Patent Publication Number: US-9414639-B2

Title: Dance shoes with improved heel and arch sections

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. National Stage (Section 371) of PCT/AU2011/000335, filed on Mar. 24, 2011, which claims the benefit under 35 USC 119(e) of U.S. Provisional Patent Application No. 61/317,155, filed on Mar. 24, 2010. 
    
    
     TECHNICAL FIELD 
     Described embodiments relate to a shoe that is form fitting and/or suitable to undergo a wide range of movement, particularly useful as a dance shoe, yoga shoe, pilates shoe, gymnastic shoe, martial arts shoe, rock climbing shoe or exercise shoe, but not limited to these purposes. 
     BACKGROUND 
     As dance is the most extreme example of movement articulation, it will be used as the example discipline throughout this document. Activities requiring precision in movement, particularly dance, require a wide range of general movements including running, jumping, spinning and sliding. The foot and ankle of the dancer will undergo further articulation, including pointing, flexing, turning, twisting, bending and rolling. To enable such a wide range of articulated movement, generally dance footwear is designed to be form fitting and flexible to complement the foot undergoing movement. 
     Typical footwear consists of two primary elements, an upper and a sole structure. The upper provides a covering for the foot that securely receives and positions the foot with respect to the sole structure. The sole structure is secured to a lower portion of the upper and is generally positioned between the foot and the ground. In addition to reducing friction from the ground, the sole structure, in conjunction with the upper, ideally should provide support and comfort for the bottom of the foot and the arch. 
     A dance shoe is designed to complement a dancer&#39;s wide range of movement and is therefore typically made up of lightweight, flexible materials. As the design is focused on the upper and sole structures being extremely flexible, these structures provide little support for the foot. The shoes permit the user to easily flex the ankle and arch region of the foot but to the detriment of ankle and arch support. 
     Further to this, a shoe that is allowed to bend and flex will have a side effect of creasing, bunching, puckering and sagging of the upper and outsole materials, creating an unwanted distraction from the clean lines ideally sought. Dance is a strict and regimented art form, any visual distraction from the ideal aesthetic framework will have an adverse effect on the dancers performance in general. In addition, the creasing, bunching, puckering and sagging caused by a flexible shoe can cause a dancer to feel ungainly and unsupported, further affecting their performance. 
     Some shoes that are flexible have been designed to assist in the flexing of the ankle and arch, reducing resistance when pointing the foot. While this provides ease of movement, it is not ideal when placed in the context of the dancer in training with regards to strengthening, protecting and maintaining their bodies against the rigours of physical activity. Dance is an extremely physical pursuit, with injury levels in line with high level athletes. Subsequently a regimented, disciplined training regime is necessary not only to achieve a high level of ability, but also to keep the body at a peak needed to prevent or minimise injury. The earlier this training begins the more likely the levels of success both artistically and physically. It is not uncommon for dancers to begin their training as young as 3 years old, and beginners older than 10 years are uncommon. Young dancers are taught from an early age to physically strengthen their bodies with exercises covering each and every muscle in the human body, including the feet. To build muscle strength the body needs resistance, so while it is important to encourage flexibility, it is also important to impose levels of resistance to the muscles. During dance training, it is estimated that a dancer might point and flex the foot as many times as once per second and on average once every 5 seconds. When placed in the context of a full dance class, or even a complete dance career spanning many years, the addition of a subtle controlled resistance to each foot flexion motion by way of dance footwear can have a significant longer term effect on muscle strength and stability. 
     In view of the above, there remains a need for a dance shoe that provides a balance between flexibility and controlled resistance, as well as a shoe that provides a clean unbroken cosmetic line that compliments and enhances a dancer&#39;s level of artistry, or that at least provides a useful alternative to prior dance shoes. 
     SUMMARY 
     Some embodiments relate to a split-sole dance shoe, comprising: 
     a thin flexible shoe upper defining an opening to receive a foot; 
     an outsole region to underlie a sole of the foot and in combination with the upper defining a heel section, an arch section and a forefoot section; and 
     thin flexible reinforcing structure coupled to the shoe upper and the outsole region and extending from adjacent the opening in an upper part of the heel section around a lower part of the heel section and through the arch section along a longitudinal direction of the shoe, the reinforcing structure broadening from adjacent the opening to substantially cup a lower posterior portion of the calcaneus and then narrowing toward the arch section, the reinforcing structure in the arch section being arranged to closely match flexion of the arch in pointe position without the appearance of bunching of the shoe upper in the arch section. 
     The reinforcing structure of the split-sole dance shoe may extend through the arch section but may not extend through the forefoot section. 
     Further embodiments relate to a split sole dance shoe, comprising: 
     a thin flexible shoe upper defining an opening to receive a foot; 
     an outsole region to underlie a sole of the foot and in combination with the upper defining a heel section, an arch section and a forefoot section; and 
     thin flexible reinforcing structure coupled to the shoe upper and the outsole region and extending from adjacent the opening around the sides and the bottom of the heel section and through the arch section, the flexible reinforcing structure following a longitudinal direction of the shoe and narrowing from a wide cupping coverage of the heel in the heel section as the reinforcing structure transitions between the heel section and the arch section, the reinforcing structure being flat and narrow through the arch section and not extending through the forefoot section. 
     The reinforcing structure of the split-sole dance shoe may comprise a semi-rigid material. The outsole region may have a heel outsole portion and a forefoot outsole portion, and the semi-rigid material may extend through the arch section and terminate adjacent the forefoot outsole portion. The semi-rigid material may broaden slightly as it transitions from the arch section to the forefoot section and may have a slightly narrowing or substantially constant width as it extends across the arch section. 
     The split-sole dance shoe may further comprise a backstrap affixed to the shoe upper and may extend along a longitudinal center-line of the shoe from the upper part of the heel section to the forefoot section. The backstrap may coincide with a central longitudinal seam extending through the outsole to the forefoot section. 
     The split-sole dance shoe may further comprise an elastic panel which may extend from adjacent the opening on one lateral side of the shoe down through the outsole region and around up to adjacent the opening on an opposite lateral side of the shoe. The elastic panel may be free of covering fabric and may interrupt the shoe upper and the outsole. The elastic panel may further allow the shoe to accommodate feet of longer lengths than would be accommodated without the elastic panel. 
     The elastic panel may be widest where it extends through the outsole region and thinnest adjacent the opening on each lateral side of the shoe, and in some embodiments may be positioned so that it extends through the outsole region at or adjacent a transition from the heel section to the arch section. The elastic panel may be angled toward the upper part of the heel section on each lateral side of the shoe and in alternative embodiments may be positioned so that it extends through the outsole region at or adjacent a transition from the arch section to the forefoot section. The elastic panel may be curved in a rearward sweep as it extends through each lateral side of the shoe. 
     The reinforcing structure of the split-sole dance shoe may have a thickness of about 2 mm to about 4 mm and may comprise a foam material. The foam material of the split-sole dance shoe may be or comprise ethylene vinyl acetate (EVA) foam, for example. The reinforcing structure may have a density of about 30 kg/m 3  to about 120 kg/m 3 . 
     The foam material may consist essentially of EVA foam and rubber. The foam material may comprise about 40% to 60% by weight of EVA foam, about 40% to 60% by weight of rubber and 0% to 20% of other material. The rubber may be synthetic rubber. The reinforcing structure may be free of material other than the foam material. Alternatively, the reinforcing structure may further comprise a thin flexible board material. 
     The reinforcing structure of the split-sole dance shoe may comprise a material selected from the group consisting of: non-woven bonded synthetic fibrous materials; counter materials; fiber boards; sponge rubber; natural rubber; neoprene; styrene-butadiene rubber (SBR); butyl rubber; silicone rubber; nitrile rubber; urethane rubber; polyurethane foam; cork; cellulosic materials; ethylene vinyl acetate (EVA) foam; polyethylene foam; cross-linked polyethylene foam; high density micro-cellular foam; and closed cell polyvinyl chloride foam. 
     A material of the upper of the split-sole dance shoe may comprise one or more of: leather; polyurethane (PU) leather; canvas; suede; cotton; nylon; Lycra; mesh and spandex. 
     Further embodiments relate to a full-sole ballet shoe, comprising: 
     a thin flexible shoe upper defining an opening to receive a foot; 
     a full outsole coupled to the shoe upper to underlie a sole of the foot and in combination with the upper defining a heel section, an arch section and a forefoot section; and 
     thin flexible reinforcing structure coupled to the shoe upper and the outsole and extending from adjacent the opening in an upper part of the heel section around a lower part of the heel section to the arch section along a longitudinal direction of the shoe, the reinforcing structure broadening from adjacent the opening to substantially cup a lower posterior portion of the calcaneus and then narrowing toward the arch section. 
     Some embodiments relate to a split-sole dance shoe, comprising: 
     a thin flexible shoe upper defining an opening to receive a foot; 
     an outsole region to underlie a sole of the foot and in combination with the upper defining a heel section, an arch section and a forefoot section, 
     first thin flexible reinforcing structure extending within the shoe across the arch section and forming part of an insert attached to the inside of the outsole; 
     second thin flexible reinforcing structure attached to the heel section and extending from adjacent the opening, around the sides and bottom of the heel section and toward the arch section. 
     The second thin flexible reinforcing structure may not extend through the arch section. 
     The first and second thin flexible reinforcing structures may consist of a foam material. The foam material may comprise EVA foam. The foam material may comprise a blen of EVA foam and rubber. 
     The split-sole dance shoe may further comprise a heel counter attached in the heel section, wherein the shoe upper and at least part of the outsole may comprise suede and wherein the second thin flexible reinforcing structure may be attached to the suede and the heel counter. 
     The insert may comprise a heel portion to underlie the heel and a forefoot portion to underlie the forefoot, with the first thin flexible reinforcing structure coupled to the heel portion at one end of the first thin flexible reinforcing structure and to the forefoot portion at an opposite end. These embodiments may apply to a jazz shoe, to a ballet shoe with an elastic panel intermediate the arch section and the heel section or to a ballet shoe having an extra board material extending through the arch section, for example. 
     In the following description, some specific embodiments are directed to a ballet shoe, while other embodiments encompass jazz shoes, tap shoes, dance sneakers and modern dance shoes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  shows a standard split sole ballet slipper in pointe position from side view; 
         FIG. 1B  shows a standard split sole ballet slipper in pointe position from ¾ back view; 
         FIG. 2A  shows a split sole ballet slipper of some embodiments in pointe position from side view; 
         FIG. 2B  shows the split sole ballet slipper of  FIG. 2A  in pointe position from ¾ back view; 
         FIG. 2C  shows the split sole ballet shoe of  FIG. 2A  with the dancer standing flat; 
         FIG. 2D  is a side view of a split sole ballet slipper of  FIG. 2A  with a semi-rigid material starting at the rear heel and finishing uninterrupted at the front outsole; 
         FIG. 2E  shows a bottom view of the split sole ballet slipper of  FIG. 2A ; 
         FIG. 2F  shows a top view of the split sole ballet slipper of  FIG. 2A ; 
         FIG. 3  shows a split sole ballet shoe of some embodiments in pointe position; 
         FIG. 4A  shows a side view of a split sole ballet shoe according to some embodiments, with the dancer standing flat; 
         FIG. 4B  shows the split sole ballet shoe of  FIG. 4A  in pointe position; 
         FIG. 4C  shows a side view of the split sole ballet slipper of  FIG. 4A  with the semi-rigid material starting at the rear heel and finishing at a forward stretch panel; 
         FIG. 4D  shows a bottom view of the split sole ballet slipper of  FIG. 4A ; 
         FIG. 4E  shows a top view of the split sole ballet slipper of  FIG. 4A ; 
         FIG. 4F  is an exploded diagram of the ballet shoe of  FIG. 4A ; 
         FIGS. 5A, 5B and 5C  illustrate steps of a construction process involving application of a semi-rigid material to a ballet shoe; 
         FIG. 6A  shows a side view of the split sole ballet shoe according to further embodiments, with the dancer standing flat; 
         FIG. 6B  shows a side view of the split sole ballet shoe of  FIG. 6A  in pointe position; 
         FIG. 6C  shows a side view of the split sole ballet slipper of  FIG. 6A ; 
         FIG. 6D  shows a bottom view of the split sole ballet slipper of  FIG. 6A ; 
         FIG. 6E  shows a top view of the split sole ballet slipper of  FIG. 6A ; 
         FIG. 7A  shows a side view of a split sole jazz shoe of some embodiments; 
         FIG. 7B  shows a bottom perspective view of the split sole jazz shoe of  FIG. 7A ; 
         FIG. 7C  shows a top view of the split sole jazz shoe of  FIG. 7A ; 
         FIG. 7D  shows a bottom view of the split sole jazz shoe of  FIG. 7A ; 
         FIG. 8A  shows a side view of the split sole jazz shoe according to further embodiments; 
         FIG. 8B  shows a bottom perspective view of the split sole jazz shoe of  FIG. 8A ; 
         FIG. 8C  shows a top view of the split sole jazz shoe of  FIG. 8A ; 
         FIG. 8D  shows a bottom view of the split sole jazz shoe of  FIG. 8A ; 
         FIG. 9A  shows a side view of the split sole jazz shoe according to some embodiments; 
         FIG. 9B  shows a bottom perspective view of the split sole jazz shoe of  FIG. 9A ; 
         FIG. 9C  shows a top view of the split sole jazz shoe of  FIG. 9A ; 
         FIG. 9D  shows a bottom view of the split sole jazz shoe of  FIG. 9A ; 
         FIG. 10A  is a side view of a full sole ballet slipper according to some embodiments; 
         FIG. 10B  is a bottom view of the full sole ballet slipper of  FIG. 10A ; 
         FIG. 10C  is a top view of the full sole ballet slipper of  FIG. 10A ; 
         FIG. 11A  is a bottom view of a split sole ballet shoe according to further embodiments; 
         FIG. 11B  is a top view of the split sole ballet shoe of  FIG. 11A ; 
         FIG. 11C  is a rear perspective view of the split sole ballet shoe of  FIG. 11A , shown in pointe position; 
         FIG. 11D  is an exploded perspective view of the split sole ballet shoe of  FIG. 11A , showing component parts thereof; 
         FIG. 12A  is a side view of a ballet shoe according to further embodiments, showing modified strap positioning; 
         FIG. 12B  is a plan view of the ballet shoe of  FIG. 12A ; 
         FIG. 13A  is an exploded perspective view of a jazz shoe according to further embodiments; 
         FIG. 13B  is a bottom perspective view of the jazz shoe of  FIG. 13A ; and 
         FIG. 13C  is a bottom view of the jazz shoe of  FIG. 13A . 
     
    
    
     DETAILED DESCRIPTION 
     In the description and drawings, like reference numerals and different reference numerals having the same last two digits are used to indicate like or analogous functions and/or features as between the embodiments. For example, the last two digits “10” are consistently used to refer to a heel section in each of the embodiments. 
     Described embodiments relate to a shoe that is form fitting and/or suitable to undergo a wide range of movement, particularly useful as a dance shoe, yoga shoe, pilates shoe, gymnastic shoe, martial arts shoe, rock climbing shoe or exercise shoe, but not limited to these purposes. As dance is the most extreme example of movement articulation, dance is used as the example movement discipline throughout this document. 
     Described embodiments generally relate to shoes or slippers suitable for use while dancing and particular illustrated embodiments are suitable for use as ballet or jazz dancing shoes. Features and functions of the described embodiments, and in particular the described flexible reinforcing structures, are also applicable to dance sneakers, tap shoes, modern dance shoes and other exercise-specific shoes. Described embodiments may improve the aesthetic appearance of a shoe undergoing movement due to foot and ankle flexion, may provide increased support for the foot undergoing movement and may offer beneficial or therapeutic resistance to the person performing the activity. 
     The embodiments described below depart from prior approaches by introducing a semi-rigid but still flexible reinforcing structure to heel and arch components of split sole shoes. When the foot is articulated, described embodiments allow a full range of motion required by a dancer and introduce a semi-rigid reinforcing material that can move with the foot, and ensure that the soft materials that make up the shoe remain smooth, and are displaced evenly, thereby eliminating or substantially reducing the appearance of any creasing, bunching, puckering and/or sagging of materials. This flexible reinforcing structure results in an unbroken formation along the line of the foot when the foot is in motion. In some cases, depending on the type of dance shoe in question, embodiments may also involve stretch panels that perform the function of reducing the visual effect of relative longitudinal movement between a foot as it flexes and the shoe materials to assist the appearance of a smooth unbroken line. This is particularly noticeable in thin, light dance shoes, such as jazz shoes and ballet shoes. 
     Described embodiments also increase the levels of support for the foot and ankle by applying the semi-rigid material to areas of the shoe that are expected to support the foot, like the heel, arch and outsole areas. This creates a flexible connection between the heel of the shoe, the outsoles of the shoe and the arch of the shoe, offering more structure and body to the shoe and subsequently more support. This same semi-rigid material, by way of the thin flexible connection between the heel, outsoles and arch of the shoe, also offers controlled resistance to the muscles of the foot when performing a flex or point motion. This controlled resistance encourages increased muscle strength over time. The application of the flexible reinforcing structure around the heel and arch sections may also improve the comfort level of dance shoes, which can increase the dancer&#39;s confidence or sense of ease during movement. 
     Described embodiments of a dance shoe comprise an outsole region coupled to, or at least partially integrally formed with, a shoe upper, including a toe or forefoot region, a heel region, a foot opening at the heel region and an arch region extending between the forefoot region and the heel region. The outsole region includes ground-engaging surfaces of the shoe, for example such as heel and forefoot outsole portions or a full outsole piece. The shoe upper may be made of a suitable flexible, durable material, for example such as leather, polyurethane (PU) leather, canvas, suede, cotton, nylon, Lycra, spandex and mesh materials (for example, polyester mesh, nylon mesh, spandex mesh, cotton mesh). The shoe can contain a single outsole combination, commonly referred to as a “full sole”, or multiple outsole constructions, commonly referred to as a “split sole”. Outsole combinations can be made of materials such as suede, leather, PU, thermoplastic rubber (TPR), vulcanised rubber, EVA foam or other shock absorbing materials. Outsoles can be made up of combinations of these materials in either single or multiple layers. 
     Embodiments contain at least one piece of semi-rigid material that has qualities that provide a flexible reinforcing structure to an otherwise soft and flexible shoe. The shoe materials must also be able to bend and flex with the motion of the foot, striking a balance between structure and flexibility. One material example that can achieve this, that is contained in some embodiments, is Ethylene Vinyl Acetate (EVA) foam. EVA foam is available in a wide range of grades, differing in thickness and density. To obtain the desired effect, a balance between these variables is needed. 
     To maintain a sleek finish with minimal disruption inside the shoe, a thickness of the semi-rigid material ranging from about 2 mm to about 4 mm is considered to be suitable. The thickness required is determined by the type of shoe being constructed. For example, a ballet shoe with a delicate soft construction may require thin 2 mm foam. As the shoe design becomes naturally more structured, thicker EVA foam may be required. For example, a jazz shoe may use 3 mm EVA foam and a tap shoe or dance sneaker may use 4 mm EVA foam. 
     To obtain the desired effect, a certain density or range of densities of the semi-rigid material is required to strike the optimal balance between flexibility, support and comfort. At the EVA foam thicknesses specified above (2 mm-4 mm), a density of around 30 kg/m 3  to around 60 kg/m 3  is considered to be suitable to give the desired effect. Some variation of thicknesses and density of EVA foams can also result in acceptable results. For example, the density can rise into the 75 to 105 kg/m 3  range or even up to 120 kg/m 3 , if the EVA foam is kept thin (e.g. 2-3 mm). In some embodiments, the foam material may comprise EVA blended or otherwise combined with a rubber material, such as a synthetic rubber material. 
     Other material examples that can achieve acceptable results as a flexible reinforcing material include other foam variants, for example such as (but without limitation) Polyurethane Foam, Polyethylene Foam, Cross-Linked Polyethylene Foam, High Density Micro Cellular Foam and closed cell PVC Foam. Such materials in different thicknesses and grades of density provide a wide range of options for implementing described embodiments. Foam has excellent buoyancy properties and provides a good balance between structure, flexibility and resistance. Foam also offers cushioning properties, further enhancing the comfort levels for the wearer. Other flexible reinforcing materials that can be employed in embodiments include, but are not limited to: felts, non-woven bonded synthetic fibres, counter materials and fibre boards, Sponge Rubber, Rubber (Natural, Neoprene, SBR, Butyl, nitrite or Buna N, Silicone, and Urethane), Cork, Flocked Fabrics and Paper (or other cellulose-based materials). Also upper materials such as leather, polyurethane (PU) leather, canvas, suede, cotton, nylon, Lycra, spandex and mesh are suitable, particularly when the semi-rigid material structure is located on the outside of the shoe. 
     In some embodiments, the semi-rigid material is attached to the shoe upper using a stitch and/or adhesive. The stitch or adhesive attaches the semi-rigid material starting at the top of the heel section, extending down and forward along a line through the side or back quarter of the shoe and extending into and through the arch section. The stitch and/or adhesive connect the semi-rigid material to both the upper and its linings or just its linings or upper. The heel back strap follows a longitudinal direction, such as along a centre-line of the shoe from the top of the heel section and around into the arch section. The semi-rigid material continues through the arch and joins the front outsole, completing the connection. The reinforcing structure of the semi-rigid material connects the heel section, rear outsole and arch sections in a semi-rigid, but flexible support structure. 
     In such embodiments, when the foot is in motion, bending and flexing, excess shoe material arising from foot flexion will travel to the ends of the shoe forward and backward, leaving a clean line under the arch and around the heel. The presence of a semi-rigid material encasing the heel and extending through the arch, all joined as one piece, increases support levels for the foot and ankle, and offers controlled resistance. 
     In some embodiments, the semi-rigid material extends around the heel and through the arch and ends at a flexible front stretch panel positioned around where the arch transitions into the forefoot. A back strap material is also attached from the heel section through into the arch section. The stretch panel serves to dissipate bunching or sagging of the material when the foot is in motion, bending and flexing. Rather than the foot flexion causing the shoe material to travel forwards and backwards to the heel and toe sections as mentioned above, the travel of the material is absorbed through the stretch panel, leaving a clean line under the arch and around the heel. The stretch panel also acts as a size leeway, allowing the wearer a more custom fit. 
     In some embodiments, the semi-rigid material is attached to the shoe upper using a stitch and/or adhesive, starting around the forefoot section of the shoe and extending along a line through the arch section. This stitch and/or adhesive connect the semi-rigid material to both the upper and its linings or just its linings or upper. A back strap material is also attached through into the arch section. This connects the front outsole section and arch section in a semi-rigid, but flexible support structure. The material continues posteriorly through the arch and ends at a flexible rear stretch panel positioned around where the arch transitions into the heel. The stretch panel serves to mitigate against bunching or sagging of the material when the foot is in motion, bending and flexing. Rather than the foot flexion causing the shoe material to seem to travel forwards and backwards to the heel and toe sections as mentioned above, the travel of the shoe material is absorbed through the stretch panel, leaving a clean line under the arch. The stretch panel also acts as a size leeway, allowing the wearer a more custom fit. The semi-rigid material encasing the heel is still present in such embodiments, but is separated from the front semi-rigid material by the back stretch panel. The rear section of semi-rigid material serves to increase support for the heel and ankle and ensure a clean smooth material line around the heel. These areas will increase support levels for the foot and ankle, and offer controlled resistance. 
     In summary, embodiments may employ the semi-rigid material as a reinforcing structure in one of three ways:
         1. The semi-rigid material starting from the heel section and extending uninterrupted until it terminates at the front outsole (forefoot) section;   2. The semi-rigid material starting from the heel section and extending until it reaches a forward located stretch panel; and   3. A divided or interrupted semi-rigid material having a portion of semi-rigid material starting from the front outsole (forefoot) section and extending rearward until it reaches a rear located stretch panel, with a further portion of semi-rigid material at least partially cupping the heel (calcaneus) in the heel section.       

       FIG. 1A  and  FIG. 1B  show a standard split sole canvas ballet slipper  100  in pointe position. When the foot is in pointe position (contracted) it is up to 20% shorter (in a straight line from heel to toe) than when standing flat in a neutral position. The muscles contract and the metatarsals compact, creating an overall shortening of the foot. For the canvas ballet slipper, the canvas material contracts with the foot and subsequently wrinkles, buckles and sags, creating an undesirable look. 
       FIGS. 2A, 2B  and  FIG. 2C  illustrate a ballet shoe in the form of a slipper  200  according to some embodiments. Slipper  200  has a heel section  210 , an arch section  240  and a forefoot section  270 . The shoe shown in  FIGS. 2A and 2B  is a split sole ballet slipper in pointe position with a semi-rigid material  220  applied as a reinforcing structure through the heel and arch sections  210 ,  240 . In the illustrated embodiments, the semi-rigid material  220  is stitched inside the shoe  200 , progressing from an upper heel portion  222  of the heel section  210  and travelling down through a mid-heel portion  224 , around a lower heel portion  226  through the heel outsole portion  212  and along a longitudinal direction, such as a centre-line, of the arch section  240 . The heel back strap  232  also continues into the arch section  240  underneath the heel outsole portion  212 . These components combine to give the shoe more body with a smooth finish, and prevent the canvas from wrinkling. As in  FIGS. 1A and 1B , the shoe material may move relative to the foot when foot flexion occurs and this is apparent from the creation of a small void of space between the foot and the ends of the shoe in the heel section  210  and toe area of the forefoot section  270  when the foot flexes to pointe position. 
       FIG. 2C  shows the split sole ballet shoe  200  with the dancer standing flat. In this position, the foot is at its longest and standard dance shoes fit the foot cleanly. 
       FIGS. 2A and 2B  show the split sole ballet shoe  200  in pointe position. In this position the foot muscles are contracted. The bones have compressed and the foot is up to 20% shorter. This diagram shows how the semi-rigid material  220  and the stitch  208  connecting it to the body of the shoe  200 , extend from the heel section  210  through the rear outsole  212  and into the arch section  240 , connecting to the forefoot outsole portion  272  of forefoot section  270 . A “cup” shape formed by the reinforcing structure in the heel section  210  and the flexible arch section  240  maintain a relatively rigid smooth clean line, with minimal wrinkling, bunching or puckering of fabric. 
       FIGS. 2D, 2E and 2F  further illustrate the split sole ballet slipper  200  shown in  FIGS. 2A to 2C , showing a side view, bottom view and top view, respectively. The presence of the semi-rigid material is shown as a grey striped area and labelled  220 , although in the illustrated embodiments it is not visible without looking inside the shoe.  FIGS. 2D and 2F  show an elastic strap attachment  204  that helps to keep the shoe connected to the foot. Such elastic straps  204  can be made up of two parts in an “X shape” arrangement as shown in the diagram or a single strap. The two part “X-shape” arrangement has been chosen for this embodiment as it maximises the connection between the heel portion of the shoe  210 , the arch portion of the shoe  240  and the forefoot portion of the shoe  270 . The “X-shape” maintains 4 contact points with the shoe, connecting the medial heel portion with the lateral forefoot section and the lateral heel section with the medial forefoot portion. In addition to assisting to reduce the effects of wrinkling and bunching of materials, this completes the support network connection, linking all portions of the shoe upper  201  with each other across the top of the foot. In other forms of footwear, laces can be used in addition to or as a replacement for straps  204 . 
     In some embodiments, for example as shown in  FIG. 10A , only a single strap  204  may be provided, extending across the foot opening defined by the shoe upper  201  and coupling to the shoe upper  201  adjacent its upper edge. Such a single strap  204  may be positioned to generally coincide with the arch section  240  or with a transition region between the arch section  240  and the heel section  210 . 
     A binding  202  extends around an upper rim of shoe upper  201  of slipper  200  to define the opening through which the foot is received in the top of slipper  200 . The binding  202  can be made up of a cotton non-stretch material with cotton drawstring, a cotton non-stretch material with elastic drawstring or an elastic binding with no drawstring. Binding  202  may be stitched, glued or otherwise affixed to the upper  201  and optionally also to the upper heel portion  222  of the semi-rigid material  220 . 
     Reference numeral  201  indicates the upper of the shoe  200 . The upper  201  may be formed as one piece stitched together through the heel and outsole or more than one piece of material. If the upper  201  is formed of one piece of material, then it extends around under portions of the heel, arch and forefoot sections to form part of the outsole. This may also be the case where the upper  201  is made up of more than one piece of fabric. The upper  201  can be made up of numerous stretch and non-stretch materials such as canvas, leather, PU, lycra, mesh, neoprene, mesh etc. Reference numeral  208  indicates the stitch line that connects the semi-rigid material  220  to the upper  201  and lining  203 . The stitch line  208  defines (and runs just inside) the edge of the semi-rigid material  220  and connects it to the upper  201  of the shoe  200 . This connection can alternatively be achieved with glue or a combination of glue and stitching. 
     The semi-rigid material  220  may be formed from a single piece of material. If two pieces of material are used to make up the semi-rigid material  220 , they may be longitudinally joined to form a line of symmetry along the join (as in  FIGS. 5A-5C ). In some embodiments, different pieces and types of material, having different material characteristics, may be used to form the semi-rigid material  220  through the heel section  210  and the arch section  240 . 
     The connection created by combining the semi-rigid material  220  to the body of the shoe  200  is significant as it is responsible for creating the semi-rigid but flexible reinforcing structure between the heel section  210  of the shoe  200 , the outsoles  212 ,  272  of the shoe  200  and the arch section  240  of the shoe  200 . For light ballet slippers in particular, it is what gives the shoe  200  its body and what allows the shoe material to maintain its shape and clean lines during movement. It also allows the shoe  200  to offer more support to the dancer&#39;s foot and ankle, maintaining a semi-rigid body of material against the foot and in turn offering controlled resistance for muscle activity. The shape and positioning of the semi-rigid material  220  is also significant to achieving the desired structural and aesthetic effects. 
     Starting at the binding  202  at the top of the heel section  210 , the semi-rigid material  220  covers part of the back of the heel but is wide enough to start forming a slight curve as it extends down around the Achilles tendon and/or ankle bone. The semi-rigid material  220  continues down towards the sole of the heel, getting wider as it travels, forming a cup shape as it wraps itself around a lower posterior part of the heel bone (calcaneus). This transition from Achilles to sole and the corresponding gradual width increase in the semi-rigid material  220  is intended to serve as a gradual increase in the rigidity of the heel section  210  as it approaches the sole of the foot. The rigidity level is selected to provide flexibility, softness and ease of movement without compromising on support and resistance. If the semi-rigid material  220  maintained the same width through into the sole of the heel section  210  and did not become wider, the increased support around the heel would be lost, the resistance would be low and the ability of the semi-rigid material  220  to reduce wrinkles on and around the heel would be reduced. 
     As the semi-rigid material  220  approaches the arch section  240 , the shape changes to roughly mimic the transitional contours of the arch. This requires a narrowing of the semi-rigid material  220  at the heel-arch transitional portion  227  and it is necessary to avoid excessive reinforcing material in the arch region  240 . This narrowing means that the semi-rigid material  220  changes from a cup shape around the heel section  210  into a flat strip  228  as it progresses from the mid and lower heel portions  224 ,  226  into the arch section  240  to allow the foot to bend naturally. However, the semi-rigid material  220  should stay wide enough in the arch section  240  to offer support and controlled resistance. If the semi-rigid material  220  is too wide in the arch section  240 , it would maintain the “cup” shape as seen in the heel section, and this would reduce flexibility through the arch. In some ballet slipper embodiments, the lateral width of the lower heel portion  226  of the semi-rigid material  220  may be between around 1.8 and 3 times the lateral width of the narrow strip portion  228  through the arch section  240 . 
       FIG. 2E  shows the back strap stitch  234  that connects the back strap  232  to the upper  201  and semi-rigid material  220 . The backstrap  232  may be made from the same material as the upper  201  or it can be made of other stretch or non-stretch materials, woven or non-woven material types, including binding material.  FIGS. 2B and 2E  shows how the backstrap  232  continues through from the top of the heel section  210  and into the arch section  240 , ending at forefoot outsole portion  272 . The backstrap  232  is an optional part of the shoe  200 . Reference numeral  229  indicates the arch-forefoot transitional portion of the semi-rigid material  220 . The semi-rigid material  220  begins to broaden to about 1.5 to 3 times its width in the arch section  240  as it approaches the front outsole  272 . This smoothes the transition from one semi-rigid material into another to reduce wrinkling, puckering and bunching of surrounding materials. However, in some embodiments, the semi-rigid material  220  maintains a substantially constant width through the arch-forefoot transitional portion. 
     The outsole of slipper  200  has heel and forefoot outsole parts  212 ,  272 . In some illustrated diagrams, the outsole is a “split outsole” in two parts and may be made up of suede. However, other embodiments may employ a full sole, such as the embodiments illustrated in  FIGS. 10A to 10C . In full sole ballet slipper embodiments, the outsole replaces much of the task performed by the semi-rigid material  220  in the arch section  240 , but its connection to the semi-rigid material in the heel section  210  (and role as part of the reinforcing structure) is still significant. The heel and forefoot outsole portions  212 ,  272  are stitched in place with stitches  214 ,  274 , respectively, connecting them to the upper  201  and semi-rigid material  220 . A toe area of the forefoot section  270  may have a pleating arrangement which shapes the material of upper  201  around the toes. 
     As with the upper  201 , the lining  203  can be made up of different stretch and non-stretch materials, such as canvas, leather, PU, Lycra, mesh, neoprene, cotton, for example.  FIG. 2F  shows the semi-rigid material  220  sitting on top of the lining  203 , but it can alternatively be placed underneath the lining  203 , in between the lining  203  and the upper  201 , concealing the semi-rigid material  220 , or the semi-rigid material  220  can be placed on the outside of the upper  201  in full view. Lining  203  can be made up of numerous materials like canvas, leather, PU, Lycra, mesh, neoprene, cotton as well as buoyant materials such as foams and its variants and rubbers and its variants. Lining  203  may be quite light and thin, with a soft feel to it. 
     The semi-rigid material  220  (and all equivalents described herein) may be formed of various different materials. Some particular embodiments comprise EVA foam. Such materials may further comprise rubber, such as natural rubber or a synthetic rubber (although synthetic rubber is preferred), in combination with the EVA foam. The EVA foam and rubber may be provided in roughly equal proportions or the material may consist of 40% to 60% EVA, 40% to 60% rubber and 0% to 20% other materials. In some embodiments, different proportions of EVA and rubber may be employed, with ranges of one of those components extending up to say 80% or 90%, with the remainder comprising the other component or other materials. In some embodiments, EVA foam may be used without any rubber. 
     The shape of heel and forefoot insole portions  207 ,  213  would normally match the general shape of the outsole. A stitch  215  or adhesive attaches the rear insole portion  207  to one or more of the upper  201 , lining  203  and semi-rigid material  220 . A similar stitch (not shown) or adhesive attaches the forefoot insole portion  213  to the upper  201  and/or lining  203  and optionally the forefoot outsole portion  272 . 
       FIG. 3  illustrates an embodiment of a split sole ballet slipper  300 . The features of slipper  300  are the same as slipper  200  described above, except that the cup shape formed by the semi-rigid material  320  is larger. The purpose of this illustration is to show how in some embodiments the semi-rigid material  320  can be larger around the heel than is outlined in  FIGS. 2A to 2F . In embodiments of slipper  300 , the semi-rigid material  320  forms a substantially larger cup around the heel of the foot starting at the upper heel portion  322  before it passes into the arch section. In such embodiments, the lateral width of the lower heel portion  326  of the semi-rigid material  320  may be between about 3 and about 8 times the lateral width of the narrow strip portion  328  through the arch section  340 . 
     The design of  FIG. 3  produces excellent results with regards to minimising creasing or bunching of materials around the heel and, provided the heel-arch transitional portion  327  is still appropriately positioned in line with the transitional contours of the heel into the arch, offers a beneficial amount of resistance to pointing and flexing of the foot in motion. The stitch  308  connecting the semi-rigid material  320  to the upper of the shoe is present, as is the optional backstrap  332 . 
       FIGS. 4A, 4B, 4C, 4D and 4E  illustrate embodiments of a split sole ballet slipper  400 . The features of slipper  400  are the same as slipper  200  described above, except that it has a forward-located stretch panel  481  interrupting the upper  401  and outsole. The presence of a semi-rigid material  420  is shown as a grey striped area. In such embodiments, the semi-rigid material  420  is attached to the shoe upper  401  using a stitch  408  and/or adhesive, starting at the heel section  410  and extending along a line through the side or back quarter of the shoe  400 , creating a heel “cup” and into the arch section  440 . The semi-rigid material narrows as it passes through the heel-arch transitional portion  427  and forms a flat strip  428 . Stitching  408 ,  414  and  434  connects the heel section  410 , rear outsole  412  and arch section  440  in a semi-rigid, but flexible support structure. The semi-rigid material  420  continues through the arch section  440  and ends at the flexible front stretch panel  481 . 
       FIG. 4D  shows the back strap stitch  434  that connects the back strap  432  to the upper  401  and semi-rigid material  420 . The backstrap  432  may be made from the same material as the upper  401  or it can be made of other stretch or non-stretch materials, woven or non-woven material types, including binding material. The backstrap  432  continues through from the top of the heel section  410  and into the arch section  440 , ending at the flexible front stretch panel  481 . 
     The stretch panel  481  is free of any coverings or other materials overlying it and can be made of a variety of stretch materials, for example such as Lycra, mesh, neoprene, stretch leather, stretch canvas, spandex, stretch PU etc. The purpose of the stretch panel is to dissipate bunching or travel of the shoe material relative to the foot when the foot is in motion, bending and flexing. Rather than the shoe material travelling (relative to the foot) forwards and backwards to the heel and toe sections, the change in length of the foot is compensated for by expansion or retraction of the stretch panel. 
     When a dancer is standing flat in a neutral position, the stretch panel  481  is longitudinally expanded (see  FIG. 4A ). When the dancer&#39;s foot is in pointe position (see  FIG. 4B ), the stretch panel  481  contracts in the manner illustrated by arrows  484 . The stretch panel  481  also acts as a size leeway, allowing the wearer a more custom fit. The presence of a semi-rigid material  420  encasing or “cupping” the heel and surrounding the arch, all joined as one piece, increases support levels for the foot and ankle, and offers controlled resistance. 
     The stretch panel  481  is shaped and located so as to be widest where it underlies the foot and effectively forms part of the outsole in a transition region between the arch section  440  and the forefoot section  470 . Stretch panel  481  extends around and up from the outsole region on each lateral side of the slipper  400 , narrowing in width and curving in a rearward sweep until it terminates at the binding  402 . As the greatest amount of expansion or contraction of the stretch panel occurs in the outsole region, the stretch panel  481  can be narrower and afford less expansion/contraction as it extends toward the binding  402 . Stretch panel  481  is stitched to adjacent parts of upper  401  and outsole portions, including the forward-most extent of semi-rigid material  420  (at arch portion  428 ) and optionally also backstrap  432 . 
     The shape of stretch panel  481  is such that, if flattened, it resembles a “W”. This is because stretch panel  481  is arc-shaped in a central area where it forms part of the outsole, providing a concave shape toward the forefoot section  470  (and a convex shape toward the arch and heel sections  440 ,  410 ), with the lateral wings of stretch panel  481  curving back toward the heel section  410 . As the stretch panel  481  travels towards the binding  402  of the shoe, it continues to curve in an arc-shape fashion along the side panel of the shoe. This shape is designed to match the contours of the side of the foot and to visually compliment design curves found throughout the shoe. 
       FIG. 4F  is an exploded view of the shoe  400 , illustrating layers and components. Elastic strap attachments  404  help to keep the shoe  400  on the wearer&#39;s foot. The elastic straps  404  can be made up of two parts in an “X shape” arrangement as shown in the diagram or alternatively as a single strap. The elastic straps  404  are attached to the upper  401 , lining  403  and binding  402 . The binding  402  is sewn to the upper  401  and lining  403  and the semi-rigid material  420  at its upper heal portion  422 . The rear insole  413  and lining  403  are sewn or adhered to the semi-rigid material  420  by stitching  414 ,  408 . The front insole  407  is sewn to the lining  403  by stitching  474  or may be adhered thereto. 
     The semi-rigid material  420  is attached to the upper  401  and lining  403 . The semi-rigid material  420  can be attached on the inside of the shoe, on top of the lining  403  as shown in  FIG. 4F  or in between the lining  403  and the upper  401 . The semi-rigid material  420  can alternatively be attached on the outside of the shoe, outside of the upper  401  in full view. The stretch panel  481  is sewn to the upper  401  and lining  403  by stitching  482 . The lining  403  is layered into the upper  401 . The backstrap  432  is attached to the upper  401  and the sole of shoe  400  by stitching  434 . The rear outsole portion  412  and front outsole portion  472  are stitched to the upper  401  by stitching  414  and  474  respectively. 
     The layers and components and their attachments (e.g. by stitching) for slippers  200 ,  300  and  600  ( FIGS. 6A to 6E ) are the same or similar to those shown and described above in relation to slipper  400 , except for the presence and location of stretch panel  481 . 
       FIGS. 5A, 5B and 5C  schematically illustrate steps of part of a shoe construction process of slipper  400  (as one example) including the application of the semi-rigid material of some embodiments. Similar principles of construction apply to the different embodiments described herein. The first step is shown in  FIG. 5A  and involves attaching the semi-rigid material  520  to back quarter panels  501  of the shoe upper and linings. This is done by either gluing or stitching  508  the semi-rigid material  520  to the lining/upper  501 , or a combination of gluing and stitching. The two panels  501  of back quarter upper and lining, plus the semi-rigid material  520  are then arranged one on top of the other, as shown in  FIG. 5B . The two panel halves  501  are then secured together with one stitch line  590 . The two halves  501  are then opened and secured by a second centre stitch  534  on the inside of the shoe and on the outside of the shoe with a backstrap  532 , as shown in  FIG. 5C . This process combines the semi-rigid material with the other shoe components to achieve a balance between rigid support and flexibility. It also gives the heel section a cupped shape that generally follows the contours of a dancer&#39;s heel without the need for moulds. The cupping of the heel by the semi-rigid material is achieved by providing curvature in both lateral and longitudinal directions around the back, bottom and sides of the heel. 
       FIGS. 6A, 6B, 6C, 6D and 6E  illustrate embodiments of a split sole ballet slipper  600 . Slipper  600  is similar to slipper  400 , except that it has a rear-located stretch panel  691  interrupting the upper  610  and outsole. A semi-rigid material  620  is shown as a grey striped area. In such embodiments, a rear located stretch panel  691  and its stitching  692  is present. The semi-rigid material  620  is attached to the shoe upper  601  using a stitch  608  and/or adhesive, starting at the forefoot section  670  of the shoe  600  and flowing along a longitudinal direction, such as a center-line, through the arch section  640 . This stitch  608  and/or adhesive connect the semi-rigid material  620  to both the upper  601  and its linings  603  or just its upper  601  or linings  603 . 
     Just as in other described embodiments, the shape and positioning of the semi-rigid material  620  is also significant to achieving desired effects. The semi-rigid material in the arch section  628  should be narrow enough to allow full range of movement of the foot, but wide enough to offer support and controlled resistance as well as to help maintain a smooth line with no wrinkling or puckering of material. 
     A back strap material  632  and its stitching  634  is also attached through into the arch section  640 . This connects the front outsole section  672  and its stitching  674 , the front insole  607  and arch section  640  in a semi-rigid, but flexible support structure. Reference numeral  629  indicates the arch-forefoot transitional portion of the semi-rigid material  620 . The semi-rigid material  620  narrows as it moves away from the front outsole  672 . This smoothes the transition from one semi-rigid material, the suede outsole  672  into another,  620  to reduce wrinkling, puckering and bunching of surrounding materials. The semi-rigid material  620  continues through the arch section  640  and ends at flexible rear stretch panel  691 . 
     The stretch panel  691  is free of any coverings or other shoe upper or outsole materials overlying it and can be made of a variety of stretch materials, for example such as Lycra, mesh, neoprene, stretch leather, stretch canvas, spandex, stretch PU etc. The stretch panel  691  serves to mitigate relative longitudinal movement of the shoe material compared to the foot when the foot is in motion, bending and flexing. Rather than the material seemingly travelling forwards and backwards to the heel and toe sections, the relative movement is at least partially absorbed through the stretch panel  691 . The stretch panel  691  also acts as a size leeway, allowing the wearer a more custom fit. 
     When a dancer is standing flat in a neutral position, the stretch panel is extended (see  FIG. 6A ). When the dancer&#39;s foot is in pointe position (see  FIG. 6B ) the stretch panel  691  contracts in the manner shown by arrows  694 . The presence of a semi-rigid material  620  encasing the heel and supporting the arch increases support levels for the foot and ankle, and offers controlled resistance. 
     The stretch panel  691  is shaped and located so as to be widest where it underlies the foot and effectively forms part of the outsole in a transition region between the arch section  640  and the heel section  610 . Stretch panel  691  generally resembles a U-shape when flattened or viewed from each end of the shoe  600 , extending around and up from the outsole region on each lateral side of the slipper  600 , narrowing in width and curving in a rearward sweep until it terminates at the binding  602  near the upper heal portion  622 . As the greatest amount of expansion or contraction of the stretch panel occurs in the outsole region, the stretch panel  691  can be narrower and afford less expansion/contraction as it extends toward the binding  602 . Stretch panel  691  is stitched to adjacent parts of upper  601  and outsole portions, including adjacent forward and rear portions of semi-rigid material  620  (at arch section  640  and heel section  610 ) and optionally also a forwardly located backstrap  632 . 
     The semi-rigid material  620  encasing or cupping the heel section  610  is still present but is separated from a front section semi-rigid material  620  by the back stretch panel  691 . The heel section of the semi-rigid material  620  serves to increase support for the heel and ankle and ensure a clean smooth material line around the heel. These semi-rigid material sections  620  provide a reinforcing structure for the shoe  600  to increase support levels for the foot and ankle, and offer controlled resistance to foot flexion. 
     The semi-rigid material  620  is attached to the upper  601  and lining  603 . The semi-rigid material  620  can be attached on the inside of the shoe, on top of the lining  603  as shown in  FIGS. 6A to 6E  or in between the lining  603  and the upper  601 . The semi-rigid material  620  can alternatively be attached on the outside of the shoe, outside of the upper  601  in full view. The stretch panel  691  is sewn to the upper  601  and lining  603  by stitching  692 . The lining  603  is layered into the upper  601 . The backstrap  632  is attached to the upper  601  and the sole of shoe  600  by stitching  634 . The rear outsole portion  612  and front outsole portion  672  are stitched to the upper  601  by stitching  614  and  674  respectively. 
       FIGS. 7A, 7B, 7C and 7D  illustrate embodiments of a leather split sole lace up jazz shoe  700 .  FIGS. 7A to 7D  show the side, bottom perspective, top and bottom views of the lace up jazz shoe  700 . The Jazz shoe  700  has a heel section  710 , an arch section  740  and a forefoot section  770 .  FIGS. 7A to 7D  show a semi-rigid material indicated as a grey striped area and labelled  720 , although in the illustrated embodiments it is not visible without looking inside the shoe. The semi-rigid material  720  is applied as a reinforcing structure through the heel and arch sections  710 ,  740 . 
     In the illustrated embodiments, the semi-rigid material  720  is stitched inside the shoe  700 , progressing from an upper heel portion  722  of the heel section  710  and travelling down through a mid-heel portion  724 , around a lower heel portion  726  through the heel outsole portion  712  and along a longitudinal centre-line of the arch section  740 . The heel back strap  732  also continues into the arch section  740  underneath the heel outsole portion  712 . These components combine to give the shoe more body with a smooth finish, and mitigate wrinkling in the material of the shoe upper  701 . 
     Similar to a ballet shoe as shown in  FIGS. 1A and 1B , the material of a jazz shoe may move relative to the foot when foot flexion occurs and this is apparent from the creation of a small void of space between the foot and the ends of the shoe in the heel section  710  and toe area of the forefoot section  770  when the foot flexes to pointe position. The semi-rigid material  720  and the stitch  708  connecting it to the body of the shoe  700 , extend from the heel section  710  through the rear outsole  712  and into the arch section  740 , connecting to the forefoot outsole portion  772  of forefoot section  770 . A cup shape formed by the reinforcing structure provided by semi-rigid material  720  in the heel section  710  and the flexible arch section  740  maintain a relatively rigid smooth clean line, with minimal wrinkling, bunching or puckering of fabric. 
       FIGS. 7A, 7B and 7C  show a lacing system  705  that helps secure the shoe to the foot. In other embodiments the lacing system  705  can be replaced by elastic straps or panels to create a laceless shoe referred to as a “slip-on”. A binding  702  extends around an upper rim of the shoe  700  to define the opening through which the foot is received in the top of shoe  700  and can be made up of a cotton non-stretch material or an elastic stretch material. Some embodiments of a jazz shoe contain no binding at all and these are manufactured using the method known as “stitch and turn”. Binding  702  may be stitched, glued or otherwise affixed to the upper  701  and optionally also to the upper heel portion  722  of the semi-rigid material  720 . 
     Reference numeral  701  indicates the upper of the shoe  700 . The upper  701  may be formed as one piece stitched together through the heel and outsole or more than one piece of material. If the upper  701  is formed of one piece of material, then it extends around under portions of the heel, arch and forefoot sections to form part of the outsole. This may also be the case where the upper  701  is made up of more than one piece of fabric. The upper  701  can be made up of numerous stretch and non-stretch materials such as canvas, leather, PU, lycra, mesh, neoprene, mesh etc. Reference numeral  708  indicates the stitch line that connects the semi-rigid material  720  to the upper  701  and lining  703 . The stitch line  708  runs just inside the edge of the semi-rigid material  720  and connects it to the upper  701  of the shoe  700 . This connection can alternatively be achieved with glue or a combination of glue and stitching. 
     The semi-rigid material  720  may be formed from a single piece of material. If two pieces of material are used to make up the semi-rigid material  720 , they may be longitudinally joined to form a line of symmetry along the join (as in  FIGS. 5A-5C ). In some embodiments, different pieces of material, having different material characteristics, may be used in the heel section  710  and the arch section  740 . 
     The connection created by combining the semi-rigid material  720  to the body of the shoe  700  is significant as it is responsible for creating the semi-rigid but flexible reinforcing structure between the heel section  710  of the shoe  700 , the outsoles  712 ,  772  of the shoe  700  and the arch section  740  of the shoe  700 . For light jazz shoes in particular, it is what gives the shoe  700  its body and what allows the shoe material to maintain its shape and clean lines during movement. It also allows the shoe  700  to offer more support to the dancer&#39;s foot and ankle, maintaining a semi-rigid body of material against the foot and in turn offering controlled resistance for muscle activity. The shape and positioning of the semi-rigid material  720  is also significant to achieving the desired structural and aesthetic effects. 
     Starting at the binding  702  at the top of the heel section  710 , the semi-rigid material  720  covers part of the back of the heel but is wide enough to start forming a slight curve as it extends down around the Achilles tendon and/or ankle and heel bones (talus and calcaneus). The semi-rigid material  720  continues down towards the sole of the heel, getting wider as it travels, forming a cup shape as it wraps itself around a lower posterior part of the heel bone (calcaneus). This transition from Achilles to sole and the corresponding gradual width increase in the semi-rigid material  720  is intended to serve as a gradual increase in the rigidity of the heel section  710  as it approaches the sole of the foot. The rigidity level is selected to provide flexibility and ease of movement without compromising on support and resistance. If the semi-rigid material  720  maintained the same width through into the sole of the heel section  710  and did not become wider, the increased support around the heel would be lost, the resistance would be low and the ability of the semi-rigid material  720  to reduce wrinkles on and around the heel would be reduced. 
     As the semi-rigid material  720  approaches the arch section  740 , the shape changes to roughly accommodate the transitional contours of the arch. This requires a narrowing of the semi-rigid material  720  at the heel arch transitional portion  727  and assists to avoid excessive reinforcing material in the arch region  740 . This narrowing means that the semi-rigid material  720  changes from a cup shape around the heel section  710  into a flat strip  728  as it progresses from the mid and lower heel portions  724 ,  726  into the arch section  740  to allow the foot to bend naturally. However, the semi-rigid material  720  should stay wide enough in the arch section  740  to offer support and controlled resistance. If the semi-rigid material  720  is too wide in the arch section  740 , it would maintain the “cup” shape as seen in the heel section, and this would reduce flexibility through the arch. In some jazz shoe embodiments, the lateral width from the longitudinal center-line to stitching  708  of the lower heel portion  726  of the semi-rigid material  720  may vary between around 1.8 and around 10 or more times the lateral width of the narrow strip portion  728  through the arch section  740 . This may also apply to jazz shoe embodiments  800  and  900 , described below. 
       FIGS. 7B and 7D  shows the back strap stitch  734  that connects the back strap  732  to the upper  701  and semi-rigid material  720 . The backstrap  732  may be made from the same material as the upper  701  or it can be made of other stretch or non-stretch materials, woven or non-woven material types, including binding material.  FIGS. 7B and 7D  shows how the backstrap  732  continues through from the top of the heel section  710  and into the arch section  740 , ending at forefoot outsole portion  772 . The backstrap  732  is an optional part of the shoe  700 . Reference numeral  729  indicates the arch-forefoot transitional portion of the semi-rigid material  720 . 
     In some embodiments the semi-rigid material  720  broadens to about 1.2 to 3 times its narrowest width in the arch section  740  as it approaches the front outsole  772 . This smoothes the transition from one semi-rigid material into another to mitigate wrinkling, puckering and bunching of surrounding materials. In other embodiments, the width of the semi-rigid material  720  may remain substantially constant through the arch-forefoot transition section. 
     The outsole of shoe  700  has heel and forefoot outsole parts  712 ,  772 . In illustrated diagrams, the outsole is a “split outsole” in two parts and may comprise EVA (Ethylene-vinyl acetate), for example. However, other embodiments may employ a full sole. In full sole embodiments, the outsole replaces much of the task performed by the semi-rigid material  720  in the arch section  740 , but its connection to the semi-rigid material in the heel section  710  (and role as part of the reinforcing structure) is still significant. The heel and forefoot outsole portions  212 ,  272  are glued in place, connecting them to the upper  701  and semi-rigid material  720 . A toe area of the forefoot section  770  may have a pleating arrangement which shapes the material of upper  701  around the toes. 
     As with the upper  701 , the lining  703  can be made up of different stretch and non-stretch materials, such as canvas, leather, PU, Lycra, mesh, neoprene, cotton, for example.  FIG. 7C  shows the semi-rigid material  720  sitting on top of the lining  703 , but it can alternatively be placed underneath the lining  703 , in between the lining  703  and the upper  701 , concealing the semi-rigid material  720 , or the semi-rigid material  720  can be placed on the outside of the upper  701  in full view. Lining  703  can be made up of numerous materials like canvas, leather, PU, Lycra, mesh, neoprene, cotton as well as buoyant materials such as foams and its variants and rubbers and its variants. 
     The shape of heel insole portion  713  and forefoot insole portion (not shown) would normally match the general shape of the outsole. A stitch  715  attaches the rear insole portion to the upper  701 , lining  703  and semi-rigid material  720 . A similar stitch (not shown) attaches the forefoot insole portion to the upper  701 , lining  703  and optionally the forefoot outsole portion  772 . Alternatively, an adhesive substance may be used to attach such parts together. 
       FIGS. 8A, 8B, 8C and 8D  illustrate embodiments of a leather split sole lace up jazz shoe  800 . Shoe  800  is the same as shoe  700 , except that it has a forward-located stretch panel  881  interrupting the upper  801  and outsole.  FIGS. 8A to 8D  show the side, bottom perspective, top and bottom views of the lace up jazz shoe  800 . The presence of a semi-rigid material  820  is shown as a grey striped area and labelled  820 . In such embodiments, the semi-rigid material  820  is attached to the shoe upper  801  using a stitch  808  and/or adhesive, starting at the heel section  810  and extending along a line through the side or back quarter of the shoe  800 , creating a heel cup, and into the arch section  840 . The semi-rigid material  820  narrows as it passes through the heel-arch transitional portion  827  and forms a flat strip  828 . Stitching  808  and  815  and/or adhesive substances connects the heel section  810 , rear outsole  812  and arch section  840  in a semi-rigid, but flexible support structure. The semi-rigid material  820  continues through the arch section  840  and ends at the flexible front stretch panel  881 . 
       FIGS. 8B and 8D  show the back strap stitch  834  that connects the back strap  832  to the upper  801  and semi-rigid material  820 . The backstrap  832  may be made from the same material as the upper  801  or it can be made of other stretch or non-stretch materials, woven or non-woven material types, including binding material. The back strap  832  continues through from the top of the heel section  810  and into the arch section  840 , ending at the flexible front stretch panel  881 . 
     The stretch panel  881  is free of any coverings or other materials of the shoe upper  801  or outsole overlying it and can be made of a variety of stretch materials, for example such as Lycra, mesh, neoprene, stretch leather, stretch canvas, spandex, stretch PU etc. The purpose of the stretch panel is to dissipate bunching or travel of the shoe material relative to the foot when the foot is in motion, bending and flexing. Rather than the shoe material travelling (relative to the foot) forwards and backwards to the heel and toe sections, the change in length of the foot is compensated for by expansion or retraction of the stretch panel. 
     When a dancer is standing flat in a neutral position, the stretch panel  881  is longitudinally expanded. When the dancer&#39;s foot is in pointe position, the stretch panel  881  contracts. The stretch panel  881  also acts as a size leeway, allowing the wearer a more custom fit. The presence of a semi-rigid material  820  encasing or cupping the heel and surrounding the arch, all joined as one piece, increases support levels for the foot and ankle, and offers controlled resistance. 
     The stretch panel  881  is shaped and located so as to be widest where it underlies the foot and effectively forms part of the outsole in a transition region between the arch section  840  and the forefoot section  870 . Stretch panel  881  generally resembles a U-shape when flattened or viewed from each end of the shoe  800 , extending around and up from the outsole region on each lateral side of the shoe  800 , narrowing in width and curving in a rearward sweep until it terminates at the binding  802 . As the greatest amount of expansion or contraction of the stretch panel occurs in the outsole region, the stretch panel  881  can be narrower and afford less expansion/contraction as it extends toward the binding  802 . Stretch panel  881  is stitched to adjacent parts of upper  801  and outsole portions, including the forward-most extent of semi-rigid material  820  (at arch portion  828 ) and optionally also backstrap  832 . 
     The semi-rigid material  820  is attached to the upper  801  and lining  803 . The semi-rigid material  820  can be attached on the inside of the shoe, on top of the lining  803  as shown in  FIG. 8C  or in between the lining  803  and the upper  801 . The semi-rigid material  820  can alternatively be attached on the outside of the shoe, outside of the upper  801  in full view. The stretch panel  881  is sewn to the upper  801  and lining  803  by stitching  882 . The lining  803  is layered into the upper  801 . The backstrap  832  is attached to the upper  801  and the sole of shoe  800  by stitching  834 . The rear outsole portion  812  and front outsole portion  872  may be glued to the upper  801 . 
       FIGS. 9A, 9B, 9C and 9D  illustrate embodiments of a leather split sole lace up jazz shoe  900 . Shoe  900  is the same as shoe  700 , except that it has a rear-located stretch panel  991  interrupting the upper  901  and outsole through the heel section  910 . 
     A semi-rigid material  920  is shown as a grey striped area. The semi-rigid material  920  is attached to the shoe upper  901  using a stitch  908  and/or adhesive, starting at the forefoot section  970  of the shoe  900  and flowing along a longitudinal center-line through the arch section  940 . This stitch  908  and/or adhesive connect the semi-rigid material  920  to both the upper  901  and its linings  903  or just its upper  901  or linings  903 . Just as in other described embodiments, the shape and positioning of the semi-rigid material  920  is also significant to achieving desired effects. The semi-rigid material in the arch section  928  should be narrow enough to allow full range of movement of the foot, but wide enough to offer support and controlled resistance as well as to help maintain a smooth line with no wrinkling or puckering of material. 
     A back strap material  932  and its stitching  934  is optionally also attached, extending from the forefoot outsole portion  972  through into the arch section  940 . This connects the front outsole section  972 , the front insole (not shown) and arch section  940  in a semi-rigid, but flexible support structure. Reference numeral  929  indicates the arch-forefoot transitional portion of the semi-rigid material  920 . The semi-rigid material  920  narrows as it moves toward the heel and away from the front outsole  972 . This smoothes the transition from one structural support material, the EVA forefoot outsole portion  972  into another, the semi-rigid material  920 , to mitigate wrinkling, puckering and bunching of surrounding materials. The forefoot portion of the semi-rigid material  920  continues through the arch section  940  and ends at flexible rear stretch panel  991 , which separates it from the heel portion of the semi-rigid material  920 . 
     The stretch panel  991  is free of any coverings or other materials of the shoe upper  901  or outsole overlying it and can be made of a variety of stretch materials, for example such as Lycra, mesh, neoprene, stretch leather, stretch canvas, spandex, stretch PU etc. The stretch panel  991  serves to mitigate relative longitudinal movement of the shoe material compared to the foot when the foot is in motion, bending and flexing. Rather than the material seemingly travelling forwards and backwards to the heel and toe sections, the relative movement is at least partially absorbed through the stretch panel  991 . The stretch panel  991  also acts as a size leeway, allowing the wearer a more custom fit. 
     When a dancer is standing flat in a neutral position, the stretch panel is extended. When the dancer&#39;s foot is in pointe position the stretch panel  991  is allowed to contract fully or partially. The presence of a semi-rigid material  920  encasing the heel and supporting the arch increases support levels for the foot and ankle, and offers controlled resistance. 
     The stretch panel  991  is shaped and located so as to be widest where it underlies the foot and effectively forms part of the outsole in a transition region between the arch section  940  and the heel section  910 . Stretch panel  991  generally resembles a U-shape when flattened or viewed from each end of the shoe  900 , extending around and up from the outsole region on each lateral side of the shoe  900 , narrowing gradually in width and curving in a rearward sweep until it terminates at the binding  902  near upper heel portion  922  of semi-rigid material  920 . As the greatest amount of expansion or contraction of the stretch panel occurs in the outsole region, the stretch panel  991  can be narrower and afford less expansion/contraction as it extends toward the binding  902 . Stretch panel  991  is stitched to adjacent parts of upper  901  and outsole portions, including adjacent rear and forward locations of semi-rigid material  920  (at arch portion  940  and heel portion  910 ) and optionally also a forwardly located backstrap  932 . 
     The heel portion of the semi-rigid material  920  encasing or cupping the heel section  910  is still present but is separated from a front section of semi-rigid material  920  by the back stretch panel  991 . The heel portion of the semi-rigid material  920  serves to increase support for the heel and ankle and ensure a clean smooth material line around the heel. These divided semi-rigid material sections  920  provide a reinforcing structure for the shoe  900  to increase support levels for the foot and ankle, and offer controlled resistance to foot flexion. 
     The semi-rigid material  920  is attached to the upper  901  and lining  903 . The semi-rigid material  920  can be attached on the inside of the shoe, on top of the lining  903  as shown in  FIG. 9C  or in between the lining  903  and the upper  901 . The semi-rigid material  920  can alternatively be attached on the outside of the shoe, outside of the upper  901  in full view. The stretch panel  991  is sewn to the upper  901  and lining  903  by stitching  992 . The lining  903  is layered into the upper  901 . The backstrap  932  is attached to the upper  901  and the sole of shoe  900  by stitching  934 . The rear outsole portion  912  and front outsole portion  972  may be glued to the upper  901 . 
     The stretch panel  481 ,  691 ,  881 ,  991  can be made up of a variety of stretch materials, for example Lycra, mesh, neoprene, stretch leather, stretch canvas, spandex, stretch PU etc. The material of the stretch panel of some embodiments is neoprene. When the shoe is off the foot, the neoprene is in a relaxed contracted state, at rest. When the shoe is placed on the foot, depending on the foot length, the neoprene is elastically lengthened (stretched). The direction of the stretch is longitudinal, making an allowance for different length feet. When the foot is placed flat on the floor, or when the dancer performs a “demi plie” movement, the foot is at its longest. In this instance, the stretch panel can be stretched in the longitudinal direction of the shoe by up to 150%. For example, a neoprene stretch panel of 6 mm relaxed, can stretch to up to 15 mm. This is a difference of 9 mm which translates to roughly two whole shoe sizes. 
     The stretch panel does not affect the width fittings of the shoe. However as the sizes increase, so does the width of the shoe, incrementally, and there is a proportional increase in the width (in the longitudinal direction of the shoe) of the stretch panel. The shoe may therefore be fitted for correct width, and the stretch panel may accommodate inaccuracies in length. 
     The semi-rigid material  720 ,  820 ,  920  and  1120  ( FIGS. 11A to 11D ) forms a larger cup around the heel on the jazz shoe embodiments because a shoe with a heel (in this case a 10 mm high heel) requires more ankle support than a shoe with no heel such as a ballet slipper. Jazz shoes (and other shoes with heels that raise the upper off the floor) may contain a “heel counter” which prevents the heel area from collapsing after a time of wear. The semi-rigid material in this example works in conjunction with the heel counter to provide additional cushioning and is basically mimicking the line of the heel counter. This is for neatness and ease of manufacturing, as well as increasing the rigidity around the ankle and increasing ankle arch support. The semi-rigid material  720 ,  820 ,  920 ,  1120  in the heel of the jazz shoe performs primarily cushioning functions, as it is much less rigid than a heel counter, but its extension as one piece (or two separate pieces for semi-rigid materials  920 ,  1120 ) through the arch is believed to have benefits in mitigating wrinkling or bunching of the shoe upper and portions of the outsole. 
     As shown in  FIG. 3 , a ballet shoe  300  according to some embodiments may employ a larger (wider) upper heel portion  322  of semi-rigid material  320  around the heel section, somewhat similar to the size of the semi-rigid material  720 ,  820 ,  920  for jazz shoe  700 ,  800 ,  900 . Upper heel portion  322  is sufficiently wide to extend some distance around each lateral side of the ballet shoe  300  adjacent the binding to an area of the foot corresponding to the vertical line of the fibula, the posterior talofibular ligament and/or the calcaneofibular ligament. In contrast, other ballet shoe embodiments described herein employ a semi-rigid material  220 ,  420 ,  620  that at the upper heel portion  222 ,  422 ,  622  slightly cups the Achilles tendon or upper posterior part of the calcaneus without extending as far as the vertical line of the fibula, the posterior talofibular ligament and/or the calcaneofibular ligament. 
       FIG. 3  depicts a ballet shoe  300  similar to ballet shoes  200 ,  400  and  600 , but with a much wider semi-rigid material around the heel section  310  to match the jazz shoe heel size. A firmer and more enveloping cupping of the heel by the semi-rigid material  320  occurs in the heel section  310 , but the semi-rigid material  320  still reduces substantially in width as it reaches the heel-arch transition  327  and passes into the arch. Such designs may provide increased heel and ankle support, but may provide more resistance to foot flexion. 
     Like the other ballet shoe embodiments shown and described, ballet shoe  300  optionally has a heel backstrap  332  stitched to an upper  301  and the semi-rigid material  320  as it extends from the binding at the back of the heel, down around the base of the heel and through the arch. Semi-rigid material  320  is attached to the lining and shoe upper  301  by stitching  308  and to the heel outsole and insole portions by stitching in the same manner as shown in the other ballet shoe embodiments. Arch section  340  and forefoot section  370  are substantially the same for shoe  300  as for shoes  200 ,  400  and  600 . 
     Referring also to  FIGS. 10A, 10B and 10C , embodiments of a full sole ballet slipper  1000  are described and shown in further detail. The slipper  1000  is similar to slipper  200 , in that it has a semi-rigid material  1020  extending from an upper heel portion adjacent the binding down over the mid-heel and around a lower posterior portion of the calcaneus through to where the heel transitions to the arch of the foot. Shoe  1000  differs from shoe  200 , however, in that a full outsole  1060 , which may be formed of a single piece of suede or light canvas, for example, is provided instead of the split sole arrangement of shoe  200 . 
     A backstrap  1032  may optionally be provided, running from adjacent the binding down around the heel along a longitudinal center-line of the shoe  1000 . Similarly, semi-rigid material  1020  is attached to the shoe upper and lining by stitching  1008 . In such embodiments, the semi-rigid material  1020  forms part of a reinforcing structure in the heel section of the shoe  1000 , with the outsole  1060  providing a reinforcing structure bridging the heel and arch sections. Thus, the semi-rigid material  1020  may extend laterally around the heel in a cupping manner, broadening from the upper heel portion adjacent the binding as it progresses down around a lower posterior portion of the calcaneus, then narrowing toward a heel-arch transition region. Such embodiments may advantageously provide increased support around the heel section of the shoe. 
     Outsole  1060  may be formed as one piece of material or more than one piece, having a rounded section underlying at least part of the heel, then tapering inwardly as it progresses through the arch section and then widening to a larger rounded area to underlie the forefoot section. This arrangement of outsole  1060  is most visible in  FIG. 10B . Outsoles  1060  may be stitched to the shoe upper by suitable stitching around an edge of the outsole piece or pieces and may be complemented by heel and forefoot insole portions positioned inside the shoe. 
     A ballet shoe or jazz shoe according to some further embodiments may employ a smaller (narrower) semi-rigid material through the heel section or arch section than is described above. In such embodiments, the cupping of the heel by the semi-rigid material is less and the support provided by the semi-rigid material as it passes into the arch is reduced relative to the embodiments described above that employ the wider semi-rigid material. 
     For ballet shoe embodiments, the thickness of the shoe upper and lining together may be around 1 mm to around 4 mm, not including outsole portions or the semi-rigid material. The maximum thickness of ballet shoe embodiments, for example including insole, lining, semi-rigid material, outer material (which may effectively be part of the upper) and outsole portion, preferably does not exceed about 8-10 mm and is preferably less than about 6 mm. 
     Described embodiments relating to a semi-rigid material in the arch section  240 ,  440 ,  640  are generally not applicable to ballet pointe shoes because of the much greater rigidity required of the sole structure of pointe shoes. However the presence of a semi-rigid material in the heel section of a pointe shoe in relation to the rigid sole structure of a pointe shoe is relevant in minimising creasing, bunching and puckering of the upper materials and its linings. 
     Referring now to  FIGS. 11A, 11B, 11C and 11D , a split-sole dance shoe  1100  according to further embodiments is shown and described. Shoe  1100  is the same as shoe  200 , except that it additionally includes a small, thin, elongate flexible board  1180  extending through the arch section  1140  and marginally into the heel and forefoot sections  1110 ,  1170 , without extending through those sections. The purpose of the board  1180  is to provide a supplement to the reinforcing structure provided by the semi-rigid material  1120  through the arch section  1140 , providing greater resistance to flexion of the foot. Such increase in resistance of flexion through the arch is not intended to be more than about an order of magnitude greater than the resistance already provided by the semi-rigid material  1120 . 
     Flexible board  1180  may have a lateral width roughly the same as, or within about 20% of, the width of the semi-rigid material  1120  through the arch section  1140 . The flexible board  1180  may be positioned along a longitudinal direction, such as a centre line, of the shoe  1100  or slightly offset therefrom. 
     Board  1180  may comprise a pulp board material, such as is commonly referred to as a “texon board”, such as is made by Texon International, or a similar board material. The thickness of the board  1180  may be around 0.5 mm to around 0.8 mm, optionally around 0.6 mm. Board  1180  may be generally rectangular or slightly trapezoidal or with slightly curved or flared ends. 
     As is illustrated in  FIG. 11D , board  1180  may be positioned as an insert inside the shoe and stitched or adhered between semi-rigid material  1120  and a lining  1103 . Alternatively, board  1180  may be stitched or adhered to one or both of lining  1103  and outsole  1101  and sandwiched therebetween. As is illustrated in  FIG. 11D , shoe  1100  is similar to other ballet shoe embodiments, in that it has one or more straps  1104 , a binding  1102 , forefoot and heel insole portions  1107 ,  1113 , a backstrap  1132  and heel and forefoot outsole portions  1112  and  1172 , all of which are stitched and/or adhered to adjacent components in the manner shown. Semi-rigid material  1120  is the same as semi-rigid material  220 , or alternatively is the same as semi-rigid material  320 , in terms of its proportions, positioning, configuration and material characteristics, as previously described. 
     Referring now to  FIGS. 12A and 12B , a split-sole ballet shoe  1200  is shown, having a strap arrangement in which straps  1205  are connected more longitudinally closely to each other on each lateral side of the opening and at a shallow acute angle (e.g. 5 to 30 degrees or so) relative to each other in the lateral direction. For reference purposes only, the relative spacing of connection points of straps  1204  is illustrated by dashed lines. The smaller longitudinal separation of the connection points of straps  1205  to the edges of the shoe upper  1201  at binding  1202  serves to direct more tension exerted by straps  1205  (when worn) through the arch section  1240 , while directing significantly less tension through the heel section  1210  than with the more longitudinally spread arrangement of straps  1204 . Thus, straps  1205  are intended to primarily direct tension through the arch section  1240  with minimal or no tension directed through the heel section  1210 . It is recognized, however, that it is difficult to eliminate tension directed through the heel section  1210  but if the tension is directed instead toward a transition region between the heel section  1210  and the arch section  1240 , this involves relatively minimal tension being applied to the heel section  1210 . The configuration of straps  1205  is thus desired to induce tension that is insufficient through the heel section  1210  to prevent the back of the shoe  1200  adjacent the heel from becoming slightly spaced from the dancer&#39;s heel when the foot is in pointe position. The allowing of this slight spacing of the back of the shoe  1200  from the dancer&#39;s heel means that the line of the shoe through the arch section  1240  stays clean and aesthetically appealing as the foot is flexed in pointe position. 
     Referring now to  FIGS. 13A, 13B and 13C , embodiments of a split-sole jazz shoe  1300  are shown and described in further detail.  FIG. 13A  illustrates an exploded view of the shoe  1300 , showing a semi-rigid material  1320  positioned in the heel section  1310  to substantially coincide with a heel counter stitched and/or adhered into the heel of the shoe  1300 . Jazz shoe  1300  is similar to shoe  800 , except the semi-rigid material is provided in two sections  1320 ,  1321  in shoe  1300 . Thus, semi-rigid material  1320  provided in the heel section  1310  represents a first thin flexible reinforcing structure, while a flat strip of the same or a similar semi-rigid material  1321  provides a second thin flexible reinforcing structure to extend across the arch section  1340 . This strip of semi-rigid material  1321  may be attached to sole and forefoot insert portions  1313  and  1314  to form an insert to be adhered and/or stitched to the inside of the outsole of shoe  1300 . 
     Like shoe  800 , shoe  1300  has a stretch panel  1381  but, because shoe  1300  does not have laces, the stretch panel  1381  is designed to expand slightly to accommodate an insertion of the foot and retention of the shoe  1300  on the foot at least in part because of tension induced by expansion of the stretch panel  1381  when worn on the dancer&#39;s foot. 
     The semi-rigid material  1320  extending across the arch section  1340  may be substantially wider than the semi-rigid material extending across the arch section in the other jazz shoe embodiments and may, for example, extend across substantially the whole lateral width of the arch section of the arch sole. In embodiments corresponding to shoe  1300 , semi-rigid materials  1320 ,  1321  may not be directly attached to each other, but they nevertheless combine to provide a desirable amount of soft flexible reinforcing structure to a shoe that would otherwise only have a heel counter, the outsole material and the lining material to act as support for the dancer&#39;s foot. 
     In the depicted embodiments of shoe  1300 , semi-rigid material  1321  extends longitudinally from roughly the heel-arch transition region to the bottom of the U-shaped stretch panel  1381  separating the arch section  1340  from the forefoot section  1370 . Thus, a semi-rigid material  1321  does not extend through to the forefoot section  1370 , instead terminating at the forward located stretch panel  1381 . 
     Various embodiments have been described herein, in combination with various different configurations, arrangements, features and functions of the depicted dance shoes. The embodiments are intended to cover various combinations of such features, functions, configurations and depicted arrangements, as may be appropriate for the type of dance shoe in question. For example, while  FIG. 10A  shows a ballet shoe with only a single strap, it should be understood that other ballet shoe embodiments described herein may have only a single strap. Equally, the arrangement of straps  1205  having a longitudinally shortened spacing between their connection points to the shoe upper and having a position generally coinciding with the arch section and/or heel-arch transition region may be applied to the other ballet shoe embodiments described herein. Additionally, while exploded diagrams have been provided to illustrate construction of some of the shoes described herein, this is provided by way of example and without limitation, as an illustrative guide to construction of the embodiments. 
     The semi-rigid materials used in the heel sections described herein are intended to be differentiated from a normal heel counter by being more flexible, softer and having lower density, thereby readily allowing flexion of the foot without uncomfortably impinging on the skin or structures of the foot around the heel or arch. 
     While embodiments are described herein in specific detail, it is to be understood that such embodiments are described by way of example and are not to be construed to be limiting with respect to equivalents or to limit the scope of the invention. 
     Throughout this specification and claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. 
     The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.