REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Application No. 60/579,471, filed Jun. 14, 2004, entitled “Anterior Trunk Support or Harness,” and incorporated herein by reference. 


   TECHNICAL FIELD OF THE INVENTION 
   The present invention relates to body harnesses and supports, and more particularly an anterior trunk support or harness. 
   BACKGROUND OF THE INVENTION 
   In general, an anterior trunk support is a device that provides upper trunk control or support. Most prior art anterior trunk supports utilize a belt, strap, panel, or harness. Each of these is formed of a flexible material and is designed to comfortably fit around a user and to hold that user in an upright position, for example connected to a wheelchair. 
   Although prior anterior trunk supports work well for their intended purpose, often they rigidly hold the user in position, allowing little to no movement from the upright position. Although this function is desired in some applications, some users may have upper body movement, and may prefer limited support instead of restrictive control. 
   Conversely, some anterior trunk supports are formed entirely of a soft, elastic material such as neoprene. Such designs allow a great deal of movement but sacrifice the support needed by users with diminished muscle tone or spastic movement. Furthermore, because the lower portion of these entirely elastic anterior supports is able to stretch, the device rides up when the user leans forward, rubbing against the user&#39;s neck and creating a choking hazard. 
   SUMMARY OF THE INVENTION 
   The following presents a simplified summary of some embodiments of the invention in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some embodiments of the invention in a simplified form as a prelude to the more detailed description that is presented later. 
   In accordance with an embodiment, an anterior trunk support is provided. The anterior trunk support is shaped like a vest and is formed of multiple materials, for example stretch and non-stretch or limited stretch materials. Each material has a “unit stretch” (also known as “unit strain”) which is a term well known in the art that is used to quantify the stretchability of a material. The unit stretch can be defined according to an equation wherein unit stretch (unit strain)=stretch (strain)/original length. 
   In accordance with an embodiment, non-stretch or limited stretch material extends over the upper belly and lower ribs of a user, and stretch material extends from the non-stretch material to over the shoulders of the user. In this manner, a wearer may lean slightly forward, with the stretchable shoulder portion flexibly permitting such movement. The stretchable material stretches with the user&#39;s shoulders, preventing the lower, non-stretch or limited stretch material from riding up the user&#39;s chest, and providing maximum comfort. Thus, unlike some prior art anterior trunk supports, a user is not rigidly locked in place. And unlike other prior art anterior trunk supports, the user is stabilized, but is still provided movement. 
   In accordance with an embodiment, the lower section of the anterior trunk support may have a low or zero unit stretch in the vertical direction with a larger unit stretch in the width direction so as to be, for practical purposes, stretchable in a width dimension only. As such, the lower section provides movement for user&#39;s respiration, thus providing additional comfort. By not stretching in the vertical direction, the anterior trunk support does not slide up the wearer&#39;s chest when tension is applied to the upper stretchable material. Thus, support is maintained, and the lower section does not approach the neck of the user. 
   The anterior trunk support may be used as a support (i.e., to position or hold an individual). Alternatively, the anterior trunk support may be used as a load-bearing harness, for attaching an item such as a backpack to a user. 
   Other features of the invention will become apparent from the following detailed description when taken in conjunction with the drawings, in which: 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side perspective view of an anterior trunk support vest in accordance with an embodiment of the invention, with the anterior trunk support vest shown on a user; 
       FIG. 2  is a side view of the anterior trunk support and user of  FIG. 1 , with the user leaning slightly forward; 
       FIG. 3  is a front view of the anterior trunk support of  FIG. 1 , with the anterior trunk support extended flat; 
       FIG. 4  is a side perspective view of a swivel buckle that may be used with the anterior trunk support of  FIG. 1 , with the swivel buckle shown detached; and 
       FIG. 5  is a top view of the swivel buckle of  FIG. 4 , with the swivel buckle shown attached. 
   


   DETAILED DESCRIPTION 
   In the following description, various embodiments of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the embodiment being described. 
   Referring now to the drawings, in which like reference numerals represent like parts throughout the several views,  FIG. 1  shows an anterior trunk support vest  20  in accordance with an embodiment of the invention. In the drawings, the anterior trunk support vest  20  is worn by a user U sitting a wheelchair  22 . However, the anterior trunk support vest  20  may be used for a number of other uses, for example for supporting a user against another device, or as a harness for attachment to a backpack or other item. 
   As can be seen in  FIG. 3 , the anterior trunk support vest  20  includes shoulder straps  24  that are attached to top straps  26 . The shoulder straps  24  extend downward to a convergence zone  30  where the shoulder straps  24  are attached to a lower portion  32  of the anterior trunk support vest  20 . The convergence zone  30  is the area at which or line along which the lower portion  32  attaches to the shoulder straps  24 . 
   The lower portion  32  is adapted and configured to fit around a trunk of a user U, and more specifically an upper portion of the belly of the user U up to and covering a lower portion of the ribcage of the user. The lower portion  32  includes two extensions  34 ,  36  that extend outward to sides of the user U. Swivel buckles  38  are attached by loops  50  at the ends of these extensions  34 ,  36 . Lower straps  40  are attached to opposite sides of the swivel buckles  38  from the loops  50 . 
   The top straps  26  are attached to a structure, for example to a top of the back of the wheelchair  22 . The lower straps  40  are also attached to a structure, for example to a bottom of the back of the wheelchair  22 , or to another suitable structure. 
   In the embodiment shown, the shoulder straps  24  are located on opposite sides of a zipper  42 . The zipper  42  also divides the lower portion  32 . The zipper  42  provides an easy way for a user, such as the user U, to install and remove the anterior trunk support vest  20 . 
   In accordance with an embodiment, the shoulder straps  24  are formed of a stretchable material, such as elastomeric foams, also known as foamed rubber. Examples are chloroprene and Ethylene Propylene Diene Monomer (EPDM). Other stretchable materials may be used, including, but not limited to, spandex fabric and/or stretchable mesh fabric. 
   In accordance with an embodiment, the lower portion  32  is formed of a different material than the shoulder straps  24 , and may, as an example, be formed of a non-stretchable material, such as a mesh material. In accordance with an alternate embodiment, the lower portion  32  is formed of a material that stretches in one direction indicated by the arrow  44  in  FIG. 3 : generally in the width dimension of a user. 
   The shoulder straps  24  and the lower portion  32  may be padded or insulated as desired to provide comfort and/or warmth for a wearer. However, such padding or insulation preferably would not hinder the stretchability of the shoulder straps  24  (and the lower portion  32 , if stretching is provided). 
   In use, the anterior trunk support vest  20  is installed on a user, such as the user U, and provides support for the user U. The shoulder straps  24  fit on opposite sides of the users neck, and the lower portion  32  is positioned on the user&#39;s chest. The shoulder straps  24  and the lower portion  32  are adjusted, for example by cinching the top straps  26  and the lower straps  40 . Alternatively, one of the lower straps  40  and top straps  26  may be fixed and the other cinched to adjust the anterior trunk support vest  20  against the user U. An end fitting buckle (not shown) may be used for cinching of each of the lower straps  40  and/or the top straps  26 . An example of such an end fitting buckle is shown in U.S. Pat. No. 6,665,913, owned by the assignee of the present invention. 
   The anterior trunk support vest  20  fits against the user U to support the user in an upright position. In accordance with an embodiment, however, the user U is free to lean forward against the resistance of the installed anterior trunk support vest  20 , and in particular against the resistance of the stretchability of the shoulder straps  24 . Because the shoulder straps  24  are stretchable, the user U can lean forward such as is shown in  FIG. 2 , without the lower portion  32  crawling upward on the torso of the user U. This feature permits some forward movement by the user U without the lower portion  32  crawling upward to the user U&#39;s neck. The amount that a user may lean forward is based upon the stretchability of the shoulder straps  24 . A person of skill in the art may chose a suitable material for the shoulder straps  24  based upon the range of motion or level of function of the user U and a particular application. 
   As can be seen in  FIG. 4 , the swivel buckles  38  each include a male connector  52  and a female receiver  54 . As is known, the male connector  52  may be inserted and snapped into the female receiver  54 . The male connector  52  is then free to rotate relative to the female receiver  54 , as shown in  FIG. 5 . The male connector  52  may be removed from the female receiver  54  by depressing a tab at the center of the male connector  52 . 
   The swivel buckles  38  provide convenience in that when the user U moves, such as leaning forward as is shown in  FIG. 2 , the lower straps  40  pivot to the most direct line of tension and avoid bunching of the anterior trunk support vest  20 , which would cause discomfort. The swivel movement of the swivel buckles  38  is shown exaggerated in phantom in  FIG. 5 . This action can also be achieved by sewing the strap loosely to a D-ring or other suitable connection structure, but the use of the buckles  38  allows the lower straps  40  to be separated for removal. 
   If unidirectional stretchable material is used for the lower portion  32 , the unidirectional material can provide ease in breathing for the user U, because it allows the chest of the user U to expand during respiration. An example of a unidirectional stretchable material is leno weave material, also known as gauze or doup weave. This material stretches primarily in one direction, but allows very limited stretching in another. Other suitable materials may be used. The material may be arranged so that the stretchable direction is aligned to extend the width of a user, such as the user U, and the limited stretch direction of the material is aligned vertically. 
   The convergence zone  30  is shaped to take maximum advantage of the stretchable qualities of the shoulder straps  24 . As can be seen in  FIG. 3 , the convergence zone  30  is rounded into an S-shape so that at its outer portions it is perpendicular to the direction of extension of the shoulder straps  24 , but at its central portion it approaches horizontal, or perpendicular to the zipper  42 . The overall rounded shape of the convergence zone  30  is perpendicular to the extension of the shoulder straps  34 . This configuration permits tension applied through the shoulder straps  24  to stretch and pull uniformly on the lower portion  32 . 
   Although the anterior trunk support vest  20  has use for supporting a person, such as a seated person upright in the wheelchair  22 , the anterior trunk support vest  20  may be used in other applications, such as for a load-bearing harness in backpacks, military equipment carrying vests, toolbelt supports, and in other applications where there is a need for a supportive harness which allows comfortable movement with minimal loss of control. The anterior trunk support vest  20  may include pockets or other structures for convenience of the particular application. For example, an anterior trunk support vest  20  used on a backpack for bicyclists may include pockets for a drinking tube and an anterior trunk support vest  20  designed for a fly fisherman&#39;s backpack may include pockets for various hooks and other fishing paraphernalia. In addition, the anterior trunk support vest  20  may be attached in a different manner, such as by being sewn directly onto a backpack or being attached directly to a toolbelt in the style of suspenders. 
   Other variations are within the spirit of the present invention. Thus, while the invention is susceptible to various modifications and alternative constructions, a certain illustrated embodiment thereof is shown in the drawings and has been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. 
   All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
   The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
   Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
An anterior trunk support. The anterior trunk support is shaped like a vest and is formed of non-stretch or limited stretch material over a lower portion that extends over the upper belly and lower ribs of a user, and stretch material that extends from the non-stretch material to over the shoulders of the user. In this manner, a wearer may lean slightly forward, with the stretchable shoulder portion flexibly permitting such movement. The lower section may be stretchable in a width dimension only. As such, the lower section provides movement for user's respiration, thus providing additional comfort. By not stretching in the vertical direction, the anterior trunk support does not slide up the wearer's chest when tension is applied to the upper stretchable material. Thus, comfort is maintained, and the lower section does not approach the neck of the user.