Patent Publication Number: US-11643760-B2

Title: Knitted component having an auxetic portion and a tensile element

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/241,302, filed Jan. 7, 2019 (and issuing as U.S. Pat. No. 10,934,641 on Mar. 2, 2021), which is a continuation of U.S. patent application Ser. No. 16/055,688, filed Aug. 6, 2018 (and issued as U.S. Pat. No. 10,184,195 on Jan. 22, 2019), which is a continuation of U.S. patent application Ser. No. 15/879,199, filed Jan. 24, 2018 (and issued as U.S. Pat. No. 10,066,327), which is a continuation of U.S. patent application Ser. No. 14/469,973, filed Aug. 27, 2014 (and issued as U.S. Pat. No. 9,903,054). Each of the applications listed in this paragraph is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Articles of apparel, footwear, and other articles can include one or more knitted components. The knitted component can add desirable flexibility and resilient stretchiness to the article. Also, the knitted component can provide suitable softness and texture to the article. The component can also be durable and strong because of the knitted component. Moreover, manufacture of the article can be facilitated due to the efficiencies provided by the knitting process. 
     For example, articles of footwear can include one or more knitted components. The knitted component can at least partially define the upper of the footwear. The knitted component can be relatively lightweight and, yet, durable enough to withstand the rigors of intense exercise. Furthermore, these knitted articles can provide a unique and attractive appearance to the footwear. Moreover, the footwear can be manufactured efficiently because of the knitted component. 
     BRIEF SUMMARY 
     A knitted component is disclosed that is formed of unitary knit construction and that is configured to stretch. The knitted component includes a knit element having an auxetic portion configured to move between a first position and a second position as the knitted component stretches. The knitted component also includes a tensile strand formed of unitary knit construction with the knit element. The auxetic portion has an area when in the first position. The tensile strand engages the knit element proximate the auxetic portion. The tensile strand is configured to be manipulated for selectively changing the area of the auxetic portion to vary a stretch characteristic of the knitted component. 
     Furthermore, an article of footwear is disclosed that includes a sole structure and an upper that is attached to the sole structure. The upper includes a stretchable knitted component formed of unitary knit construction. The knitted component includes a knit element having an auxetic portion. The auxetic portion is configured to move between a first position and a second position as the knitted component stretches. The knitted component further includes a tensile strand formed of unitary knit construction with the knit element. The auxetic portion has an area when in the first position. The tensile strand engages the auxetic portion. The tensile strand is configured to be manipulated for selectively changing the area of the auxetic portion to vary a stretch characteristic of the knitted component. 
     Moreover, a knitted component is disclosed that is formed of unitary knit construction. The knitted component is configured to stretch. The knitted component includes a knit element with an auxetic portion that is configured to move between a first position and a second position as the knitted component stretches. The auxetic portion has a border. The knitted component further includes a tensile strand that is inlaid within the knit element and is formed of unitary knit construction with the knit element. The auxetic portion has an area when in the first position. The tensile strand extends across the auxetic portion and engages a first location and a second location of the border. The tensile strand is configured to be manipulated for selectively moving the first location relative to the second location to change the area of the auxetic portion to vary a stretch characteristic of the knitted component. 
     Other systems, methods, features and advantages of the present disclosure will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the present disclosure, and be protected by the following claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the present disclosure. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views. 
         FIG.  1    is an isometric view of a knitted component with auxetic portions according to exemplary embodiments of the present disclosure; 
         FIG.  2    is a detail view of the knitted component of  FIG.  1    according to exemplary embodiments of the present disclosure; 
         FIG.  3    is a detail view of the knitted component of  FIG.  1    according to additional embodiments of the present disclosure; 
         FIG.  4    is a top view of the knitted component of  FIG.  1    shown in a first, neutral position; 
         FIG.  5    is a top view of the knitted component of  FIG.  1    shown in a second, stretched position; 
         FIG.  6    is a detail view of  FIG.  4   , wherein a portion of the knitted component is shown in the neutral position; 
         FIG.  7    is a detail view of  FIG.  5   , wherein the portion of the knitted component is shown in the stretched position; 
         FIG.  8    is a detail view of  FIG.  4   , wherein the portion of the knitted component is shown in the neutral position; 
         FIG.  9    is a detail view of  FIG.  5   , wherein the portion of the knitted component is shown in the stretched position; 
         FIG.  10    is a top view of the knitted component of  FIG.  1    shown in an adjusted neutral position; 
         FIG.  11    is a top view of the knitted component of  FIG.  10    shown in a stretched position; 
         FIG.  12    is a detail view of  FIG.  10   , wherein the portion of the knitted component is shown in the neutral position; 
         FIG.  13    is a detail view of  FIG.  11   , wherein the portion of the knitted component is shown in the stretched position; 
         FIG.  14    is a detail view of the knitted component shown in a neutral position according to additional embodiments of the present disclosure; 
         FIG.  15    is a detail view of the knitted component of  FIG.  14    shown in a stretched position; 
         FIG.  16    is a detail view of the knitted component of  FIG.  14    shown in an adjusted neutral position; 
         FIG.  17    is a detail view of the knitted component of  FIG.  16    shown in a stretched position; 
         FIG.  18    is a plan view of a knitted component for an article of footwear according to additional embodiments of the present disclosure; 
         FIG.  19    is a lateral view of an article of footwear with the knitted component of  FIG.  18   ; 
         FIG.  20    is a top view of the article of footwear of  FIG.  19    shown in a neutral position; 
         FIG.  21    is a top view of the article of footwear of  FIG.  20    shown in an adjusted neutral position; 
         FIG.  22    is a front view of an article of apparel with a knitted component shown in a neutral position; and 
         FIG.  23    is a front view of the article of apparel of  FIG.  22   , wherein the knitted component is in an adjusted neutral position. 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     The following discussion and accompanying figures disclose a variety of concepts relating to knitted components. These knitted components can be used and/or incorporated in various objects, such as an article of footwear, an article of apparel, or other articles. 
     Moreover, the following discussion and accompanying figures disclose knitted components that exhibit auxetic characteristics during stretching. It will be appreciated that the term “auxetic” as used herein will generally refer to objects that have a negative Poisson&#39;s ratio. Thus, when stretching force is applied to an auxetic knitted component, the knitted component can elongate in the same direction that the stretching force is applied, and the knitted component can also expand in another direction, for example, in a direction that is perpendicular to the applied force. Furthermore, the term “auxetic” as used herein will refer to objects that exhibit a negative Poisson&#39;s ratio within certain kinds of stretching and that exhibit a positive Poisson&#39;s ratio within other kinds of stretching. 
     Furthermore, the knitted components can have resiliency for recovering back toward an unstretched or neutral position once the stretching force is reduced. For example, in some embodiments, the knitted component can include one or more portions that exhibit auxetic characteristics when stretched and that recover back toward the neutral position when released. 
     Additionally, the following discussion and accompanying figures disclose a variety of concepts that allow auxetic portions and/or stretching characteristics of the knitted component to be selectively varied. For example, in some embodiments, the knitted component can include one or more features that allow a user to select and change the size, shape, and/or surface area of the auxetic portion. As a result, the user can alter the stretch characteristics of the auxetic portion and/or the stretch characteristics of the knitted component. 
     Configurations of Exemplary Knitted Components 
     Referring initially to  FIG.  1   , a knitted component  100  is illustrated according to exemplary embodiments of the present disclosure. Knitted component  100  can have a variety of shapes, sizes, and characteristics. Also, knitted component  100  can be configured and/or incorporated into a specific object. For example, knitted component  100  can be incorporated into an article of footwear in some embodiments. In additional embodiments, knitted component  100  can be incorporated into an article of apparel. 
     As shown in the exemplary embodiment of  FIG.  1   , knitted component  100  can be relatively thin and sheet-like. Knitted component  100  can also be flexible and stretchable in some embodiments. Additionally, in some embodiments, knitted component  100  can be resilient. As such, the knitted component  100  can stretch when a stretching load is applied, and when the stretching load is reduced, the knitted component  100  can recover back toward its original size. By way of example,  FIG.  4    illustrates knitted component  100  in a neutral position, and  FIG.  5    illustrates knitted component  100  in a stretched position. 
     As shown in  FIG.  1   , knitted component  100  can define a polygonal shape. In some embodiments, for example, knitted component  100  can define a quadrilateral and can include four sides. More specifically, as shown in  FIGS.  1  and  4   , knitted component  100  can include a first edge  112 , a second edge  114 , a third edge  116 , and a fourth edge  118 . Edges  112 ,  114 ,  116 ,  118  can be disposed at any suitable angle relative to each other. Thus, knitted component  100  can define a rectangle, a parallelogram, or other quadrilateral. However, it will be appreciated that knitted component  100  can have any suitable shape, including a rounded shape, such as a circle, an oval, or other rounded shape. 
     Additionally, knitted component  100  can include a front face  120  and a back face  122 . Knitted component  100  can have any suitable thickness measured between front face  120  and back face  122 . The thickness can be substantially constant across knitted component  100  in some embodiments. In other embodiments, the thickness can vary. Also, in some embodiments, front face  120  and/or back face  122  can define one or more raised areas, one or more recessed areas, ribs, waves, or other surface variations. 
     Moreover, knitted component  100  can extend in various directions. For example, knitted component  100  can span primarily in a first direction  140  and a second direction  142 . Also, a thickness of knitted component  100  can be measured between front face  120  and back face  122  substantially in a third direction  139 . Moreover, third edge  116  and fourth edge  118  extend substantially in the first direction  140 , and first edge  112  and second edge  114  extend substantially in the second direction  142 . 
     Knitted component  100  can be formed from a plurality of interconnected yarns, cables, fibers, filaments, or other strands. Also, knitted component  100  can be formed of unitary knit construction. 
     As defined herein and as used in the claims, the term “unitary knit construction” means that the knitted component  100  is formed as a one-piece element through a knitting process. That is, the knitting process substantially forms the various features and structures of knitted component  100  without the need for significant additional manufacturing steps or processes. A unitary knit construction may be used to form a knitted component having structures or elements that include one or more courses of yarn or other knit material that are joined such that the structures or elements include at least one course in common (i.e., sharing a common strand or common yarn) and/or include courses that are substantially continuous between each portion of the knitted component  100 . With this arrangement, a one-piece element of unitary knit construction is provided. 
     Although portions of knitted component  100  may be joined to each other following the knitting process, knitted component  100  remains formed of unitary knit construction because it is formed as a one-piece knit element. Moreover, knitted component  100  remains formed of unitary knit construction when other elements (e.g., an inlaid strand, a closure element, logos, trademarks, placards with care instructions and material information, and other structural elements) are added following the knitting process. 
     Knitted component  100  can generally include a knit element  130  and one or more tensile strands  132 . Knit element  130  and tensile strand  132  can be formed of unitary knit construction with each other. 
     Knit element  130  can define a majority of knitted component  100 . Thus, knit element  130  can substantially define front face  120 , back face  122 , first edge  112 , second edge  114 , third edge  116 , and fourth edge  118  in some embodiments. Knit element  130  can be stretchable in some embodiments. To provide this stretchability, knit element  130  may be formed with a yarn or strand that is configured to stretch, such as an elastic yarn, in some embodiments. Also, in some embodiments, knit element  130  may be stretchable due to the knit structure used to form the knit element  130 . 
     Also, at least a portion of tensile strand  132  can extend across and/or through knit element  130  in some embodiments. For example, tensile strand  132  can include a first end  141 , a second end  143 , and a middle portion  145  that extends longitudinally between first end  141  and second end  143 . As shown in  FIGS.  1  and  4   , middle portion  145  can extend across and through knit element  130 . First end  141  and second end  143  can extend out from and can be exposed from knit element  130 . Specifically, in some embodiments, first end  141  can extend from third edge  116 , second end  143  can extend from fourth edge  118 , and middle portion  145  can extend across knit element  130  substantially in the second direction  142 . However, it will be appreciated that tensile strand  132  can be disposed relative to knit element  130  in any suitable location. For example, in other embodiments, first end  141  and/or second end  143  of tensile strand  132  can be unexposed and embedded in knit element  130 . Also, in some embodiments, one or more areas of middle portion  145  can be exposed from knit element  130 . 
     Tensile strand  132  can provide support to knitted component  100 . More specifically, in some embodiments, tension of strand  132  can allow knitted component  100  to resist deformation, resist stretching, or otherwise provide support for an object that is disposed proximate knitted component  100 . Also, tensile strand  132  can be used to vary, adjust, tailor, select, or otherwise change one or more characteristics of knit element  130  and knitted component  100 . For example, strand  132  can be manipulated by the wearer, by the manufacturer, by an automated actuator, or by another input to change the characteristic. By manipulating strand  132 , various characteristics can be changed. For example, in some embodiments, stretchiness, stretch resistance, range of stretching of knitted component  100 , or other characteristics relating to stretching can be varied. Also, in some embodiments, one or more dimensions of knitted component  100  can be changed by adjusting tensile strand  132 . 
     Referring now to  FIGS.  2  and  3   , knit element  130  and tensile strand  132  will be discussed in greater detail according to various embodiments. As shown in  FIG.  2   , knit element  130  of knitted component  100  may be formed from at least one yarn  134 , cable, filament, fiber, or other strand that is manipulated (e.g., with a knitting machine) to form a plurality of intermeshed loops. The loops can be intermeshed in a plurality of courses  136  extending in the second direction  142  and a plurality of wales  138  extending in the first direction  140 . Moreover, as shown in  FIG.  2   , knit element  130  and tensile strand  132  can be formed of unitary knit construction. 
     Tensile strand  132  can be attached to and engaged with knit element  130  in any suitable fashion. For example, in some embodiments, at least a portion of strand  132  can be inlaid within one or more courses  136  and/or wales  138  of knit element  130  such that strand  132  can be incorporated during the knitting processes on the knitting machine. More specifically, as shown in the embodiment of  FIG.  2   , tensile strand  132  can alternate between being located: (a) behind loops formed from yarn  134 ; and (b) in front of loops formed from yarn  134 . In effect, tensile strand  132  weaves through the unitary knit construction of knit element  130 . As a result, in some embodiments, tensile strand  132  can be disposed within knit element  130  between front face  120  and back face  122  of knitted component  100 . 
     In the embodiment of  FIG.  2   , strand  132  is shown inlaid within a single course  136  and, thus, strand  132  extends primarily in the second direction  142 . However, it will be appreciated that strand  132  can be inlaid within a single wale  138  of knit element  130  such that strand  132  extends primarily in the first direction  140 . In other embodiments, different segments of strand  132  can extend along different courses  136  of knit element  130 . Additionally, in some embodiments, different segments of strand  132  can extend along different wales  138  of knit element  130 . Furthermore, in some embodiments, strand  132  can extend across knit element  130  in both the first direction  140  and the second direction  142 . 
     Yarn(s)  134  that form knit element  130  can be of any suitable type. For example, yarn  134  of knit element  130  can be made from cotton, elastane, rayon, wool, nylon, polyester, or other material. Also, in some embodiments, yarn  134  can be elastic and resilient. As such, yarn  134  can be stretched in length from a first length, and yarn  134  can be biased to recover to its first length. Thus, such an elastic yarn  134  can allow knit element  130  to stretch elastically and resiliently under the influence of a force. When that force is reduced, knit element  130  can recover back its neutral position. 
     Furthermore, in some embodiments, yarn  134  can be at least partially formed from a thermoset polymer material that can melt when heated and that can return to a solid state when cooled. As such, yarn  134  can be a fusible yarn and can be used to join two objects or elements together. In additional embodiments, knit element  130  can include a combination of fusible and non-fusible yarns. In some embodiments, for example, knitted component  100  can be constructed according to the teachings of U.S. Patent Publication No. 2012/0233882, which published on Sep. 20, 2012, and the disclosure of which is hereby incorporated by reference in its entirety. Knitted component  100  can also be constructed according to the teachings of U.S. Patent Publication No. 2014/0150292, which published on Jun. 5, 2014, and which is hereby incorporated by reference in its entirety. 
     Additionally, in some embodiments, a single yarn  134  can form each of the courses  136  and wales  138  of knit element  130 . In other embodiments, knit element  130  can include a plurality of yarns. For example, different yarns can form different courses  136  and/or different wales  138 . In additional embodiments, a plurality of yarns can cooperate to define a common loop, a common course, and/or a common wale. For example, as shown in  FIG.  3   , knitted component  100  can include a plurality of yarns that are grouped together, that overlie each other, and that extend generally in the same longitudinal direction through respective courses  136 . In some embodiments, for example, a first yarn  135  can be formed from at least one of a thermoset polymer material and natural fibers (e.g., cotton, wool, silk). Also, a second yarn  137  may be formed from a thermoplastic polymer material, such as a fusible yarn of the type disclosed in U.S. Pat. No. 6,910,288, issued Jun. 28, 2005 to Dua, entitled “Footwear Incorporating a Textile with Fusible Filaments and Fibers,” and which is hereby incorporated by reference in its entirety. 
     Tensile strand  132  can also be of any suitable type of strand, yarn, cable, cord, filament (e.g., a monofilament), thread, rope, webbing, or chain, for example. In comparison with the yarn(s)  134  of knit element  130 , the thickness of tensile strand  132  may be greater. In some configurations, tensile strand  132  may have a significantly greater thickness than the yarns of knit element  130 . Although the cross-sectional shape of tensile strand  132  may be round, triangular, square, rectangular, elliptical, or irregular shapes may also be utilized. Moreover, the materials forming tensile strand  132  may include any of the materials for the yarn  134  of knit element  130 , such as cotton, elastane, polyester, rayon, wool, and nylon. As noted above, tensile strand  132  may exhibit greater stretch-resistance than knit element  130 . As such, suitable materials for tensile strand  132  may include a variety of engineering filaments that are utilized for high tensile strength applications, including glass, aramids (e.g., para-aramid and meta-aramid), ultra-high molecular weight polyethylene, and liquid crystal polymer. As another example, a braided polyester thread may also be utilized as tensile strand  132 . 
     Tensile strand  132  and other portions of knitted component  100  can additionally incorporate the teachings of one or more of commonly-owned U.S. patent application Ser. No. 12/338,726 to Dua et al., entitled “Article of Footwear Having An Upper Incorporating A Knitted Component”, filed on Dec. 18, 2008 and published as U.S. Patent Application Publication Number 2010/0154256 on Jun. 24, 2010; U.S. patent application Ser. No. 13/048,514 to Huffa et al., entitled “Article Of Footwear Incorporating A Knitted Component”, filed on Mar. 15, 2011 and published as U.S. Patent Application Publication Number 2012/0233882 on Sep. 20, 2012; U.S. patent application Ser. No. 13/781,336 to Podhajny, entitled “Method of Knitting A Knitted Component with a Vertically Inlaid Tensile Element”, filed on Feb. 28, 2013 and published as U.S. Patent Application Publication Number 2014/0237861 A1 on Aug. 28, 2014, each of which is hereby incorporated by reference in its entirety. 
     Referring now to  FIGS.  1  and  4   , knit element  130  will be discussed in greater detail according to exemplary embodiments. Knit element  130  can include multiple knit structures, zones, areas, or portions that are formed of unitary knit construction but that have different characteristics. These different characteristics can relate to appearance, stitch density, texture, stretch resistance, elasticity, resilience, or other characteristics. 
     For example, knit element  130  can include a first region  150  proximate first edge  112 , a second region  152  proximate second edge  114 , and a third region  154  disposed between first and second regions  150 ,  152 . In some embodiments, first region  150  and second region  152  can be substantially uniform and continuous. In contrast, third region  154  can include a plurality of knit zones that differ in one or more ways. For example, third region  154  can include one or more auxetic portions  156  and an adjacent zone  158  that is disposed adjacent the auxetic portion(s)  156 . 
     In some embodiments represented in  FIGS.  1  and  4   , third region  154  can include a plurality of auxetic portions  156  that are spaced apart from each other in the first direction  140  and the second direction  142 . Adjacent zone  158  of knit element  130  can be defined between auxetic portions  156 . In some embodiments, adjacent zone  158  can continuously encompass, border, or surround one or more of auxetic portions  156 . Adjacent zone  158  can also be substantially continuous (i.e., formed as a one-piece element with) one or more auxetic portions  156 . Also, adjacent zone  158  can be substantially continuous with first region  150  and second region  152  in some embodiments. Thus, auxetic portions  156 , adjacent zone  158 , first region  150 , and second region  152  can be formed of unitary knit construction. Additionally, as represented in  FIG.  1   , auxetic portions  156  can be exposed on front face  120  and back face  122  of knit element  130 . Moreover, in some embodiments, auxetic portions  156  can be incorporated in adjacent zone  158  of knit element  130  through known intarsia knitting processes. 
     In some embodiments, auxetic portions  156  can be defined by a border  159  and an interior area  161 . Border  159  can demarcate the respective auxetic portion  156  from adjacent zone  158  of knit element  130  in some embodiments. In some embodiments, border  159  can continuously encompass and frame interior area  161 . Furthermore, the size or area of interior area  161  of auxetic portion  156  can be defined within border  159 . Also, in some embodiments, border  159  can be spaced apart from edges  112 ,  114 ,  116 ,  118  of knitted component  100 . In other embodiments, border  159  can intersect first edge  112 , second edge  114 , third edge  116 , and/or fourth edge  118 . 
     Auxetic portion  156  can have any suitable size or area. For example, in some embodiments, auxetic portion  156  can have an area between approximately 0.25 square inches (in2) to approximately 5 square inches (in2) when in the unstretched, neutral position. 
     Auxetic portions  156  can have one or more different physical properties than first region  150 , second region  152 , and/or adjacent zone  158 . For example, auxetic portions  156  can be more elastic, more stretchable, and less stiff than first region  150 , second region  152 , and/or adjacent zone  158 . Stated differently, auxetic portions  156  can have a smaller degree or smaller amount of stretch resistance than first region  150 , second region  152 , and/or adjacent zone  158 . 
     These differences in elasticity can be achieved in various ways. For example, in some embodiments, the knit construction of auxetic portion  156  can be different from first region  150 , second region  152 , and/or adjacent zone  158  to cause auxetic portions  156  to be more elastic than first region  150 , second region  152 , and adjacent zone  158 . 
     Additionally, in some embodiments, auxetic portions  156  can be constructed from yarns that are more elastic than the yarns of first region  150 , second region  152 , and/or adjacent zone  158  to cause this difference in elasticity. More specifically, in some embodiments, auxetic portions  156  can be formed using one or more elastic, stretchable yarns. In contrast, first region  150 , second region  152 , and adjacent zone  158  can be formed using less elastic or substantially inelastic yarns. 
     Also, in some embodiments, first region  150 , second region  152 , and adjacent zone  158  can be formed from yarns made from a thermoplastic. In some embodiments, these thermoplastic yarns can be heated and partially melted and fused to adjacent yarns to impart additional stiffness to the respective areas of knit element  130 . In some embodiments, these thermoplastic yarns can be absent from auxetic portions  156 . 
     In additional embodiments, a coating or skin can be applied to first region  150 , second region  152 , and adjacent zone  158  to impart additional stiffness to these areas of knit element  130 . This coating or skin can be absent from auxetic portions  156 . 
     Knitted component  100  can stretch from a first position (i.e., neutral position) represented in  FIG.  4    to a second position (i.e., stretched position) represented in  FIG.  5   . It will be appreciated that  FIGS.  4  and  5    represent an exemplary embodiment of the stretching of knitted component  100 ; however, it will be appreciated that knitted component  100  can exhibit different stretching behavior without departing from the scope of the present disclosure. 
     As shown in the embodiment of  FIG.  5   , a stretching force can be applied as indicated by arrows  157 . As a result, knitted component  100  can stretch such that first edge  112  and second edge  114  move away from each other and such that knitted component  100  elongates in the first direction  140 . Because the auxetic portions  156  exhibit auxetic characteristics, this stretching can also cause third edge  116  and fourth edge  118  to move away from each other and cause knitted component  100  to become wider in the second direction  142 . For example, as shown in  FIG.  5   , third region  154  can bulge in the second direction  142  whereas first region  150  and second region  152  can remain substantially the same width in the second direction  142 . This stretching behavior will be discussed in greater detail below. 
     Moreover, as discussed in detail below, tensile strand  132  can engage knit element  130  proximate at least one of the plurality of auxetic portions  156 . Tensile strand  132  can engage any number of the auxetic portions  156 . Additionally, tensile strand  132  can be manipulated to selectively change one or more dimensions of auxetic portion  156 . As a result, stretching behavior of auxetic portion  156  and/or knit element  130  can be selectively changed. 
     Embodiments of Auxetic Portions 
     Auxetic portions  156  will now be discussed in detail according to exemplary embodiments. Initially, the shape and geometry of auxetic portions  156  will be discussed with reference to  FIGS.  4 ,  6 , and  8   . It will be appreciated that auxetic portions  156  shown in  FIGS.  6  and  8    can be representative of other auxetic portions  156  of knitted component  100 . 
     Border  159  of auxetic portions  156  may have any kind of geometry. In some embodiments, one or more borders  159  may have a polygonal geometry. The shape of auxetic portion  156  may be characterized as a regular polygon in some embodiments, such that angles defined between adjacent sides are equal to corresponding angles within the polygon. Also, border  159  may be characterized as comprising a particular number of vertices and edges (or sides). These edges can be substantially straight in some embodiments. Additionally, these edges can be curved in some embodiments. 
     Other geometries are also possible, including a variety of polygonal and/or curved geometries. Exemplary polygonal shapes that may be used with one or more of auxetic portions  156  include, but are not limited to, regular polygonal shapes (e.g., triangular, rectangular, pentagonal, hexagonal, etc.) as well as irregular polygonal shapes or non-polygonal shapes. Other geometries could be described as being quadrilateral, pentagonal, hexagonal, heptagonal, octagonal or other polygonal shapes with reentrant sides. Moreover, some embodiments can include borders  159  having a geometry that includes both straight edges connected via vertices as well as curved or non-linear edges without any points or vertices. 
     With regard to the embodiments of  FIGS.  6  and  8   , auxetic portion  156  may be characterized as having six sides and six vertices. For example, auxetic portion  156  can include a first side  164 , a second side  166 , a third side  168 , a fourth side  170 , a fifth side  172 , and a sixth side  174 . Additionally, auxetic portion  156  can include a first vertex  176 , a second vertex  178 , a third vertex  180 , a fourth vertex  182 , a fifth vertex  184 , and a sixth vertex  186 . First side  164  and sixth side  174  can intersect at first vertex  176 . First side  164  and second side  166  can intersect at second vertex  178 . Second side  166  and third side  168  can intersect at third vertex  180 . Third side  168  and fourth side  170  can intersect at fourth vertex  182 . Fourth side  170  and fifth side  172  can intersect at fifth vertex  184 . Fifth side  172  and sixth side  174  can intersect at sixth vertex  186 . 
     Additionally, in some embodiments, the geometry of auxetic portion  156  can be shaped substantially as a so-called re-entrant triangle. Accordingly, auxetic portion  156  can be characterized as a triangle with sides that, instead of being straight, have an inwardly-pointing vertex at the midpoint of the side. Thus, second vertex  178 , fourth vertex  182 , and sixth vertex  186  can be disposed closer to a center of interior area  161  than first vertex  176 , third vertex  180 , and fifth vertex  184 . Stated differently, second vertex  178 , fourth vertex  182 , and sixth vertex  186  can each be characterized as an “inwardly-pointing vertex.” In contrast, first vertex  176 , third vertex  180 , and fifth vertex  184  can each be characterized as an “outwardly-pointing vertex.” Inwardly-pointing vertices  178 ,  182 ,  186  can define an exterior angle  167  (i.e., a re-entrant angle). In some embodiments, exterior angle  167  can range from approximately 120 degrees to 180 degrees. Additionally, the vertices of auxetic portion  156  may define a plurality of interior angles  165 . For example, interior angles  165  can be defined at first vertex  176 , third vertex  180 , and fifth vertex  184 . In some embodiments, first vertex  176 , third vertex  180 , and fifth vertex  184  can have an interior angle  165  that is less than 180 degrees when auxetic portion  156  is in the neutral, unstretched position. 
     In some embodiments, auxetic portions  156  may be arranged in a regular pattern on knit element  130 . Auxetic portions  156  can be substantially evenly spaced from each other across knit element  130 . In some embodiments, auxetic portions  156  may be arranged such that each vertex of one auxetic portion  156  is disposed near the vertex of another auxetic portion  156  (e.g., an adjacent or nearby auxetic portion  156 ). More specifically, in some embodiments, first vertex  176  of one auxetic portion  156  can be disposed near, or adjacent to, fourth vertex  182  of another auxetic portion  156 . Similarly, second vertex  178  of one auxetic portion  156  can be disposed near, or adjacent to, a fifth vertex  184  of another auxetic portion  156 . Moreover, third vertex  180  of one auxetic portion  156  can be disposed near, or adjacent to, a sixth vertex  186  of another auxetic portion  156 . 
     As knit element  130  stretches from the neutral position of  FIGS.  4 ,  6 , and  8    to the stretched position of  FIGS.  5 ,  7 , and  9   , auxetic portions  156  can deform. The size or area of interior area  161  can increase as knit element  130  stretches. 
     More specifically, as shown in  FIGS.  6  and  7   , a representative interior angle  165  is indicated at third vertex  180 , between second side  166  and third side  168 . A representative exterior angle  167  is indicated at fourth vertex  182 , between third side  168  and fourth side  170 . By comparing  FIGS.  6  and  7   , it is apparent that interior angles  165  and/or exterior angles  167  can increase when auxetic portion  156  stretches. As shown in the auxetic portions  156  of  FIGS.  6 - 9   , each interior angle  165  and each exterior angle  167  can increase proportionally; however, it will be appreciated that different interior angles  165  and/or different exterior angles  167  can increase disproportionately in some embodiments. 
     Also, in some embodiments, auxetic portion  156  can deform auxetically as knit element  130  stretches. For example, it is apparent from comparing  FIG.  7    to  FIG.  6    that auxetic portion  156  enlarges in both the first direction  140  and the second direction  142  as knitted component  100  stretches. 
     More specifically, as shown in  FIGS.  6  and  8   , knit element  130  proximate auxetic portion  156  can have a respective unstretched length  188  measured in the first direction  140  and a respective unstretched width  192  measured in the second direction  142 . When a stretching force is applied as represented by arrows  157  in  FIGS.  7  and  9   , knit element  130  can have a stretched length  190  as well as a stretched width  194 . Stretched length  190  can be greater than unstretched length  188 , and stretched width  194  can be greater than unstretched width  192 . Moreover, knit element  130  proximate auxetic portion  156  can define a stretching range. This stretching range can be measured in the first direction  140  as the difference between the stretched length  190  and the unstretched length  188 . This stretching range can additionally be measured in the second direction  142  as the difference between the stretched width  194  and the unstretched width  192 . In additional embodiments, the stretching range can be measured as the difference between the surface area of the auxetic portion  156  in its stretched position and the surface area of the auxetic portion  156  in its unstretched, neutral position shown in  FIG.  6   . 
     Thus, knit element  130  proximate auxetic portion  156  can stretch auxetically due to the stretching force represented by arrows  157 . Because of this deformation, as shown in  FIG.  5   , knit element  130  can bulge in the second direction  142 , especially in third region  154 , when stretched in the first direction  140 . In some embodiments, once the stretching force is reduced, the resiliency of auxetic portions  156  can cause auxetic portions  156  to recover back toward the neutral position of  FIGS.  6  and  8   . Accordingly, knit element  130  can stretch readily and can be biased to recover back to its unstretched position. 
     Tensile Strand and Associated Auxetic Portion 
     As mentioned above, tensile strand  132  can extend across knit element  130 . Tensile strand  132  can engage one or more auxetic portions  156 . For example, as shown in  FIGS.  4  and  8   , the plurality of auxetic portions  156  can include a first auxetic portion  162 , to which tensile strand  132  is engaged. Also, as shown in  FIGS.  4  and  6   , the plurality of auxetic portions  156  can include a second auxetic portion  160 , and tensile strand  132  can be spaced apart and disengaged from second auxetic portion  160 . 
     As shown in  FIG.  8   , tensile strand  132  can extend across first auxetic portion  162  primarily in the second direction  142 . Tensile strand  132  can intersect border  159  of auxetic portion  162  at a first point  196  and at a second point  198 . In some embodiments, first point  196  can be located along sixth side  174 , and second point  198  can be located along first side  164 . A segment of tensile strand  132  can also extend across interior area  161  of auxetic portion  162  between first point  196  and seconds point  198 . It will be appreciated, however, that tensile strand  132  can extend across any suitable portion of auxetic portion  162  without departing from the scope of the present disclosure. 
     Also, in some embodiments, tensile strand  132  can be inlaid within one or more courses  136  and/or wales  138  that define auxetic portion  162 . For example, in some embodiments, tensile strand  132  can be inlaid within a single course  136  defining auxetic portion  162 . In other embodiments, tensile strand  132  can extend from one course  136  to another course  136  as it extends across auxetic portion  162 . In still other embodiments, tensile strand  132  can be inlaid within one or more wales  138  of auxetic portion  162 . 
     In some embodiments, tensile strand  132  can be fixed to knit element  130  proximate auxetic portion  162 . For example, tensile strand  132  can be fixed to knit element  130  proximate border  159 . More specifically, in some embodiments, tensile strand  132  can be fixed to knit element  130  proximate first point  196  and/or second point  198 . For example, tensile strand  132  can be fixed at point  196  and/or point  198  using adhesives, via a fastener, via a knot, or in another way. 
     In other embodiments, tensile strand  132  can engage knit element  130  via friction; however, tensile strand  132  can slide along its longitudinal axis relative to first point  196  and/or second point  198  and remain engaged with knit element  130  at first point  196  and/or second point  198 . For example, in some embodiments, tensile strand  132  can movably engage knit element  130  in this manner at first point  196  and second point  198 . 
     Because tensile strand  132  engages knit element  130 , for example, proximate auxetic portion  162 , tensile strand  132  can be manipulated to alter, move, modify, change, or distort auxetic portion  162 . For example, the user can manipulate tensile strand  132  to select and change the area, size, and/or geometry of interior area  161  of auxetic portion  162 . In some embodiments, increasing tension of tensile strand  132 , for example by pulling on tensile strand  132 , can increase the size of interior area  161 . In other embodiments, increasing tension of tensile strand  132  can decrease the size of interior area  161 . The stretching characteristics of knit element  131 , such as the range of stretching or knit element  131 , can be related to the size of interior area  161 . As such, the stretching characteristics of auxetic portion  156  and, thus, knit element  130  can be changed using tensile strand  132 . 
     For example as shown in  FIGS.  10  and  12   , the user can manipulate tensile strand  132  to alter auxetic portion  162  by pulling first end  141  and second end  143  away from each other as represented by the arrows  200 . As such, tensile strand  132  can pull first point  196  and second point  198  of auxetic portion  162  away from each other. For comparison, the original neutral position of auxetic portion  162  is shown with broken lines in  FIG.  12   . The adjusted neutral position of auxetic portion  162  is shown with solid lines. Arrows  201  represent movement of border  159 . Specifically, as shown in  FIG.  12   , first side  164  and sixth side  174  of auxetic portion  162  can rotate generally about first vertex  176  and move away from each other due to manipulation of tensile strand  132 . This can also cause second vertex  178  and sixth vertex  186  to move outward from the center of auxetic portion  162 . Thus, by pulling on tensile strand  132 , the interior area  161  of auxetic portion  162  can be increased. Moreover, the representative zone of knit element  130  shown in  FIG.  12    can have a length  202  and a width  204  as a result of altering auxetic portion  162 . 
     In some embodiments, length  202  and width  204  shown in  FIG.  12    can be substantially equal to the original length  188  and width  192 , respectively, shown in  FIG.  8   . Stated differently, in some embodiments, the size of knit element  130  can remain substantially the same despite adjustment of the size of auxetic portion  162 . In other embodiments, adjustment of auxetic portion  162  can cause changes to the overall size of knit element  130 . 
     Stretching of knit element  130  after adjustment of auxetic portion  162  is represented in  FIG.  13    according to some embodiments. As shown, when knit element  130  is stretched in the first direction  140  as represented by arrows  157 , auxetic portion  162  can elongate from its adjusted length  202  to a stretched length  206 , and auxetic portion  162  can widen from its adjusted width  204  to its stretched width  208 . 
     In some embodiments, under the same amount of stretching force (represented by arrows  157 ), the stretched length  206  of  FIG.  13    can be greater than the stretched length  190  of  FIG.  9   . Likewise, the stretched width  208  of  FIG.  13    can be greater than the stretched width  194  of  FIG.  9   . Thus, it will be appreciated that by increasing the area of interior area  161  of auxetic portion  162  using tensile strand  132 , one can increase the stretching range of auxetic portion  162 . 
     Adjusting the stretching characteristics of auxetic portion  162  using tensile strand  132  can cause adjustment to the stretching characteristics of knit element  130 . For example, as shown in  FIG.  11   , third edge  116  and/or fourth edge  118  of knit element  130  can define a convex or bulged region  210  in areas that are proximate auxetic portion  162 . In some embodiments, third edge  116  and fourth edge  118  can both define bulged regions  210  when knit element  130  is stretched. Accordingly, tensile strand  132  can be used to increase the stretching range of one or more portions of knit element  130 . 
     In the embodiment of  FIGS.  8 ,  10 , and  12   , tensile strand  132  is manipulated to increase the size of interior area  161  of auxetic portion  162  when knit element  130  is in a neutral position. As a result, as shown in  FIGS.  9 ,  11 , and  13   , the stretching range of auxetic portion  162  and knit element  130  is increased. However, it will be appreciated that tensile strand  132  can be used to modify stretching characteristics of auxetic portions  156  and knit element  130  in other ways without departing from the scope of the present disclosure. 
     For example, in some embodiments, tensile strand  132  can be manipulated to reduce the size of interior area  161  of one or more auxetic portions  156 . As a result, the stretching range of knit element  130  can be decreased. Furthermore, in some embodiments, tensile strand  132  can be manipulated to increase the size of interior area  161  of auxetic portion(s)  156 , and the stretching range of knit element  130  can be decreased as a result. Additionally, in some embodiments, tensile strand  132  can be manipulated to decrease the size of interior area  161  of auxetic portion(s)  156 , and the stretching range of knit element  130  can be increased as a result. 
       FIGS.  14 - 17    illustrate an additional embodiment of tensile strand  132  and auxetic portion  162 . This embodiment can be substantially similar to the embodiment of  FIGS.  8 - 12   , except that tensile strand  132  can be routed across knit element  13  differently. 
     For example, as shown in  FIG.  14   , tensile strand  132  can extend across knit element  130  and auxetic portion  162  in both first direction  140  and second direction  142 . In some embodiments, tensile strand  132  can zig-zag across auxetic portion  162 . Thus, in some embodiments, tensile strand  132  can extend through multiple courses  136  and multiple wales  138  as tensile strand  132  extends across auxetic portion  162  and knit element  130 . 
     Additionally, tensile strand  132  can engage knit element  130  proximate second vertex  178 , fourth vertex  182 , and sixth vertex  186  of auxetic portion  162  as shown in the embodiment of  FIG.  14   . Tensile strand  132  can be fixed to one or more of these vertices in some embodiments. Also, in some embodiments, tensile strand  132  can be engaged to one or more of these vertices as a result of being inlaid within knit element  130  proximate these vertices. However, tensile strand  132  can move (e.g., slide along its longitudinal axis) relative to these vertices in some embodiments. 
     Specifically, in some embodiments, tensile strand  132  can be fixed to fourth vertex  182 , and tensile strand  132  can be inlaid in second and sixth vertices  178 ,  186 . As such, tensile strand  132  can move relative to second and sixth vertices  178 ,  186 . Thus, tensile strand  132  can be fixed to knit element  130  at fourth vertex  182 , and tensile strand  132  can be movably engaged with knit element  130  at second and sixth vertices  178 ,  186 . 
       FIG.  15    illustrates auxetic portion  162  when knit element  130  is stretched as represented by arrows  157 . As shown, auxetic portion  162  can stretch in a manner that is substantially similar to the embodiment of  FIG.  9   . 
     As shown in  FIG.  16   , ends of tensile strand  132  can be pulled as represented by arrows  200 . As a result, tensile strand  132  can pull second vertex  178 , fourth vertex  182 , and sixth vertex  186  inward toward each other as represented by arrows  212  in  FIG.  16   . Thus, the size of interior area  161  can be reduced by pulling ends of tensile strand  132 . 
     When knit element  130  is stretched in the first direction  140  as represented by arrows  157  in  FIG.  17   , auxetic portion  162  can stretch and enlarge. However, by comparing  FIG.  15    and  FIG.  17    it becomes apparent that the adjusted stretched length  206  can be less than the original stretched length  190 . Likewise, the adjusted stretched width  208  can be less than the original stretched width  194 . 
     Accordingly, tensile strand  132  can be used for adjusting the size of auxetic portion  162 . In some embodiments, tensile strand  132  can be pulled to make auxetic portion  162  larger or smaller, depending on how tensile strand  132  engages auxetic portion  162 . As a result, the stretching behavior of knit element  130  can be selected. In some embodiments, such as those embodiments of  FIGS.  11  and  13   , knit element  130  can have an increased range of stretching due to adjustments to the size of auxetic portion  162 . In other embodiments, such as the embodiment of  FIG.  17   , knit element  130  can have a decreased range of stretching due to adjustments to the size of auxetic portion  162 . 
     In some embodiments, after auxetic portion  162  has been adjusted using tensile strand  132 , tensile strand  132  can be secured relative to knit element  130  such that auxetic portion  162  remains at its adjusted, neutral size. For example, first end  141  and/or second end  143  can be secured at a fixed location relative to tensile strand  132  for maintaining tension in tensile strand  132  and maintaining auxetic portion  162  at its adjusted size. In some embodiments, first end  141  and second end second end  143  can be secured directly together, for example in a knot, to maintain set tension in tensile strand  132 . In additional embodiments, a fastener, a spool, or other object can be included for detachably securing to tensile strand  132  to maintain the selected tension in tensile strand  132 . Moreover, in some embodiments, when tensile strand  132  is released, the resiliency of knit element  130  can cause auxetic portion  162  to recover to its original, neutral, and unstretched size. 
     Article of Footwear with Adjustable Auxetic Portion 
     Various objects and articles can be constructed that include knitted components of the type discussed above. For example, as shown in  FIGS.  18 - 21   , a knitted component  1030  for an article of footwear  1000  is illustrated according to exemplary embodiments. 
     As shown in  FIGS.  19 - 21   , footwear  1000  can generally include a sole structure  1010  and an upper  1020 . Upper  1020  can include a knitted component  1030 . Knitted component  1030  is shown independently in  FIG.  18    and is shown associated with sole structure  1010  and other features in  FIGS.  19 - 21   . As will be discussed, knitted component  1030  can include one or more features described above with respect to  FIGS.  1 - 17   . Thus, knitted component  1030  can include one or more auxetic portions, and at least one of those auxetic portions can be adjustable. 
     For reference purposes, footwear  1000  may be divided into three general regions: a heel region  1002 , a midfoot region  1003 , and a forefoot region  1004 . Heel region  1002  can generally include portions of footwear  1000  corresponding with rear portions of the wearer&#39;s foot, including the heel and calcaneus bone. Midfoot region  1003  can generally include portions of footwear  1000  corresponding with middle portions of the wearer&#39;s foot, including an arch area. Forefoot region  1004  can generally include portions of footwear  1000  corresponding with forward portions of the wearer&#39;s foot, including the toes and joints connecting the metatarsals with the phalanges. 
     Footwear  1000  can also include a medial side  1005  and a lateral side  1006 . Medial side  1005  and lateral side  1006  can extend through forefoot region heel region  1002 , midfoot region  1003 , and forefoot region  1004  in some embodiments. Medial side  1005  and lateral side  1006  can correspond with opposite sides of footwear  1000 . More particularly, lateral side  1006  can correspond with an outside area of the wearer&#39;s foot (i.e., the surface that faces away from the other foot), and medial side  1005  can correspond with an inside area of the wearer&#39;s foot (i.e., the surface that faces toward the other foot). Heel region  1002 , midfoot region  1003 , forefoot region  1004 , medial side  1005 , and lateral side  1006  are not intended to demarcate precise areas of footwear  1000 . Rather, heel region  1002 , midfoot region  1003 , forefoot region  1004 , medial side  1005 , and lateral side  1006  are intended to represent general areas of footwear  1000  to aid in the following discussion. 
     Footwear  1000  can also extend along various directions. For example, footwear  1000  can extend along a longitudinal direction  1007 , a transverse direction  1008 , and a vertical direction  1009 . Longitudinal direction  1007  can extend generally between heel region  1002  and forefoot region  1004 . Transverse direction  1008  can extend generally between medial side  1005  and lateral side  1006 . Also, vertical direction  1009  can extend substantially perpendicular to both longitudinal direction  1007  and transverse direction  1008 . It will be appreciated that longitudinal direction  1007 , transverse direction  1008 , and vertical direction  1009  are merely included for reference purposes and to aid in the following discussion. 
     Embodiments of sole structure  1010  will now be discussed with reference to  FIG.  19   . Sole structure  1010  can include an upper surface  1011  that is attached to upper  1020  and can include a lower surface  1013  that faces away from upper  1020  and that defines a ground engaging surface of sole structure  1010 . In some embodiments, sole structure  1010  can include a midsole  1012  and an outsole  1014 . Midsole  1012  can include a resiliently compressible material, fluid-filled bladders, and the like. As such, midsole  1012  can cushion the wearer&#39;s foot and attenuate impact and other forces when running, jumping, and the like. Midsole  1012  can at least partially define upper surface  1011  of sole structure  1010 . Outsole  1014  can be secured to the midsole  1012  and can include a wear resistant material, such as rubber and the like. Outsole  1014  can also include tread and other traction-enhancing features. Outsole  1014  can define the lower surface  1013  of sole structure  1010 . 
     Also, in some embodiments, sole structure  1010  can include one or more auxetic portions that allow sole structure  1010  to stretch and deform auxetically. For example, in some embodiments, sole structure  1010  and/or other aspects of footwear  1000  can include features disclosed in U.S. patent application Ser. No. 14/470,067, entitled “Auxetic Sole With Upper Cabling”, the disclosure of which is incorporated by reference in its entirety. 
     Embodiments of upper  1020  will now be discussed with reference to  FIGS.  19 - 21   . As shown, upper  1020  can define a void  1022  that receives a foot of the wearer. Stated differently, upper  1020  can define an interior surface  1021  that defines void  1022 , and upper  1020  can define an exterior surface  1023  that faces in a direction opposite interior surface  1021 . When the wearer&#39;s foot is received within void  1022 , upper  1020  can at least partially enclose and encapsulate the wearer&#39;s foot. Thus, upper  1020  can extend about heel region  1002 , midfoot region  1003 , forefoot region  1004 , medial side  1005 , and lateral side  1006  in some embodiments. 
     Upper  1020  can include a main opening  1024  that provides access into and out of void  1022 . Upper  1020  can also include a throat  1028 . Throat  1028  can extend from collar main opening  1024  toward forefoot region  1004 . Throat  1028  dimensions can be varied to change the width of footwear  1000  between medial side  1005  and lateral side  1006 . Thus, throat  1028  can affect fit and comfort of article of footwear  1000 . 
     In some embodiments, such as the embodiment of  FIGS.  19 - 21   , throat  1028  can be an “open” throat  1028 , in which upper  1020  includes a throat opening  1025  that extends from main opening  1024  toward forefoot region  1004  and that is defined between medial side  1005  and lateral side  1006 . In other embodiments, throat  1028  can be a “closed” throat  1028 , in which upper  1020  is substantially continuous and uninterrupted between medial side  1005  and lateral side  1006 . 
     Additionally, throat  1028  can include a tongue  1026  that is disposed within throat opening  1025 . For example, in some embodiments, tongue  1026  can be attached at its forward end to forefoot region  1004 , and tongue  1026  can be detached from medial side  1005  and lateral side  1006 . Accordingly, tongue  1026  can substantially fill throat opening  1025 . 
     Article of footwear  1000  can further include a securing member  1015  for selectively adjusting the fit of footwear  1000  on the wearer&#39;s foot. In some embodiments, securing member  1015  can include a shoelace  1017 . However, it will be appreciated that securing member  1015  can include a strap, a buckle, hook-and-loop tape, buttons, or other types of members that allow for selecting how tightly footwear  1000  fits to the wearer&#39;s foot. As shown in the embodiment of  FIGS.  19 - 21   , shoelace  1017  can extend back and forth between medial side  1005  and lateral side  1006  and can be secured to both. Thus, by changing tension of shoelace  1017 , the girth of upper  1020  in the transverse direction  1008  can be adjusted. Also, once the fit is desirable, the user can tie shoelace  1017  into a knot to secure footwear  1000  in the selected configuration. 
     Many conventional footwear uppers are formed from multiple material elements (e.g., textiles, polymer foam, polymer sheets, leather, synthetic leather) that are joined through stitching or bonding, for example. In contrast, at least a portion of upper  1020  is formed and defined by knitted component  1030 . Knitted component  1030  can be formed of unitary knit construction. 
     In some embodiments, knitted component  1030  can define at least a portion of the void  1022  within upper  1020 . Also, in some embodiments, knitted component  1030  can define at least a portion of exterior surface  1023 . Furthermore, in some embodiments, knitted component  1030  can define at least a portion of interior surface  1021  of the upper  1020 . Additionally, in some embodiments, knitted component  1030  can define a substantial portion of heel region  1002 , midfoot region  1003 , forefoot region  1004 , medial side  1005 , and lateral side  1006  of upper  1020 . Thus, knitted component  1030  can encompass the wearer&#39;s foot in some embodiments. Also, in some embodiments, knitted component  1030  can compress the wearer&#39;s foot to secure to the wearer&#39;s foot. 
     Thus, upper  1020  can be constructed with a relatively low number of material elements. This can decrease waste while also increasing the manufacturing efficiency and recyclability of upper  1020 . Additionally, knitted component  1030  of upper  1020  can incorporate a smaller number of seams or other discontinuities. This can further increase manufacturing efficiency of footwear  1000 . Moreover, interior surface  1021  of upper  1020  can be substantially smooth and uniform to enhance the overall comfort of footwear  1000 . 
     Features of knitted component  1030  will now be discussed in greater detail according to various embodiments. Knitted component  1030  can generally include a knit element  1031 . Knit element  1031  can correspond to knit element  130  discussed above in relation to  FIGS.  1 - 17   . Knitted component  1030  can also generally include at least one tensile strand  1050 . Tensile strand  1050  can correspond to tensile strand  132  discussed above in relation to  FIGS.  1 - 17   . Knit element  1031  and tensile strand  1050  can be formed of unitary knit construction. 
     Knit element  1031  will now be discussed in greater detail with reference to  FIG.  18   . Knit element  1031  can define a majority of knitted component  1030  and upper  1020  in some embodiments. 
     Knit element  1031  can include a lateral portion  1038  and a medial portion  1040 . Lateral portion  1038  can define lateral side  1006  of upper  1020  and can be configured to cover over and lie against a lateral area of the wearer&#39;s foot. Furthermore, medial portion  1040  can define medial side  1005  of upper  1020  and can be configured to cover over and lie against a medial area of the wearer&#39;s foot. As shown in  FIG.  18   , lateral portion  1038  and medial portion  1040  can be joined at a forward portion  1039  of knit element  1031 . Forward portion  1039  can define forefoot region  1004  of upper  1020  and can be configured to cover over the wearer&#39;s toes, metatarsals, and adjacent areas of the foot. Moreover, lateral portion  1038  can include a lateral rear edge  1032  and medial portion  1040  can include a medial rear edge  1034 . Furthermore, knit element  1031  can include an outer peripheral edge  1036  and an inner peripheral edge  1037 . Outer peripheral edge  1036  can extend from lateral rear edge  1032 , along lateral portion  1038 , along forward portion  1039 , and along medial portion  1040  to terminate at medial rear edge  1034 . Inner peripheral edge  1037  can similarly extend from lateral rear edge  1032 , along lateral portion  1038 , along forward portion  1039 , and along medial portion  1040  to terminate at medial rear edge  1034 . 
     When knit element  1031  is assembled to define upper  1020 , rear edge  1032  and rear edge  1034  can be joined together to define a seam  1042  in heel region  1002  as shown in  FIGS.  20  and  21   . Also, inner peripheral edge  1037  can define main opening  1024  and throat opening  1025 . Furthermore, outer peripheral edge  1036  can be disposed proximate to sole structure  1010 . In some embodiments, outer peripheral edge  1036  can be covered over by sole structure  1010 . Furthermore, in some embodiments, a strobel can be attached to outer peripheral edge  1036 , and the strobel and can overlap and attach to upper surface  1011  of sole structure  1010  such that outer peripheral edge  1036  is proximate sole structure  1010 . 
     In some embodiments, tongue  1026  can be a part that is independent of knit element  1031 . Tongue  1026 , for example, can be attached via stitching, adhesives, fasteners, or other connecting device to forward portion  1039  of knit element  1031 . In other embodiments, tongue  1026  can be integrally attached to forward portion  1039 , medial portion  1040 , or lateral portion  1038  of knit element  1031 . 
     As shown in  FIGS.  18 - 21   , knit element  1031  can further include one or more auxetic portions  1056 . It will be appreciated that knit element  1031  can include any number of auxetic portions  1056 . Auxetic portions  1056  can also have any suitable shape. Moreover, auxetic portions  1056  can be disposed in any suitable location on knit element  1031 . Auxetic portions  1056  can increase stretchability of knit element  1031  and upper  1020 . Thus, auxetic portions  1056  can be provided in locations of upper  1020  where increased stretchability is desired. This stretchability can allow upper  1020  to better accommodate and conform to the contoured surfaces of the foot. Stretching of auxetic portions  1056  an also allow the wearer&#39;s foot to more easily flex inside upper  1020  while upper  1020  maintains a comfortable and supportive fit. 
     Auxetic portions  1056 , in some embodiments, can correspond to auxetic portions  156  described above with respect to  FIGS.  1 - 17   . Thus, auxetic portions  1056  can generally have a shape of a so-called re-entrant triangle. However, auxetic portions  1056  can have a different shape without departing from the scope of the present disclosure. 
     In some embodiments, auxetic portions  1056  of knit element  1031  can include a medial auxetic portion  1058  and a lateral auxetic portion  1060 . In some embodiments, medial auxetic portion  1058  can be disposed in medial portion  1040  of knit element  1031 , and lateral auxetic portion  1060  can be disposed in lateral portion  1038 . Also, in some embodiments, medial and lateral auxetic portions  1058 ,  1060  can be disposed in midfoot region  1003 . Furthermore, medial and lateral auxetic portions  1058 ,  1060  can be spaced apart at a distance from outer edge  1036  and inner peripheral edge  1037 . Additionally, in some embodiments, medial and lateral auxetic portions  1058 ,  1060  can partially define respective portions of interior surface  1021  and exterior surface  1023  of upper  1020 . 
     As such, auxetic portions  1056  can allow for a high degree of stretching of upper  1020 , especially in the midfoot region  1003  on medial side  1005  and lateral side  1006 . For example, flexure of the wearer&#39;s foot can cause a stretching force to be applied to upper  1020  in the longitudinal direction  1007 . As a result, areas of upper  1020  proximate auxetic portions  1056  can stretch in the longitudinal direction  1007 . Also, as a result of the auxetic nature of upper  1020 , this longitudinal stretching can cause areas of upper  1020  proximate auxetic portions  1056  to stretch in the transverse direction  1008  and/or the vertical direction  1009  as well. 
     Moreover, like the embodiments described above with respect to  FIGS.  1 - 17   , the size of auxetic portions  1056  can be adjusted in a selective manner using tensile strand  1050 . By adjusting the size of auxetic portions  1056 , the stretching characteristics of upper  1020  can be selected and varied. For example, in embodiments similar to  FIGS.  14 - 17   , manipulation of tensile strand  1050  can reduce the size of auxetic portion  1056  to reduce the range of stretching of knitted component  1030  and upper  1020 . In other embodiments similar to  FIGS.  8 - 13   , manipulation of tensile strand  1050  can increase the size of auxetic portion  1056  to increase the range of stretching of knitted component  1030  and upper  1020 . 
     It will be appreciated that knitted component  1030  can include any number of tensile strands  1050 . Also, tensile strands  1050  can be routed through any suitable area of knit element  1031 . 
     In some embodiments represented in  FIG.  18   , knitted component  1030  can include a medial tensile strand  1062 , which extends across knit element  1031  generally within medial portion  1040 . Knitted component  1030  can further include a lateral tensile strand  1064 , which extends across knit element  1031  generally within lateral portion  1038 . 
     As shown in  FIG.  18   , medial tensile strand  1062  can include a first end  1066 , a second end  1068 , and a middle section  170 . In the embodiment illustrated, medial tensile strand  1062  zigs-zags between outer peripheral edge  1036  and inner peripheral edge  1037  of medial portion  1040  as it extends generally in the longitudinal direction  1007 . Also, second end  1068  can be disposed forward of the first end  1066  in the longitudinal direction  1007 . The first end  1066  can be disposed in midfoot region  1003  while second end  1068  can be disposed proximate to forward portion  1039  of knit element  1031 . Moreover, middle section  1070  of medial tensile strand  1062  can extend continuously between first end  1066  and second end  1068 . 
     Furthermore, portions of medial tensile strand  1062  can be exposed from knit element  1031  while other portions of medial tensile strand  1062  can be enclosed, inlaid, or otherwise covered by knit element  1031 . For example, in some embodiments, first end  1066 , second end  1068 , and/or portions of middle section  1070  can be exposed from knit element  1031 . Also, portions of middle section  1070  can be enclosed, inlaid, or otherwise covered by knit element  1031 . 
     In some embodiments, middle section  1070  of medial tensile strand  1062  can define a plurality of transverse sections  1082  that extend generally in the transverse direction  1008  as shown in  FIG.  18   . Transverse sections  1082  can be inlaid within knit element  1031  in some embodiments. 
     Also, middle section  1070  can define a plurality of medial lace loops  1072 . Medial lace loops  1072  can extend between adjacent transverse sections  1082  and can be exposed from knit element  1031 . Also, medial lace loops  1072  can be disposed adjacent inner peripheral edge  1037  of medial portion  1040 . As shown in  FIGS.  19 - 21   , shoelace  1017  can be received within medial lace loops  1072  to secure shoelace  1017  to medial side  1005  of upper  1020 . 
     Furthermore, as shown in  FIG.  18   , middle section  1070  of medial tensile strand  1062  can define a plurality of outer sections  1084 . Outer sections  1084  can extend between adjacent transverse sections  1082 . In other embodiments, one or more outer sections  1084  can terminate proximate outer peripheral edge  1036 . Outer sections  1084  can extend from and can be exposed from outer peripheral edge  1036 . As represented in  FIGS.  19 - 21   , when knit element  1031  is assembled and attached to sole structure  1010 , outer sections  1084  can be attached and fixed to sole structure  1010 . 
     Accordingly, in some embodiments, medial tensile strand  1062  can provide support and/or stretch resistance to medial side  1005  of article of footwear  1000 , especially in the vertical direction  1009 . Also, medial tensile strand  1062  can attach shoelace  1017  to upper  1020 . 
     Similarly, lateral tensile strand  1064  can include a first end  1074 , a second end  1076 , and a middle section  178 . In the embodiment illustrated, lateral tensile strand  1064  zigs-zags between outer peripheral edge  1036  and inner peripheral edge  1037  of lateral portion  1038  as it extends generally in the longitudinal direction  1007 . Also, second end  1076  can be disposed forward of the first end  1074  in the longitudinal direction  1007 . The first end  1074  can be disposed in midfoot region  1003  while second end  1076  can be disposed proximate to forward portion  1039  of knit element  1031 . Moreover, middle section  1078  of lateral tensile strand  1064  can extend continuously between first end  1074  and second end  1076 . 
     Furthermore, portions of lateral tensile strand  1064  can be exposed from knit element  1031  while other portions of lateral tensile strand  1064  can be enclosed, inlaid, or otherwise covered by knit element  1031 . For example, in some embodiments, first end  1074 , second end  1076 , and/or portions of middle section  1078  can be exposed from knit element  1031 . In other words, first end  1074 , second end  1076 , and/or portions of middle section  1078  can define “exposed segments” of tensile strand  1064 . Also, portions of middle section  1078  can be enclosed, inlaid, or otherwise covered by knit element  1031 . In other words, middle section  1078  can define “inlaid segments” of tensile strand  1064 . 
     In some embodiments, middle section  1078  of lateral tensile strand  1064  can define a plurality of transverse sections  1086  that extend generally in the transverse direction  1008  as shown in  FIG.  18   . Transverse sections  1086  can be inlaid within knit element  1031  in some embodiments. 
     Also, middle section  1078  can define a plurality of lateral lace loops  1080 . Lateral lace loops  1080  can extend between adjacent transverse sections  1086  and can be exposed from knit element  1031 . Also, lateral lace loops  1080  can be disposed adjacent inner peripheral edge  1037  of lateral portion  1038 . As shown in  FIGS.  19 - 21   , shoelace  1017  can be received within lateral lace loops  1080  to secure shoelace  1017  to lateral side  1006  of upper  1020 . 
     Furthermore, as shown in  FIG.  18   , middle section  1078  of lateral tensile strand  1064  can define a plurality of outer sections  1088 . Outer sections  1088  can extend between adjacent transverse sections  1086 . In other embodiments, one or more outer sections  1088  can terminate proximate outer peripheral edge  1036 . Outer sections  1088  can extend from and can be exposed from outer peripheral edge  1036 . As represented in  FIGS.  19 - 21   , when knit element  1031  is assembled and attached to sole structure  1010 , outer sections  1088  can be attached and fixed to sole structure  1010 . 
     Accordingly, in some embodiments, lateral tensile strand  1064  can provide support and/or stretch resistance to lateral side  1006  of article of footwear  1000 , especially in the vertical direction  1009 . Also, lateral tensile strand  1064  can attach shoelace  1017  to upper  1020 . 
     In some embodiments, tensile strands  1050  can engage auxetic portions  1056 , and tensile strands  1050  can be manipulated for adjusting the size of auxetic portions  156 . For example, in some embodiments, medial tensile strand  1062  can engage medial auxetic portion  1058 , and lateral tensile strand  1064  can engage lateral auxetic portion  1060 . 
     As shown in the embodiment of  FIGS.  18 - 21   , tensile strands  1050  can engage auxetic portions  1056  similar to the embodiment of  FIGS.  14 - 17   . As such, tensile strands  1050  can engage the internal vertices of auxetic portions  1056 . However, it will be appreciated that tensile strands  1050  can engage auxetic portions  1056  similar to the embodiment of  FIGS.  8 - 13    in other embodiments. Additionally, tensile strands  1050  can engage other areas of auxetic portions  1056  without departing from the scope of the present disclosure. 
     Accordingly, by pulling or otherwise manipulating tensile strand  1050 , the user can change the size of auxetic portions  1056 . For example, with regard to knitted component of  FIG.  18   , the first end  1066  of medial tensile strand  1062  can be pulled to reduce the size of medial auxetic portion  1058  in some embodiments. Similarly, the first end  1074  of lateral tensile strand  1064  can be pulled to reduce the size of lateral auxetic portion  1060  in some embodiments. 
     In other situations where sole structure  1010  is attached, the user can pull the rearmost medial lace loop  1072  away from sole structure  1010 . This can cause medial auxetic portion  1058  to become smaller. Similarly, the user can pull the rearmost lateral lace loop  1080  away from sole structure  1010 . This can cause lateral auxetic portion  1060  to become smaller. 
     In some embodiments, article of footwear  1000  can include a securement device used for substantially maintaining the set tension in tensile strands  1050 . As a result, the set size of auxetic portions  1056  can be maintained. 
     For example, in some embodiments, shoelace  1017  can engage tensile strands  1050  for substantially maintaining the set tension in tensile strands  1050 . Generally, shoelace  1017  can have an unsecured position, wherein shoelace  1017  unsecures tensile strand  1050  relative to knit element  1031  to allow tensile strands  1050  to be manipulated for adjusting auxetic portions  1058 ,  1060 . Shoelace  1017  can also have a first secured position, represented in  FIG.  20   , wherein shoelace  1017  can maintain a first amount of tension in tensile strands  1050  for maintaining auxetic portions  1058 ,  1060  at a first size. Furthermore, shoelace  1017  can have a second secured position, represented in  FIG.  21   , wherein shoelace  1017  can maintain a second amount of tension in tensile strands  1050  for maintaining auxetic portions  1058 ,  1060  at a second size. 
     More specifically,  FIG.  20    illustrates an embodiment in which shoelace  1017  has been relatively loosely tied to the wearer&#39;s foot, thereby causing tensile strands  1050  to have relatively low tension.  FIG.  21    illustrates the embodiment with shoelace  1017  tied relatively tightly to the foot, thereby causing tensile strands  1050  to have relatively high tension. It will be appreciated that the wearer&#39;s foot is at rest and footwear  1000  is generally in a neutral position in both  FIGS.  20  and  21   . 
     Because auxetic portions  1056  are larger in size when shoelace  1017  is tied loosely, knit element  1031  and upper  1020  can have a larger range of stretching as described in detail above. In contrast, the smaller auxetic portions  1056  exhibited when shoelace  1017  is tied tightly can allow knit element  1031  and upper  1020  to have a smaller range of stretching. 
     Accordingly, in some embodiments, the user can select how much they want upper  1020  to stretch in longitudinal direction  1007 , transverse direction  1008 , and/or vertical direction  1009  in response to an input force. As such, stretching behavior of upper  1020  can be tailored to the wearer&#39;s needs and desires. 
     Article of Apparel with Adjustable Auxetic Portion 
     Referring now to  FIGS.  22  and  23   , another embodiment of the present disclosure is illustrated. As shown, an article of apparel  2001  can incorporate a knitted component  2030 . Knitted component  2030  can include one or more auxetic portions  2056 . Knitted component  2030  can also include a tensile strand  2050  configured for adjusting the size of auxetic portion  2056 . By changing tension in tensile strand  2050 , the size of auxetic portion  2056  can be selected and changed. As such, the stretching characteristics, such as the range of stretching of knit element  2031  can be selected and changed. 
     As shown in  FIGS.  22  and  23   , article of apparel  2001  can be a shirt, sweatshirt, or other article worn on the torso and/or arms. However, it will be appreciated that article of apparel  2001  can be configured for covering other areas of the body. In some embodiments, knitted component  2030  can define a majority of article of apparel  2001 . In other embodiments, knitted component  2030  can define a localized area of apparel  2001 . 
     Moreover, auxetic portion  2056  can be incorporated in any suitable area of apparel  2001 . For example, auxetic portion  2056  can be incorporated in an area of apparel  2001  proximate an anatomical joint. Thus, auxetic portion  2056  can affect stretching of apparel  2001  that occurs when the wearer flexes the joint. Also, in some embodiments, auxetic portion  2056  can be incorporated in an area that stretches due to flexure of the wearer&#39;s muscles or other movements. Specifically, as shown in the illustrated embodiment, auxetic portion  2056  can be incorporated in a sleeve  2005  in an area that is proximate the wearer&#39;s elbow. As such, auxetic portion  2056  can stretch, for example, due to flexure of the elbow joint. More specifically, apparel  2001  can stretch and elongate along a longitudinal axis  2007  of sleeve  2005  due to flexure of the elbow joint. Additionally, because of the auxetic nature of apparel  2001 , sleeve  2005  can stretch in a circumferential direction extending about longitudinal axis  2007  as a result of this stretching. As such, this circumferential stretching can effectively loosen sleeve  2005  from the wearer&#39;s arm in some embodiments. Moreover, like the embodiments discussed above, the range of stretching proximate the elbow joint can be adjusted using tensile strand  2050 . 
     As shown in  FIGS.  22  and  23   , knitted component  2030  can include a knit element  2031  and one or more tensile strands  2050 . In some embodiments, tensile strand  2050  can include a first end  2051 , a second end  2053 , and a middle section  2055  that is defined between first end  2051  and second end  2053 . 
     In some embodiments, tensile strand  2050  can extend generally along a longitudinal axis  2007  of a sleeve  2005  of apparel  2001 . Also, in some embodiments, first end  2051  can be disposed in a proximal region of sleeve  2005 , and second end  2053  can be disposed in a distal region of sleeve  2005 . 
     Tensile strand  2050  can be engaged to auxetic portion  2056  in any suitable fashion. For example, in some embodiments, tensile strand  2050  can engage auxetic portion  2056  in a manner corresponding to  FIGS.  8 - 13   . In other embodiments, tensile strand  2050  can engage auxetic portion  2056  in a manner corresponding to  FIGS.  14 - 17   . It will be appreciated that tensile strand  2050  can be engaged with auxetic portion  2056  in other ways as well without departing from the scope of the present disclosure. 
     Similar to the embodiments discussed above, the user can pull on tensile strand  2050  to change the size of auxetic portion  2056 . As a result, the stretching range of sleeve  2005  can be selected and adjusted. Thus, in some embodiments, the wearer can configure the sleeve  2005  to have a larger range of flexion when desired. The wearer can alternatively configure the sleeve  2005  to have a smaller range of flexion when desired. 
     In some embodiments, first end  2051  can be fixed to knit element  2031 . In contrast, second end  2053  can be exposed from knit element  2031  and can extend from knit element  2031 . The wearer can pull on second end  2053 , for example, to adjust auxetic portion  2056 . Assuming that auxetic portion  2056  is in the position of  FIG.  22   , for example, the wearer can pull on second end  2053  to adjust auxetic portion  2056  to the larger size position of  FIG.  23   . As a result, the user can enlarge the range of stretching of apparel  2001 . 
     Additionally, in some embodiments, apparel  2001  can include a securement device  2008 . Securement device  2008  can be used to secure tensile strand  2050  and, thus, auxetic portion  2056  at the selected size and position. Securement device  2008  can include a clamp, a tie, a spool, or other implement that detachably secures tensile strand  2050  to knit element  2031 . In the embodiment illustrated, for example, securement device  2008  is shown schematically and proximate a cuff  2009  of apparel  2001 . Securement device  2008  can detachably secure second end  2053  to cuff  2009  to maintain auxetic portion at the desired size. In additional embodiments, securement device  2008  can be a removable knot formed in tensile strand  2050 , and the knot can interfere with cuff  2009  to prevent second end  2053  from sliding into knit element  2031  when sleeve  2005  stretches. 
     It will be appreciated that apparel  2001  can also include additional tensile strands  2050  with additional auxetic portions  2056  at different areas. These auxetic portions  2056  can be individually adjusted such that the respective areas of apparel  2001  can exhibit different stretch characteristics. 
     In summary, the knitted components discussed above can include knitted auxetic portions that allow knitted component to readily stretch in multiple directions as a result of a stretching force that is applied in one of those directions. The amount or range of stretching can be affected, selected, and varied by changing the size of the auxetic portions. For example, the size of auxetic portions can be conveniently changed by manipulating and changing tension within tensile strands. Thus, the knitted component can be tailored according to the needs and desires of the user. 
     While various embodiments of the present disclosure have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the present disclosure. Accordingly, the present disclosure is not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims. Moreover, as used in the claims, “any of” when referencing the previous claims is intended to mean (i) any one claim, or (ii) any combination of two or more claims referenced.