distance between where the extendable adjustment mechanism is coupled to the cantilever arm and to the upper link is approximately 10 %" when the seat assembly is in a sitting position and approximately 14" when the seat assembly is in an upright position.

23 The integrated system of claim 20 wherein the cantilever arm extends away from an axis of the seat post and wherein the distance between the seat post and the location at which the upper and lower links are joined to the cantilever arm is sufficient to bring the center of gravity of a user seated on the seat bottom adjacent to an axis of the seat post.

25. A method of positioning a user's body in an ergonomic position with respect to a work piece comprising: providing a body positioning system that comprises: a seat assembly having a seat bottom and a seat back secured to a parallel linkage, the seat assembly being moveable such that the seat bottom and seat back of the seat assembly will support a user at and between sitting and upright positions; a knee brace oriented for rotation toward and away from the seat assembly; and, a pair of arm rests mounted on an arm member that is coupled to the seat assembly such that the arm rests rotate with and maintain substantially the same attitude with respect to the seat back during movement of the seat assembly; adjusting the seat back to an appropriate angle; adjusting the arm rests to an appropriate height; raising the seat assembly from a sitting position to a desired height and wherein the arm rests maintain their angular and spatial orientation with respect to the seat back; rotating the knee brace into contact with the user's knees; positioning a work station adjacent the body positioning system, the work station comprising: a base having a bottom and upstanding sides; an upper link and a lower link rotatively coupled to the sides of the base; a work surface having a pair of flanges, each flange mounted on an opposing side of the work surface, the upper and lower link being rotatively coupled to the flanges of the work surface; and wherein the upper and lower links are substantially the same length as measured between the locations at which they are respectively coupled to the base and the work surface, the distance between the respective links at their points of connection to the base and work surface being substantially the same; and, raising the work surface of the work station to an ergonomically correct height with respect to the user positioned in the body positioning system.

26. A work station positioned comprising: a base having a bottom and upstanding sides; an upper link and a lower link rotatively coupled to the sides of the base; a work surface having a pair of flanges, each flange mounted on an opposing side of the work surface, the upper and lower link being rotatively coupled to the flanges of the work surface; the upper and lower links being substantially the same length as measured between the locations at which they are respectively coupled to the base and the work surface, the distance between the respective links at their points of connection to the base and work surface being substantially the same; and, an extendable adjustment mechanism for rotating the upper and lower links between a lower position and an upper position, the angular orientation of the work surface with respect to the base remaining substantially the same at and between the lower and upper positions thereof.

27. The work station of claim 26 wherein the upper and lower links are constructed and arranged to telescopically collapse together when the upper and lower links are rotated to their lower position.

28. The work station of claim 26 further comprising one or more auxiliary work holders coupled to the work surface.

29. The work station of claim 28 wherein at least one of the auxiliary work holders is a keyboard tray.