Abstract:
A generally U- or oval shaped flexible plastic stance guide lies flat on terrain, regardless of terrain contour, and defines a central opening for placement of a foot on the terrain. Gently sloped leading and trailing edges with an arcuate or planar median between the leading and trailing edges provide a palpable low-profile periphery around the opening. Parallel and perpendicular guide markings facilitate positioning and orienting the guide and a foot for a particular task. The bottom may be textured with spikes to enhance frictional engagement.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to stance training, and, more particularly, to a contoured guide that has a foot opening and conforms to terrain. 
       BACKGROUND 
       [0002]    For beginning baseball and softball players, finding the right stance is critical for hitting success at the plate. Upon watching professional baseball players today, one might begin to think that there isn&#39;t a single correct stance, and that&#39;s a correct assumption. However, when beginning to play ball and acclimating oneself to a proper stance and swing mechanics, there are time-tested guidelines to follow. 
         [0003]    One key to a proper stance is foot positioning. Unfortunately, beginners may have difficulty consistently positioning their feet for a proper stance, and it may be impractical for a parent or coach to correct foot positioning while a batter is at the plate. Additionally, it may be dangerous for a parent or coach to approach a batter, particularly an eager novice, at the plate. Even if a coach initially positions the player&#39;s feet, many novice batters have a tendency to move their feet before taking a swing. 
         [0004]    The same challenges apply to golf. Proper stance, including foot positioning relative to a tee and ball, is critical for an effective swing. Again, beginners may have difficulty consistently positioning their feet for a proper stance, and it may be impractical and dangerous for a parent or coach to correct foot positioning while a golfer is addressing the ball. 
         [0005]    Other sports requiring a proper stance and swing, such as cricket, may also present the same challenges. In each case, a novice may not know or remember where to place his or her feet. In each case, intervention by a coach or parent may be impractical (e.g., time consuming, embarrassing, or against the rules during an official game or match), risk injury to the instructor, and an inferior method for teaching the player to independently properly locate his or her feet. In each case the player may move his or her feet, after proper positioning, without being aware that such movement has taken place. 
         [0006]    Many other activities also require a proper stance. Nonlimiting examples of such activities include firearm training, archery and combat. By way of example, the “Weaver stance” for shooting a firearm entails positioning the feet in a boxing stance, with the non-shooting side foot ahead of the shooting side foot. A person shooting right-handed will have the right foot angled out to approximately forty-five degrees to the side and to the rear at shoulder length. In contrast, the “Isosceles stance” for shooting a firearm involves positioning the feet shoulder width apart, with the support-side foot slightly forward, and the knees bent, shifting the center of mass forward to help the shooter better control recoil. In archery, with a right hand bow, the archer&#39;s left foot will be on the “down range” side or the target side of the shooting line, with feet spaced approximately shoulder width apart and parallel to the shooting line. 
         [0007]    In combat, various stances, including open and closed stances, are used, with increased lateral distance between the lead and rear foot in an open stance. While open stances are more stable than closed stances, they leave one vulnerable to groin attacks and expose a larger portion of the body to an opponent. Closed stances help agility, but can be unstable. As with stances for many other activities, the bend in the knees, the height relative to a normal standing position, and the shifting of body weight over one foot, the other foot, or evenly, varies according to combat objectives. 
         [0008]    What is needed is a device that does not interfere with the activity, is intuitive and easy to use, can be setup and configured in in a matter seconds, can be used on various terrains with various users having various stances and physiques, and allows a user&#39;s foot to maintain contact with actual terrain during use. The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above. 
       SUMMARY OF THE INVENTION 
       [0009]    To solve one or more of the problems set forth above, a stance guide according to principles of the invention is comprised of a plastic ring or u-shaped apparatus that lies flat on terrain, regardless of terrain contour, and defines a central opening for placement of a foot on the terrain. The apparatus includes gently sloped leading and trailing edges, with an arcuate or planar median between the leading and trailing edges. The sloped edges provide a palpable periphery around the opening. The maximum height of the apparatus is not more than an inch. While palpable, the gradual slope and limited overall height do not cause appreciable flexion, eversion, inversion, extension or pronation of foot or ankle of a user traversing the apparatus. Thus, risk of injury is minimized. The apparatus also includes guide markings to facilitate positioning and orienting the apparatus for a particular task. The bottom of the apparatus may be textured with spikes or other protrusions to enhance frictional engagement with the terrain. Such frictional engagement resists sliding motion of the apparatus when contacted by a user&#39;s foot. To further lock the apparatus in place, in one exemplary embodiment the apparatus includes one or more apertures through which an elongated pointed shank of a golf tee may extend into the ground, with the head of the tee recessed or substantially flush with the median. 
         [0010]    Advantageously, once a pair of stance guides is properly positioned, such as by a user, coach or trainer, the user may readily locate his or her feet while standing on actual terrain, and traverse the apparatus without risks of injury or unintentionally moving the apparatus. 
         [0011]    In one exemplary embodiment, a stance guide according to principles of the invention includes a front side having a front side length greater than a width of a shoe of a user, a left end and a right end opposite the left end. A left side extends from the left end of the front side. The left side is elongate (i.e., long in relation to width) and substantially perpendicular to the front side. A right side extends from the right end of the front side. The right side is elongate and substantially perpendicular to the front side and substantially aligned with, spaced apart from, and parallel to the left side. The front side, left side, and right side form a generally U-shape with a stance space defined between the left side and the right side. The stance space has a width defined by a distance between the left side and the right side. The width is greater than the width of the shoe of a user. 
         [0012]    In another exemplary embodiment, the guide also includes a back side having a length about equal to the length of the front side. The back side is spaced apart from the front side and generally parallel to the front side. In this embodiment the guide is generally O or oval shaped. 
         [0013]    In each embodiment, the front side, left side and right side are integrally formed and comprised of flexible plastic. The stance guide conforming to a contour of a terrain on which the stance guide is placed. 
         [0014]    Each of the front side, left side and right side has an outer edge and an opposite inner edge. The outer edge is sloped to an outer edge height, and the inner edge is sloped to an inner edge height. The inner edge height is less than the outer edge height, and the outer edge height does not exceeding one inch. The sloped outer edge and sloped inner edge may each be a filleted, beveled or chamfered outer edge. 
         [0015]    The guide includes several guidelines for guide alignment as well as foot alignment. The front side has a middle between the left end and the right end, with a central guideline at the middle. The central guideline is visible and substantially parallel to the left side and right side. The central guideline at the middle of the front side is palpable and is comprised of a linear embossment (i.e., embossed feature) or a linear debossment (i.e., debossed feature). A front edge guideline on the front side is generally perpendicular to the central guideline, has a front edge guideline length that is less than the front side length, has a first end adjacent to the left end of the front side, has a second end adjacent to the right end of the front side, and extends linearly between the left end and the right end of the front side. The front edge guideline on the front side is palpable and comprised of a linear embossment or a linear debossment. A left guideline and a right guideline are also provided. The left guideline is parallel to and spaced apart from the right guideline. The left guideline and the right guideline are perpendicular to the central guideline. The left guideline extends from the first end of the front edge guideline along a portion of the left side. The right guideline extends from the second end of the front edge guideline along a portion of the right side. 
         [0016]    The front side, left side and right side each have a bottom surface from which a plurality of terrain engaging protrusions extend downwardly. The terrain engaging protrusions may be conical protrusions. 
         [0017]    The flexible plastic includes a plasticizer and may also include an additive, such as a thermochromic additive causing the stance guide to change color at a determined temperature or a phosphorescent additive causing the stance guide phosphoresce (e.g., glow in the dark). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The foregoing and other aspects, objects, features and advantages of the invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where: 
           [0019]      FIG. 1  is a plan view of an exemplary ring-shaped stance guide according to principles of the invention; and 
           [0020]      FIG. 2  is a bottom view of an exemplary ring-shaped stance guide according to principles of the invention; and 
           [0021]      FIG. 3  is a bottom perspective view of an exemplary ring-shaped stance guide according to principles of the invention; and 
           [0022]      FIG. 4  is a first side view of an exemplary ring-shaped stance guide according to principles of the invention; and 
           [0023]      FIG. 5  is a second side view of an exemplary ring-shaped stance guide according to principles of the invention; and 
           [0024]      FIG. 6  is a top perspective view of an exemplary ring-shaped stance guide according to principles of the invention; and 
           [0025]      FIG. 7  is a section view of section A-A of the exemplary ring-shaped stance guide of  FIG. 1  according to principles of the invention; and 
           [0026]      FIG. 8  is a section view of section B-B of the exemplary ring-shaped stance guide of  FIG. 1  according to principles of the invention; and 
           [0027]      FIG. 9  is a plan view of an exemplary u-shaped stance guide according to principles of the invention; and 
           [0028]      FIG. 10  is a bottom perspective view of an exemplary u-shaped stance guide according to principles of the invention; and 
           [0029]      FIG. 11  is a top perspective view of an exemplary u-shaped stance guide according to principles of the invention; and 
           [0030]      FIG. 12  is a section view of section C-C of the exemplary u-shaped stance guide of  FIG. 9  according to principles of the invention; and 
           [0031]      FIG. 13  is a section view of section D-D of the exemplary u-shaped stance guide of  FIG. 9  according to principles of the invention; and 
           [0032]      FIG. 14  provides a perspective view of an exemplary u-shaped stance guide according to principles of the invention with an exemplary shoe in an exemplary stance position; and 
           [0033]      FIG. 15  provides a plan view of an exemplary u-shaped stance guide according to principles of the invention with an exemplary shoe in an exemplary stance position; and 
           [0034]      FIG. 16  provides a top perspective view of an exemplary u-shaped stance guide according to principles of the invention with exemplary golf tees as stakes; and 
           [0035]      FIG. 17  provides a bottom perspective view of an exemplary u-shaped stance guide according to principles of the invention with exemplary golf tees as stakes and tee storage compartments molded into the bottom surface of the guide; and 
           [0036]      FIG. 18  is a bottom perspective view of an exemplary ring-shaped stance guide without spikes according to principles of the invention; and 
           [0037]      FIG. 19  is a front view of an exemplary ring-shaped stance guide without spikes according to principles of the invention; and 
           [0038]      FIG. 20  is a bottom perspective view of an exemplary u-shaped stance guide without spikes according to principles of the invention; and 
           [0039]      FIG. 21  is a front view of an exemplary u-shaped stance guide without spikes according to principles of the invention. 
       
    
    
       [0040]    Those skilled in the art will appreciate that the figures are not intended to be drawn to any particular scale; nor are the figures intended to illustrate every embodiment of the invention. The invention is not limited to the exemplary embodiments depicted in the figures or the specific components, configurations, shapes, relative sizes, ornamental aspects or proportions as shown in the figures. 
       DETAILED DESCRIPTION 
       [0041]    Referring now to  FIGS. 1 and 6 , top views of an exemplary ring-shaped stance guide  100  according to principles of the invention is provided. A central oblong opening  110  is sized (w 1 , l 1 ) to receive a user&#39;s foot. A length (l 1 ) of approximately 12 inches and a width (w 1 ) of approximately 6 inches will accommodate most adult shoes. However, the invention is not limited to a guide having an opening  110  of approximately 6 by 12 inches. Rather, stance guides according to principles of the invention may have central openings sized to receive children or adult shoes. Thus, by way of example, lengths (l 1 ) of 6 to 15 inches and widths (w 1 ) of 4 to 9 inches may be utilized. Additionally, openings having shapes that are not oblong may be utilized without departing from the scope of the invention. The overall length (l 2 ) and width (w 2 ) may exceed the aperture length and width (l 1 , w 1 ) by a few inches or more. 
         [0042]    The ring-shaped stance guide  100  is a bisymmetric structure that includes opposed right and left sides  130 ,  135 , and opposed back and front sides  140 ,  145 . Each of the sides  130 ,  135 ,  140 ,  145  includes a gradually sloped outer periphery  115  terminating at an outer edge  105 , a gradually sloped inner periphery  125 , and an intermediate median  120  that extends from the inner periphery  125  to the outer periphery  115 . The gradually sloped edges may be beveled, filleted or chamfered. Nonlimiting examples include half bullnose, demi-bullnose, ¼ top round, ogee-bullnose, and dupont edges. 
         [0043]    With reference to  FIG. 5 , the overall height (h 1 ) of the guide, including spikes  170 , is less than two inches, preferably about an inch. The height (h 2 ) of the guide, excluding spikes  170 , is about an inch. 
         [0044]    The limited height and gradually sloped edges are palpable, yet avoid pronounced flexion, eversion, inversion, extension or pronation of a foot or ankle of a user traversing the apparatus. A user may readily sense the edges, to determine that his or foot is moving out of position. Additionally, players may traverse the guide  100  without stubbing against the side edges. 
         [0045]    The exemplary stance guide includes a plurality of parallel  150 ,  160 ,  165  and an orthogonal  155  guidelines. Each guideline may be embossed, debossed, imprinted or adhered to the guide  100 . The guidelines include a pair of spaced apart parallel line  160 ,  165  and an orthogonal line  155  that intersects each of the parallel lines  160 ,  165  near an end of each parallel line, adjacent to the front side  145  of the guide  100 . The parallel lines  160 ,  165  extend from about the front side  145  along about at least 25% to 50% of the right and left sides  130 ,  135 . A central guideline  150  extends towards the outer periphery of the front side  145  from the middle of the intersecting guideline  155 . The central guideline  150  bisects or abuts the orthogonal line  155  at its middle and runs parallel to the parallel side lines  160 ,  165 . The middle of the intersecting guideline  155  coincides with the middle or centerline longitudinal axis of the stance guide  100  that runs along overall length l 2 . The central guideline  150  facilitate alignment with a target, such as a point relative to a golf tee or a point in a batter&#39;s box. The parallel lines  160 ,  165 , facilitate positioning of a foot with toes between the lines. 
         [0046]      FIGS. 2 through 5  provide views of the bottom of the exemplary ring-shaped stance guide according to principles of the invention. An array of generally conical spikes  170  is provided along the bottom surface near the outer periphery of the guide  100 . The spikes  170  are an optional feature that enhance frictional engagement with certain terrain, such as turf (natural or artificial), dirt, clay and the like. The spikes  170  may be integrally formed with the guide  100  or separately formed and permanently or removably attached to the bottom of the guide  100 . If separately formed, the spikes  170  may be comprised of metal, plastic or composites. 
         [0047]      FIG. 7  provides a section view of section A-A of the exemplary ring-shaped stance guide  100  of  FIG. 1  according to principles of the invention. The cross section  180  includes a substantially planar bottom  182 , a curved inner peripheral edge  188 , a curved peripheral outer edge  184 , and a generally planar intermediate surface  186  extending from the curved inner peripheral edge  188  to the curved peripheral outer edge  184 . The height of the curved peripheral outer edge  184  is greater than the height of the curved inner peripheral edge  188 . Thus, the planar intermediate surface  186  slopes upwardly from the curved inner peripheral edge  188  to the curved peripheral outer edge  184 . 
         [0048]      FIG. 8  provides a section view of section B-B of the exemplary ring-shaped stance guide  100  of  FIG. 1  according to principles of the invention. The cross section  190  includes a substantially planar bottom  192 , a curved inner peripheral edge  198 , a curved peripheral outer edge  194 , and a generally planar intermediate surface  196  extending from the curved inner peripheral edge  198  to the curved peripheral outer edge  194 . The height of the curved peripheral outer edge  194  is greater than the height of the curved inner peripheral edge  198 . Thus, the planar intermediate surface  196  slopes upwardly from the curved inner peripheral edge  198  to the curved peripheral outer edge  194 . 
         [0049]    A user&#39;s foot, when positioned in the central aperture  110 , will contact the curved inner peripheral edges  188 ,  198 , if moved, backwards or forwards or to one side or another, appreciably out of position. The relatively low curved inner peripheral edges  188 ,  198  are easily sensed (palpable) to the user, without substantially straining the user&#39;s foot or ankle. Thus, the inner peripheral edges  188 ,  198  sensibly alert the user to foot positioning. 
         [0050]    The curved peripheral outer edges  184 ,  194  allow a person to traverse the guide, without injury. For example, if the guide  100  is left in a batter&#39;s box, a player sliding into home plate may traverse a portion of the guide  100 , sliding over the curved peripheral outer edges  184 ,  194  without injury. 
         [0051]    A stance guide according to principles of the invention is not limited to a ring-shape.  FIGS. 9 and 11  provide top views of an exemplary u-shaped stance guide  200  according to principles of the invention. A central concave opening  202 , accessible between ends  265 ,  270 , is sized (w 3 , l 3 ) to receive a user&#39;s foot. A length (l 3 ) of approximately 8 to 12 inches and a width (w 3 ) of approximately 6 inches will accommodate most adult shoes. However, the invention is not limited to a guide having an opening  202  of approximately 6 by 8 to 12 inches. Rather, stance guides according to principles of the invention may have central openings sized to receive children or adult shoes. Thus, by way of example, lengths (l 3 ) of 6 to 15 inches and widths (w 3 ) of 4 to 9 inches may be utilized. Additionally, concave openings having shapes that are not oblong may be utilized without departing from the scope of the invention. The overall length (l 4 ) and width (w 4 ) may exceed the aperture length and width (l 3 , w 3 ) by a few inches or more. 
         [0052]    The u-shaped stance guide  200  is a symmetric structure that includes opposed right and left sides  240 ,  255 , joined by a generally perpendicular front side  225 . Each of the sides  225 ,  240 ,  255  includes a gradually sloped outer periphery  220 ,  235 ,  250  terminating at an outer edge  205 , a gradually sloped inner periphery  230 ,  245 ,  260  and an intermediate median  210 ,  215 ,  225  that extends from the inner periphery  230 ,  245 ,  260  to the outer periphery  220 ,  235 ,  250 . The gradually sloped edges may be beveled, filleted or chamfered. Nonlimiting examples include half bullnose, demi-bullnose, ¼ top round, ogee-bullnose, and dupont edges. 
         [0053]    The overall height of the u-shaped guide  200 , including spikes, and excluding spikes, may be about the same as the heights of the ring-shaped embodiment  100 . 
         [0054]    The limited height and gradually sloped edges are palpable, yet avoid pronounced flexion, eversion, inversion, extension or pronation of a foot or ankle of a user traversing the apparatus. A user may readily sense the edges, to determine that his or foot is moving out of position. Additionally, players may traverse the guide  200  without stubbing against the side edges. 
         [0055]    The exemplary u-shaped stance guide  200  includes a plurality of parallel  275 ,  285 ,  290  and an orthogonal  280  guidelines. Each guideline may be embossed, debossed, imprinted or adhered to the guide  200 . The guidelines include a pair of spaced apart parallel line  285 ,  290  and an orthogonal line  280  that intersects each of the parallel lines  285 ,  290  near an end of each parallel line, adjacent to the front side  220  of the guide  200 . The parallel lines  285 ,  290  extend from about the front side  225  along about at least 25% to 50% of the right and left sides  240 ,  255 . A central guideline  275  extends towards the outer periphery of the front side  225  from the middle of the intersecting guideline  280 . The central guideline  275  bisects or abuts, or comes close to bisecting or abutting, the orthogonal line  280  at its middle and runs parallel to the parallel side lines  285 ,  290 . The middle of the intersecting guideline  275  coincides with the middle or centerline longitudinal axis of the stance guide  200  that runs along overall length l 4 . The central guideline  275  facilitate alignment with a target, such as a point relative to a golf tee or a point in a batter&#39;s box. The parallel lines  285 ,  290 , facilitate positioning of a foot with toes between the lines. 
         [0056]      FIG. 10  provides a view of the bottom of the exemplary u-shaped stance guide  200  according to principles of the invention. An array of generally conical spikes  290  is provided along the bottom surface near the outer periphery of the guide  200 . The spikes  290  are an optional feature that enhance frictional engagement with certain terrain, such as turf (natural or artificial), dirt, clay and the like. The spikes  290  may be integrally formed with the guide  200  or separately formed and permanently or removably attached to the bottom of the guide  200 . If separately formed, the spikes  290  may be comprised of metal, plastic or composites. 
         [0057]      FIG. 12  provides a section view of section C-C of the exemplary u-shaped stance guide  200  of  FIG. 8  according to principles of the invention. The cross section  290  includes a substantially planar bottom  299 , a curved inner peripheral edge  296 , a curved peripheral outer edge  298 , and a generally planar intermediate surface  297  extending from the curved inner peripheral edge  296  to the curved peripheral outer edge  298 . The height of the curved peripheral outer edge  298  is greater than the height of the curved inner peripheral edge  296 . Thus, the planar intermediate surface  297  slopes upwardly from the curved inner peripheral edge  296  to the curved peripheral outer edge  298 . 
         [0058]      FIG. 13  provides a section view of section D-D of the exemplary u-shaped stance guide  200  of  FIG. 1  according to principles of the invention. The cross section  300  includes a substantially planar bottom  303 , a curved inner peripheral edge  302 , a curved peripheral outer edge  304 , and a generally planar intermediate surface  301  extending from the curved inner peripheral edge  302  to the curved peripheral outer edge  304 . The height of the curved peripheral outer edge  304  is greater than the height of the curved inner peripheral edge  302 . Thus, the planar intermediate surface  301  slopes upwardly from the curved inner peripheral edge  302  to the curved peripheral outer edge  304 . 
         [0059]    A user&#39;s foot, when positioned in the concave aperture  202 , will contact the curved inner peripheral edges  230 ,  245 ,  260 , if moved, forwards or to one side or another, appreciably out of position. The relatively low curved inner peripheral edges  230 ,  245 ,  260  are easily sensed (palpable) to the user, without substantially straining the user&#39;s foot or ankle. Thus, the inner peripheral edges  230 ,  245 ,  260  sensibly alert the user to foot positioning. 
         [0060]    The curved peripheral outer edges  220 ,  235 ,  250  allow a person to traverse the guide, without injury. For example, if the guide  200  is left in a batter&#39;s box, a player sliding into home plate may traverse a portion of the guide  200 , sliding over the curved peripheral outer edges  220 ,  235 ,  250  without injury. 
         [0061]    As discussed above, the bottom of the guide may be textured with spikes or other protrusions to enhance frictional engagement with the terrain. Such frictional engagement resists sliding motion of the apparatus when contacted by a user&#39;s foot. To further lock the apparatus in place, in one exemplary embodiment the guide may include one or more apertures through which an elongated pointed shank of a golf tee may extend into the ground, with the head of the tee recessed or substantially flush with the median. 
         [0062]    A guide  100 ,  200  according to principles of the invention may be comprised of rubber, natural rubber, synthetic rubber, polymers of the organic compound isoprene, artificial elastomer synthesized from petroleum byproducts, and/or any of various plastics. All such materials are referred to herein as an elastomer. In an exemplary implementation, the guide  100 ,  200  is comprised of a flexible rubber, plastic or polymeric material, such as a polyisoprene, latex, isoprene (2-methyl-1,3-butadiene), chloroprene (2-chloro-1,3-butadiene), isobutylene (methylpropene), polyvinyl chloride (PVC), polyethylene, polypropylene, polystyrene, acrylics, cellulosics, acrylonitrile-butadiene-styrene terpolymers, urethanes, thermo-plastic resins, thermo-plastic elastomers (TPE), acetal resins, polyamides, polycarbonates and polyesters. One nonlimiting example is an expanded plastic material, such as a two-pound density expanded polystyrene, which is weather resistant, very durable, and light weight. A plasticizer, such as a phthalate ester, may be included in the plastic to enhance flexibility and durability. Another example is ethylene propylene diene monomer (M-class) rubber (EPDM), which exhibits outstanding heat, ozone, and weather resistance. While many other materials may be used alone or in combination with the aforementioned materials and/or other materials, without departing from the scope of the present invention, preferably the material is relatively inexpensive, easy to use in manufacturing operations and results in an aesthetically acceptable, flexible, durable, weather resistant product. The material may further include additives to provide desired properties such as desired colors, structural characteristics, glow-in-the dark properties and thermal reactivity (e.g., color changes according to heat). 
         [0063]    By way of example and not limitation, the guide  100 ,  200  may optionally be formulated to change color when it reaches a predetermined or higher temperature. This can be accomplished by mixing a thermochromic additive (e.g., thermochromic pigment) to the base material in an amount that is sufficient to achieve a desired color changing range. As an example, a mixture of approximately 5% to 30% (pbw) of Matsui International Co., Inc.&#39;s Chromicolor concentrate may be introduced to the base material, to provide a plastic structure that visibly changes color at a determined elevated temperature, such as approximately 90 degrees Fahrenheit or higher. 
         [0064]    Alternatively, a photochromic additive may be added to the base material in an amount that is effective to achieve a desired color change when the guide  100 ,  200  is exposed to certain lighting conditions. As an example, a mixture of approximately 5% to 35% (pbw) of Matsui International Co., Inc.&#39;s Photopia additive may be introduced to the base material, to provide a plastic structure that visibly changes color in the presence of sunlight or ultraviolet light. 
         [0065]    As another alternative, phosphorescent polymer additives, such as aluminate based phosphors, may be added to adsorb light energy and continue to release that energy as visible light after the energy source is removed. Advantageously, such an embodiment provides a guide  100 ,  200  that is easy to locate in darkened conditions, making the device easy to spot even at nighttime. 
         [0066]    The guide  100 ,  200  may be produced using any suitable manufacturing techniques known in the art for the chosen material, such as (for example) injection, compression, structural foam, blow, or transfer molding; polyurethane foam processing techniques; vacuum forming; and casting. Preferably, the manufacturing technique is suitable for mass production at relatively low cost per unit, and results in an aesthetically acceptable product with a consistent acceptable quality. 
         [0067]    With reference to  FIGS. 14 and 15  an exemplary shoe  400 , which would be worn by a user, is shown in a stance position relative to the exemplary u-shaped stance guide  200  according to principles of the invention. Understandably, the shoe may also be similarly placed in the space (i.e., central oblong opening  110 ) of the ring-shaped guide  100 . 
         [0068]    Also shown in  FIGS. 14 and 15 , and more clearly in  FIGS. 16 and 17 , are golf tees  405  and  410 , inserted through correspondingly shaped and sized apertures  415  and  420 , in the guide  200 , to anchor the guide  200  into terrain. The location and number of such apertures and corresponding tees may vary, without departing from the invention. Optionally, the bottom of the guide  200  includes storage compartments for the tees  425 ,  430 , which may be tee-shaped cavities molded into the bottom and sized and configured to securely receive and hold the tees in place for storage and transport. When used, the tees may be popped out of their compartments and inserted into the apertures  415 ,  420 , from the top side of the guide, with the shank of the tee extending into the terrain. Understandably, such tees  405 ,  410  and apertures  415 ,  420  may be similarly use in the ring-shaped guide  100 . 
         [0069]    Spikes, while desirable for traction in many applications on turf, are not necessary and possible detrimental when the guide is used on certain surfaces such as flooring.  FIGS. 18 and 19  provide bottom perspective and front views of an exemplary ring-shaped stance guide without spikes according to principles of the invention. Similarly,  FIGS. 20 and 21  provide bottom perspective and front views of an exemplary u-shaped stance guide without spikes according to principles of the invention. In each case, the bottom surface may be comprised of the same material as the body of the guide, or may be overmolded or coated with a non-slip elastomeric material. 
         [0070]    While an exemplary embodiment of the invention has been described, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. With respect to the above description then, it is to be realized that the optimum relationships for the components and steps of the invention, including variations in order, form, content, function and manner of operation, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. The above description and drawings are illustrative of modifications that can be made without departing from the present invention, the scope of which is to be limited only by the following claims. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents are intended to fall within the scope of the invention as claimed.