Abstract:
A body-mimicking system ergonomically integrates a user with a work station while promoting active sitting and proactive positioning. Particularly, cooperative structures are provided to timely promote healthy and productive postures in task seating operations through the maintenance of ergonomic access and reach to a work station at all times. The system enables a user to effortlessly and dynamically shift from a conventional seating position to a lean/stand posture, and any health posture in between, without disrupting the task at hand. When viewed in its cooperative aspects of clinically preferred human postures and its anticipation of the next best posture in relation to a specific user the system operates as a synergistic biomechanical system. Further, the system discloses dynamic body support systems coordinated to support a person and shaped to be comfortable, in both the sitting and lean/stand postures and all the discrete postures in between during dynamic and static excursions of the user through the various postures.

Description:
BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a body positioner structured to provide healthy postures by promoting active sitting and proactive positioning. The positioner enables accurate and repeatable correlation between a user&#39;s body and a work station by enabling quick postural adjustments based on the preferred postural excursions of the user. Particularly, the body positioner is preferably integrated with at least one work station such as, for example, a computer or manufacturing station. More particularly, the invention provides integration of the positioner with a seating task station, enabling quick dynamic adjustments for optimal alignment and orientation of the positioner and the user relative to the seating task station within a plurality of healthy postures and ergonomic ranges, to promote worker health, comfort and productivity. 
     2. Description of Related Art 
     In the early 1970&#39;s Jerome Congleton, a leading ergonomist, was the first to introduce the concept of the neutral position to the task seating industry. Further, A. C. Mandal in a book relating to unhealthy postures of school children, emphasized the need to tilt the pelvis forward in order to maintain a proper balance of the weight of the upper body on the spine. These and other ergonomic research over the last three decades have shown that certain postural orientations, particularly during sitting, affect the body weight distribution on the spine and generally result in injury or long term pain. For the most part therefore, ergonomic research over the past three decades appears to support the concept of proper body weight distribution by maintaining certain postures. However, no system exists which would enable a person, particularly engaged in work involving task seating systems and related operations, to shift into comfortable postures within a preferred set of healthy postural configurations and ergonomic positions, quickly without disrupting work. 
     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. Modern work stations such as computer related work at the office require that the operator be oriented in a sedentary position. When a subject is in a limited movement sitting position muscle stress and discomfort set in. Specifically, during sitting, the vertebral column transmits the weight of the body through the pelvis to the lower limbs. When the vertebral column experiences prolonged stress due to sedentary postures, a deformity of the spine may result leading to serious medical problems such as kyphosis which is characterized by a posterior curvature of the vertebral column. Further, prolonged sedentary sitting may contribute and/or aggravate scoliosis, characterized by a lateral curvature of the vertebral column and lordosis, characterized by an anterior curvature of the vertebral column. Movements of the vertebral column are freer in the cervical and lumbar regions and these regions are the most frequent sites of aches. The main movements of the vertebral column are flexion or forward bending, extension or backward bending, lateral bending or lateral flexion, and rotation or twisting of the vertebra relative to each other. Some circumduction which consists of flexion-extension and lateral bending also occurs. It is imperative, therefore that a body positioning system provide movement, at the very least, to the cervical and lumbar regions of the vertebral column. 
     In addition to the vertebral column, a body support system implemented to position a person proximal to a work station must be ergonomically balanced with the work station. In this regard the upper limb, which is the organ of manual activity, should be allowed to move freely. Further, the upper limb which includes 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 work station. 
     Similarly, a well-designed body support system should consider neck and head position. The neck contains vessels, nerves, and other structures connecting the head and the trunk. There are several causes of neck pain. As it relates to neck pain resulting from bad postures, muscle strain and protrusion of a cervical intervertebral disc may be the cause. Many vital structures are located in the neck and proper positioning and support of the neck must be made to avoid muscle strain. Further, posterior positioning of the head is important to avoid strain, headache and head pain. 
     Thoracic support is also vital to promote good breathing and elimination of stress on the thoracic vertebrae. As is well known clinically, the lungs are the essential organs of respiration. The inspired air is brought in close relationship to the blood in the pulmonary capillaries. Thus, proper positioning and thoracic support enhances the efficiency of the lungs to supply optimal oxygen levels to the blood. This is key to worker overall health and productivity. 
     The lower limb is the organ of locomotion and is also a load bearing element. The parts of the lower limb are comparable to those of the upper limb. The lower limb is heavier and stronger than the upper limb. Since a vast number of vital networks of arterial vessels are located in the lower limb, it is clinically important to promote the flow of blood through these arterial vessels. Thus, in sedentary postures, frequent removal of weight off the lower limb is recommended to eliminate muscle tension, fatigue and related degenerative joint disease. 
     In general, the present state of the art is incapable of providing users with the option to switch to different comfortable/healthy postures while keeping them within an ergonomic range of a work station in a manner that is non-disruptive to the task being performed. Particularly, the current state of the art does not provide a “active sitting and proactive positioning” system which incorporates the support of the various body parts and promotes healthy postures and comfort at work stations. 
     Accordingly there is a need for a body positioning system capable of providing fluidic and timely transposition of a user into various preferred and healthy postural configurations, to maintain comfortable ergonomic ranges to a task seating work station at all postures and enhance health and productivity, relative to a defined space-volume envelope of the positioning system and, preferably, to a work station integrated therewith. 
     SUMMARY OF THE INVENTION 
     The present invention is based on heretofore unrealized objectives to successfully integrate human performance with comfort and health. Specifically, in the preferred embodiment, the invention implements principles of “active sitting and proactive positioning” in which the subject is temporally encouraged to change to various comfort and health postures while maintaining ergonomically compatible access and reach to a work station at all times. 
     The invention provides a user with a selection of discrete and dynamic medically preferred health postures. Specifically, the invention utilizes, inter alia, the principle that to prevent cumulative trauma disorder (CTD) the pelvis must always be positioned in an orientation similar to an erect/tilted position during standing. The basic discrete postures of the present invention include a recline seated posture, a recline neutral posture/breath easy posture and a recline standing posture. The invention incorporates these discrete postures to generate a full range of dynamic hybrid postures continuously shiftable and adjustable to prevent injury, discomfort and fatigue while enhancing health and comfort. Further, the invention proactively positions the user to be placed within an ergonomic range of the work station, at all postural configurations, to enhance productivity. 
     The invention enables the user to move in and out of the discrete and dynamic postures without disrupting the task at hand. One of the significant benefits derived from this active sitting aspect of the invention is that the user is provided with a full range of joint movement in the legs and torso during the excursion through the various postures. Further, the postures enhance the respiratory system and relieve muscle stress. The user may also perform occasional stretch exercises, by shifting through these various postures, to increase vital fluid flow and circulation in the torso and lower parts of the body. 
     The invention includes a body positioning system having components designed to be compatible with human physiology and enhancement of healthy postures at work stations. Specifically, the major components include a seat/back support, a body support component for below the knee and a foot rest body support all being independently and correlatively operable at the option(s) of the user to navigate through various postures while maintaining ergonomic reach to the work station. More specifically, the seat/back support and the support for below the knee comprise pressure surfaces having ergonomically optimized/compatible geometric shapes to enable a smooth transition from one posture to the next in addition to the provision of proper body support and healthy positions at all postural configurations. Further, the surfaces are made of materials specifically structured to eliminate excessive resistance, during the user&#39;s dynamic excursions through the various postures or during any static posture, without regard to the type and fabric of clothing worn by the user. Since the pressure surfaces/bearing surfaces are implemented to shiftably serve as back and seat support at various postures the interaction between the surfaces and the users clothing is critical to promote smooth transition of the user from one posture to the other. 
     The controls and actuators implemented in the present invention, which control the body positioning system seat/back angle adjustment, seat height adjustment and lower body part support angle adjustment, are ergonomically designed to have a high level of accessibility and availability to the user. Further, the actuators are set to meet the anthropometric fit requirements of a world population. Particularly, the controls are designed and located to enable a user to quickly and easily shift from one posture to another without disruption of the task being performed. 
     The present invention further provides robust features integrated to enhance productivity and worker effectiveness. The user is generically integrated with the positioning system and work station such that all the components are positioned to be readily accessible and available to the user while enabling work to progress concurrent with multiple posture position shifting. Further, the work station is designed to attenuate the transfer of vibration to the positioner by strategically installing vibration dampeners and shock absorbing connections at points of contact between the user, the work station, work tools and the positioner. 
     The office environment is one of the many work areas in which the present invention could be advantageously implemented. The body positioning system is dimensionally optimized to fit into most office space and is highly mobile to be compatible with movable wall offices. Further, the system of the present invention is modularized to stand alone or to be built into multiple work station areas. 
     In the preferred embodiment, the controls and mechanical systems are versatile to adapt to various power supply systems. Further, ease of assembly and disassembly make the system advantageously flexible to accommodate the user&#39;s choices and be compatible with various production and work area environments. 
    
    
     With these and other features, advantages and objects of the present invention which may become apparent, the various aspects of the invention may be more clearly understood by reference to the following detailed description of the preferred embodiment, the appended claims and to the several drawings herein contained. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view assembly drawing of the preferred embodiment; 
     FIG. 2 is an isometric view describing in greater detail correlatively adjustable joints and links; 
     FIG. 3 is an isometric view showing in greater detail of the adjustable support systems and mechanism; 
     FIG. 4 is an isometric view of the structural details of actuating members of the positioner; 
     FIG. 5 is a further detail isometric view of actuating members and cooperative structural links; 
     FIG. 6 is an isometric view of piston actuation and engagement details and structures for rotating pressure surfaces about a 90° angle; 
     FIG. 7 is an isometric view of the structure and actuation control lines from the triggers which operate the push-pull pistons; 
     FIG. 8 is a cross section of the side support loop structure; 
     FIG. 9 is an isometric view of the control lock mechanism for the work surfaces such as the monitor and keyboard support including lower body support mechanism in greater detail; 
     FIG. 10 is an isometric view of the actuating mechanism for the lower body support; 
     FIG. 11 is an isometric view showing underlying structural connections and organization of a piston and the lower body support; 
     FIG. 12 is an isometric view of the rotational position control/lock mechanism for adjusting the work tool support surfaces and connections thereof; 
     FIG. 13 is an isometric view of the main structural base and support assembly; 
     FIG. 14 is a simulation view of the multi-posture range of the present invention; 
     FIG. 15 is an isometric view of the present invention integrated with a computer cosole/station; 
     FIG. 16 is an isometric view of the positioner being used in non-integrated set up in an assembly type environment; 
     FIG. 17 is an isometric view of an alternate embodiment of the positioner with the knee support structure and pad removed; 
     FIG. 18 an isometric view showing detailed structural parts of the file holder; 
     FIG. 19 is a detail isometric view of the mouse cage; and 
     FIG. 20 is a detail isometric view of the monitor platform with vibration dampener. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention anticipates 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 a healthy posture such that body weight and pressure are distributed to eliminate undue discomfort, pain, fatigue, muscular and skeletal strain. Thus, one of the significant features of the present invention is the elimination of discomfort and potential injury caused by most sitting postures when the individual is forced to sit in an upright posture or other unhealthy postures for an extended time period. 
     With reference to FIG. 1, a perspective assembly view is shown of the present invention. In particular, the body positioning system  10  is shown integrated with work station  12 . As depicted herein, work station  12  is a computer work station where any type of computer, small enough to fit on an office desk, is implemented. A desktop computer may be connected to the local area network and configured with sufficient memory and storage to perform standard or specialist business computing tasks. Current technology offers full-function desktop computers which can be turned into portable notebook computers. When in the office, the small computer sits in a docking station and can connect to a local area network. Although body positioning system  10  can be used independently, FIG. 1 shows one of the preferred embodiments in which a computer work station  12  is integrated with it. Specifically, the computer work station  12  includes support surfaces and structures for a monitor, keyboard and a central processing unit (CPU). As discussed hereinbelow, the integrated system is designed not only to promote clinically advantageous ergonomic postures but incorporates bio-mechanical design features to eliminate any physical discomfort caused by eye strain, muscle stress, and improper spinal configuration during long term task activity at computer work station  12 . Further, the present invention provides a user with a selection of discrete and dynamic medically preferred health postures based on a coordinated, accurate and repeatable orientation of body positioning system  10  and work station  12 . More specifically, a plurality of basic discrete postures including a recline seated posture, a recline neutral posture/breath easy posture and a recline standing posture are implemented to set a user at positioning system  10  at various orientations. The 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. The invention utilizes ease of adjustment and proactively motivates the operator/user to be positioned within an ergonomic range of work station  12 , during all postures thus enhancing health and productivity. As will be discussed hereinbelow, one of the advantages of the proactive aspect of the invention is the structural cooperation of the elements of positioning system  10  and work station  12  to advance, favor, promote motion and nimble transformation of the user from one posture to the next. Particularly, positioning system  12  is a synergistic bio-mechanical system designed to anticipate and become synergistic with the next best postural orientation of the human body ranging from a convention seated, with full body stretch option, to a lean-stand with the fully body in a substantially vertical posture. 
     Still referring to FIG. 1 in more detail, an integrated body positioning and work station system is shown. Specifically, body positioning system  10  and work station  12  are shown integrated to correlatively operate as an integrated unit. Positioning system  10  includes pressure bearing surfaces  14  and  15  and a pair of articulating side supports  16 . Pressure bearing surfaces  14  and  15  are adjustably and resiliently attached at joint  18 . Pressure bearing surface  14  includes a contact surface (back support) and outer formed surface to encase reinforcing frames therein. The inner surface includes geometric shapes to cradle the user at lumbar, lower back and shoulder blade regions during sitting, neutral and lean-stand positions and the several postures in between. The outer surface is preferably removable and is centrally cumbered to encase an upper end section of joint  18  which is secured to outer surface of pressure bearing surface  14 . Further, articulating side supports  16  are attached to pressure bearing surface  15 . Pressure bearing surface  15  is rotatably and tiltably connected to a top end of pedestal  20 . Pressure bearing surface  15  includes an upper and lower formed surfaces. The upper part of pressure bearing surface  15 , which functions as a seat and back support depending upon the user&#39;s temporal posture, generally includes a declivity with anticlined arcuate edges at opposite sides. This geometric shape of surface  15  provides a bio-mechanical system which articulates with the user&#39;s body to effectively support the gluteal and lumbosacral regions. At its bottom end, pedestal  20  is pivotally and adjustably secured to stabilizers  22  and connector arm  23 . Connector arm  23  interconnects stabilizers  22  with base structure  24 . Lower body support pad  26  including link member  27  are mounted on base structure  24 . 
     Work station  12  includes tool platforms  28  and  32  separated by connection members  34 . Further, work station  12  includes platforms  36 ,  38  and  40  hingeably and adjustably connected to column  42 . Swivel mounted leg  44  provides support to tool platforms  28  and  32  at the fore end. Platform  45 , formed to support coffee cups, cans and similar containers in addition to writing tools is adjustably and swingably mounted on swivel, mounted to work surface  32 . Mouse cage  39  is set on platform  38  where a keyboard is preferably located. As will be discussed hereinbelow, the platforms are adjustably interconnected by utilizing maneuverable compound linkage framework  46 . Specifically, as will be disclosed hereinbelow, when body positioning system  10  is translated through various postural positions, work station  12  is accurately and continuously maintained within the ergonomic range of the user by timely manipulating compound linkage framework  46 . Work station  12  preferably includes file holder  47  which is designed to be compatible with the many ergonomic features of the present invention. 
     Referring next to FIG. 2, a portion of work station  12  is removed to clearly show some of the major interactive elements of the invention. Particularly, body positioning system  10  is shown with triggers  48  embedded in articulating side supports  16 . As will be discussed in more detail hereinbelow, the loop geometry of articulating side supports  16  is structurally and ergonomically optimized to promote tactility and accessibility (See also FIG.  16 ). Specifically, a user is prompted to keep the elbows bent and resting on the top depression of articulating side supports  16 . Triggers  48  are located immediately forward under the declivity of articulating arm  16 . This arrangement proactively encourages the user to keep the elbows backwards thus pushing the thorax forward. As the user actuates triggers  48 , the thorax is extended anteriorly and this in turn tilts the pelvis forward throughout the various postural excursions of the user. This is one of the many distinguishing features of the present invention. Prior art devices such as ergonomic chairs and supports are generally designed to locate and provide lumbar support. In sharp contrast, the present invention enables the pelvis to be tilted forward irrespective of the position of the lumbar curve. Each basic posture of the present invention leans the upper body back about 15 degrees beyond the vertical. This allows all of the upper body weight to be distributed throughout pressure bearing surfaces  14  and  15  while platforms  36  and  38  are moved to easily accessible positions. In the preferred embodiment, platform  36  is used to support a screen/monitor or similar device, and as indicated above, a keyboard is placed on platform  38 . Mouse cage  39  includes a pad and a structure to retain the mouse in place when platform  38  is shifted laterally and tilted toward or away from positioner  10 . The tiltability/rotatability of platform  38  is one of the many innovative and bio-mechanical features of the invention. Platform  38  is independently tiltable to conform to the many various orientations of the user. Specifically when the user is in stand/near stand or lean/stand posture platform  38  is inclined away from positioner  10  to provide an ergonomically healthy and non-stressful positioning of the hands. Platform  38  is rotatable toward and away from positioning system  10  to eliminate positions of the hand which may cause compression of the median nerve at specific postures. Generally, a prolonged compression of the median nerve will likely result in carpal tunnel syndrome which results in a progressive loss of coordination and strength in the thumb if the cause of the median nerve compression is not alleviated. This further results in difficulty in performing fine movements. In cases of severe compression of the median nerve, there is a likely risk of atrophy of some of the muscles in the hand. Yet another innovative aspect of the present invention is mouse cage  39  which is designed to secure the mouse to be accessible and available at any of the positions of platform  38 . 
     Still referring to FIG. 2, support plate  50  is shown cantilevered from link arm  49 . Further, link arm  49  is secured to a telescoping section of support column  42 . Support plate  50  is adjustably pivotable and provides support for tool platforms  28  and  32  at the rear end. Compound linkage framework  46  includes flex joints  54  and  56  connected to intermediate members  58 . Platform  36  is cantilevered at joint  37  via flex joint  56 . Further, compound linkage framework  46  includes flex joints  60  and  62  connected to intermediate members  64 . Platform  38  is cantilevered at joint  68  via flex joint  62 . 
     Directing attention to FIG. 3 now, a detailed section of a manual positioning and locking mechanism for pressure surface  14  is shown. Height adjustment mechanism  72  is a commercially available component such as one manufactured by Milsco or equivalent. Mechanism  72  enables pressure bearing surface  14  to be raised or lowered by the user to various positions along the upper end section of joint  18 . The mechanism enables height adjustment of pressure surface  14  to fit the user&#39;s specific physiological and lumbar configurations. Particularly, as pressure surfaces  14  and  15  articulate to assume a substantially vertical position, the relative adjustment and positioning of these surfaces become critical in providing proper support at selected parts of the body such as the dorsal, gluteal and lumbosacral regions. In this regard, mechanism  72  is integrated to enable an independent and coordinated adjustment of pressure surface  14 . 
     Referring now to FIG. 4, reinforcing structural frame  74  is shown. Structural frame  74  includes a plurality of parallel bars  75  with fore member  76  and aft member  78 . Structural frame  74  is secured to aft member  78 . Specifically, cap link  80  is rotatably secured to the top end of pedestal  20 . Cap link  80  is preferably an extruded substantially hollow cylindrical stub having a first open end and a second closed end. The top end of pedestal  20  is rotatably secured to the open end of cap link  80 . At the closed end of cap link  80  a plurality of attachment brackets  81  are distally disposed thereon and provide a hinge connection and support to parallel bars  75 . 
     FIGS. 5 and 6 show in more detail the connection between cap link  80  and structural frame  74 . Specifically, FIG. 6 depicts one of the many significant and inventive features of the present invention. Pressure surface  15  and joint  18  are rotated through about a 90° displacement to create a near vertical orientation thereof. More specifically, whereas prior to rotation, structural frame  74  and joint  18  are substantially perpendicular to each other, after the 90° translation, they are transposed into a substantially co-planar relations. As described hereinbelow, this coordinated and dynamic orientation of structural frame  74  and joint  18  provides various ergonomically desirable positions of pressure surfaces  14  and  15  such that a user is enabled to progressively change postures from sitting to lean/stand position. The mechanism for the rotation is preferably a piston with pneumatic, hydraulic, electric or equivalent drive. For example, air cylinder  82  is shown bearing against fixed block  84 . Block  84  is pivotably connected to structural frame  74 . Cylinder  82  is linked to block  84  and when the piston is extended structural frame  74  is rotated to the full extension of the piston. Preferably, structural frame  74  is rotated through 90° to assume a substantially vertical orientation. 
     Directing attention to FIG.  7 ,one of the many significant features of the present invention is shown. Specifically, parallel bars  75  and bar linkage  86  provide an articulating structural linkage which maintain joint  18  perpendicular to the horizontal plane at all times. FIG. 7 shows the near side of 2-bar connection to joint  18 . A second set of symmetric 2-bar connection on the far side of joint  18  forms a 4-bar linkage. Each 2-bar linkage is connected to brackets  81 . Accordingly, when structural frame  74  translates from a horizontal to a substantially vertical position, joint  18  is elevated through the radius of rotation while maintaining its original vertical orientation relative to stabilizers  22  and connector arm  23 . This arrangement enables pressure surface  14  to maintain a vertical orientation at all times. Further, FIG. 7 shows cylinder  88  encased in pedestal  20 . Cylinder  88  is implemented to move or adjust structural frame  74  up or down. Both cylinder  82  and  88  are actuated by triggers  48  each embedded under articulating arm  16 . For example, right trigger  48  may be used to actuate cylinder  82  and left trigger  48  may be used to activate cylinder  88 . Exemplary control line  90  is shown connecting trigger  48  to cylinder  82 . Similarly control line  92  is partially shown extending from cylinder  88  to the other trigger  48  (not shown). Each side support  16  is secured to each parallel bar  75 . As discussed hereinbelow, side support  16  includes a geometric loop with various features adapted for articulation and enhancement of ergonomic positioning of the user. 
     FIG. 8 depicts a detailed structure of side support  16  and control line  90  embedded therein. The shape of side support  16  is an ellipsoidal loop with one end narrower than the other and further having one side bulging outward and the opposite side depressed inward. Trigger  48  is secured on the inner surface of the narrower side proximate to the depressed region. Trigger  48  is set to be tactile and is accessible to a person resting the palm of the hand on the top surface of the depressed region. Further, the depressed region promotes sure-grip and control by users specially during the articulation of side support  16  which rotates in conjunction with structural frame  74 . Member  94  provides rigidity to the outer elastic member  96 . Member  94  may be made of structural grade steel, aluminum or equivalent whereas member  96  is preferably semi rigid urethane, rubber, polyvinyl or equivalent. Control line  90  is connected to trigger  48  through an internal cavity  98 . Retention bracket  100  is used to pivotally secure trigger  48  such that when trigger  48  is squeezed, control line  90  is activated to thereby actuate cylinder  82  or cylinder  88 , depending upon which one of the two triggers  48  is being used. Each of triggers  48  can be activated separately or can be used simultaneously together. 
     Referring now to FIG. 9, and isometric view of the control mechanism for the work surfaces such as monitor support  36  and keyboard support  38  including lower body support mechanism are shown. Specifically, compound linkage framework  46  includes flex joints  54  and  60  secured on support column  42 . The flex joints enable several degrees of freedom/adjustment in the thri-axis primary planes. One of the many unique aspects of the arrangement includes the use of single support column  42  to fixably secure articulating flex joints  46 . This arrangement and structure enables space-volume efficiencies and provides an interference free, independent and simultaneous adjustments of support platforms  51  and  61  on which monitor support  36  and keyboard support  38  are mounted, respectively. 
     Still referring to FIG. 9, lower body support pad  26  including link member  27  are shown mounted on base structure  24 . Base structure  24  includes a generally increasing gradient from the near end to the far end. This gradient is preferably about 15°. The gradient enables the user to assume a firm foot grip on the non-skid surface of base structure  24 . In an alternate embodiment, the gradient is preferably greater than 15° to provide support for the feet and provide balance in lieu of lower body support pad  26 . Lower body support pad  26  is articulated by cylinder  102 . Button  104  activates cylinder  102  to rotate and hold in place lower body support pad  26 . As will be seen hereinbelow, connector arm  23  is a tension member and serves as a bridge between lower body support structure and articulating pressure surfaces  14  and  15 . Further, base structure  24  operates as a counter weight and center of gravity stabilizer against articulating pressure surfaces  14  and  15 , the associated structures therewith and the weight of the user which generate variable dynamic rotational moments about pedestal  20 . 
     FIG. 10 shows further details of link member  27  and cylinder  102 . Button  104  is connected to control line  108  and actuates cylinder  102 . Cylinder  102  rotates link member  27  and fixes it at a desired angle. Support pad  26  is secured to reinforcing structural angle  106 . Support pad  26  includes resilient outer surfaces having substantially parabolic shapes. Support pad  26  serves various functions. Some of the important bio-mechanical and structural advantages of support pad  26  include its implementation to provide an adjustable fulcrum to the user&#39;s body in cooperation with articulating pressure surfaces  14  and  15 . Further, pad  26  operates as a body balancer and posture adjustment mechanism. When the user shifts from a sitting posture to a lean/stand posture, support pad  26  is implemented to bear some of the shifting weight. In this regard, support pad  26  acts as a body balancer and a point at which the user may shift the center of gravity (combined own center of gravity of the user and positioner system  10  under both dynamic and static conditions) without falling or sliding out of articulating pressure surfaces  14  and  15 . Yet another cooperative structural aspect of support pad  26  includes its implementation as a transitional dynamic weight support and stabilizer. The parabolic oblong shape of support pad  26  promotes rotation at the knee and shin regions such that the user is enabled to rotatably transpose from one posture to another by adjusting the pressure and angular orientation of support pad  26  using operating button  104 . Support pad  26  may also be implemented as an adjustable leg rest. The user may be positioned in a normal sitting position with the leg stretched out and the posterior aspect of the legs resting on support pad  26 . 
     Referring now to FIG. 11, a detailed view of support pad  26  is shown. Particularly link  107  provides a secure link between cylinder  102 , link member  27  and structural angle  106 . Link member  27  is rotatable through approximately 75° with about 45° toward the user from the vertical and about 30° away from the user from the vertical. The user presses button  104  to actuate cylinder  102  and applies bodily pressure on support pad  26  to adjust it away from the knees/legs. In the alternate button  104  is pressed to allow support pad  26  to rotate towards the user. In either case releasing button  104  locks support pad  26  in position. 
     FIG. 12 shows the rotation, articulation and positioning in single or combination of 3-dimensional planes of platforms  36 ,  38  including the compound linkage comprising intermediate members  58  and  64  preferably formed of bar linkages. Specifically, column  42  supports a plurality of work stations preferably cantilevered therefrom. More specifically, the use of single column  42  enables the stacking of various work stations without the complication of interference and crowding which may result due to multiple supports and columns. Flex joints  54 ,  56 ,  60  and  62  enable articulation and rotation in three dimensions. Specifically, joints  54  and  60  coupled with threaded screw  103  enable universal adaptability for adjustment in three-dimensions. Screw  103  is adjusted by link member  109  indexing up or down. This movement results in changes of the leverage of gas spring  111  and thereby enables adjustment for varying weights. For example, when the load to be supported at platform  36  or  38  is heavy, link member  109  is indexed downward to shorten the extension of intermediate members  58  and  64  thereby reducing the length of the cantilever and increasing the capacity to carry a heavy load. Alternately, when link member  109  is indexed upwards, joints  58  and  64  extend outward thus reducing the capacity to carry a cantilevered load at platforms  36  and  38  and as well extending the reach of the assembly orthogonally from column  42 . The flexibility and adjustability of each of the structural components individually and in combination enables the assembly of FIG. 12 to be most versatile for supporting work tools and highly synergistic with positioner  10 . Flex joints  54 , and  56  enable full 360° rotation at column  42 . Further, flex joints  56  and  62  provide a coupling for a full 360° rotation of joints  57  and  68  respectively. Additionally, pivots  113  cooperate with bar linkage of intermediate members  58  and  64  to be responsive to the changes in leverage of gas spring  111 . Yet another feature of the invention includes the rotatability of platform  36  and the rotatability and tiltability of platform  38 . Platform  36  is structured to support a computer screen or similar work tools. Platform  38  is well suited to carry a keyboard or similar work tools which may need to be adjusted in several orientations. One of the many unique aspects of the structure includes its lockability in any position after adjustment. Specifically, the user is enabled to configure the position of the work tools to be compliant and ergonomically congruent with positioner  10 . More specifically, the user applies minimum manual pressure to adjust the position of support platform  36  or  38  as needed. Platforms  36  and  38  remain locked in position after adjustments have been made. Thus, the tool support platform structure of the present invention provides several degrees of freedom to orient the work tools and is designed to be synergistic with positioner  10  by allowing quick dynamic adjustments relative to a desired postural configuration. 
     Referring now to FIG. 13, the underlying structural assembly of positioner  10  is shown. Preferably, the material of construction is structural grade steel, aluminum or equivalent. The framework includes fore and aft assemblies connected by member  123 . Fore assembly comprises members  122  which are preferably welded to member  123  and extend in symmetrical angular relations therefrom. The aft assembly includes rectangular structures  124  and  126  secured to member  123 . 
     FIG. 14 is a representation of the ergonomic multi-posture range of the present invention. In the seated position the user preferably engages pressure surfaces  14  and  15  and support pad  26 . The user then activates trigger  48  and button  104  to shift to a breatheasy position. As pressure surfaces  14  and  15  rotate the angle between the torso and the lower part of the body increases and support pad  26  is actuated forward and rotated to prevent the user from sliding off pressure surface  15 . As the user continues to rotate with pressure surfaces  14  and  15  it is preferable to adjust the position of support pad  26  and lock it in place so that the user can negotiably maintain contact with pressure bearing surfaces  14  and  15  and keep the body in balance. 
     FIG. 15 is a representative depiction of positioner  10  integrated with computer work station  12 . Monitor or screen  130  is placed within the visual and ergonomic ranges of the operator. Keyboard  132  is set for easy access to the hands and CPU  134  is placed within the ergonomic range of the operator while clearing any possible interference with positioner  10 , especially during articulation, thus allowing timely postural adjustments by the user. 
     FIG. 16 is another embodiment of the present invention. Positioner  10  is shown with work station  136  and a worker set in position. In this embodiment work station  136  is not attached or integrated with positioner  10 . In order to ensure stability and safety, base structure  24  is filled with stabilizing weights such as water, sand or equivalent. The embodiment shows a typical work station  136 , such as an assembly line, in which a task is performed in a substantially sitting position. The implementation of positioner system  10  advantageously enables the worker to shift through various ergonomic postures without interrupting the task at hand. As discussed hereinabove, the present invention enables the worker to benefit from active sitting through timely movements of the muscles and the body and from proactive positioning which forms the body into clinically advantageous postures. Specifically, three basic adjustment actuators which include (two) triggers  48  and button  104  are used to easily transform the user from a sitting to lean/stand posture. 
     FIG. 17 is yet another embodiment of the present invention. Positioner  10  is shown without support pad  26 . In this embodiment, base structure  24  includes a gradient of about 25° or higher to enable balance and support of the user&#39;s weight. This embodiment is alternately advantageous in operations where support pad  26  may interfere with the work station or may be undesirable for other reasons. The omission of support pad  26  is compensated for by the increased inclination/gradient of base structure  24 . 
     FIG. 18 shows a reference holder/working file display  47 . Holder  47  includes support base  142  with telescoping column  144  supported at one end thereon. The other end of telescoping column  144  supports a substantially L-shaped structure  146  which includes a mortised section at the leg having edge structure  148  about the perimeter of the cutout. Files and folders are suspended through the cutout and supported on edge structure  148 . 
     Directing attention to FIG. 19 now, a detail of the mouse cage structure  39  is shown. Specifically, mouse  150  is supported on pad  152 . Retaining structure  154  forms a partial fence to secure mouse  150  in place. This is particularly important when platform  38  rotates/tilts away from the user to provide an ergonomically beneficial positioning of the user in the lean/stand posture. Mouse cage  19  allows mouse  150  to be accessible and available regardless of the tilt angle of platform  38 . 
     FIG. 20 is a detail drawing showing vibration dampener  155  secured on top of platform  36 . Vibration dampener may be constructed from 4# EVA black foam or equivalent. Dampener  155  advantageously reduces/eliminates the transfer of vibration and undulatory movement from the joints and links. 
     Accordingly, the present invention utilizes structures which cooperate with a user&#39;s body to form a dynamic bio-mechanical system to promote active sitting and proactive positioning within a range of clinically preferred healthy human postures. Positioner system  10  is typically integrated with work station  12  although, as is shown in exemplary embodiment of FIG. 16, it can be independently used at various seated task operations. Similarly, some components of the present invention may be omitted to adapt to specialized applications. Further, various components may be modified to adapt to specific work environments. 
     While the preferred embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes, variations and modifications may be made therein without departing from the present invention in its broader aspects. 
     Thus, 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.