CA1340997C - Shoe with naturally contoured sole - Google Patents

Abstract

A construction for a shoe, particularly an athletic shoe such as a running shoe, includes a sole that conforms to the natural shape of the foot, particularly the sides, and that has a constant thickness in frontal plane cross sections. The thickness of the shoe sole side contour equals and therefore varies exactly as the thickness of the load-bearing sole portion varies due to heel lift, for example. Thus, the outer contour of the edge portion of the sole has at least a portion which lies along a theoretically ideal stability plane for providing natural stability and efficient motion of the shoe and foot particularly in an inverted and everted mode. In a more conventional embodiment, wherein the side contours of the shoe sole are formed by variations in the bottom surface alone, the edge portion of the sole is contoured and defined by an arc of a circle having a radius equal to the thickness of the sole portion of the sole and its center at a point lying oil the plane of the upper surface of the sole thickness.

Description

:iHOE WITH NATURALLY CONTOURED SOLE
Background of the Invention This invention relates to a shoe or other foot-wear, such as a street shoe,. athletic shoe, and especially a running shoe with a contoured sole. More: particularly, this invention relates to a novel contoured sole design for a shoe which improves the inherent stability and efficient motion of the load-bearing shod foot in extreme lateral motion. Still more particularly, this invention relates to a shoe wherein the shoe sole has an upper, foot sole-contacting surface that conforms to the natural shape of the foot, particularly the curved sides. Finally, this invention relates to a shoe sole with the load-bearing portions having a constant thickness when measured in frontal plane cross sections, so that the lower, ground-contacting surface parallels the upper, foot-contacting surface permitting the foot to react naturally with the ground as it would if the foot were bare, while continuing to protect and cushion the foot.
By way of introduction, barefoot populations universally have a very low incidence of running "overuse" injuries, despite very high activity levsals. In contrast, such injuries are very common in shoe shod populations, even for activity levels well below "overuse". Thus,, it is a continuing problem with a shod population to reduce or eliminate such injuries and to improve the cushioning and protection for the foot. It is primarily to an understanding of the reasons for such problems and to proposing a novel solution a<:cordin~3 to the invention to which this improved shoe is directed.
A wide variety of designs are available for running shoes which are intended to provide stability, but which lead to a constraint in the natural efficient motion of the foot and ankle.
However, such designs which can accommodate free, flexible motion in contrast create a l~~ck of control or stability. A popular existing shoe de;aign incorporates an inverted, outwardly-flared 1340997, shoe sole wherein the around engaging surface is wider than the heel engaging portion. However, such shoes are unstable in extreme situations because the shoe sole, when inverted or on edge, immediately becomes supported only by the sharp bottom sole edge where the entire weight, of the body, multiplied by a factor of approximately three at running peak, is concentrated. Since an unnatural lever arm and force moment are created under such conditions, the foot rind ankle are destabilized and, in the extreme, beyond << certa:in point of rotation about the pivot point of the shoe sole edge, forcibly cause ankle strain. In contrast, the unshod foot. is always in stable equilibrium without a 'comparable lever arm or force moment and, at its maximum range of inversion motion,, about 20°, the base of support on the barefoot heel actually broadens substantially as the calcaneal tuberosity contacts the grovand. This is in contrast to the conventionally available shoe sole bottom which maintains a sharp, unstable edge.
Existing running shoes interfere with natural foot and ankle bi.omechanics, disrupting natural stability and efficient natural motion. 'they do so by altering the natural position of the foot relative to the around, during the load-bearing phase of running or walking. The foot in its natural, bare state is in direct contact with the ground, so :its relative distance from the ground is obviously constant at zero. Even when the foot tilts naturally from side to side, either moderately when running or extremely when st.umblina or tripping, the distance always remains constant at zero.
In contrast, existing shoes maintain a constant distance from the ground - the thickness of the shoe sole - only when they are perfectly flat on the ground. ids soon as the shoe is tilted, 1340gg7 the distance between foot and ground begins to change unnaturally, as the shoe sole pivots around the outside corner edge. With conventional athletic shoes, the distance most typically increases at first due to the flared sides and then decreases; many street shoes with relatively wide heel width follow that pattern, though some with narrower Izeels only decrease. All existing shoes continue to decrease the distance all the way down to zero, by tilting through 50 degrees, resulting in ankle sprains and breaks.
A corrected shoe sole design, however, avoids such unnatural interference by neutrally maintaining a constant distance between foot and ground, even when the shoe is tilted sideways, as if in effect the shoe: sole were not there except to cushion and protect. Unlike existing shoes, the corrected shoe would move with the foot's natural sideways pronation and supination motion on the ground. To the problem of using a shoe sole to maintain a naturally constant distance during that sideways motion, there are two possible geometric: solutions, depending upon whether just the lower horizontal plane of the shoe sole surface varies to achieve natural contour cr bot.h upper and lower surface planes vary.
In the two plane solution, the naturally contoured design, (which will be described in detail) both upper and lower surfaces or planes of the shoe sole vary to conform to the natural contour of the human foot. The two plane solution is the most fundamental concept and naturally most effective. It is the only pure geometric solution to the mathematical problem of maintaining constant distance between foot and ground, and the most optimal, in the same sense that round is only shape for a wheel and perfectly round is most optimal. On the other hand, it is the least similar to existing designs of the two possible solutions and 1340gg~
requires computer aided design and injection molding manufacturing techniques.
In the more=_ conventional one plane solution, the quadrant contour side design, which will be described in Figures 29-37, the side contours are foamed by variations in the bottom surface alone.
The upper surf«ce or plane of the shoe sole remains unvaryingly flat in frontal. plane cross sections, like most existing shoes, while the plane of the bottom shoe sole varies on the sides to provide a contour that preserves natural foot and ankle biomechanics. 'Though less optimal than the two plane solution, the one plane quadrant contour side design is still the only optimal single plane solution to the problem of avoiding disruption of natural human biomech anics. The one plane solution ,is the closest to existing shoe sole design, and therefore the easiest and cheapest to manufacture with existing equipment. Since it is more conventional in appe;3rance than the two plane solution, but less biomechanically effective, the one plane quadrant contour side design is prefs:rable for dress or street shoes and for light ' exercise, like casual. walking.
CA-A-1 176 458 shows footwear with an outsole, particularly constructed for anti-skid characteristics on an ice surface, with a contoured side portion that does not maintain the same thickness as the underneath sole portion, when measured in frontal plane cross sections.
It is thus an overall objective of this invention to provide a novel shoe design which approximates the barefoot. It has been discovered, by investigating the most extreme range of ankle motion to :tear the point of ankle sprain, that the abnormal motion of an inversion ankle sprain, which is a tilting to the outside or an outward rotation of the foot, is accurately simulated while stationary. With this observation, it can be seen that the extreme range :;tabil.ity of the conventionally shod foot is distinctly inferior ~~o the barefoot and that the shoe itself creates a gross instability which would otherwise not exist.

Even more important, a normal barefoot running motion, which approxim~3tely includes a 7° inversion and a 7° eversion motion, does not occur with shod feet, where a 30° inversion and eversion is common. Such a normal barefoot motion is geometrically unattainable because the average running shoe heel is approximately 60% larger than the width of the human heel. As a result, the shoe heel and the human heel cannot pivot together in a natural manner;
rather, the hum;3n her=_1 has to pivot within the shoe but is resisted from doing so b~~ the shoe heel counter, motion control devices, and the lacing and binding of the shoe upper, as well as various types of anatomical supports interior to the shoe.
Thus, it is an overall objective to provide an improved shoe design which is not based on the inherent' contradiction present in current shoe designs which make the goals of stability and efficient natural motion incompatible and even mutually exclusive. It is another overall object of the invention to provide a new contour design which simulates the natural barefoot motion in running and thus avoids the inherent contradictions in current designs.
It is another objective of this invention to provide a running shoe which overcomes the problem of the prior art.
It is another objective of this invention to provide a shoe wherein the outer extent of the flat portion of the sole of the shoe includes all of the support structures of the foot but which extends no further than the outer edge of the flat portion of the foot sole' so that the horizontal plane outline of the top of the flat portion of the shoe sole coincides as nearly as possible with the load-bearing portion of the foot sole.

It is: another objective of the invention to provide a shoe having a sole which includes a side contoured like the natural form of the side or edge of the human foot and conforming to it.
It is another objective of this invention to provide a novel shoe structure in which the contoured sole includes a shoe sole thickness that is precisely constant in both side portions and contoured portions, when measured in frontal plane cross sections, and therefore biomechanically neutral, even if the shoe sole is tilted to either side, or forward or backward.
It is another objective of this invention to provide a shoe having a sole fully contoured like and conforming to the natural form of the non-load-bearing human foot and deforming under load by flattening just as the foot does.
It is still another objective of this, invention to provide a new atable shoe design wherein the heel lift or wedge increases in the sagittal plane the thickness of the shoe sole or toe taper decrease therewith so that the sides of the shoe sole which naturally conform to the sides of the foot also increase or decrease by exactly the same amount, so that the thickness of the shoe sole in a frontal planar cross section is always constant.
It is another objective of this invention to provide a shoe having a shoe having a naturally contoured design as described wherein the sides of the shoe are abbreviated to essential structural supp~~rt and propulsion elements to provide flexibility and in which tine density of the shoe sole may be increased to compensate for increased loading.
It is another objective of this invention to provide a shoe sole design which includes a plurality of freely articulating essential structural support elements in the sole of the shoe which are consistent with the sole of the foot and are free to move independently of each other to follow the motion of the freely articulating ban.. structures of the foot.
It is ;still another object of this invention to provide a shoe of the type described wherein the material of the sole is removed except beneath essential structural support elements of the foot.
It is anothear object of this invention to provide a shoe of the type described with treads having an outer or a base surface which follows thE= theoretically ideal stability plane.
It is yet another overall object of this invention to provide a shoe construction having a design defined by the natural shape of an unl.oade~i foot and which deforms upon loading to approximate at least the theoretically ideal stability plane.
It is :>till another object of this invention to provide a shoe construction wherein a plot of the range of inversion and eversion motion defines a curve with substantially no vertical component variation over a range of at least 40 degree.
It is :;till another object of this invention to provide a shoe having a ~;ole edge surface which terminates in a laterally extending portion made: from a flexible material and structured to terminate upon loading in a position which approximates or is in parallel with the theoretically ideal stability plane.
It is yet another object of this invention to provide a shoe with a p:Lural:ity of frontal plane slits located at predetermined locations in said shoe sole.
It is still another objective of this invention to provide a correct: method Qf measuring the thickness of shoe sole contours.

It is another objective of the invention to provide a shoe having a sole which includes a rounded sole edge contoured like the natural form of the side or edge of the human foot but in a geometrically preci:>e manner so that the shoe sole thickness is precisely constant, even if the shoe sole is tilted to either side, or forward or backward.
It is another objective of this invention to provide a novel shoe struct=ure in which the contoured sole includes at its outer edge portions a contoured surface described by a radius equal to the thickness of the shoe sole with a center of rotation at the outer edge of then top of the shoe sole.
It is ~jnoth~~r objective of this invention to provide a sole structure of th.e type described which includes at least portions of outer edge quadrants wherein the outer edge of each quadrant coincide: with the horizontal plane of the top of the sole while the other edge is perpendicular to it.
It is will another object of this invention to provide a shoe sole of the type described wherein the bottom or outer sole of the shoe includes most or all of the special contours of the new design, while other portions of the shoe such as the midsole and heel lift are: produced conventionally.
It is still another object of this invention to provide a shoe of the type described which further includes enhancements which are include3 in t:.he structure which defines the theoretically ideal stability plane.
It is ;till another object of this invention to provide a shoe of the type described wherein the enhancements which are included in the structure which defines the theoretically ideal _ g _ stability plane are applied to the single plane or the dual-plane embodiments of the invention as here described.
These and other objectives of the invention will become apparent from a detailed description of the invention which follows taken in conjunci:ion with the accompanying drawings.
Brief Description of the Drawinas In the drawings:
Fig. 1 is a perspective view of a typical running shoe known to the prior ari= to which the invention is applicable;
Fig. 2 shows, in Figs. 2A and 2B, the obstructed natural motion of the shoe heel in frontal planar cross section rotating inwardly or outwardly with the shoe sole having a flared bottom in a conventional prior art design such as in Fig. 1; and in Figs. 2C
and 2D, the efficient: motion of a narrow rectangular shoe sole design;
Fig. 3 is a frontal plane cross section showing a shoe sole of uniform tlzickn~ess that conforms to the natural shape of the human foot, the novel shoe design according to the invention;
Fig. 4 shows, in Figs. 4A-4D, a load-bearing flat component of a shoe sole and naturally contoured stability side component, as well as a preferred horizontal periphery of the flat load-bearing portion of the shoe sole when using the sole of the invention;
Fig. 5 is diagrammatic sketch in Figs. 5A and 5B, showing the novel contoured side sole design according to the invention with variable heel lift;
Fig. 6 is a side view of the novel stable contoured shoe according to the invention showing the contoured side design;
- g _ Fig. 7D is a top view of the shoe sole shown in Fig. 6, wherein Fig. 7A is a cross-sectional view of the forefoot portion taken along liners 7A of Figs. 6 or 7; Fig. 7B is a view taken along lines 7B of Figs.. 6 and 7; and Fig. 7C is a cross-sectional view taken along the heel along lines 7C in Figs. 6 and 7;
Fig. Et is a drawn comparison between a conventional flared sole show of the prior art and the contoured shoe sole design according to the invention;
Fig. 5~ shows, in Figs. 9A-9C, the extremely stable conditions for the novel shoe sole according to the invention in its neutral and extreme situations;
Fig. 13 is a side cross-sectional view of the naturally contoured sole side showing in Fig. l0A how the sole maintains a constant distance from the ground during rotation of the shoe edge;
and showing in Fig. lOB how a conventional shoe sole side cannot maintain a constant distance from the ground.
Fig. 11 shows, in Figs. 11A-11E, a plurality of side sagittal plane cro:~s-sectional views showing examples of conventional soles thickness variations to which the invention can be applied;
Fig. 1;? shows, in Figs. 12A-12D, frontal plane cross-sectional views of the shoe sole according to the invention showing a theoretically ideal stability plane and truncations of the sole side contour to reduce shoe bulk;
Fig. 13 shows, in Figs. 13A-13C, the contoured sole design according to the invention when applied to various tread and cleat patterns;

Fig. 1~E illustrates, in a rear view, an application of the sole accordS.ng to the invention to a shoe to provide an aesthetically pleasing and functionally effective design;
Fig. 1!i shows a fully contoured shoe sole design that follows the natural contour of the bottom of the foot as well as the sides.
Fig. lE> is a diagrammatic frontal plane cross-sectional view of static forces acting on the ankle joint and its position relative to the shoe sole according to the invention during normal and extreme inversion and eversion motion.
Fig. 17 is a diagrammatic frontal plane view of a plurality of moment curves of the center of gravity for various degrees of inversion for the shoe sole according to the invention, and contrasted to the motions shown in Fig. 2:
Fig. lE. shows, in Figs. 18A and 18B, a rear diagrammatic view of a human heel, as relating to a conventional shoe sole (Fig.
18A) and to the ::ole of the invention (Fig. 18B);
Fig. 19 shows the naturally contoured sides design extended to the other natural contours underneath the load-bearing foot such as the main longitudinal arch;
Fig. 20 illustrates the fully contoured shoe sole design extended to the bottom of the entire non-load-bearing foot;
Fig. 21 shows the fully contoured shoe sole design abbreviated alonc3 the sides to only essential structural support and propulsion e'.~ements;
Fig. 2illustrates the application of the invention to provide a street shoe with a correctly contoured sole according to the invention and side edges perpendicular to the ground, as is typical of a street shoe;

~34099~
Fig. 2:3 shows a method of establishing the theoretically ideal stability plane using a perpendicular to a tangent method;
Fig. 2~4 shows a circle radius method of establishing the theoretically ideal stability plane.
Fig. 25 illustrates an alternate embodiment of the invention wherein the sole structure deforms in use to follow a theoretically ideal :>tability plane according to the invention during deformation;
Fig. 2f shows an embodiment wherein the contour of the sole according to the invention is approximated by a plurality of line segments;
Fig. 2~ illustrates an embodiment wherein the stability sides are determined geometrically as a section of a ring; and Fig. 28 shows a shoe sole design that~ allows for unobstructed natural eversion/inversion motion by providing torsional flexibility in the instep area of the shoe sole.
Fig. 29 is a diagrammatic chart showing, in Figs. 29A-29C, the outer contoured sides related to the sole of the novel shoe design according to the invention;
Fig. 30 is diagrammatic sketch in Figs. 30A and 30B, showing the novel contoured side sole design according to the invention with variable heel lift;
Fig. 31 is a side cross-sectional view of the quadrant sole side showing how the sole maintains a constant distance from the ground during rotation of the shoe edge;
Fig. 32 shows, in Figs. 32A-32C, frontal plane cross-sectional views of the shoe sole according to the invention showing a theoretically ideal stability plane and truncations of the sole edge quadrant to :reduce shoe bulk;

Fig. 33 illustrates, in Figs. 33A-33C, heel cross sectional views of a conventional street shoe (Fig. 33A), and the application of the invention shown in Fig. 33B to provide a street shoe (Fig. 33C) with a correctly contoured sole according to the invention;
Fig. 34 :>hows, in a diagrammatic rear view, a relationship between the calcaneal tuberosity of the foot and the use of a wedge with the shoe of the invention;
Fig. :35 illustrates an alternate embodiment of the invention wherein the' sole structure deforms in use to follow a theoretically ideal tability plane according to the invention during deformation;
Fig. 36 shows an embodiment wherein the contour of the sole according to the invention is approximated by a'plurality of chord segments; and Fig. 37 shows in a diagrammatic view the theoretically ideal stability ;plane.
Fig. 3F3 shows several embodiments wherein the bottom sole includes most or all of the special contours of the new designs and retains a flat upper surface.
Fig. 39, in Figs. 39A - 39C, show frontal plane cross sections of an er~hance~ment to the previously-described embodiment.
Fig. 40 shows, in Figs. 40A - 40C, the enhancement of Fig. 39 applied t:o thEa naturally contoured sides embodiment of the invention.
Detailed Description of the Preferred Embodiment A perspective view of an athletic shoe, such as a typical running shoe, a~~cording to the prior art, is shown in Fig. 1 wherein a runnin~~ shoe 20 includes an upper portion 21 and a sole ~ 340997 22. Typically, ouch a sole includes a truncated outwardly flared construction of the type best seen in Fig. 2 wherein the lower portion 22a of the sole heel is significantly wider than the upper portion 22b where thca sole 22 joins the upper 21. A number of alternative sole designs are known to the art, including the design shown in U.S. Patent No. 4,449,306 to Cavanagh wherein an outer portion of the sole of the running shoe includes a rounded portion having a radius of curvature of about 2omm. The rounded portion lies along appro:Kimately the rear-half of the length of the outer side of the mid-sole and heel edge areas wherein the remaining border area is provided with a conventional flaring with the exception of a transition zone. The U.S. Patent to Misevich, No.
4,557,059 also :shows an athletic shoe having a contoured sole bottom in the region of the first foot strike, in h shoe which otherwise uses an inverted flared sole.
In such prior art designs, and especially in athletic and in running shoes, the typical design attempts to achieve stability by flaring the heel a:> shown in Figs. 2A and 2B to a width of, for example, 3 to 3-~1/2 :inches on the bottom outer sole 22a of the average male shoe: size (lOD). On the other hand, the width of the corresponding human heel foot print, housed in the upper 21, is only about 2.25 in. for the average foot. Therefore, a mismatch occurs in that the heel is locked by the design into a firm shoe heel counter which supports the human heel by holding it tightly and which may a7.so b~e re-enforced by motion control devices to stabilize the heel. Thus, for natural motion as is shown in Figs.
2A and 2B, the human heel would normally move in a normal range of motion of approximately 15°, but as shown in Figs. 2A and 2B the human heel cannot: pivot except within the shoe and is resisted by ~~4099~
the shoe. Thus, Fig. 2A illustrates the impossibility of pivoting about the center edge of the human heel as would be conventional for barefoot support .about a point 23 defined by a line 23a perpendicular to the heel and intersecting the bottom edge of upper 21 at a point 24. The lever arm force moment of the flared sole is at a maximum at 0' and only slightly less at a normal 7°
inversion or eve~rsion and thus strongly resists such a natural motion as is illustrated in Figs. 2A and 2B. In Fig. 2A, the outer edge of the heel must compress to accommodate such motion. Fig.
2B illustrates that normal natural motion of the shoe is inefficient in that the center of gravity of the shoe, and the shod foot, is forced upward:Ly, as discussed later in connection with Fig. 17.
A narrow rectangular shoe sole design of heel width approximating human hee:1 width is also known and is shown in Figs.
2C and 2D. It appears to be more efficient than the conventional flared sole shown in Figs. 2A and 2B. Since the shoe sole width is the same as human so7.e width, the shoe can pivot naturally with the normal 7° inversion/eversion motion of the running barefoot.
In such a design, the lever arm length and the vertical motion of the center of gravity are approximately half that of the flared sole at a normal 7° inversion/ever~;ion running motion. However, the narrow, human heel width rectangular shoe design is extremely unstable and therefore prone to ankle sprain, so that it has not been well received. Thus, neither of these wide or narrow designs is satisfactory.
Fig. 3 shows in a frontal plane cross section at the heel (center of ankle joint) the general concept of the applicant's design: a shoe sole 28 !that conforms to the natural shape of the 'Y.

human foot 2'7 and that has a constant thickness (s) in frontal plane cross sections. The surface 29 of the bottom and sides of the foot 27 should correspond exactly to the upper surface 30 of the shoe sole a:8. The' shoe sole thickness as measured in frontal plane cross sections is defined as the shortest distance (s) between any point on t:he upper surface 30 of the shoe sole 28 and the lower surf;~ce 31 by definition, the surfaces 30 and 31 are consequently parallel (Figs. 23 and 24 will discuss measurement methods more fu:Lly). un effect, the applicant's general concept is a shoe sole 28 that wraps around and conforms to the nature contours of the foot 27 as if the shoe sole 28 were made of a theoretical single flat sheet of shoe sole material of uniform thickness, wrapped around the foot with no distortion or deformation of that sheet as it is bent to the foot's contours. To overcome real world deformation problems associated with such bending or wrapping around contours, actual construction of the shoe sole contours of uniform thickness will preferably involve the use of multiple sheet :Lamination or injection molding techniques.
Figs. 4A, 4B, and 4C illustrate in frontal plane cross section a significant element of the applicant's shoe design in its use of naturally contoured stabilizing sides 28a at the outer edge of a shoe sole 28b illustrated generally at the reference numeral 28. It is thus a maim feature of the applicant's invention to eliminate the unnatura:L sharp bottom edge, especially of flared shoes, in favor of a naturally contoured shoe sole outside 31 as shown in Fig. 3. The side or inner edge 30a of the shoe sole stability side 2ga is contoured like the natural form on the side or edge of the human foot, as is the outside or outer edge 31a of the shoe sole stability side 28a to follow a theoretically ideal stability plane. According to the invention, the thickness (s) of the shoe sole 28 is maintained exactly constant, even if the shoe sole is tilted to either side, or forward or backward. Thus, the naturally contoured stabilizing sides 28a, according to the applicant's invention, are defined as the same as the thickness 33 of the shoe sole 28 so that, in cross section, the shoe sole comprises a stabl'.e shoe sole 28 having at its outer edge naturally contoured stabilizing sides 28a with a surface 31a representing a portion of a theoretically ideal stability plane and described by naturally contou:ced sides equal to the thickness (s) of the sole 28. The top of the shoe: sole 30b coincides with the shoe wearer's load-bearing fooi~print, since in the case shown the shape of the foot is assumed to be .load-bearing and therefore flat along the bottom. A top edge 32 of the naturally contoured stability side 28a can be located at any point along the contoured side 29 of the foot, while the inner edge 33 of the naturally contoured side 28a coincides with the perpendicular sides 34 of the load-bearing shoe sole 28b. In practice, the shoe sole 28 is preferably integrally formed fror,~ the portions 28b and 28a. Thus, the theoretically ideal stability plane includes the contours 31a merging into the lower surface 31b of the sole 28.
Preferably, the peripheral extent 36 of the load-bearing portion of the sale 28b of the shoe includes all of the support structures of the foot but extends no further than the outer edge of the foot sole 37 as defined by a load-bearing footprint, as shown in Fig. 4D, which is a top view of the upper shoe sole surface 30b. Fig. 4D thus illustrates a foot outline at numeral 37 and a recommended sole outline 36 relative thereto. Thus, a horizontal plane outline of the top of the load-bearing portion of the shoe sole, therefore exclusive of contoured stability sides, ~i should, preferably, coincide as nearly as practicable with the load-bearing portion oo the foot sole with which it comes into contact. Such a horizontal outline, as best seen in Figs. 4D and 7D, should remain uniform throughout the entire thickness of the shoe sole eliminating negative or positive sole flare so that the sides are exactly perpendicular to the horizontal plane as shown in Fig. 4B. Preferably, the density of the shoe sole material is uniform.
Another significant feature of the applicant's invention is illustrated diagrammatically in Fig. 5. Preferably, as the heel lift or wedge 38 of thickness (sl) increases the total thickness (s + sl) of the combined midsole and outersole 39 of thickness (s) in an aft direction of t:he shoe, the' naturally contoured sides 28a increase in thickness exactly the same amount according to the principles discussed in connection with Fig. 4. Thus, according to the applicant's design, the thickness of the inner edge 33 of the naturally contoured side is always equal to the constant thickness (s) of the load-bearing shoe sole 28b in the frontal cross-sectional plane.
As shown in Fig. 5B, for a shoe that follows a more conventional horizontal plane outline, the sole can be improved significantly ac:cordin<3 to the applicant's invention by the addition of a naturally contoured side 28a which correspondingly varies with the thickness of the shoe sole and changes in the frontal plane according to the shoe heel lift 38. Thus, as illustrated in Fig. 5B, the thickness of the naturally contoured side 28a in the heel secaion is equal to the thickness (s + sl) of the shoe sole 28 which is thicker than the shoe sole 39 thickness (s) shown in Fig. 5A by an amount equivalent to the heel lift 38 lg ._ >, thickness (sl). In the generalized case, the thickness (s) of the contoured side is thus always equal to the thickness (s) at the forefoot of the shoe ;sole.
Fig. 6 illustrates a side cross-sectional view of a shoe to which the invention has been applied and is also shown in a top plane view in fig. 7. Thus, Figs. 7A, 7B and 7C represent frontal plane cross-secaions 'taken along the forefoot, at the base of the fifth metatarsal, and at the heel, thus illustrating that the shoe sole thickness is constant at each frontal plane cross-section, even though that thickness varies from front to back, due to the heel lift 38 as shown in Fig. 6, and that the thickness of the naturally cont~~ured sides is equal to the shoe sole thickness in each Fig. 7A-7<: cross section. Moreover, in Fig. 7D, a horizontal plane overview of the left foot, it can be seen that the contour of the sole follows the preferred principle in matching, as nearly as practical, 'the load-bearing sole print shown in Fig. 4D.
Fig. 8 thus contrasts in frontal plane cross section the conventional flared sole 22 shown in phantom outline and illustrated in Fig. 2 with the contoured shoe sole 28 according to the invention as shown in Figs. 3-7.
Fig. 9 is :suitable for analyzing the shoe sole design according to the applicant's invention by contrasting the neutral situation show:z in Fic~. 9A with the extreme tilting situations shown in Figs. 9B and 9C. Unlike the sharp sole edge of a conventional shoe as shown in Fig. 2, the effect of the applicant's invention having a naturally contoured side 28a is totally neutral allowing the shod foot to react naturally with the ground 43, in either an inver-sion or eversion mode. This occurs in part because of the unvarying thickness along the ;hoe sole edge which keeps the foot sole ~3409g~
equidistant from the ground in a preferred case. Moreover, because the shape of the edge 31a of the shoe contoured side 28a is exactly like that of the edge of the foot, the shoe is enabled to react naturally with the ground in a manner as closely as possible simulating the foot. Thus, in the neutral position shown in Fig.
9, any point 40 on the surface of the shoe sole Sob closest to ground lies at a distance (s) from the ground surface 43. That distance (s) remains <:onstant even for extreme situations as seen in Figs. 9B and 9C.
A main point of the applicant's invention, as is illustrated in Figs. 9B and 9C, is that the design shown is stable in an in extremis situation. The theoretically ideal plane of stability is where the stability plane is defined as sole thickness which is constant under all load-bearing points of the foot sole for any amount from 0° to 90° rotation of the sole to either side or front and ba<:k. In other words, as shown in Fig. 9, if the shoe is tilted from 0° to 90° to either side or from 0° to 90° forward or backw,~rd representing a 0 ° to 90 ° foot dorsiflexion or 0 ° to 90 °
plantarflexion, the foot will remain stable because the sole thickness (s) between the foot and the ground always remain constant because of the exactly contoured sides. By remaining a constant distance from the ground, the stable shoe allows the foot to react to the ground as if the foot were bare while allowing 1=he foot to be protracted and cushioned by the shoe.
In its preferred embodiment, the new naturally contoured sides will effectively position and hold the foot onto the load-bearing foot print section of the shoe sole, reducing or eliminating the need for heel counters and other relatively rigid motion control devices.

Fig. l0A i7.lustrates how the inner edge 30a of the naturally contoured sole side 28a is maintained at a constant distance (s) from the ground through various degrees of rotation of the edge 31a of the shoe sole such as is shown in Fig. 9.
Figure lOB shows how a conventional shoe sole pivots around its lower edge 42, which is its center of rotation, instead of around the upper edge 40, which, as a result, is not maintained at constant distance (s) from the ground, as with the invention, but is lowered to .7(s) at: 45° rotation and to zero at 90°
rotation.
Fig. 11 shows typical conventional sagittal plane shoe sole thickness variations, such as heel lifts or wedges 38, or toe taper 38a, or full sole taper 38b, in Figs. 11A-11E and how the naturally contoured sides 28a equal and therefore vary with those varying thicknesses as discussed in connection with Fig. 5.
Fig. 7.2 illu:>trates an embodiment of the invention which utilizes varying portions of the theoretically ideal stability plane 51 in the naturally contoured sides 28a in order to reduce the weight and bulk o!: the sole, while accepting a sacrifice in some stability of the: shoe. Thus, Fig. 12A illustrates the preferred embodiment as described above in connection with Fig. 5 wherein the outer edge 31a of the naturally contoured sides 28a follows a theoretically ideal stability plane 51. As in Figs. 3 and 4, the contoured surfaces 31a, and the lower surface of the sole 31b lie along the i~heoretically ideal stability plane 51. The theoretically ideal stability plane 51 is defined as the plane of the surface of 'the bottom of the shoe sole 31, wherein the shoe sole conforms t:o the natural shape of the wearer's foot sole, particularly the sides'., and has a constant thickness in frontal plane cross sections. As shown in Fig. 12B, an engineering trade-off results in an abbreviation within the theoretically ideal stability plane 51 by forming a naturally contoured side surface 53a approximating the natural contour of the foot (or more geometrically regular, which is less preferred) at an angle relative to the upper plane of the shoe sol<~ 28 so that only a smaller portion of the contoured side 28a defined by the constant thickness lying along the surface 31a is coplanar with i~he theoretically ideal stability plane 51.
Figs. 12C and 12;D show similar embodiments wherein each engineering trade-off shown resu:Lts in progressively smaller portions of contoured side 28a, which lies along the theoretically ideal stability plane 51. The portion of the surface 31a merges into the upper side surface 53a of the natu rally contoured side.
The embodiment of Fig. 12 may be desirable for portions of the shoe sole which. are less frequently used so that the additional part of the side' is used less frequently. For example, a shoe may typically roll out laterally, in an inversion mode, to about 20°
on the order of 100 times for each single time it rolls out to 40°.
For a basketball shoe, shown in Fig. 12B, the extra stability is needed. Yet, i:he added shoe weight to cover that infrequently experienced range of rnotion is about equivalent to covering the frequently encounter range. Since, in a racing shoe this weight might not be desirable, an engineering trade-off of the type shown in Fig. 12D is possible. A typical running/jogging shoe is shown in Fig. 12C. The range of possible variations is limitless but includes at lea~~t the maximum of 90° in inversion or eversion, as shown in Fig. l~;A.
Fig. 13 shows. the theoretically ideal stability plane 51 in defining embodiments. of the shoe sole having differing tread or cleat patterns. Thus, Fig. 13 illustrates that the invention is applicable to shoe soles having conventional bottom treads.
Accordingly, Fig'. 13A is similar to Fig. 12B further including a 1 340 gg 7 tread portion 60, whilLe Fig. 13B is also similar to Fig. 12B
wherein the sole includes a cleated portion 61. The surface 63 to which the cleat bases a:re affixed should preferably be on the same plane and paral:Le1 the: theoretically ideal stability plane 51, since in soft ground that surface rather than the cleats become load-bearing. The embodiment in F.ig. 13C is similar to Fig. 12C
showing still an alternative tread construction 62. In each case, the load-bearing outer ;surface of the tread or cleat pattern 60-62 lies along the theoretically ideal stability plane 51.
Fig. 7.4 shows, in a rear cross sectional view, the application of the invention to a shoe to produce an aesthetically pleasing and functionally effective design. Thus, a practical design of a shoe incorporating the invention is feasible, even when applied to shoes incorporating heel lifts 38 and a combined midsole and outersole 3f. Thus, use of a sole surface and sole outer contour which track the theoretically ideal stability plane does not detract from the commercial appeal of shoes incorporating the invention.
Fig. 1!5 shows a fully contoured shoe sole design that follows the natural contour of all of the foot, the bottom as well as the sides. 'The fully contoured shoe sole assumes that the resulting slightly rounc9ed bottom when unloaded will deform under load and flatten just as the human foot bottom is slightly rounded unloaded but flattens under load; therefore, shoe sole material must be of such composition as to allow the natural deformation following that of the foot. The design applies particularly to the heel, but to the rest oi-.' the shoe sole as well. By providing the closest match to i:he natural shape of the foot, the fully contoured design allows the foot to function as naturally as possible. Under f~

load, Fig. 15 would deform by flattening to look essentially like Fig. 14. Seen in this light, the naturally contoured side design in Fig. 14 is a more conventional, conservative design that is a special case of the more general fully contoured design in Fig. 15, which is the closest to the natural form of the foot, but the least conventional. The amount of deformation flattening used in the Fig. 14 design, which obviously varies under different loads, is not an essential element of the applicant's invention.
Figs. 14 and 15 both show in frontal plane cross section the essential concept 'underlying this invention, the theoretically ideal stabilit~t plane', which is also theoretically ideal for efficient natural motion of all kinds, including running, jogging or walking. Fig. 15 shows the most general case of 'the invention, the fully contoured design, which conforms to the natural shape of the unloaded foot. For any given individual, the theoretically ideal stability plane 51 is determined, first, by the desired shoe sole thickness (s) in a frontal plane cross section, and, second, by the natural shape o:E the individual's foot surface 29, to which the theoretica'_ly ideal stability plane 51 is by definition parallel.
For the special case shown in Fig. 14, the theoretically ideal stability plane for any particular individual (or size average of individuals) is determined, first, by the given frontal plane cross section shoe sole thickness (s); second, by the natural shape of the individual's foot; and, third, by the frontal plane cross section width of the individual's load-bearing footprint 30b, which is defined as th~~ upper surface of the shoe sole that is in physical contact: with a.nd supports the human foot sole, as shown in Fig. 4.
The theoreti~~ally ideal stability plane for the special case is composed conceptually of two parts. Shown in Figs. 14 and 4 the first part is a line segment: 31b of equal length and parallel to 30b at a constant distance (s) equal to shoe sole thickness.
This correspor..ds to <~ conventional shoe sole directly underneath the human foot, and also corresponds to the shoe sole portion 28b under flattened portion of the bottom of the load-bearing foot sole. The second part is the naturally contoured stability side outer edge 31a located at each side of the first part, line segment 31b. Each point on the contoured side outer edge 31a is located at a distance which is exactly shoe sole thickness (s) from the closest point on the contoured side inner edge 30a, consequently, the inner and outer contoured edges 31a and 30a are by definition parallel.
In summary, the theoretically ideal stability plane is the essence of this invention because it is used to determine a geometrically F~recise bottom contour of the shoe sole based on a top contour that conforms to the contour of the foot. This invention specifically claims the exactly determined geometric relationship just described. It can be stated unequivocally that any shoe sole contour, even of similar contour, that exceeds the theoretically ideal stability plane will restrict natural foot motion, while any less than that plane will degrade natural stability, in direct proportion to the amount of the deviation.
Fig. 16 illustrates in a curve 70 the range of side to side inversion/eversion motion of the ankle center of gravity 71 from the shoe according to the invention shown in frontal plane cross section at the ankle. Thus, in a static case where the center of gravity 71 :lies at approximately the mid-point of the sole, and assuming that the shoe inverts or everts from 0° to 20°
to 40°, as shown in progressions 16A, 16B and 16C, the locus of points of motion for the center of gravity thus defines the curve 70 wherein the center of gravity 71 maintains a steady level motion 1~4 ~ , with no vertical component through 40° of inversion or eversion.
For the embodiment shown, the shoe sole stability equilibrium point is at 28° (at point 74) and in no case is there a pivoting edge to define a rotation point as in the case of Fig. 2. The inherently superior, side to side stability of the design provides pronation control (or eversion), as well as lateral (or inversion) control.
In marked contrast to conventional shoe sole designs, the applicant's shoe design creates virtually no abnormal torque to resist natural i.nversion/eversion motion or to destabilize the ankle joint.
Fig. 17 thus compares the range of motion of the center of gravity for the invention, as shown in curve 70, in comparison to curve 80 for the conventional wide heel flare and a curve 82 for a narrow rectangle the width of a human heel. Sihce the shoe stability limit is 28° in the inverted mode, the shoe sole is stable at the 20° approximate barefoot inversion limit. That factor, and the broad base of support rather than the sharp bottom edge of the prior art, make the contour design stable even in the most extreme case as shown in Figs. 26A-16C and permit the inherent stability of the barefoot to dominate without interference, unlike existing designs, by providing constant, unvarying shoe sole thickness in frontal plane cross sections. The stability superiority of the contour side design is thus clear when observing how much flatter its center of gravity curve 70 is than in existing popular wide flare design 80. The~ curve demonstrates that the contour side design has significantly more efficient natural 7°
inversion/eversion motion than the narrow rectangle design the width of a human heel, atte~ very much more efficient than the conventional wide: flare design: at the same time, the contour side ~34099~
design is more :table ,in extremis than either conventional design because of the absence of destabilizing torque.
Fig. 18A illustrates, in a pictorial fashion, a comparison of a cross :section at the ankle joint of a conventional shoe with a cross section of a shoe according to the invention when engaging a heel. As seen in Fig. 18A, when the heel of the foot 27 of the wearer engages an upper s>urface of the shoe sole 22, the shape of the i_°oot he>el and the shoe sole is such that the conventional shoe sole 22 conforms to the contour of the ground 43 and not to the contour of the sides of the foot 27. As a result, the conventional shoe: sole 22 cannot follow the natural 7°
~inversion/eversi_on motion of the foot, and that normal motion is resisted by the shoe upper 21, especially when strongly reinforced by firm heel counters and motion control devices. This interference with nal:ural motion represents the fundamental misconception of the currently available designs. That misconception on which existing shoe designs are based is that, while shoe uppers are considered as a part of the foot and conform to the shape of the foot, the shoe sole is functionally conceived of as a part of the ground and is therefore shaped flat like the ground, rather than contoured like the foot.
In contrast, the new design, as illustrated in Fig. 18B, illustrates a correct conception of the shoe sole 28 as a part of the foot and an extension of the foot, with shoe sole sides contoured exactly like those of the foot, and with the frontal plane thickness of the shoe sole between the foot and the ground always the same and therefore completely neutral to the natural motion of the foot. With the correct basic conception, as described in connection with this invention, the shoe can move naturally with the foot, instead of restraining it, so both natural stability and natural efficient motion coexist in the same shoe, with no inherent contradiction in design goals.
Thus, 'the contoured shoe design of the invention brings together in one ahoe design the cushioning and protection typical of modern shoes, with the freedom from injury and functional efficiency, meaning speed, and/or endurance, typical of barefoot stability and natural. :freedom of motion. Significant speed and endurance improvements are anticipated, based on both improved efficiency and en the ability of a user to train harder without injury.
These figures also illustrate that the shoe heel cannot pivot plus or minus 7 d~:grees with the prior art shoe of Fig. 18A.
In contrast, the shoe heel in the embodiment of Fic~. 18B . pivots with the natural motion of the foot heel.
Figs. :19A-D illustrate, i:n frontal plane cross sections, the naturally contoured sides design extended to the other natural contours underneath the load-bearing foot, such as the main longitudinal arch, the metatarsal (or forefoot) arch, and the ridge between the heads of the metatarsals (forefoot) and the heads of the distal phala.nges (noes). As shown, the shoe sole thickness remains constant as the: contour of the shoe sole follows that of the sides and bottom of: the load-bearing foot. Fig. 19E shows a sagittal plane cross section of the shoe sole conforming to the contour of the 'oottom of the load-bearing foot, with thickness varying accordin~l to thca heel lift 38. Fig. 19F shows a horizontal plane top view oi: the left foot that shows the areas 85 of the shoe sole that correspond to the flattened portions of the foot sole that are in contact with the ground when load-bearing. Contour lines 86 and 87 ..how approximately the relative height of the shoe sole contours above the flattened load-bearing areas 85 but within roughly the peripheral extent 35 of the upper surface of sole 30 shown in Fig. 4. A horizontal plane bottom view (not shown) of Fig. 19F would be the exact reciprocal or converse of Fig. 19F
(i.e. peaks and valleys contours would be exactly reversed).
Figs. 20A-D show, in frontal plane cross sections, the fully contoured shoe sole design extended to the bottom of the entire non-load-bearing foot. Fig. 20E shows a sagittal plane cross section. The shoe sole contours underneath the foot are the same as Figs. 1.9A-E except that there are no flattened areas corresponding to the flzittened areas of the load-bearing foot. The exclusively rounded contours of the shoe sole follow those of the unloaded foot. A heel lift 38, the same as that of Fig. 19, is incorporated in 'this embodiment, but is not shown in Fig. 20.
Fig. 21 shows the horizontal plane top view of the left foot corresponding to the fully contoured design described in Figs.
20A-E, but abbreviated ailong the sides to only essential structural support and propulsion elements. Shoe sole material density can be increased in t:he unabbreviated essential elements to compensate for increased pressure loading there. The essential structural support element:a are the base and lateral tuberosity of the calcaneus 95, the heads of the metatarsals 96, and the base of the fifth metatarsal 97. They must be supported both underneath and to the outside for stability. The essential propulsion element is the head of first distal phalange 98. The medial (inside) and lateral (outside) side: supporting the base of the calcaneus are shown in Fig. 21 oriented roughly along either side of the horizontal plane subtalar ankle joint axis, but can be located also more conventionally along the longitudinal axis of the shoe sole.
Fig. 21 shows that the naturally contoured stability sides need not be used except in the identified essential areas. Weight savings and flexibilit~~ improvements can be made by omitting the non-essential stability sides. Contour lines 85 through 86 show approximately t:he relative height of the shoe sole contours within roughly the peripheral extent 35 of the undeformed upper surface of shoe sole 30 shown in Fig. 4. A horizontal plane bottom view (not shown) of Fig. 27. would be the exact reciprocal or converse of Fig. 21 (i.e. peaks and valleys contours would be exactly reversed).
Fig. 22A shows a development of street shoes with naturally contoured sole sides incorporating the features of the invention. Fig. 22A develops a theoretically ideal stability plane 51, as describfad above, for such a street shoe, wherein the thickness of the naturally contoured sides equals the shoe sole thickness. The resulting street shoe with a correctly contoured sole is thus shoran in frontal plane heel cross section in Fig. 22A, with side edges perpendicular to the ground, as is typical. Fig.
22B shows a similar street shoe with a fully contoured design, including the bottom of the sole. Accordingly, the invention can be applied to an unconventional heel lift shoe, like a simple wedge, or to the most conventional design of a typical walking shoe with its heel separated from the forefoot by a hollow under the instep. The invention can be applied just at the shoe heel or to the entire shoe sole. With the invention, as so applied, the stability and natural motion of any existing shoe design, except high heels or spike heels, can be significantly improved by the naturally contou~~ed shoe sole design.

Fig. 23 shows, a method o1: measuring shoe sole thickness to be used to construct the theoretically ideal stability plane of the naturally contoured side design. The constant shoe sole thickness of this design is measured at any point on the contoured sides along a line that, first, is perpendicular to a line tangent to that point on the surface of the naturally contoured side of the foot sole and, second, that passes through the same foot sole surface point.
Fig. 24 illustrates another approach to constructing the theoretically ideal stability plane, and one that is easier to use, the circle radius method. By that method, the pivot point (circle center) of a compass is placed at the beginning of the foot sole's natural side cor,"tour (Frontal plane cross section) and roughly a 90° arc (or much less, if estimated accurately) of~a circle of radius equal to (s) or ;shoe sole thickness is drawn describing the area farthest away from the foot sole contour. That process is repeated all along the foot sole's natural side contour at very small intervals (the smaller, the more accurate). When all the circle sections are drawn, the outer edge farthest from the foot sole contour (again, frontal plane cross section) is established at a distance of "s" and that auter edge coincides with the theoretically ideal stability plane. Both this method and that described in Fic~. 23 would be used for both manual and CADCAM
design applications.
The shoe sole according t.o the invention can be made by approximating the contours, as indicated in Figs. 25A, 25B, and 26.
Fig. 25A shows a fronta~Z plane cross section of a design wherein the sole materi~il in areas 107 is so relatively soft that it deforms easily t:o the contour of shoe sole 28 of the proposed invention. In th,e proposed approximation as seen in Fig. 25B, the heel cross section includes a sole upper surface 101 and a bottom sole edge surface 102 following when deformed an inset theoretically ideal stability plane 51. The sole edge surface 102 terminates in a laterally extending portion 103 joined to the heel of the sole 28. The laterally-extending portion 103 is made from a flexible material and structured to cause its lower surface 102 to terminate during deformation to parallel the inset theoretically ideal stability F~lane 57.. Sole material in specific areas 107 is extremely soft to allow :sufficient deformation. Thus, in a dynamic case, the outer edge contour assumes approximately the theoreti-cally ideal stability shape described above as a result of the deformation of the portion 103. The top surface 101 similarly deforms to approximately parallel the natural contouY of the foot as described by lines 30a and 30b shown in Fig. 4.
It is presently contemplated that the controlled or programmed deformation can be provided by either of two techniques.
In one, the shoe :sole sides, at especially the midsole, can be cut in a tapered fashion or grooved so that the bottom sole bends inwardly under pressure to the correct contour. The second uses an easily deformable material 107 in a tapered manner on the sides to deform under pressure to the correct contour. While such techniques produce stability and natural motion results which are a significant improvement over conventional designs, they are inherently inferp.or to contours produced by simple geometric shaping. First, the <~ctual deformation must be produced by pressure which is unnatural and does not occur with a bare foot and second, only approximations are possible by deformation, even with sophisticated de;~ign and manufacturing techniques, given an individual's particular running gait or body weight. Thus, the deformation process is limited to a minor effort to correct the contours from surfaces approximating the ideal curve in the first instance.
The theoreti<:ally ideal stability plane can also be approximated by a plurality of line segments 110, such as tangents, chords, or otheo lines. as shown in Fig. 26. Both the upper surface of the shoe sole 28, which coincides with the side of the foot 30a, and the bottom surface 31a of the naturally contoured side can be approximated. While a single flat plane 110 approximation many correct many of the biomechanical problems occurring with existing' designs, because it can provide a gross approximation of the both natural contour of the foot and the theoretically ideal suability plane 51, the single plane approximation is presently not preferred, since it is the least optimal. By increasing the number of flat planar surfaces formed, the curve more closely approximates the ideal exact design contours, as previously described. Single and double plane approximations a,_e shown as line segments in the cross section illustrated in Fig. 26.
Fig. 27 shows a frontal. plane cross section of an alternate embodiment far the invention showing stability sides component 28a that are determined in a mathematically precise manner to conform approximately to the sides of the foot. (The center or load-hearing shoe sole component 28b would be as described in Fig. 4). T.he component sides 28a would be a quadrant of a circle of ra~3it~s (r + r'), where distance (r) must equal sole thickness (s); consequently the sub-quadrant of radius (r') is removed from quadrant (r + r'). In geometric terms, the component 1 34p gg 7 side 28a is thus a quarter or other section of a ring. The center of rotation 115 of the quadrants i.s selected to achieve a sole upper side surface 30a that closely approximates the natural contour of the side of t:he human foot.
Fig. 27 provides a direct bridge to another invention by the applicant, a shoe sole design with quadrant stability sides.
Fig. 28 shows a shoe :sole design that allows for unobstructed natural inversion/eversion motion of the calcaneus by providing maximum shoe sole flexibility particularly between the base of the calc;aneus 125 (heel) and the metatarsal heads 126 (forefoot) along an axi:a 120. An unnatural torsion occurs about that axis if flexibility is insufficient so that a conventional shoe sole interferes with the inversion/eversion motion by restraining it. The object of the design is to allow the relatively more mobile (in eversion and inversion) calcaneus to articulate freely and independently from the relatively more fixed forefoot, instead of the fixed or fused structure or lack of stable structure between the two in conventional designs. In a sense, freely articulating joints are created in the shoe sole that parallel those of the foot. The design is to remove nearly all of the shoe sole material between the heel and the forefoot, except under one of the previously described essential structural support elements, the base of then fifth metatarsal 97. An optional support for the main longitudinal arch 121 may also be retained for runners with substantial foot p;ronation, although would not be necessary for many runners. The forefoot can be subdivided (not shown) into its component esss:ntial :>tructural support and propulsion elements, the individual heads of the metatarsal and the heads of the distal phalanges, so that each major articulating joint set of the foot 1 340 gg 7 is paralleled by a freely articulating shoe sole support propulsion element, an anthropomorphic design; various aggregations of the subdivisions are also possible. An added benefit of the design is to provide better fle:~tibility along axis 122 for the forefoot during the toe-off propulsive phase of the running stride, even in the absence of any other embodiments of the applicant's invention;
that is, the benefit exists for conventional shoe sole designs.
Fig. 2~3A showa in sagittal plane cross section a specific design maximizing flexibility, with large non-essential sections removed for flexibility and connected by only a top layer (horizontal plane) of non-stretching fabric 123 like * Dacron polyester or*Kevlar. Fig. 28B shows another specific design with a thin top sole: layer 124 instead of fabric and a different structure for the flexibility sections: a design variation that provides greater structural support, but less flexibility, though still much more than conventional designs. Not shown is a simple, minimalist approach, which is comprised of single frontal plane slits in the shoe sole material (all layers or part): the first midway between th,e base of the calcaneus and the base of the fifth metatarsal, and the second midway between that base and the metatarsal heads. Fig. 28C shows a bottom view (horizontal plane) of the inversionjeversion flexibility design.
Fig. 2!3 illustrates in frontal plane cross section a significant element of 'the applicant's shoe design in its use of stabilizing quadrants 26 at the outer edge of a shoe sole 28b illustrated generally at: the reference numeral 28. It is thus a main feature of the ;applicant's invention to eliminate the unnatural sharp bottom edge, especially of flared shoes, in favor of a rounded shoe sole Badge 25 as shown in Fig. 29. The side or Trade mark edge 25 of the shoe sole 28 is contoured much like the natural form on the side or Edge of the human foot, but in a geometrically precise manner to follow a theoretically ideal stability plane.
According to the invention, the thickness (s) of the shoe sole 28 is maintained exactly constant, even if the shoe sole is tilted to either side, or i:orward or backward. Thus, the side stabilizing quadrants 26, according to the applicant's invention, are defined by a radius 25a which is the same as the thickness 34 of the shoe sole 28b so that, in cross section, the shoe sole comprises a stable shoe sole 28 having at its outer edges quadrants 26 a surface 25 representing a portion of a theoretically ideal stability plane and described by a radius 25a equal to the thickness (s) of the sole and a quadrant center of rotation at the outer edge 41 at t:he top of the shoe sole 30b, which coincides with the shoe wearer's load-bearing footprint. An outer edge 32 of the quadrant 26 coincides with the horizontal plane of the top of the shoe sole 28b, while the other edge of the quadrant 26 is perpendicular to the edge 32 and coincides with the perpendicular sides 34 of the shoe sole 28b. In practice, the shoe sole 28 is preferably integrally formed from the portions 28b and 26. The outer edge 32 may also extend to lie at an angle relative to the sole upper surfac~_. Thus, the theoretically ideal stability plane includes the contours 25 merging into the lower surface 31b of the sole 28b.
Preferably, th.e peripheral. extent of the sole 36 of the shoe includes all of the support structures of the foot but extends no further than the outE:r edge of the foot sole 37 as defined by a load-bearing footprint, as shown in Fig. 4D, which is a top view of the upper shoe sole surface 30b. Fig. 4D thus illustrates a foot outline at numeral 37 and a recommended sole outline 36 relative thereto.. Thus, a horizontal plane outline of the top of the shoe sole should, preferably, coincide as nearly as practicable with the load-bearing portion of the foot sole with which it comes into contact. Such a horizontal outline, as best seen in Fig. 4D, should remain uniform throughout the entire thickness of the shoe sole eliminating negative or positive sole flare so that the sides are exactly perpendicular to the horizontal plane as shown in Fig.
29B. Preferably, the density of the shoe sole material is uniform.
Another signii'icant feature of the applicant's invention is illustrated diagrammatically in Fig. 30. Preferably, as the heel lift or wedgre increases the thickness (s) of the shoe sole in an aft direction of the shoe, the side quadrants 26 increase about exactly the same amount according to the principles'discussed in connection with Fig. 29. Thus, according to the applicant's design, the radius 25a of curvature (r) of the side quadrant is always equal i.o the constant thickness (s) of the shoe sole in the frontal cross sectional plane.
As shown in Fig. 30B, far a shoe that follows a more conventional horizontal plane outline, the sole can be improved significantly according to the applicant's invention by the addition of oui:er edge quadrant 26 having a radius which correspondingly varies with the thickness of the shoe sole and changes in the frontal plane according to the shoe heel lift.
Thus, as illustrated in Fig. 30B, the radius of curvature of the quadrant 26a is equal 'to the thickness sl of the shoe sole 28b which is thicker than t:he shoe sole (s) shown in Fig. 30A by an amount equivalent to tlhe heel lift: (s-sl) . In the generalized case, the radius (rl) of the quadrant is thus always equal to the thickness (s) of the shoe sole.
Fig. 37. illustrates how the center of rotation of the quadrant sole side 41 is maintained at a constant distance (s) from the ground through various degrees of rotation of the edge 25 of the shoe sole, in contrast to Figure loB. By remaining a constant distance from the ground, the stable shoe allows the foot to react to the ground as if the foot were bare while allowing the foot to be protected and cushioned by the shoe. In its preferred embodiment, the new contoured design assumes that the shoe uppers 21, including heel counters and other motion control devices, will effectively position and hold the foot onto the load-bearing foot print section of the shoe sole.
Fig. 32 illusitrates an embodiment of the invention which utilizes only a portion of the theoretically ideal stability plane 51 in the quadrants 26 .in order to reduce the weight and bulk of the sole, while accepting a sacrifice in some stability of the shoe. Thus, Fid. 32A illustrates the preferred embodiment as described above in connection with Fig. 30 wherein the outer quadrant 50 follows a theoretically ideal stability plane 51 about a center 52 and defines a surface 53 which is coplanar (or at an angle) with the upper surface of the shoe sole 54. As in Fig. 29, the contoured surfaces !50, and the lower surface of the sole 54A
lie along the theoretically ideal stability plane. As shown in Fig. 32B, an engineering trade-of.f results in an abbreviation within the ideal stability plane 51 by forming a quadrant surface 53a at an angle relative: to the upper plane of the shoe sole 54 so that only a portion of the quadrant defined by the radius lying along the surface 50a is coplanar with the theoretically ideal stability plane °_.1. Fig. 32C shows a similar embodiment wherein the engineering tirade-off results in a portion 50b which lies along the theoretically ideal stability plane 51. The portion 50b merges into a second portion 56 which itself.' merges into the upper surface 53a of the quadrant.
The embodiment. of Fig. 32 may be desirable for portions of the shoe sole which are less frequently used so that the additional part of the side is used less frequently. For example, a shoe may typically roll out laterally, in an inversion mode, to about 20 degree on the order of 100 times for each single time it rolls out to 40 degree. Yet, the added shoe weight to cover that entire range is about equivalent to covering the limited range.
Since in a racing shoe this weight might not be desirable, an engineering trade-off of the type shown in Fig. 32C is possible.
Fig. 3°., in Figs. 33A-33C, shows a development of a street shoe with a~ contoured sole incorporating the features of the invention. Fig. ..3A shows a heel cross section of a typical street shoe 94 having a sole portion 79 arid a heel lift 81. Fig. 33B
develops a theoreticall;r ideal stability plane 51, as described above, for such a street shoe, wherein the radius (r) of curvature of the sole edgE~ is equal to the shoe sole thickness. The resulting street shoe with a correctly contoured sole is thus shown in Fig. 33C, with a reduced side edge thickness for a less bulky and more aestheti~~ally pleasing look. Accordingly, the invention can be applied to an unconventional heel lift shoe, like a simple wedge, or to the most conventional design of a typical walking shoe with its heel separated from the forefoot by a hollow under the instep. For the embodiment of Fig. 33, the theoretically ideal stability plane is determined by the shoe sole width and thickness, ;;
1 340 gg 7 using an optimal human heel width as measured along the width of the hard human heel tissue on which the heel is assumed to rotate in an inversion/eversion mode. With the invention, as so applied, the stability and natural motion of any existing shoe design, except high heels or spike heels, can be significantly improved by contouring the bottom sole to the theoretically ideal stability plane.
Figs. 34A and 34B show the possible desirability of using wedge inserts 84 with t:he sole of the invention to support the calcaneal tuberosity. As seen in Fig. 34A, the calcaneal tuberosity 99 is unsupported when a shoe of the prior art is inverted through an angle of 20 degrees. This is about the natural extreme limit of calcaneal inversion motion at which point the calcaneal tubero:city, :located on the lateral side of the calcaneus, makes contact with the ground and restricts further lateral motion. When the conventional wide shoe sole reaches such an inversion limit, the sole leaves the calcaneal tuberosity 99 completely unsupported in the area :100, whereas when the foot is bare, the calcaneal tuberosity contacts the ground, providing a firm base of support. To address this situation, a wedge 84 of a relatively firm material, usually roughly equivalent to the density of the midsole and the heel lift, is located on top of the shoe sole under the insole i.n the lateral heel area_ to support the lateral calcaneal tubero;sity. Thus, such a wedge support can also be used with the sole of the invention as shown in Fig. 34B.
Usually, such a wedge will taper toward the front of the shoe and is contoured to tree shape>. of the calc:aneus and its tuberosity. If preferred, the wedge can be integrated with and be a part of a typical contoured heel o:E an insole.

The shoe sole according to the invention can be made by approximating the>. contours, as indicated in Figs. 35 and 36. In the proposed approximation as seers in Fig. 35, the heel cross section includes a sole upper surface 101 and a sole edge surface 104 following the theoretically ideal stability plane 51. The sole edge surface 104 terminates in a laterally extending portion 105 joined to the heel 106. The laterally-extending portion 105 is made from a flexible material and structured to cause its lower surface 105a to t:erminai=a during deformation at the theoretically ideal stability ?lane. Thus, in a dynamic case, the outer edge contour assumes approximately the shape described above as a result of the deformation of the portion 105.
It is presently contemplated that the controlled or programmed deformation can be provided by either of two techniques.
In one, the shoe sole sides, at especially the midsole, can be cut in a tapered fashion or grooved so that the bottom sole bends inwardly under pressure to the correct contour. The second uses an easily deformable material in a tapered manner on the sides to deform under pressure to the correct contour. while sucn techniques produce stability and natural motion results which are a significant improvement over conventional designs, they are inherently inferior to contours produced by simple geometric shaping. First, the actual deformation must be produced by pressure which is unnatural and does not occur with a bare foot and second, only approximations are possible by deformation, even with sophisticated design :and manufacturing techniques, given an individual's parv~icular running gait or body weight. Thus, the deformation process is limited to a minor effort to correct the contours from surfaces approximating the ideal curve in the first instance.
The theoretically ideal stability curve 51 can also be approximated by a plurality of line segments 110, such as tangents or chords, shown in Fig. 36. While a single flat plane approximation mar corrE~ct many of the biomechanical problems occurring with existing designs, because it removes most the area outside of the theoretically ideal stability plane 51, the single plane approximation is presently not preferred, since it is the least optimal. E~y incre>.asing the number of flat planar surfaces formed, the curve more closely approximates exactly the ideal design contour, as previously described.
Fig. 3'7 showa in frontal plane cross section the essential concept: underlying this invention, the t=heoretically ideal stability plane, which is also theoretically ideal for efficient natural motion of all kinds, including running, jogging or walking.
For an.y particular individual (or size average of individuals), tree theoretically ideal stability plane is determined, first:, by t:he given shoe sole thickness (s), and, second, by the frontal plane cross section width of the individual's load-bearing footprint 30b, which is defined as the upper surface of t:he shoe' sole that is in physical contact with and supports the human foot sole.
The theoretically ideal stability plane is composed conceptionally of two parts. The first part is a line segment 31b of equal length and parallel to 3Ub at a constant distance (s) equal to shoe sole thickness. This corresponds to a conventional shoe sole directly underneath the human foot. The second part is a quadrant edge 25 or quarter of a circle (which may be extended up to a half circle) at each side of the first part, line segment 31b. The quadrant; edge 25 is at radius (r), which is equal to shoe sole thickness (;~), from a center of rotation 41, which is the outermost point on each side of the line segment 30b. In summary, the theoretically ideal stability plane is the essence of this invention because it is used to determine a geometrically precise bottom contour of the shoe sole. And, this invention specifically claims the exactly determined geometric relationship just described. It c:an be stated unequivocally that any shoe sole contour, even o~F simi7Lar quadrant contour, that exceeds the theoretically idE~al stability plane will restrict natural foot motion, while any lesser contour will degrade natural stability.
That said, iii is possible that an adjustment to a definition included in i~he preceding conception might be made at some point in the future not on a theoretical basis, but an empirical one. It is conceivable that, in contrast to the rest of the foot, a definition of line segment 30b at the base of the human heel could be the width of the very hard tissue (bone, cartilage, etc.), instead of the load-bearing footprint, since it is possible that the heel width is t:he geometrically effective pivoting width which the shoe heel must precisely equal in order to pivot optimally with the human heel. For a typical male size lOD, that very hard tissue heel width is 1.75 inches, versus 2.25 inches for the load-bearing footp~~int of the heel. Though not optimal, narrower heel wi<9th 30b assumptions, even much narrower, may be used in non-athletic street shoes to obtain a significant propor-tion of the increases ity stability and efficiency provided by the invention, while retaining a more traditional appearance, espe-cially with higher heeled shoes.
It is an empirical question, though, not a question of theoretical framework. Until more empirical work is done, optimal heel width must be based on assumption. The optimal width of the human heel pivot is, however, a scientific question to be determined empirically Lf it can be, not a change in the essential theoretically ideal stability plane concept claimed in the invention. Moreover, lthe more narrow the definition, the more important exact fit becomes and relatively minor individual misalignments could produce pronation control problems, for example, that necLate any possible advantage.
Fig. 3B show:> a non-optimal but interim or low cost approach to shoe sole construction, whereby the midsole and heel lift 127 are produced conventionally, or nearly so (at least leaving the midsole bottom surface flat, though the sides can be contoured), while the bottom or outer sole 128 includes most or all of the special contours of the new design. Not only would that completely or mostly limit the special contours to the bottom sole, which would be molded specially, it would also ease assembly, since two flat surfaces. of the' bottom of the midsole and the top of the bottom sole could. be mated together with less difficulty than two contoured surfaces, as would be the case otherwise. The advantage of this approach is seen in the naturally contoured design example illustrated in Fig. 38A, which shows some contours on the relatively softer midsole sides, which are subject to less wear but benefit from greater traction for stability and ease of deformation, whi:Le the relatively harder contoured bottom sole provides good wear for t:he load-bearing areas. Fig. 38B shows in a quadrant side design t:he concept applied to conventional street shoe heels, which are usually separated from the forefoot by a hollow instep area under the main longitudinal arch. Fig. 38C
shows in frontal plane cross section the concept applied to the quadrant sided oz- sing le plane design and indicating in Fig. 38D
in the shaded area 129 o:E the bottom sole that portion which should be honeycombed (axis on the horizontal plane) to reduce the density of the relatively hard outer sole to that of the midsole material to provide for relatively uniform shoe density. Fig. 38E shows in bottom view the outline of a bottom sole 128 made from flat material which c:an be conformed topologically to a contoured midsole of either the one or two plane designs by limiting the side areas to be mated to the essential support areas discussed in Fig.
21; by that method, the contoured midsole and flat' bottom sole surfaces can be made to join satisfactorily by coinciding closely, which would be topologically impossible if all of the side areas were retained on the boiaom sole.
Figs. 39A-39C, frontal plane cross sections, show an enhancement to the previously described embodiments of the shoe sole side stability quadrant invention. As stated earlier, one major purpose of that design is to allow the shoe sole to pivot easily from side to side with the foot 90, thereby following the foot's natural inversion and eversion motion; in conventional designs shown in Fig. 39a, such foot motion is forced to occur within the shoe. upper 21, which resists the motion. The enhancement is to position exactly and stabilize the foot, especially the heel, relative to the preferred embodiment of the shoe sole; doing so facilitates the shoe sole's responsiveness in following the foot's natural motion. Correct positioning is 1 340 gg 7 essential to the invention, especially when the very narrow or "hard tissue" dei:inition of heel width is used. Incorrect or shifting relative position will reduce the inherent efficiency and stability of the side c~aadrant design, by reducing the effective thickness of the quadrant side 26 to less than that of the shoe sole 28b. As shown in Fp.g. 39B and 39C, naturally contoured inner stability sides 131 hold the pivoting edge 31 of the load-bearing foot sole in the correct position for direct contact with the flat upper surface of the conventional shoe sole 22, so that the shoe sole thickness (s) is maintained at a constant thickness (s) in the stability quadrant sides 26 when the shoe is everted or inverted, following the theoretically ideal stability plane 51.
The for~r of th~a enhancement is inner shoe sole stability sides 131 that follow the natural contour of the sidhs 91 of the heel of the foot 90, thereby cupping the heel of the foot. The inner stability sides :L31 can be located directly on the top surface of the shoe sols~ and heel contour, or directly under the shoe insole (or integral to it), or somewhere in between. The inner stability sides are similar in structure to heel cups integrated in insoles currently in common use, but differ because of its material density, which can be relatively firm like the typical mid-sole, not so:Et like the insole. The difference is that because of their higher relative density, preferably like that of the uppermost midsole, the inner stability sides function as part of the shoe sole, which provides structural support to the foot, not 'just gentle cushioning and abrasion protection of a shoe insole. In th~~ hroa~dest sense, though, insoles should be considered structurally and functionally as part of the shoe sole, as should any shoe material between foot and ground, like the 1 340 gg 7 bottom of the shoe upper' in a slip-:lasted shoe or the board in a board-lasted shoe.
The inner stability side enhancement is particularly useful in converting existing conventional shoe sole design embodiments 22, as constructed within prior art, to an effective embodiment of the side stability quadrant 26 invention. This feature is impo~~tant in constructing prototypes and initial production of the invention, as well as an ongoing method of low cost production, since such production would be very close to existing art.
The inner stability sides enhancement is most essential in cupping the sides and back of the heel of the foot and therefore is essential on t:he upper edge of t:he heel of the shoe sole 27, but may also be e~aended around all ar any portion of the remaining shoe sole upper edge. The size of the inner stability sides should, however, taper down in proportion to any reduction in shoe sole thickness in the sagittal plane.
Figs. 40A-40C, frontal plane cross sections, illustrate the same inner shoe sole stability sides enhancement as it applies to the previously described embodiments of the naturally contoured sides design. The enhancement positions and stabilizes the foot relative to the shoe sole, and maintains the constant shoe sole thickness (s) of t=he naturally contoured sides 28a design, as shown in Figs. 408 and 4oC; Fig. 40A shows a conventional design. The inner shoe sole stability sides 131 conform to the natural contour of the foot sides 29, which determine the theoretically ideal stability plane 51 for the shoe sole thickness (s). The other features of the enhancement as it applies to the naturally contoured shoe sole sides embodiment 28 are the same as described 47 _.

previously under Figs. 39A-39C for the side stability quadrant embodiment. It i;s clear from comparing Figs. 40C and 39C that the two different apF~roache::, that with quadrant sides and that with naturally contoured sides, can yield some similar resulting shoe sole embodiments through the use of inner stability sides 131. In essence, both ap~~roache:a provide a low cost or interim method of adapting existing conventional "flat sheet" shoe manufacturing to the naturally contoured design described in previous figures.
Thus, it will clearly be understood by those skilled in the art that the foregoing description has been made in terms of the preferred embodiment and various changes and modifications may be made without departing from the :>cope of the present invention which is to be defined k>y the appen<9ed claims.
_ 4g ._

Claims (108)

1. A shoe sole construction for a shoe, comprising:
a shoe sole having a flat sole portion including an upper, foot sole-contacting surface;
a shoe sole also having at least one contoured side portion merging with the flat sole portion and the contoured side portion having an upper, foot sole-contactirag surface conforming to the curved shape of at least a part of one side of the foot sole of a wearer;
and t:he shoe sole having a uniform thickness, when measured in frontal plane cross sections, in all direct load-bearing parts of the shoe sole;
the direct load-bearing parts of the shoe sole includes both that part of the sole portion and that part of the contoured side portion which become directly load-bearing when the shoe sole on the ground is tilted sideways, away from an upright position;
the unifarm thickness of the shoe sole extends through at least a contoured side portion providing direct structural support between foot sole and ground through a sideways tilt of at least 20 degrees;
said shoe sole thickness being defined as the shortest distance between any point on an upper, foot sole-contacting surface of said shoe sole and a lower, ground-contacting surface of said shoe sole, when measured in frontal plane cross sections;
said flag sole portion having a varying thickness when measured in sagittal plane cross sections, said thickness being greater in the heel area than in the forefoot area;

said thickness of the contoured side portion equalling and therefore varying directly with the thickness of the flat sole portion to which it is merged, when the thickness is measured in the frontal plane cross sections;
the uniform thickness of the shoe sole is different in at least two frontal plane cross sections wherein the shoe sole has a contoured side portion of at least 20 degrees, so that there are at least two different contoured side portion thicknesses, when measured in frontal plane cross sections;
whereby the constant thickness in frontal plane cross sections, including the side portion, maintains foot stability like when bare, especially during pronation and supination motion.

2. The sole construction as set forth in claim 1 wherein said contoured side portion merges with at least a heel portion of said sole portion.

3. The sole construction as set forth in claim 2 wherein said contoured side portion merges with at least a lateral heel portion of said sole portion.

4. The sole construction as set forth in claim 1 wherein said contoured side portion merges with at least a sole portion. under the base of the fifth metatarsal.

5. The sole construction as set forth in claim 3 wherein said contoured side portion extends along only selected portions of the periphery of said shoe sole portion.

6. The sole construction as set forth in claim 3 wherein said contoured side portion merges with at least a lateral and medial heel portion of said sole portion.

7. The sole construction as set forth in claim 3 wherein the lower ground-contacting surface of the shoe sole is connected to the upper foot-contacting surface by a contoured side surface.

8. The sole construction as set forth in claim 3 wherein at least a part of said contoured side portion is determined in frontal plane cross sections by using a section of a ring with a thickness equalling the shoe sole thickness to approximate the contour of the side of the foot sole of a wearer and maintain exactly the thickness of the shoe sole portion.

9. The sole construction as set forth in claim 2 wherein said contoured side portion merges with at least a medial heel portion of said sole portion.

10. The sole construction as set forth in claim 1 wherein the side portion extends entirely around the horizontal contour of the sole portion at an edge thereof.

11. The shoe role construction as set forth in claim 3 wherein at least a portion of non-essential shoe sole sections are removed for flexibility and connected by a top layer of flexible and inelastic material.

12. The shoe role construction as set forth in claim 3 wherein said shoe sole includes at least one frontal plane slit for flexibility.

13. The shoe sole construction as set forth in claim 3 wherein at least one frontal plane slit is located midway between the base of the calcaneus and the base of the fifth metatarsal, and another midway between that base and the metatarsal heads.

14. The shoe sole construction as set forth in claim 3 wherein said contoured side portion is located only at a plurality of support and propulsion elements, including the base and lateral tuberosity of the calcaneus, the head of the first and fifth metatarsals, the base of the fifth metatarsal, and the head of the first distal phalange to provide said shoe sole with flexibility paralleling the foot sole flexibility of a wearer;
whereby said shoe sole maintains the inherent stability and uninterrupted motion of said foot throughout sideways pronation and supination motion.

15. The shoe role construction as set forth in claim 14 wherein the density of the retained shoe sole side portions is greater than the density of the material used in said shoe sole flat portion, in order to compensate for increased pressure loading during inversion and eversion motion of said foot.

16. The shoe role construction as set forth in claim 14 wherein said contoured side portion is only retained at all said support and propulsion elements.

17. The sole construction as set forth in claim 3 wherein the amount of any shoe sole side portions of said uniform thickness is determined by the degree of shoe sole stability desired and the shoe sole weight and bulk required to provide said stability;
the amount of said coplanar contoured sides that is provided said shoe sole being sufficient to maintain the stability of the wearer's foot throughout the range of foot inversion and eversion motion for which said shoe is intended;
said range including any wearer's foot inversion and eversion motion up to a maximum of 90 degrees.

18. The sole construction as set forth in claim 3 wherein the amount of any shoe sole contoured side that is provided said shoe sole is sufficient to maintain lateral stability of the wearer's foot throughout its full range of sideways motion, including at least 7 degrees of pronation and at least 7 degrees of supination, as measured at the heel, said lateral stability being like that of the wearer's foot when bare.

19. The shoe sole construction as set forth in claim 3 wherein said ground-contacting portion of said shoe sole portion includes bottom treads including a plurality of cleats, an outermost surface of said bottom treads lying along the ground contacting surface of said shoe sole.

20. The shoe sole construction as set forth in claim 3, wherein said shoe sole is a street shoe sole having the lower ground-contacting surface of the shoe sole connected to the upper foot-contacting surface by a planar side surface that is vertically-oriented.

21. The shoe role construction as set forth in claim 20 wherein said street shoe sole has a hollow instep area.

22. The shoe sole construction as set forth in claim 3 wherein a load-bearing outer surface of the sole is constructed in frontal plane cross sections by the circle radius method using the surface contour of a wearer's foot sole as a locus of centers of the radii and radii equal to the thickness of the flat sole portion to construct a composite outer, ground-contacting surface of the shoe sole.

23. The shoe sole construction as set forth in claim 3 wherein at least part of the upper surface of said flat sole portion conforms to the contours of the sole of the load-bearing foot of the wearer.

24. The shoe sole construction as set forth in claim 3 wherein said shoe sole is made of material of such composition as to allow a structural deformation of the shoe sole following a structural deformation of the wearer's foot sole, thus allowing the shoe sole to deform by flattening under a wearer's body weight load like the wearer's foot sole does under the same load, so that the shoe sole conforms to the shape of the wearer's foot sole when under a body weight load;
whereby said shoe sole structure maintains intact the firm lateral stability of the wearer's foot, as demonstrated when said foot is unshod and tilted out laterally in inversion to the extreme 20 degree limit of the range of motion of the ankle joint of the wearer's foot.

25. The shoe sole construction as set forth in claim 3 wherein at least a portion of the upper surface of said flat sole portion conforms to the contour of the bottom of the wearer's foot sole when not under a load.

26. The role construction set forth in claim 3 wherein articulating joints are formed in the shoe sole that parallel those in the foot by retaining only part of the sole portion material between the heel and the forefoot, except under the base of the fifth metatarsal, which is fully supported like the heel and forefoot; and except for including an upper layer of flexible and inelastic top sole connecting the forefoot, heel, and fifth metatarsal base portions;
an amount of shoe sole material is retained that is sufficient to allow the load-bearing inversion and eversion motion provided said shoe sole by said articulating joints to parallel the inversion and eversion motion of the wearer's foot sole provided by said foot joints;
whereby said shoe sole maintains the full range of inversion and eversion motion of said wearer's foot without restraining it, while also providing stable support to the structural support elements of the foot.

27. The sole construction set forth in claim 26 wherein a shoe side support for the main longitudinal arch is retained.

28. A shoe sale construction for a shoe, comprising:
a shoe stile with an upper, foot sole-contacting surface that conforms to the shape of a wearer's foot sole, including at least part of the curved bottom portion of the foot sole when the foot is non-load-bearing and including at least a portion of a curved side of the foot sole;
and the shoe sole has a constant thickness, when measured in frontal plane cross sections, wherever the shoe sole is directly load-bearing;
the direct load-bearing portion of the shoe sole includes both that part of the curved bottom portion and that part of the curved side portion which become directly load-bearing when the shoe sole on the ground is tilted sideways, away from an upright position;
said shoe sole thickness being defined as the shortest distance between any point on an upper foot sole-contacting surface of said shoe sole and a lower ground-contacting surface of said shoe sole, when measured in frontal plane cross sections;
said thickness varying when measured in the sagittal plane and being greater in a heel area than a forefoot area;
the uniform thickness of the shoe sole extends through at least a contoured side portion providing direct structural support between foot sole and ground through a sideways tilt of at least 45 degrees;
the uniform thickness of the shoe sole is different in at least two frontal plane cross sections wherein the shoe sole has a contoured side portion of at least 45 degrees, so that there are at least two different contoured side portion thicknesses, when measured in frontal plane cross sections;
at least one frontal plane cross section is taken proximate to a head of the wearer's fifth metatarsal and at least one other frontal plane cross section is taken proximate to a base of the wearer's fifth metatarsal;
whereby the constant thickness in frontal plane cross sections, including the side portion, maintains foot stability like when bare, especially during extreme pronation and supination motion.

29. A shoe sole construction for a shoe, comprising:
a shoe sole having an upper, foot-contacting surface that conforms to the shape of a wearer's foot sole and including a portion of at least a curved side of the foot sole;
and the shoe sole also having a uniform thickness so that a lower, ground-contacting surface parallels said upper surface, when measured in frontal plane cross sections;
the upper and lower surfaces of the shoe sole are parallel, when measured in frontal plane cross sections, wherever the shoe sole is directly load-bearing;
the direct load-bearing portion of the shoe sole includes both that part of the curved bottom portion and that pant of the curved side portion which become directly load-bearing when the shoe sole on the ground is tilted sideways, away from an upright position;
said shoe sole including a heel area with a thickness that is greater than a forefoot area;
the uniform thickness of the shoe sole extends through at least a contoured side portion providing direct structural support between foot sole and ground through a sideways tilt of at least 90 degrees;
whereby a constant thickness when in frontal plane cross sections maintains foot stability like when bare, especially during extreme pronation and supination motion.

30. A shoe sole, comprising:
a shoe sole having a sole portion including an upper, foot sole-contacting surface;
the shoe sole also having at least one contoured side portion merging with the sole portion and the contoured side portion having an upper, foot sole-contacting surface conforming to the curved shape of at least a part of one side of the foot sole of a wearer;
and the shoe sole having a uniform thickness, when measured in frontal plane cross sections, in at least a part of the shoe sole providing direct structural support between the wearer's load-bearing foot sole and ground;
the direct load-bearing part of the shoe sole includes both that part of the sole portion and that part of the contoured side portion which become directly load-bearing when the shoe sole on the ground is tilted sideways, away from an upright position;
wherein the uniform thickness of the shoe sole extends through at least a contoured side portion providing direct structural support between a foot sole and ground through a sideways tilt of at least 20 degrees;
said shoe sole thickness being defined as the shortest distance between any point on an upper, foot sole-contacting surface of said shoe sole and a lower, ground-contacting surface of said shoe sole, when measured in frontal plane cross sections;
wherein the lower, ground-contacting surface of the shoe sole is therefore parallel to the upper foot sole-contacting surface of the shoe sole, when measured in frontal plane cross sections;
said sole portion having a varying thickness when measured in sagittal plane cross sections, said thickness being greater in the heel area than in the forefoot area;
said thickness of the contoured side portion equalling and therefore varying directly with the thickness of the sole portion to which it is merged, when the thickness is measured in the frontal plane cross sections;
wherein the uniform thickness of the shoe sole is respectively different when measured in at least two frontal plane cross sections wherein the shoe sole has a contoured side portion of at least 20 degrees, so that there are at least two different contoured side portion thicknesses, when measured in frontal plane cross sections;
whereby, as measured in frontal plane cross sections, the uniform thickness of the shoe sole, especially including the side portion, maintains a lateral stability of the foot on the shoe sole like that when the foot is bare on the ground, especially during sideways pronation and supination motion occurring when the shoe sole is in contact with the ground.

31. A shoe sole, comprising:
a shoe sole having an upper, foot-contacting surface at least a portion of which conforms to the shape of a wearer's forefoot sole, including at least a portion of a curved side of the wearer's forefoot sole proximate to a head of a fifth metatarsal of the foot;
and said shoe sole portions having a uniform thickness, when measured in frontal plane cross sections;
the direct load-bearing part of the shoe sole includes both that part of the bottom portion and that part of the curved side portion which become directly load-bearing when the shoe sole on the ground is tilted sideways, away from an upright position;
said shoe sole including a heel area with a thickness that is greater than a forefoot area;
the uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through at least a contoured side portion providing direct structural support between foot sole and ground through a sideways lilt of at least 60 degrees;
wherein the shoe sole has at least a side portion, which adjoins said contoured side portion proximate to the head of the fifth metatarsal, with a thickness that is not uniform through a sideways tilt of at least 60 degrees, in order to save weight and to increase flexibility;
whereby, as measured in frontal plane cross sections, the shoe sole's uniform thickness between the upper, foot-contacting surface and the parallel lower, ground-contacting surface maintains a lateral stability of the forefoot on the shoe sole like that when the foot is bare on the ground, especially during extreme sideways pronation and supination motion occurring when the shoe sole is in contact with the ground.

32. The shoe sole as set forth in claim 31, wherein the uniform thickness of the shoe sole portion extends through at least part of a contoured side portion providing direct structural support between foot sole and ground through a sideways tilt angle of at least 90 degrees;
whereby the amount of any shoe sole contoured side that is provided the shoe sole is sufficient to maintain lateral stability of the wearer's foot throughout the most extreme range of sideways motion, including at least 90 degrees of inversion and eversion; said lateral stability being like that of the wearer's foot when bare.

33. The shoe role construction as set forth in claim 31, wherein the uniform thickness of the shoe sole portion extends through at least part of a contoured side portion providing direct structural support between foot sole and ground through a sideways tilt angle of at least 100 degrees;
whereby the amount of any shoe sole contoured side that is provided the shoe sole is sufficient to maintain lateral stability of the wearer's foot throughout the most extreme range of sideways motion, including at least 100 degrees of inversion and eversion; said lateral stability being like that of the wearer's foot when bare.

34. A shoe sole, comprising:
a shoe sole with an upper, foot sole-contacting surface that conforms substantially to the shape of at least part of a sole of a wearer's foot, including at least part of one curved side of the foot sole;
the shoe sole is characterized by at least a part of the load-bearing portions of the shoe sole having a substantially uniform thickness, so that a lower, ground-contacting surface substantially parallels said upper surface, when measured in frontal plane cross sections;
said shoe sole thickness being defined as the shortest distance between any point on an upper, foot sole-contacting surface of said shoe sole and a lower, ground-contacting surface of said shoe sole, when measured in frontal plane cross sections;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through at least one contoured side portion at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt of 20 degrees;
the shoe sole thickness is varying when measured in sagittal plane cross sections and is greater in a heel area than in a forefoot area; and the substantially uniform thickness of the shoe sole is different when measured in at least two separate frontal plane cross sections wherein the shoe sole has at least one contoured side portion with the substantially uniform thickness extending through at least a sideways tilt of 20 degrees, so that there are at least two different thicknesses of the contoured side portions, when measured in frontal plane cross sections.

35. The shoe sole construction as set forth in claim 34, wherein said shoe sole has at least one sole portion including an upper, foot sole-contacting surface and at least one contoured side portion including an upper, foot sole-contacting surface;
said contoured side portion merging with said at least one sole portion;
and said upper foot sole-contacting surfaces conforming substantially to the shape of the sole of the foot of the wearer, including at least a curved side of the foot sole;
said at least cane sole portion and said at least one contoured side portion having a substantially uniform thickness when measured in frontal plane cross sections;
said shoe sole thickness being defined as about the shortest distance between any point on the upper, foot-contacting surface and the closest point on the lower, ground-contacting surface, when measured in frontal plane cross sections.

36. The shoe sole construction as set forth in claim 34, wherein at least a part of the shoe sole is made of flexible material;
said flexibility being Such that a ground-contacting part of the shoe sale deforms to flatten against the ground under a wearer's body weight load.

37. The shoe sole construction as set forth in claim 36, wherein said at least one contoured side portion merges with at least a sole portion substantially proximate to a head of the fifth metatarsal of the wearer's foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said at least one contoured side portion at least to the head of the fifth metatarsal at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt of 20 degrees.

38. The shoe sole construction as set forth in claim 36, wherein said at least one contoured side portion merger with at least a sole portion substantially proximate to a base of the fifth metatarsal of the wearer's foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said at least one contoured side portion at the base of the fifth metatarsal at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt of 20 degrees.

39. The shoe sole construction as set forth in claim 36, wherein said at least one contoured side portion merger with at least a sole portion substantially proximate to a head of the first metatarsal of the wearer's foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said at least one contoured side portion at the head of the first metatarsal at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt of 20 degrees.

40. The shoe sole construction as set forth in claim 36, wherein said at least one contoured side portion merger with at least a sole portion substantially proximate to a head of the first distal phalange of the wearer's foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said at least one contoured side portion at the head of the first distal phalange at least high enough to provide direct structural support between sole of foot and ground through a sideways tilt of 20 degrees.

41. The shoe sole construction as set forth in claim 36, wherein said at least one contoured side portion merges with at least a sole portion substantially proximate to a lateral tuberosity of the calcaneus of the wearer's foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said at least one contoured side portion at the lateral tuberosity of the calcaneus at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt of 20 degrees.

42. The shoe sole construction as set forth in claim 36, wherein said at least one contoured side portion merger with at least a medial sole portion substantially proximate to a base of the calcaneus of the wearer's foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said at least one contoured side portion at the base of the calcaneus at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt angle of 20 degrees.

43. The shoe sole construction as set forth in claim 37 further comprising a contoured side portion which merges with air least a sole portion substantially proximate to a base of the fifth metatarsal of the wearer' s foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said contoured side portion at the base of the fifth metatarsal at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt of 20 degrees.

44. The shoe aole construction as set forth in claim 37, further comprising a contoured side portion which merges with av least a sole portion substantially proximate to a head of the first metatarsal of the wearer's foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said contoured side portion at the head of the first metatarsal at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt of 20 degrees.

45. The shoe sole construction as set forth in claim 44, further comprising a contoured side portion which merges with ate least a sole portion substantially proximate to a head of the first distal phalange of the wearer's foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said contoured side portion at the head of the first distal phalange at least high enough to provide direct structural support between sole of foot and ground through a sideways tilt of 20 degrees.

46. The shoe role construction as set forth in claim 43, further comprising a contoured side portion which merges vaith at least a sole portion substantially proximate to a lateral tuberosity of the calcaneus of the wearer's foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said contoured side portion at the lateral tuberosity of the calcaneus at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt of 20 degrees.

47. The shoe sole construction as set forth in claim 46, further comprising a contoured side portion which merges with at least a medial sole portion substantially proximate to a base of the calcaneus of the wearer's foot;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said contoured side portion at the base of the calcaneus at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt of 20 degrees.

48. The shoe sole construction as set forth in claim 37, further comprising a contoured side portion which merges with at least a sole portion substantially proximate to a lateral tuberosity of the calcaneus of the wearer's foot the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through said contoured side portion at the lateral tuberosity of the calcaneus at least high enough to provide direct load-bearing support between sole of foot and ground through a sideways tilt of 20 degrees.

49. The shoe sole construction as set forth in claim 37, wherein at least a substantial part of at least one said sole portion is merged with said at least one contoured side portion.

50. The shoe sole construction as set forth in claim 41, wherein at least two said contoured side portions, including one said contoured side portion substantially proximate to the head of the first metatarsal and one said contoured side portion substantially proximate to the first distal phalange, are separated by an area directly between them with no said contoured side portion, in order to save weight and to increaae flexibility.

51. The shoe sole construction as set forth in any one of claims 34, 35 and 37 to 48 wherein at least two said contoured side portions are separated by an area directly between them having at least one said sole portion that is merged with a contoured side portion having a thickness which is less than the thickness of the at least one sole portion, in order to save weight and to increase flexibility;
the thiclcnesses of the contoured side portion and the at least one sole portion being measured in frontal plane cross sections.

52. The shoe sole construction as set forth in claim 36, wherein at least part of the upper surface of at least one sole portion conforms substantially to the contours of the structurally flattened sole of the wearer's foot that is structurally deformed by load-bearing the wearer's body weight.

53. The shoe sole construction as set forth in claim 36, wherein at least part of the upper surface of at least one sole portion conforms substantially to the contour of a curved bottom of the sole of the wearer's foot when not structurally flattened under the wearer's body weight load.

54. The shoe sole construction as set forth in claim 36, wherein, at least in a heel area, at least a part of the upper surface of at least one sole portion conforms substantially to the contour of a curved bottom of the sole of the wearer's foot when not structurally flattened under the wearer's body weight load.

55. The shoe sole construction as set forth in claim 36, wherein at least a part of the upper surface of at least one said sole portion is substantially flat.

56. The shoe sole construction as set forth in any one of claims 34 - 36, wherein the density of at least one said contoured side portion is greater than the density of the material used in said at least one sole portion, in order to compensate for increased pressure loading during inversion and eversion motion of said foot.

57. The shoe sole construction as set forth in claim 36, wherein at least said at least one contoured side portion having a substantially uniform thickness, as measured in frontal plane cross sections, provides direct load-bearing support between sole of foot and ground through a sideways tilt of at least 30 degrees merges with a heel portion of said at least one sole portion;
and the substantially uniform thickness of the shoe sole in the heel portion with said at least one contoured side portion of at least 30 degrees, as measured in a frontal plane cross section, is different from the substantially uniform thickness of the shoe sole in a forefoot portion which extends through said at least one contoured side portion providing direct load-bearing support between the sole of the foot and ground through a sideways tilt of at least 30 degrees, also as measured in frontal plane cross sections.

58. The shoe sole construction as set forth in claim 36, wherein the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through at least said at least one contoured side portion providing direct load-bearing support between sole of foot and ground through a sideways tilt of at least 45 degrees;

the uniform thickness of the shoe sole is different in at least two frontal plane cross sections wherein the shoe sole has said at least one contoured side portion of at least 45 degrees, so that there are at least two different thicknesses of the said at least one contoured side portion, when measured in frontal plane cross sections;
the thiclcness of said at least one contoured side portion is measured with at least one frontal plane cross section taken proximate to a head of the wearer's fifth metatarsal and the thickness of said at least one contoured side portion is measured in at least one other frontal plane cross section taken proximate to a base of the wearer's fifth metatarsal.

59. The shoe sole construction as set forth in claim 36, wherein the substantially uniform thickness of the forefoot of the shoe sole is different in at least two frontal plane cross sections wherein the shoe sole has at least one said contoured side portion with a substantially uniform thickness extending through a sideways tilt of at least 45 degrees, so that there are at least two different thicknesses of said at least one contoured side portion in the shoe sole forefoot, when measured in frontal plane cross sections.

60. The shoe sole construction as set forth in claim 36, wherein the shoe sole has a substantially uniform thickness, when measured in frontal plane cross sections, in any portions of the shoe sole providing direct support. between the wearer's load-bearing foot sole and the ground;

the load-bearing portions of the shoe sole includes both any portion of said at least one sole portion and any portion of said at least one contoured side portion which become directly load-bearing when the shoe sole on the ground is tilted sideways, away from an upright position;
the substantially uniform thickness of the shoe sole extends through at least said at least one contoured side portion providing direct structural support between the sole of the foot and ground through a sideways tilt of at least 20 degrees;
whereby, as measured in frontal plane cross sections, the substantially uniform thickness of the shoe sole, especially including said at least one contoured side portion, maintains a lateral stability of the foot on the shoe sole like that when the foot is bare on the ground, especially during sideways pronation and supination motion occurring when the shoe sole is in contact with the ground.

61. The shoe sole construction as set forth in any one of claims 34 - 36 and 37 - 48, wherein the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through at least part of said at least one contoured side portion providing direct load-bearing structural support between the sole of the foot and ground through a sideways tilt of at least 30 degrees.

62. The shoe sole construction as set forth in any one of claims 34 - 36 and 37 - 48, wherein the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through at least part of said at least one contoured side portion providing direct load-bearing structural support between the sole of the foot and ground through a sideways tilt of at least 45 degrees.

63. The shoe dole construction as set forth in any one of claims 34 - 36 and 39 - 48, wherein the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through at least part of said at least one contoured side portion providing direct load-bearing structural support between the sole of the foot and ground through a sideways tilt of at least 90 degrees;
whereby the amount of any shoe sole said at least one contoured side portion that is provided as part of the shoe sole is sufficient to maintain lateral stability of the wearer's foot throughout an extreme range of sideways motion, including at least 90 degrees of inversion and eversion; said lateral stability being like that of the wearer's foot when bare.

64. The shoe role construction as set forth in any one of claims 34 - 36 and 37 - 48, wherein the substantially uniform thickness of the shoe sole, when measured in frontal plane cross sections, extends through at least part of a contoured side portion providing direct load-bearing structural support between the sole of the foot and ground through a sideways tilt of at least 100 degrees;
whereby the amount of any shoe sole contoured side that is provided the shoe sole is sufficient to maintain lateral stability of the wearer's foot throughout an extreme range of sideways motion, including at least 100 degrees of inversion and eversion; said lateral stability being like that of the wearer's foot when bare.

65. The shoe sole construction as set forth in any one of claims 34 - 36, wherein the lower ground-contacting surface of the shoe sole is connected to the upper foot-contacting surface by a non-ground-contacting surface forming an outside edge of the shoe sole;
when measured in frontal plane cross sections, the distance between any point on the outside edge surface and the closest paint of an upper, foot-contacting surface of the shoe sole is less than the previously defined substantially uniform thickness of the ground-contacting portions of the shoe sole;
that lessor distance is reduced gradually, starting from the thickness of the ground-contacting portions, so that the outside edge tapers gradually from the lower ground-contacting surface to the upper foot-contacting surface thereby avoiding the creation of any sharp edge for the shoe sole to pivot on unstably when tilted sideways to an extreme end of a normal range of pronation and supination foot motion on the ground.

66. The shoe sole construction as set forth in any one of claims 34, 48 and 52 - 55, wherein the outer surface of the shoe sole has a plurality of cleats affixed to it;
the surface to which the base of the cleats are affixed becomes ground-contacting on any ground sufficiently soft for the cleats to penetrate the ground fully, thereby obtaining their traction benefit;
consequently, that cleat-affixing surface is defined as the lower, ground-contacting surface for purposes of measuring the shoe role uniform thickness in frontal plane cross sections;
the cleat-affixing surface therefore parallels the upper, foot contacting surface, when measured in frontal plane cross sections.

67. The shoe sole construction as set forth in any one of claims 34 - 36, wherein at least a part of the curved structure of said at least one contoured side portion includes a tread pattern on the ground-contacting surface.

68. The shoe sole construction as set forth in any one of claims 34 - 36, wherein at least a part of the at least one sole portion and the at least one contoured side portion are integrally formed into a unitary shoe sole structure.

69. The shoe sole construction as set forth in any one of claims 34, 42, 52 - 55 and 57 - 60, wherein at least a part of a load-bearing portion of the shoe sole comprises at least a midsole and an outer sole.

70. The shoe sole construction as set forth in any one of claims 34 - 36, wherein the at least one sole portion and the at least one side portion of the shoe sole are sufficient to maintain the load-bearing portion of the sole of the wearer's foot at a substantially constant distance from the ground, when measured in frontal plane cross sections, that substantially constant distance being the thickness of the shoe sole, even when the shoe is tilted to the side by lateral foot motion on the ground including pronation and supination, whether during locomotion or at an extreme limit of range of motion, such as about 20 degrees inversion or eversion of the heel of the wearer's foot.

71. The shoe sole construction as set forth in any one of claims 34 - 36, wherein a shoe upper is connected to at least a part of said shoe sole.

72. The shoe sole construction as set forth in any one of claims 34 - 36, wherein an athletic shoe upper is connected to at least a part of said shoe sole.

73. The shoe sole as set forth in claim 36, wherein at least one said sole portion and at least one said side portion of the shoe sole are sufficient to maintain the load-bearing portion of said sole of said wearer's foot at a substantially constant distance from said ground, when measured in frontal plane cross sections, especially during extreme sideways pronation and supination motion occurring when the shoe sole is in contact with the ground, said substantially constant distance being said substantially uniform thickness of the shoe sole.

74. A shoe sole, comprising:
a shoe sale with an upper, foot sole-contacting surface that substantially conforms to the shape of a wearer's foot sole, including at least one portion of the curved bottom of the foot sole when not structurally flattened under the wearer's body weight load and including at least one portion of a curved side of the foot sole;
and the shoe sole has a substantially uniform thickness, when measured in frontal plane cross sections, in at least a part of the shoe sole providing direct structural support between the wearer's load-bearing foot sole and ground;
wherein the direct load-bearing part of the shoe sole includes both that part of the curved bottom portion and that part of the curved side portion which become directly load-bearing when the shoe sole on the ground is tilted sideways, away from an upright position;
said shoe sole thickness being defined as the shortest distance between any point on an upper, foot sole-contacting surface of said shoe sole and a lower, ground-contacting surface of said shoe sole, when measured in frontal plane cross sections;
the load-bearing part of the lower, ground-contacting surface of the shoe sole is therefore parallel to the upper foot sole-contacting surface of the shoe sole, when measured in frontal plane cross sections;
said shoe sole thickness varying when measured in the sagittal plane and being greater in a heel area than a forefoot area;
the substantially uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through the curved bottom portion and at least a curved side portion providing direct structural support between foot sole and ground through a sideways tilt of at least 7 degrees; and, the substantially uniform thickness of the shoe sole is different when measured in at least two separate frontal plane cross sections.

75. The shoe sole construction as set forth in claim 74, wherein the shoe sole is made of flexible material structurally exhibiting flexibility;
said flexibility being such that the shoe sole deforms to flatten against the ground under a wearer's body weight load.

76. A shoe sole, comprising:
a shoe sole hawing an upper, foot-contacting surface at least a portion of which conforms to the shape of a sole of a wearer's heel, including at least a portion of at least one curved side of the wearer's foot sole proximate to a calcaneus of a wearer's foot;
and said shoe sole portions having a uniform thickness, when measured in frontal plane cross sections;
the direct load-bearing part of the shoe sole includes both that part of the bottom portion and that part of the curved side portion which become directly load-bearing when the shoe sole on the ground is tilted sideways, away from an upright position;
said shoe sole including a heel area with a thickness than is greater than a forefoot area;
the uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through at least a contoured side portion providing direct structural support between foot sole and ground through a sideways tilt of at least 30 degrees;
wherein the shoe sole has at least a side portion, which adjoins said contoured side portion proximate to the calcaneus, with a thickness that is not uniform through a sideways tilt of at least 30 degrees, in order to save weighty and to increase flexibility;
whereby, as measured in frontal plane cross sections, the shoe sole's uniform thickness between the upper, foot-contacting surface and the parallel lower, ground-contacting surface maintains a lateral stability of the heel on the shoe sole like that when the foot is bare on the ground, especially during extreme sideways pronation and supination motion occurring when the shoe sole is in contact with the ground.

77. The shoe role as set forth in claim 76, wherein said part of the upper, foot-contacting surface that conforms to the shape of a sole of a wearer's heel includes at least a portion of at least a lateral and a medial curved side of the wearer's foot sole proximate to a calcaneus of said foot;
and wherein the shoe sole has at least two side portions, which adjoin said contoured side portions proximate to the calcaneus, with a thickness that is not uniform through a sideways tilt of at least 30 degrees, in order to save weight and to increase flexibility.

78. The shoe sole as set forth in claim 76, wherein the uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through at least one contoured side portion providing direct structural support between foot sole and ground through a sideways tilt of at least 45 degrees;
and wherein the shoe sole has at least a side portion, which adjoins said contoured side portion proximate to the calcaneus, with a thickness that is not uniform through a sideways tilt of at least 45 degrees, in order to save weight and to increase flexibility.

79. The shoe sole as set forth in claim 77, wherein the uniform thickness of the shoe sole, as measured in frontal plane cross sections, extends through at least a lateral and a medial contoured side portion providing direct structural support between foot sole and ground through a lateral and a medial sideways tilt of at least 45 degrees;
and wherein the shoe sole has at least two side portions, which adjoin said contoured side portions proximate to the calcaneus, with a thickness that is not uniform through a sideways tilt of at least 45 degrees, in order to save weight and to increase flexibility.

80. A shoe sole, comprising:
an upper, foot sole-contacting surface that conforms substantially to the shape of at least a part of a sole of a wearer's foot, said shape including at least a part of the load-bearing portion of at least a curved side of the foot sole; and a lower ground-contacting surface;

said shoe sole has at least a sole portion including said foot sole contacting surface and at least one contoured side portion merging with said sole portion and conforming substantially to the shape of the corresponding side of the sole of said foot;
said shoe sole thickness is varying when measured in sagittal plane cross sections and is greater in the heel area than in the forefoot area;
said sole portion and said contoured side portion have a substantially uniform thickness, when measured in front plane cross sections;
said shoe sole thickness being defined as about the shortest distance between any point on said upper, foot sole-contacting surface and the closest point on said lower, ground-contacting, when measured in frontal plane cross sections;
said substantially uniform thickness of said shoe sole is different when measured in at least two separate frontal plane cross sections wherein the shoe sole has at least one said contoured side portion of at least 20 degrees, so that there are at least two different thicknesses of said at least one contoured side portion, when measured in frontal plane cross sections.

81. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having a sole portion and at least one outwardly contoured side portion connected to said sole portion;
characterized in that said at least one outwardly contoured side portion has an outer surface with at least an upper part formed by a sole layer other than a bottom sole, as measured in a frontal plane cross section.

82. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a sole with an inner, foot-sole supporting surface that is in a contoured shape which substantially conforms to a naturally curved shape of at least a sole of a wearer's foot, including at least a portion of a curved bottom of the foot sole that is not structurally flattened under a wearer's body weight load;
characterized in that said shoe sole has an outer surface that is in a similar contoured shape which substantially conforms to said naturally curved shape of at least said sole of said wearer's foot, including said at least said portion of said curved bottom of the foot sole, the shoe sole thus having at least one curved bottom portion; and said at least one curved bottom portion being located proximate to at least one of the following essential or optional structural support elements of said wearer's foot: the base and lateral tuberosity of the calcaneus, the heads of the metatarsals, the base of the fifth metatarsal, and the main longitudinal arch.

83. The shoe sole as set forth in claim 81, wherein said shoe sole has an outwardly contoured side portion located proximate to at least one of: the base and lateral tuberosity of the calcaneus, the heads of the metatarsals, the base of the fifth metatarsal, the first distal phalange and the main longitudinal arch.

84. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having a sole portion and at least one outwardly contoured side portion connected to said sole portion;
the sole with an inner, foot-sole supporting surface that is in a naturally contoured shape which substantially conforms to a naturally curved shape of at least a sole of a wearer's foot, including at least one portion of a curved side of the foot sole, said foot sole being structurally flattened under a wearer's body weight load;
the shoe sole having a thickness in a heel section that is greater than a forefoot section;
characterized in that said shoe sole has an outer surface that also is in a similar naturally contoured shape which substantially conforms to said naturally curved shape of at least a sole of a wearer's foot, including at least one portion of a curved side of the foot sole, the shoe sole thus having at least one curved side portion;
said at least one contoured side portion being located proximate to at least one of the following essential or optional structural support elements of said wearer's foot: the base of the calcaneus, the lateral tuberosity of the calcaneus, the base of the fifth metatarsal, and the main longitudinal arch; and said at least one outwardly contoured side portion has at least a part with a thickness that is greater than a thickness of a sole portion, as measured in at least one frontal plane cross section.

85. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
said shoe sole having at least one sole portion with a substantially uniform thickness and at least one contoured side portion merging with said sole portion;
a shoe sole having an upper, foot sole-supporting surface and a lower, ground-contacting surface;
said shoe sole also having an outside edge surface that is not load-bearing;

characterized in that said contoured side portion being defined at least in part by an arc of a substantially circular surface having at least a part with a radius than is greater than the thickness of said sole portion and having the center of said radius lying at a point of a plane defined by an upper surface of said sole portion, as measured in an about frontal plane cross section;
said part of said contoured side portion with said greater radius extending from the sole portion through an arc of at least 20 degrees, as measured in an about frontal plane cross section;
said at least one contoured side portion being located proximate to at least one of the following bones which are essential or optional structural support elements of said wearer's foot: the base and lateral tuberosity of the calcaneus, the base of the fifth metatarsal, and the main longitudinal arch;
the shoe sole has at least a side portion, which adjoins said contoured side portion proximate to said at least one wearer's foot bone, without said greater radius extending through an arc of at least 20 degrees, in order to save weight and to increase flexibility.

86. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having an upper, foot sole-supporting surface that conforms substantially to the natural shape of at least a part of a sole of a wearer's foot and a lower, ground--contacting surface;
said shoe sole also having an outside edge surface that is not load-bearing;
said shoe sole having at least one sole portion and at least one naturally contoured side portion merging with said sole portion;

said naturally contoured sole portion having an upper, foot sole-supporting surface that conforms substantially to at least a part of a curved side of said foot sole;
characterized in that at least a section of said at least one role portion and at least a section of said at least one naturally contoured side portion have a substantially uniform thickness, as measured in about frontal plane cross sections;
said shoe sole thickness being defined as about the shortest distance between any point on about said upper, foot sole-supporting surface and the closes point on about lower, ground-contacting surface, as measured in about frontal plane cross sections; and said substantially uniform thicknesses, as measured in an about frontal plane cross section, extend through said at least one naturally contoured side portion sufficiently far up said curbed side of the wearer's foot sole to maintain said substantially uniform thicknesses between said sole of the wearer's foot and the around through a sideways tilt of at least 20 degrees, either of inversion or of eversion;
said at least one contoured side portion being located proximate to at least one of the following bones which are essential or optional structural support elements of said wearer's foot: the base and lateral tuberosity of the calcaneus, the heads of the metatarsals, the base of the fifth metatarsal, and the main longitudinal arch;
the shoe sole has at least a side portion, which adjoins said contoured side portion proximate to said at least one wearer's foot bone, with a thickness that is not uniform through a sideways tilt of at least 20 degrees, in order to save weight and to increase flexibility.

87. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
said shoe sole having at least one sole portion with a substantially uniform thickness and at least one contoured side portion merging with said sole portion;
a shoe sole having an upper, foot sole-supporting surface and a lower, ground-contacting surface;
said shoe sole also having an outside edge surface that is not load-bearing;
characterized in that said contoured side portion being defined at least in part by an arc of a substantially circular surface having a radius substantially equal to the thickness of said sole portion and having the center of said radius lying at a point of a plane defined by an upper surface of said sole portion, as measured in an about front plane cross section;
said radius of said contoured side portion extending from the role portion through an arc of at least 20 degrees, as measured in an about frontal plane cross section;
said at least one contoured side portion being located proximate to at least one of the following bone which are essential or optional structural support elements of said wearer's foot: the base and lateral tuberosity of the calcaneus, the heads of the metatarsals, the base of the fifth metatarsal, and the main longitudinal arch;
the shoe sole has at least a side portion, which adjoins said contoured side portion proximate to said at least one wearer's foot bone, without said radius extending through an arc of at least 20 degrees, in order to save weight and to increase flexibility.

88. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
said shoe sole: having at least one sole portion with a substantially uniform thickness and at least one contoured side portion merging with said sole portion;
a shoe sole having an upper, foot sole-supporting surface and a lower, ground-contacting surface;
said shoe sole also having an outside edge surface that is not lead-bearing;
characterized in that said contoured side portion being defined at least in part by an arc of a substantially circular surface having a radius substantially equal to the thickness of said sole portion and having the center of said radius lying at a point of a plane defined by an upper surface of said sole portion, as measured in an about frontal plane cross section;
said radius of said contoured side portion extending from the sole portion through an arc of at least 20 degrees, as measured in an about frontal plane cross section;
said shoe sole has at least two different substantially uniform thicknesses of at least two said sole portions, as measured in two separate about frontal plane cross sections, with two said contoured side portions having different radii substantially equal to said different thicknesses, said radii extending through said at least one contoured side portion at least through an arc of 20 degrees.

89. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having a sole portion and at least one outwardly contoured side portion connected to said sole portion;

characterized in that said at least one outwardly contoured side portion has at least a part with material having a density that is different than a density of material of a part of said sole portion, as measured in a frontal plane cross section.

90. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
characterized in that a sole with an upper surface that does not conform to the natural shape of a wearer's foot sole;
said surface proximate to an area of extremely soft material that deforms easily, so that under a load said upper surface deforms easily to a shape of an inner, foot-sole supporting surface that is in a naturally contoured shape which substantially conforms to a naturally curved shape of at least a sole of a wearer's foot, including at least a curved portion of said foot sole; and said at least one curved portion being located proximate to at least one of the following essential, propulsion, or optional structural support elements of said wearer's foot: the base and lateral tuberosity of the calcaneus, the heads of the metatarsals, the base of the fifth metatarsal, the first distal phalange, and the main longitudinal arch.

91. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
characterized in that a shoe sole has an outer surface that is not similar to a naturally contoured shape substantially conforming to a naturally curved shape of at least a sole of a wearer's foot;
said surface proximate to an area of extremely soft material that deforms easily, so that under a load said outer surface deforms to a surface that is in a shape at least similar to a shape which substantially conforms to said naturally curved shape of at least said sole of said wearer's foot, the shoe sole thus having at least one curved portion; and said at least one curved portion being located proximate to at least one of the following essential, propulsion, or optional structural support elements of said wearer's foot: the base and lateral tuberosity of the calcaneus, the heads of the metatarsals, the base of the fifth metatarsal, the first distal phalange, and the main longitudinal arch.

92. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having a sole portion and at least one outwardly contoured side portion connected to said sole portion;
said at least one outwardly contoured side portion being located at least proximate to at least one of: a fifth metatarsal head bone of a wearer's foot, a base of a fifth metatarsal bone of a wearer's foot, and a lateral tuberosity of a calcaneus bond of a wearer's foot;
a thickness of said shoe sole in at least a part of a heel area is different from said thickness in at least a part of a forefoot area;
characterized in that the structure of said shoe sole has a substantial equivalency of the lateral stability of the structure of said foot sole that is demonstrated by the wearer simulating a common inversion ankle sprain, doing so while standing in a stationary position to reduce and control forces on the ankle joint;
first, tilting out a portion of the wearer's unshod foot laterally in inversion to the extreme 20 degree limit of the range of motion of the subtalar ankle joint of the wearer's foot to demonstrate a firm lateral stability provided by said foot sole;
second, repeating the same inversion motion by the wearer shod with the shoe sole with said at least one contoured side portion located proximate to said fifth metatarsal heed to demonstrate the substantially equivalent firm lateral stability; and third, in contrast, again repeating the same inversion motion, very carefully, by the wearer shod with a conventional shoe sole to demonstrate its comparatively gross lack of lateral stability.

93. The shoe sole as set forth in claim 92, wherein said at least one outwardly contoured side portion is located at least proximate to all three bones of a wearer's foot; and said inversion ankle sprain simulation is conducted including a forefoot, midtarsal, and heel portion of said wearer's foot and shoe soles.

94. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having a sole portion and at least one outwardly contoured side portion connected to said sole portion;
said at least one outwardly contoured side portion being located at least proximate to a fifth metatarsal head bone of a wearer's foot;
said at least one outwardly contoured side portion having an indentation or abbreviation of said side portion;
characterized in that the structure of said shoe sole maintaining said wearer's foot sole at a substantially constant distance from the ground, as measured in at least one frontal plane cross section, during lateral inversion by a forefoot portion said wearer's foot in said shoe sole when load-bearing on said ground.

95. The shoe sole as set forth in claim 94, wherein said at least one outwardly contoured side portion is also located at least proximate to a base of a fifth metatarsal bone of a wearer's foot; and said shoe sole with said outwardly contoured side portion maintains a substantially constant distance between said fifth metatarsal base of said wearer's foot and said ground, as measured in at least one frontal plane cross section.

96. The shoe sole as set forth in any one of claims 94-95, wherein said at least one outwardly contoured side portion is also located at least proximate to a lateral tuberosity of a calcaneus bone of a wearer's foot; and said shoe sole with said outwardly contoured side portion maintains a substantially constant distance between said lateral calcaneal tuberosity of said wearer's foot and said ground, as measured in at least one frontal plane cross section.

97. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having a sole portion and at least one outwardly contoured side portion connected to said sole portion;
characterized in that said at least one outwardly contoured side portion has a contour radius that exceeds 90 degrees, so that an upper part of said contoured side portion is recurved inwardly toward a wearer's foot;
said at least one outwardly contoured side portion being located proximate to one of the following bones of said wearer's foot: a lateral tuberosity of a calcaneus, a base of a calcaneus, a main longitudinal arch and a bare of fifth metatarsal.

98. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having a sole portion and at least one outwardly contoured side portion connected to said sole portion;
said shoe sole having an inner surface conforming to at least part of a curved side of a sole of a wearer's foot and an outer surface for contacting the ground;
said shoe sole having a heel lift, midsole and outersole;
characterized in that said at least one outwardly contoured side portion with said ground-contacting surface exceeding a contour radius of 70 degrees;
said at least one outwardly contoured side portion being located proximate to one of the following essential structural support, propulsion, or optional elements of said wearer's foot: a lateral tuberosity of a calcaneus, a base of a calcaneus, and a base of fifth metatarsal, a head of a fifth metatarsal, a head of a first metatarsal, a first distal phalange, and a main longitudinal arch.

99. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having a sole portion and at least one outwardly contoured side portion connected to said sole portion;
said shoe sole having an inner surface conforming to at least part of a curved side of a sole of a wearer's foot and an outer surface for contacting the ground;

said shoe sole having a heel lift, midsole and outersole;
characterized in that said at least one outwardly contoured side portion with said ground-contacting surface exceeding a contour radius of 50 degrees;
said at least one outwardly contoured side portion being located proximate to one of the following essential structural support elements of said wearer's foot: a lateral tuberosity of a calcaneus and a base of a calcaneus.

100. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having a sole portion and at least one outwardly contoured side portion connected to said sole portion;
characterized in that said at least one outwardly contoured side portion is located proximate to one of:
a base of a fifth metatarsal bone of a wearer's foot and a main longitudinal arch; and the shoe sole has at least a side portion, which adjoins said contoured side portion, with a lesser shoe sole thickness, in order to save weight and to increase flexibility.

101. A shoe sole for a shoe or other footwear, comprising a shoe sole with an upper, foot sole-supporting surface that conforms substantially to the shape of at least part of a sole of a wearer's foot, including at least part of one curved side of the foot sole; the shoe sole is characterized by at least a part of a load-bearing portion of the shoe sole having a substantially uniform thickness, so that a lower, ground-contacting surface substantially parallels said upper surface, when measured in at least two frontal plane cross sections; said shoe sole thickness being defined as the shortest distance between any point on an upper, foot sole-supporting surface of said shoe sole and a lower, ground-contacting surface of said shoe sole, when measured in at least two frontal plane cross section; the substantially uniform thickness of the shoe sole; as measured in frontal plane cross sections, extends through at least one contoured side portion at least high enough to provide direct load-bearing support between said sole of foot and ground through a sideways milt of 20 degrees; the shoe sole thickness is greater in a heel area than in a forefoot area; and the substantially uniform thickness of the shoe sole is different when measured in at least two separate frontal plane cross sections wherein the shoe sole has at least one contoured side portion with the substantially uniform thickness extending through at least a sideways tilt of 20 degrees, so that there are at least two different thicknesses of the contoured side portions, when measured in frontal plane cross sections, wherein said at least one contoured side portion is sufficient to maintain lateral stability of the wearer's foot throughout its full range of sideways supination motion substantially equivalent to that of the wearer's foot when bare on the ground, the method comprising the steps of:
said substantial equivalency of the lateral stability of the structure of said shoe sole demonstrated by the wearer, who can simulate a common inversion ankle sprain, doing so while standing in a stationary position to reduce and control forces on the ankle joint, the step of demonstrating including the steps of:
first, tilting out the wearer's unshod foot laterally in inversion to the extreme 20 degree limit of the range of motion of the subtalar ankle joint of the wearer's foot to demonstrate firm lateral stability;
second, repeating the same inversion motion by the wearer shod with the shoe sole with said at least one contoured side portion with substantially uniform thickness to demonstrate the substantially equivalent firm lateral stability; and third, in contrast, again repeating the same inversion motion, very carefully, by the wearer shod with any conventional shoe sole to demonstrate its comparatively gross lack of lateral stability.

102. A contoured sole of a shoe, for supporting a foot of a wearer, the sole comprising:
a sole member having an outer surface for contacting the ground, and an inner surface for contacting the foot of the wearer;
the outer surface having a heel portion at a location substantially corresponding to a calcaneus of the foot of the wearer, a midtarsal portion at a location substantially corresponding to a midtarsal of the foot of the wearer, and a forefoot portion, the sole member also having a medial side and a lateral side;
the heel portion having a lateral heel part at a location substantially corresponding to the lateral tuberosity of the calcaneus of the foot of the wearer, and a medial heel part at a location substantially corresponding to the base of the calcaneus of the foot of the wearer;
the midtarsal portion being between the forefoot portion and heel portion, and having a lateral midtarsal part at a location substantially corresponding to the base of a fifth metatarsal of the foot of the wearer;
the forefoot portion having a forward medial forefoot part at a location substantially corresponding to the head of the first distal phalange, a rear medial forefoot part at a location substantially corresponding to the head of a first metatarsal of the foot of the wearer, and a rear lateral forefoot part at a location substantially corresponding to the head of a fifth metatarsal of the foot of the wearer;
characterized in that the sole containing a convexly rounded bulge at the lateral heel part; at the forward medial forefoot part; at the rear medial forefoot part; at the rear lateral forefoot part; and at the lateral midtarsal part; the bulges projecting convexly at air least one of the outer surfaces under the sole member, the medial side of the sole member, and the lateral side of the sole member;
the sole also has an indentation between the rear lateral forefoot part bulge and the lateral midtarsal part bulge; a further indentation between the lateral heel part bulge and the lateral midtarsal part bulge;
and a still further indentation between the forward medial forefoot part bulge and the rear medial forefoot part bulge.

103. A contoured sole of a shoe, for supporting a foot of a wearer, the sole comprising:
a sole member having an outer surface for contacting the ground, and an inner surface for contacting the foot of the wearer;
the outer surface having a heel portion at a location substantially corresponding to a calcaneus of the foot of the wearer, a midtarsal portion at a location substantially corresponding to a midtarsal of the foot of the wearer, and a forefoot portion, the sole member also having a medial side and a lateral side;
the heel portion having a lateral heel part at a location substantially corresponding to the lateral tuberosity of the calcaneus of the foot of the wearer, and a medial heel part at a location substantially corresponding to the base of the calcaneus of the foot of the wearer;
the midtarsal portion being between the forefoot portion and heel portion, and having a lateral midtarsal part at a location substantially corresponding to the base of a fifth metatarsal of the foot of the wearer;
the forefoot portion having a forward medial forefoot part at a location substantially corresponding to the head of the first distal phalange, a rear medial forefoot part at a location substantially corresponding to the head of a first metatarsal of the foot of the wearer, and a rear lateral forefoot part at a location substantially corresponding to the head of a fifth metatarsal of the foot of the wearer;
characterized in that the sole containing a convexly rounded bulge at at least one of: the medial heel part; they lateral heel part; the forward medial forefoot part; the rear medial forefoot part; the rear lateral forefoot part; and the lateral midtarsal part;
the bulges projecting convexly at at least one of the outer surface, the medial side and the lateral side of the sole member; the bulge comprising at least in part an area of increased material density for the sole member, to form a structural support or propulsion element for the foot of the wearer.

104. A contoured sole of a shoe, for supporting a foot of a wearer, the sole comprising:
a sole member having an outer surface for contacting the ground, and an inner surface for contacting the foot of the wearer;
the outer surface having a heel portion at a location substantially corresponding to a calcaneus of the foot of the wearer, a midtarsal portion at a location substantially corresponding to a midtarsal of the foot of the wearer, and a forefoot portion, the sole member also having a medial side and a lateral side;
the heel portion having a lateral heel part at a location substantially corresponding to the lateral tuberosity of the calcaneus of the foot of the wearer, and a medial heel part at a location substantially corresponding to the base of the calcaneus of the foot of the wearer;
the midtarsal portion being between the forefoot portion and heel portion, and having a lateral midtarsal part at a location substantially corresponding to the base of a fifth metatarsal of the foot of the wearer;
the forefoot portion having a forward medial forefoot part at a location substantially corresponding to the head of the first distal phalange, a rear medial forefoot part at a location substantially corresponding to the head of a first metatarsal of the foot of the wearer, and a rear lateral forefoot part at a location substantially corresponding to the head of a fifth metatarsal of the foot of the wearer;
characterized in that the sole containing a convexly rounded bulge at the rear lateral forefoot part; at the medial heel part; and at the lateral heel part; the bulges being convex at at least one of the outer surfaces, the medial side and the lateral side of the sole member.

105. A contoured sole of a shoe, for supporting a foot of a wearer, the sole comprising:
a sole member having an outer surface for contacting the ground, and an inner surface for contacting the foot of the wearer;
the outer surface having a heel portion at a location substantially corresponding to a calcaneus of the foot of the wearer, a midtarsal portion at a location substantially corresponding to a midtarsal of the foot of the wearer, and a forefoot portion, the sole member also having a medial side and lateral side;

the heel portion having a lateral heel part at a location substantially corresponding to the lateral tuberosity of the calcaneus of the foot of the wearer, and a medial heel part at a location substantially corresponding to the base of the calcaneus of the foot of the wearer;
the midtarsal portion being between the forefoot portion and heel portion, and having a lateral midtarsal part at a location substantially corresponding to the base of a fifth metatarsal of the foot of the wearer;
the forefoot portion having a forward medial forefoot part at a location substantially corresponding to the head of the first distal phalange, a rear medial forefoot part at a location substantially corresponding to the head of a first metatarsal of the foot of the wearer, and a rear lateral forefoot part at a location substantially corresponding to the head of a fifth metatarsal of the foot of the wearer;
characterized in that the sole containing a convexly rounded bulge at the forward medial forefoot part, the sole including a further bulge at at least one of the rear lateral and medial forefoot parts, the sole further including a transverse indentation in the outer surface of the sole, between the forward forefoot part bulge and the rear forefoot part bulge; the bulges being contoured at the inner surface so that the sole member extends upwardly at at least one of the lateral and medial sides for conforming with at least part of a side of the foot of the wearer.

106. A contoured sole of a shoe, for supporting a foot of a wearer, the sole comprising:
a sole member having an outer surface for contacting the ground, and an inner surface for contacting the foot of the wearer;
the outer surface having a heel portion at a location substantially corresponding to a calcaneus of the foot of the wearer, a midtarsal portion at a location substantially corresponding to a midtarsal of the foot of the wearer, and a forefoot portion, the sole member also having a medial side and a lateral side;
the heel portion having a lateral heel part at a location substantially corresponding to the lateral tuberosity of the calcaneus of the foot of the wearer, and medial heel part at a location substantially corresponding to the base of the calcaneus of the foot of the wearer;
the midtarsal portion being between the forefoot portion and heel portion, and having a lateral midtarsal part at a location substantially corresponding to the base of a fifth metatarsal of the foot of the wearer;
the forefoot portion having a forward medial forefoot part at a location substantially corresponding to the head of the first distal phalange, a rear medial forefoot part at a location substantially corresponding to the head of a first metatarsal of the foot of the wearer, and rear lateral forefoot part at a location substantially corresponding to the head of a fifth metatarsal of the foot of the wearer;
characterized in that the sole containing a convexly rounded bulge at the rear medial forefoot part; the rear lateral forefoot part; and the lateral midtarsal part; the bulges being convex from at least one of the outer surface, the medial side and the lateral side of the sole member.

107. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having at least one midtarsal sole portion with a surface for contacting the ground;
characterized in that said at least one midtarsal sole portion is located proximate to at least one of the following bones of a wearer's foot: a base of a fifth metatarsal and a main longitudinal arch; and said at least one midtarsal sole portion is at least substantially separated from a forefoot portion and from a heel portion by another midtarsal sole portion without said ground-contacting surface, in order to save weight: and to increase flexibility, while maintaining the structural stability of said wearer's foot.

108. A shoe sole for a shoe or other footwear, such as an athletic shoe or a street shoe, comprising:
a shoe sole having a sole portion and at least one outwardly contoured side portion connected to said sole portion;
said at least one contoured side portion being located proximate to at least one of the following bones which are essential support or optional structural support elements of said wearer's foot: the base of the calcaneus, the lateral tuberosity of the calcaneus, the base of the fifth metatarsal, the head of the fifth metatarsal, the head of the first metatarsal, and the main longitudinal arch;
characterized in that said sole portion has a variation in thickness when measured in a sagittal plane cross section at least proximate to said at least one outwardly contoured side portion.