SHOE SOLE STRUCTURES

Abstract: A shoe sole (28) with contoured side portions (28a).

Description: SHOE SOLE STRUCTURES BACKGROUND OF THE INVENTION This invention relates generally to the struc- ture of soles of shoes and other footwear, including soles of street shoes, hiking boots, sandals, slippers, and moccasins. More specifically, this invention relates to the structure of athletic shoe soles, including such examples as basketball and running shoes. Still more particularly, this application explicitly includes an alternate definition of the inner surface of the theoretically ideal stability plane as being complementary to the shape of the wearer's foot, instead of conforming to the wearer's foot sole or to a shoe last approximating it either for a specific individ¬ ual; such alternate definition is more like a standard shoe last that approximates the exact shape and size of the individual wearer's foot sole for mass production. This application also includes the broadest possible definition for the inner surface of the contoured shoe sole sides that still defines over the prior art, namely any position between roughly paralleling the wearer's foot sole and roughly paralleling the flat ground. Still more particularly, in its simplest con- ceptual form, thiε invention relates to variations in the structure of such shoes having a sole contour which fol¬ lows a theoretically ideal stability plane as a basic concept, but which deviates substantially therefrom out¬ wardly, to provide greater than natural stability, so that joint motion of the wearer is restricted, especially the ankle joint; or, alternately, which deviates substan¬ tially therefrom inwardly, to provide less than natural stability, so that a greater freedom of joint motion is allowed. Alternately, substantial density variations or bottom sole designs are used instead of, or in combina¬ tion with, substantial thickness variations for the same purpose. These shoe sole modifications are research indicating that they are necesεary and useful to correct important interrelated anatomical/biomechanical imbal¬ ances or deformities of surprising large magnitude in both individuals or major population groups. More particularly, in its simplest conceptual form, this invention is the structure of a conventional shoe sole that has been modified by having its sides bent up so that their inner surface conforms to a shape nearly identical but slightly smaller than the shape of the outer surface of the sides of the foot sole of the wearer (instead of the shoe sole sides conforming to the ground by paralleling it, as is conventional) . The shoe sole sides are sufficiently flexible to bend out easily when the shoes are put on the wearer's feet and therefore the shoe soles gently hold the sides of the wearer's foot sole when on, providing the equivalent of custom fit in a mass-produced shoe sole. Still more particularly, this invention relates to shoe sole structures that are formed to conform to the all or part of the shape of the wearer's foot sole, whether under a body weight load or unloaded, but without contoured stability sides as defined by the applicant. Still more particularly, this invention relates to variations in the structure of such soles using a theoretically ideal stability plane as a basic concept, especially including structures exceeding that plane. Still more particularly, this invention relates to contoured shoe sole sides that provide support for sideways tilting of any angular amount from zero degrees to 180 degrees at least for such contoured sides proxi- mate to any one or more or all of the essential stability or propulsion structures of the foot, as defined below and previously. Finally, this invention disclosed in this con- tinuation-in-part application uses soft materials or voids to enable a shoe sole to conform or be complemen¬ tary to the wearer's foot sole and/or to enable the shoe sole to compress to a uniform thickness or to vary within the thickness parameters established in the applicant's prior patents or as defined below, the thickness being measured in frontal or transverse plane cross sections. The parent '598 application clarified and expanded the applicant's earlier filed U.S. Patent Appli- cation 07/680,134, filed April 3, 1991. The applicant has introduced into the art the concept of a theoretically ideal stability plane as a structural basis for shoe sole designs. The theoretically ideal stability plane was defined by the applicant in previous copending applications as the plane of the surface of the bottom of the shoe sole, wherein the shoe sole conforms to the natural shape of the wearer's foot sole, particularly its sides, and has a conεtant thickness in frontal or transverse plane cross sections. Therefore, by definition, the theoretically ideal stability plane is the surface plane of the bottom of the shoe sole that parallels the surface of the wearer's foot sole in transverse or frontal plane cross sections. The theoretically ideal εtability plane concept as implemented into shoes such as street shoes and athletic shoes is presented in U.S. Patent Numbers 4,989,349, issued February 5, 1991 and 5,317,819, issued June 7, 1994, both of which are incorporated by refer- ence; and pending U.S. Patent Application Serial Number 462,531 filed June 5, 1995, and Serial Number 472,979 filed June 7, 1995; Application No. 07/400,714, filed August 30, 1989; 07/416,478, filed October 3, 1989; 07/424,509, filed October 20, 1989; 07/463,302, filed January 10, 1990; 07/469,313, filed January 24, 1990; 07/478,579, filed February 8, 1990; 07/539,870, filed June 18, 1990; 07/608,748, filed November 5, 1990; 07/783,145, filed October 28, 1991; and 07/926,523, filed Auguεt 10, 1992. PCT applications based on the above patents and applications have been publiεhed as WO 90/00358 of January 25, 1990 (part of the '349 Patent, all of the '819 patent and part of '714 application) ; WO 91/03180 of March 21, 1991 (the remainder of the '714 application) ; WO 91/04683 of April 18, 1991 (the '478 application); WO 91/05491 of May 02, 1991 (the '509 application); WO 91/10377 of July 25, 1991 (the '302 application); WO 91/11124 of August 08, 1991 (the '313 application); WO 91/11924 of August 22, 1991 (the '579 application); WO 91/19429 of December 26, 1991 (the '870 application); WO 92/07483 of May 14, 1992 (the '748 application); WO 92/18024 of October 29, 1992 (the '598 application); and WO 94/03080 of February 17, 1994 (the '523 application). All of above publications are incorporated by reference in this application to support claimed prior embodiments that are incorporated in combinations with new elements disclosed in this application. This new invention is a modification of the inventions disclosed and claimed in the earlier applica¬ tions and develops the application of the concept of the theoretically ideal stability plane to other shoe struc¬ tures. Each of the applicant's applications is built directly on its predecessors and therefore all possible combinations of inventions or their component elements with other inventions or elements in prior and subsequent applications have always been specifically intended by the applicant. Generally, however, the applicant's applications are generic at such a fundamental level that it is not possible as a practical matter to describe every embodiment combination that offers substantial improvement over the existing art, as the length of this deεcription of only some combinations will testify. Accordingly, it is a general object of thiε invention to elaborate upon the application of the prin¬ ciple of the theoretically ideal εtability plane to other εhoe εtructures. The purpose of the earlier '523 application was to specifically describe some of the most important com¬ binations, especially those that constitute optimal ones, that exist between the applicant's U.S. Patent Applica¬ tion 07/400,714, filed August 30, 1989, and subsequent patentε filed by the applicant, particularly U.S. Patent Application 07/416,478, filed October 3, 1989, as well aε other combinations. The purpose of U.S. Patent Applica¬ tion 472,979 filed June 7, 1995, is to incorporate other elements from the applicant's patents, applications, and publiεhed PCT applications as well as to introduce new inventions with which the prior incorporated inventions can be combined. The applicant explicitly stateε that virtually all of hiε prior and herein disclosed inven- tions can be usefully combined with others to provide better shoe sole stability, safety, and cushioning com¬ pared to the existing art, but are mathematically far too numerous to list all those that are important here, despite the extreme length of this application. This application describes only some of the most important combinations and shows even fewer, strictly for the pur¬ poεe of economy. The '714 application indicated that existing running shoeε are unneceεεarily unεafe. They profoundly diεrupt natural human biomechanics. The resulting unnat¬ ural foot and ankle motion leads to what are abnormally high levels of running injurieε. Proof of the unnatural effect of shoes has come quite unexpectedly from the discovery that, at the extreme end of its normal range of motion, the unshod bare foot is naturally stable, almost unsprainable, while the foot equipped with any shoe, athletic or otherwise, is artificially unstable and abnormally prone to ankle sprains. Consequently, ordinary ankle sprainε muεt be viewed aε largely an unnatural phenomena, even though fairly common. Compelling evidence de onεtrates that the stability of bare feet is entirely different from the stability of shoe-equipped feet. The underlying cause of the universal instabil- ity of shoeε iε a critical but correctable design flaw. That hidden flaw, so deeply ingrained in existing shoe designs, is so extraordinarily fundamental that it has remained unnoticed until now. The flaw is revealed by a novel new biomechanical test, one that is unprecedented in its simplicity. It is easy enough to be duplicated and verified by anyone; it only takes a few minutes and requires no scientific equipment or expertise. The sim- plicity of the test belies its surprisingly convincing results. It demonstrateε an obviouε difference in εta- bility between a bare foot and a running εhoe, a differ¬ ence so unexpectedly huge that it makes an apparently subjective test clearly objective instead. The test proves beyond doubt that all existing shoes are unsafely unstable. The broader implications of this uniquely unam¬ biguous diεcovery are potentially far-reaching. The same fundamental flaw in existing shoes that is glaringly exposed by the new test alεo appearε to be the major cauεe of chronic overuse injuries, which are unusually common in running, as well as other sport injurieε. It causes the chronic injuries in the εame way it causes ankle sprainε; that is, by seriouεly diεrupting natural foot and ankle biomechanics. It was a general object of the '714 invention to provide a shoe sole which, when under load and tilting to the side, deforms in a manner which closely parallels that of the foot of its wearer, while retaining nearly the same amount of contact of the shoe sole with the ground as in its upright state. It was still another object of the '714 inven¬ tion to provide a deformable shoe sole having the upper portion or the sides bent inwardly somewhat so that when worn the sideε bend out eaεily to approximate a cuεtom fit. It waε still another object of the '714 inven¬ tion to provide a shoe having a naturally contoured sole which is abbreviated along itε εideε to only eεεential εtructural εtability and propulεion elementε, which are combined and integrated into the εame discontinuous shoe sole structural elements underneath the foot, which approximate the principal structural elements of a human foot and their natural articulation between elements. The '478 invention relates to variations in the structure of such shoes having a sole contour which fol- lows a theoretically ideal stability plane as a basic concept, but which deviates therefrom outwardly, to pro¬ vide greater than natural stability. Still more particu¬ larly, this invention relates to the use of structureε approximating, but increasing beyond, a theoretically ideal stability plane to provide greater than natural stability for an individual whose natural foot and ankle biomechanical functioning have been degraded by a life¬ time use of flawed exiεting εhoeε. The '478 invention iε a modification of the inventions disclosed and claimed in the earlier applica¬ tion and developε the application of the concept of the theoretically ideal εtability plane to other εhoe εtruc- tures. As such, it presentε certain εtructural ideas which deviate outwardly from the theoretically ideal stability plane to compensate for faulty foot biomechan- icε caused by the major flaw in existing shoe designs identified in the earlier patent applications. The shoe sole designs in the '478 application are based on a recognition that lifetime use of existing shoes, the unnatural design of which is innately and seriously flawed, has produced actual structural changes in the human foot and ankle. Existing εhoeε thereby have altered natural human biomechanicε in many, if not most, individuals to an extent that muεt be compensated for in an enhanced and therapeutic design. The continual repe¬ tition of serious interference by existing shoes appears to have produced individual biomechanical changes that may be permanent,so simply removing the cause is not enough. Treating the reεidual effect muεt alεo be under- taken. Accordingly, it waε a general object of the '478 invention to elaborate upon the application of the principle of the theoretically ideal εtability plane to other shoe εtructureε. It was still another object of the '478 inven¬ tion to provide a shoe having a sole contour which devi- ateε outwardly in a conεtructive way from the theoreti¬ cally ideal εtability plane. It was another object of the '478 invention to provide a sole contour having a shape naturally contoured to the shape of a human foot, but having a shoe sole thicknesε which iε increaεes somewhat beyond the thick- neεε εpecified by the theoretically ideal εtability plane. It is another object of this invention to pro¬ vide a naturally contoured shoe sole having a thickness somewhat greater than mandated by the concept of a theo¬ retically ideal stability plane, either through most of the contour of the sole, or at preselected portions of the sole. It is yet another object of this invention to provide a naturally contoured εhoe sole having a thick¬ ness which approximates a theoretically ideal stability plane, but which varies toward either a greater thicknesε throughout the sole or at spaced portionε thereof, or toward a εimilar but lesser thicknesε. The '302 invention relates to a shoe having an anthropomorphic sole that copies the underlying support, εtability and cuεhioning εtructures of the human foot. Natural stability is provided by attaching a completely flexible but relatively inelastic shoe sole upper directly to the bottom sole, enveloping the sideε of the midεole, inεtead of attaching it to the top εurface of the shoe sole. Doing so puts the flexible εide of the εhoe upper under tenεion in reaction to deεtabilizing sideways forces on the εhoe cauεing it to tilt. That tenεion force is balanced and in equilibrium because the bottom sole is firmly anchored by body weight, so the destabilizing sideways motion iε neutralized by the ten¬ εion in the flexible εides of the shoe upper. Still more particularly, this invention relates to support and cush¬ ioning which is provided by shoe sole compartments filled with a pressure-transmitting medium like liquid, gas, or gel. Unlike εimilar existing εystems, direct physical contact occurs between the upper surface and the lower surface of the compartments, providing firm, stable εup¬ port. Cushioning is provided by the transmitting medium progressively causing tension in the flexible and semi- elastic sides of the shoe sole. The compartments provid- ing support and cushioning are similar in εtructure to the fat pads of the foot, which simultaneously provide both firm support and progressive cushioning. Existing cushioning systemε cannot provide both firm εupport and progreεεive cuεhioning without alεo obεtructing the natural pronation and εupination motion of the foot, because the overall conception on which they are based is inherently flawed. The two most commer¬ cially successful proprietary syεtemε are Nike Air, based on U.S. Patents Nos. 4,219,945 issued September 2, 1980, 4,183,156 issued September 15, 1980, 4,271,606 issued June 9, 1981, and 4,340,626 isεued July 20, 1982; and Aεicε Gel, based on U.S. Patent No. 4,768,295 isεued September 6, 1988. Both of theεe cuεhioning systems and all of the other less popular ones have two essential flaws. First, all such syεtems suspend the upper sur¬ face of the shoe sole directly under the important struc¬ tural elements of the foot, particularly the critical the heel bone, known as the calcaneus, in order to cushion it. That is, to provide good cuεhioning and energy return, all εuch εyεtemε support the foot's bone struc¬ tureε in buoyant manner, as if floating on a water bed or bouncing on a trampoline. None provide firm, direct structural support to those foot support structureε; the shoe sole surface above the cushioning syεtem never comes in contact with the lower shoe sole surface under routine loads, like normal weight-bearing. In existing cushion¬ ing systemε, firm εtructural εupport directly under the calcaneuε and progreεsive cushioning are mutually incom¬ patible. In marked contrast, it is obvious with the simplest tests that the barefoot is provided by very firm direct εtructural support by the fat pads underneath the bones contacting the sole, while at the same time it is effectively cushioned, though this property is underde¬ veloped in habitually shoe shod feet. Second, because such existing proprietary cush¬ ioning systems do not provide adequate control of foot motion or stability, they are generally augmented with rigid structures on the sides of the shoe uppers and the shoe soles, like heel counters and motion control devices, in order to provide control and stability. Unfortunately, these rigid structures seriously obstruct natural pronation and supination motion and actually increase lateral instability, as noted in the applicant's pending U.S. Patent Applications Nos. 07/219,387, filed on July 15, 1988; 07/239,667, filed on September 2, 1988; 07/400,714, filed on Auguεt 30, 1989; 07/416,478, filed on October 3, 1989; and 07/424,509, filed on October 20, 1989, aε well aε in PCT Application No. PCT/US89/03076 filed on July 14, 1989. The purpose of the inventions diεclosed in these applications was primarily to provide a neutral design that allows for natural foot and ankle biomechanics aε cloεe aε poεεible to that between the foot and the ground, and to avoid the serious interfer¬ ence with natural foot and ankle biomechanics inherent in existing shoes. In marked contrast to the rigid-sided propri- etary designε diεcuεεed above, the barefoot provides stability at it sides by putting those εideε, which are flexible and relatively inelaεtic, under extreme tension caused by the pressure of the compresεed fat padε; they thereby become temporarily rigid when outεide forces make that rigidity appropriate, producing none of the desta¬ bilizing lever arm torque problems of the permanently rigid sides of existing designε. The applicant's '302 invention simply attempts, as closely as poεεible, to replicate the naturally effec¬ tive εtructureε of the foot that provide stability, sup¬ port, and cushioning. Accordingly, it was a general object of the '302 invention to elaborate upon the application of the principle of the natural basis for the εupport, stability and cushioning of the barefoot to shoe structures. It was still another object of the '302 inven- tion to provide a shoe having a sole with natural εtabil¬ ity provided by attaching a completely flexible but rela¬ tively inelaεtic εhoe εole upper directly to the bottom εole, enveloping the sides of the midsole, to put the side of the shoe upper under tension in reaction to destabilizing εideways forces on a tilting shoe. It was still another object of the '302 inven¬ tion to have that tension force is balanced and in equi¬ librium because the bottom sole is firmly anchored by body weight, so the destabilizing sidewayε motion is neutralized by the tension in the εideε of the shoe upper. It was another object of the '302 invention to create a shoe sole with support and cuεhioning which iε provided by shoe sole compartments, filled with a pres- εure-tranεmitting medium like liquid, gaε, or gel, that are similar in structure to the fat pads of the foot, which simultaneouεly provide both firm support and pro- greεεive cuεhioning. These and other objects of the invention will become apparent from a detailed deεcription of the inven¬ tion which follows taken with the accompanying drawings. BRIEF SUMMARY OF THE INVENTION The continuation-in-part application U.S. Pat- ent Application No. 462,531 filed June 5, 1995, broadened the definition of the theoretically ideal stability plane, as defined in the '786 and all prior applications filed by the applicant. The '819 patent and subεequent applications have defined the inner surface of the theo¬ retically ideal stability plane as conforming to the shape of the wearer's foot, especially its sides, so that the inner surface of the applicant's shoe sole invention conforms to the outer surface of the wearer's foot sole, eεpecially it sides, when measured in frontal plane or transverse plane cross sections. This new application explicitly includeε an upper εhoe εole surface that is complementary to the shape of all or a portion the wearer's foot sole; "con¬ forming" to that foot sole shape remainε the beεt mode, εince it gives to one skilled in the art the moεt exact direction or goal, εo that one εkilled in the art can uεe whatever means are available to achieve the closest con- formance posεible, much aε the art iε uεed to achieve an accurate fit for a wearer. In addition, this application describes shoe contoured sole side deεignε wherein the inner εurface of the theoretically ideal εtability plane lies at some point between conforming or complementary to the shape of the wearer's foot sole, that is — roughly paralleling the foot sole including its side — and par¬ alleling the flat ground; that inner surface of the theo¬ retically ideal stability plane becomes load-bearing in contact with the foot sole during foot inversion and eversion, which is normal εideways or lateral motion. The basis of this design was introduced in the appli¬ cant's '302 application relative to Fig. 9 of that appli¬ cation. Additionally, this application describes shoe εole εide deεigns wherein the lower surface of the theo¬ retically ideal stability plane, which equates to the load-bearing surface of the bottom or outer shoe sole, of the shoe sole side portions is above the plane of the underneath portion of the shoe sole, when measured in frontal or transverεe plane cross sections; that lower surface of the theoretically ideal stability plane becomes load-bearing in contact with the ground during foot inversion and eversion, which is normal sideways or lateral motion. Although the inventions described in this application may in many caseε be leεs optimal than those previously described by the applicant in earlier applica¬ tions, they nonetheleεε distinguish over all prior art and still do provide a significant stability improvement over existing footwear and thus provide significantly increased injury prevention benefit compared to existing footwear. In its simpleεt conceptual form, the appli¬ cant's earlier invention discloεed in his '714 applica¬ tion is the structure of a conventional shoe sole that has been modified by having itε εideε bent up so that their inner surface conforms to a shape nearly identical but slightly smaller than the shape of the outer surface of the foot sole of the wearer (instead of the shoe sole sides being flat on the ground, as is conventional) . This concept is like that described in Fig. 3 of the applicant's 07/239,667 application; for the applicant's fully contoured design described in Fig. 15 of the '667 application, the entire shoe sole — including both the εides and the portion directly underneath the foot — is bent up to conform to a shape nearly identical but slightly smaller than the contoured shape of the unloaded foot sole of the wearer, rather than the partially flat¬ tened load-bearing foot sole shown in Fig. 3. In this continuation-in-part application, the use of this invention with otherwise conventional shoeε with any εide sole portion, including contoured sideε with uniform or any other thickness variation or denεity variation, including bottom εole tread variation, eεpe- cially including those defined below by the applicant, is further clarified. This theoretical or conceptual bending up must be accomplished in practical manufacturing without any of the puckering distortion or deformation that would neces¬ sarily occur if such a conventional shoe sole were actu- ally bent up simultaneously along all of its the sideε; consequently, manufacturing techniques that do not require any bending up of shoe sole material, such as injection molding manufacturing of the shoe sole, would be required for optimal results and therefore is prefera¬ ble. It is critical to the novelty of this fundamen¬ tal concept that all layers of the shoe sole are bent up around the foot sole. A small number of both street and athletic shoe soleε that are commercially available are naturally contoured to a limited extent in that only their bottom soles, which are about one quarter to one third of the total thickness of the entire shoe sole, are wrapped up around portions of the wearers' foot soles; the remaining soles layers, including the insole, midsole and heel lift (or heel) of such shoe soles, constituting over half of the thicknesε of the entire shoe εole, remainε flat, conforming to the ground rather than the wearers' feet. (At the other extreme, some shoes in the existing art have flat midsoles and bottom soleε, but have insoles that conform to the wearer's foot sole.) Consequently, in existing contoured shoe soles, the total shoe sole thicknesε of the contoured εide por¬ tionε, including every layer or portion, is much lesε than the total thickneεs of the sole portion directly underneath the foot, whereas in the applicant's prior shoe sole inventionε, including the '819 patent and '714 and '478 application, aε well as the applicant's other pending applications, the shoe sole thicknesε of the contoured side portions are the same as the thicknesε of the εole portion directly underneath the foot, meaning uniform thickness as meaεured in frontal or transverse plane crosε sections, or at least similar to the thick¬ ness of the sole portion directly underneath the foot, meaning a thickness variation of up to 25 percent, as measured in frontal or transverse plane cross sectionε. Thiε continuation-in-part application explic¬ itly defines those thickness variations, aε meaεured in frontal or transverse plane cross sections, of the appli¬ cant's εhoe εoles from 26 percent up to 50 percent, which distinguisheε over all known prior art; the earlier '478 application εpecified thickneεs and density variations of up to 25 percent. In addition, for shoe sole thickneεε deviating outwardly in a conεtructive way from the theoretically ideal εtability plane, the shoe sole thicknesε variation of the applicant'ε shoe soles is increased in this appli- cation from 26 to 50 percent, and from 51 percent to 100 percent in some extreme cases, generally in the forefoot, as meaεured in frontal or transverse plane cross εec¬ tionε. This application similarly increases construc- tive denεity variationε, aε most typically measured in durometers on a Shore A scale, to include 26 percent up to 50 percent and from 51 percent to 200 percent. The same variations in shoe bottom sole design can provide similar effects to the variation in shoe sole denεity deεcribed above. In addition, any of the above deεcribed thick¬ neεε variationε from a theoretically ideal εtability plane can be uεed together with any of the above deεcribed density or bottom sole design variations. All portions of the εhoe εole are included in thickneεε and denεity meaεurement, including the εockliner or insole, the midsole (including heel lift or other thicknesε variation meaεured in the εagittal plane) and bottom or outer sole. The above described thickness and density vari¬ ations apply to the load-bearing portions of the con¬ toured sides of the applicant's shoe εole inventionε, the side portion being identified in Fig. 4 of the '819 pat¬ ent. Thickness and density variations described above are measured along the contoured side portion. The εide portion of the fully contoured design introduced in the '819 patent in Fig. 15 cannot be defined as explicitly, since the bottom portion is contoured like the sideε, but should be measured by estimating the equivalent Fig. 4 figure; generally, like Figs. 14 and Fig. 15 of the '819 patent, assuming the flattened sole portion shown in Fig. 14 corresponds to a load-bearing equivalent of Fig. 15, so that the contoured sides of Figs. 14 and Fig. 15 are esεentially the same. Alternately, the thicknesε and density varia¬ tions described above can be measured from the center of the eεεential structural support and propulsion elements defined in the '819 patent. Those elements are the base and lateral tuberosity of the calcaneus, the heads of the metatarsals, and the base of the fifth metatarsal, and the head of the firεt diεtal phalange, reεpectively. Of the etatarεal heads, only the first and fifth metatarsal headε are uεed for such measurement, since only those two are located on lateral portions of the foot and thus proximate to contoured stability sides of the applicant'ε shoe sole. This major and conspicuous structural differ- ence between the applicant's underlying concept and the existing shoe sole art is paralleled by a similarly dra¬ matic functional difference between the two: the afore¬ mentioned equivalent or similar thickness of the appli¬ cant's shoe sole invention maintains intact the firm lateral stability of the wearer's foot, that stability as demonstrated when the foot is unshod and tilted out lat¬ erally in inversion to the extreme limit of the normal range of motion of the ankle joint of the foot. The εideε of the applicant's shoe sole invention extend suf- ficiently far up the εideε of the wearer's foot sole to maintain the lateral stability of the wearer's foot when bare. In addition, the applicant's shoe sole inven¬ tion maintains the natural stability and natural, unin- terrupted motion of the wearer's foot when bare through¬ out its normal range of sidewayε pronation and supination motion occurring during all load-bearing phases of loco¬ motion of the wearer, including when the wearer iε εtand- ing, walking, jogging and running, even when the foot is tilted to the extreme limit of that normal range, in contrast to unstable and inflexible conventional shoe soles, including the partially contoured existing art described above. The sideε of the applicant's shoe sole invention extend sufficiently far up the sides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact thickness and material density of the shoe sole sideε and their specific contour will be determined empirically for individuals and groups using εtandard biomechanical techniques of gait analysiε to determine those combinations that best provide the barefoot stabil¬ ity described above. Finally, the shoe sole sideε are made of mate¬ rial εufficiently flexible to bend out eaεily when the εhoes are put on the wearer's feet and therefore the shoe soles gently hold the sideε of the wearer's foot εole when on, providing the equivalent of custom fit in a masε-produced shoe sole. In general, the applicant's preferred shoe sole embodiments include the structural and material flexibility to deform in parallel to the natural deformation of the wearer's foot sole as if it were bare and unaffected by any of the abnormal foot biomechanics created by rigid conventional shoe sole. At the same time, the applicant's preferred shoe sole embodiments are sufficiently firm to provide the wearer's foot with the structural εupport necessary to maintain normal pronation and supination, as if the wearer's foot were bare; in contrast, the excessive soft- neεε of many of the εhoe εole materialε used in shoe soles in the existing art cauεe instability in the form of abnormally excessive foot pronation and supination. Directed to achieving the aforementioned objects and to overcoming problems with prior art shoes, a shoe according to the '714 invention compriseε a sole having at least a portion thereof following the contour of a theoretically ideal stability plane, and which fur- ther includes rounded edges at the finishing edge of the sole after the last point where the constant shoe sole thickness is maintained. Thus, the upper surface of the sole does not provide an unsupported portion that creates a destabilizing torque and the bottom surface does not provide an unnatural pivoting edge. In another aspect in the '714 application, the shoe includes a naturally contoured sole structure exhib¬ iting natural deformation which closely parallels the natural deformation of a foot under the same load. In a preferred embodiment, the naturally contoured side por¬ tion of the sole extendε to contours underneath the load- bearing foot. In another embodiment, the sole portion is abbreviated along its sides to essential support and propulsion elements wherein those elements are combined and integrated into the same discontinuous shoe sole structural elementε underneath the foot, which approxi¬ mate the principal structural elements of a human foot and their natural articulation between elements. The density of the abbreviated shoe sole can be greater than the density of the material used in an unabbreviated shoe sole to compensate for increased preεεure loading. The eεsential support elementε include the baεe and lateral tuberosity of the calcaneus, heads of the metatarsal, and the base of the fifth metatarsal. The '714 application shoe sole iε naturally contoured, paralleling the shape of the foot in order to parallel its natural deformation, and made from a mate¬ rial which, when under load and tilting to the side, deforms in a manner which closely parallels that of the foot of its wearer, while retaining nearly the same amount of contact of the shoe sole with the ground as in its upright εtate under load. A deformable εhoe εole according to the invention may have itε εideε bent inwardly εomewhat so that when worn the sideε bend out eaεily to approximate a cuεtom fit. Directed to achieving the aforementioned objects and to overcoming problems with prior art shoeε, a εhoe according to the '478 invention comprises a sole having at least a portion thereof following approximately the contour of a theoretically ideal εtability plane, preferably applied to a naturally contoured εhoe sole approximating the contour of a human foot. In the appli¬ cant's εhoe sole inventions, the εhoe sole thicknesε of the contoured εide portionε are at leaεt εimilar to the thickneεε of the sole portion directly underneath the foot, meaning either a thickness variation from 5 to 10 percent or from 11 to 25 percent, as measured in frontal or transverεe plane cross sectionε. In another aεpect of the '478 invention, the shoe includes a naturally contoured sole structure exhib¬ iting natural deformation which closely parallels the natural deformation of a foot under the same load, and having a contour which approximates, but increases beyond the theoretically ideal stability plane. When the shoe sole thicknesε is increased beyond the theoretically ideal stability plane, greater than natural stability results; when thicknesε is decreased, greater than natu¬ ral motion results. In a preferred embodiment of the '478 inven¬ tion, such variations are consistent through all frontal plane cross sections so that there are proportionally equal increaεes to the theoretically ideal stability plane from front to back. That is to say, a 25 percent thickneεε increase in the lateral stability sideε of the forefoot of the εhoe εole would alεo have a 25 percent increases in lateral stability sideε proximate to the base of the fifth metatarsal of a wearer's foot and a 25 increase in the lateral εtability εideε of the heel of the εhoe εole. In alternative embodimentε, the thickneεs may increaεe, then decrease at respective adjacent loca¬ tions, or vary in other thickness sequenceε. The thick- neεε variations may be symmetrical on both sides, or asymmetrical, particularly since it may be desirable to provide greater εtability for the medial side than the lateral side to compensate for common pronation problemε. The variation pattern of the right shoe can vary from that of the left shoe. Variation in shoe εole denεity or bottom εole tread can also provide reduced but similar effects. This invention relates to shoe sole structures that are formed 'to conform to the all or part of the shape of the wearer's foot sole, either under a body weight load (defined as one body weight or alternately as any body weight force) , but without contoured stability εideε aε defined by the applicant. Still more particularly, this invention relates to variations in the structure of εuch soles using a theoretically ideal εtability plane aε a basic concept, especially including structures exceeding that plane. Finally, this invention relates to contoured shoe sole sides that provide support for sidewayε tilting of any angular amount from zero degreeε to 150 degreeε at leaεt for such contoured sideε proximate to any one or more or all of the eεεential εtability or propulεion εtructureε of the foot, as defined below and previously. These and other features of the invention will become apparent from the detailed description of the invention which follows. BRIEF DESCRIPTION OF THE DRAWINGS Figs. 1 through 9 are from prior copending applications of the applicant, with some new textual specification added. Figs. 1-3 are from the '714 appli¬ cation; Figs. 4-8 are from the '478 application; and Fig. 9 is from the '302 application. Figs. IA to IC [8] illustrate functionally the principles of natural deformation as applied to the shoe soles of the '667 and '714 invention. Fig. 2 showε variations in the relative density of the shoe sole including the shoe insole to maximize an ability of the sole to deform naturally. Fig. 3 εhowε a shoe having naturally contoured sideε bent inwardly εomewhat from a normal εize εo then when worn the shoe approximates a custom fit. Fig. 4 shows a frontal plane cross section at the heel portion of a shoe with naturally contoured sideε like thoεe of Fig. 24, wherein a portion of the εhoe εole thickneεε is increased beyond the theoretically ideal stability plane. Fig. 5 is a view similar to Fig. 4, but of a shoe with fully contoured sides wherein the sole thick¬ neεε increases with increasing distance from the center line of the ground-engaging portion of the sole. Fig. 6 is a view similar to Figs. 29 and 30 showing still another density variation, one which is asymmetrical. Fig. 7 shows an embodiment like Fig. 25 but wherein a portion of the shoe sole thickness is decreased to less than the theoretically ideal stability plane. Fig. 8 shows a bottom sole tread design that provides a εimilar denεity variation aε that in Fig. 6. Fig. 9 iε the applicant'ε new εhoe εole design in a sequential εerieε of frontal plane croεs sections of the heel at the ankle joint area that correspondε exactly to the Fig. 42 serieε below. Fig. 10 iε the applicant'ε custom fit design utilizing downsized flexible contoured shoe sole εides in combination with a thicknesε greater than the theoreti¬ cally ideal stability plane. Fig. 11 is the same custom fit design in combi- nation with εhoe εole side portions having a material with greater density than the sole portion. Figs. 12-23 are from the '714 application. Fig. 12 is a rear view of a heel of a foot for explaining the use of a stationery sprain simulation teεt. Fig. 13 iε a rear view of a conventional run¬ ning εhoe unεtably rotating about an edge of itε εole when the shoe sole is tilted to the outside. Fig. 14 iε a diagram of the forceε on a foot when rotating in a shoe of the type shown in Fig. 2. Fig. 15 is a view similar to Fig. 3 but showing further continued rotation of a foot in a shoe of the type shown in Fig. 2. Fig. 16 is a force diagram during rotation of a εhoe having motion control deviceε and heel counterε. Fig. 17 is another force diagram during rota¬ tion of a shoe having a constant shoe sole thickness, but producing a destabilizing torque because a portion of the upper sole surface is unsupported during rotation. Fig. 18 shows an approach for minimizing desta¬ bilizing torque by providing only direct εtructural εup¬ port and by rounding edgeε of the sole and its outer and inner surfaces. Fig. 19 shows a shoe εole having a fully con¬ toured deεign but having sides which are abbreviated to the essential structural stability and propulsion ele¬ ments that are combined and integrated into discontinuous structural elements underneath the foot that simulate those of the foot. Fig. 20 is a diagram serving as a basis for an expanded discussion of a correct approach for measuring shoe sole thicknesε. Fig. 21 showε εeveral embodimentε wherein the bottom εole includeε moεt or all of the εpecial contourε of the new designs and retainε a flat upper εurface. Fig. 22, in Figε. 22A - 22C, εhow frontal plane croεε sections of an enhancement to the previously- described embodiment. Fig. 23 showε, in Figε. 23A - 23C, the enhance¬ ment of Fig. 39 applied to the naturally contoured εideε embodiment of the invention. Figs. 24-34 are from the '478 application. Fig. 24 shows, in frontal plane cross section at the heel portion of a shoe, the applicant'ε prior invention of a εhoe sole with naturally contoured sideε baεed on a theoretically ideal εtability plane. Fig. 25 shows, again in frontal plane crosε εection, the moεt general caεe of the applicant's prior invention, a fully contoured shoe sole that follows the natural contour of the bottom of the foot as well as its sides, also baεed on the theoretically ideal stability plane. Fig. 26, as seen in Figs. 26A to 26C in frontal plane cross section at the heel, shows the applicant's prior invention for conventional shoeε, a quadrant-εided shoe sole, based on a theoretically ideal stability plane. Fig. 28 is a view similar to Figs. 4 ,5 & 27 wherein the sole thicknesεeε vary in diverεe sequences. Fig. 29 is a frontal plane cross section show- ing a density variation in the midsole. Fig. 30 iε a view similar to Fig. 29 wherein the firmest denεity material iε at the outermost edge of the midsole contour. Fig. 31 shows a variation in the thickness of the sole for the quadrant embodiment which is greater than a theoretically ideal stability plane. Fig. 32 shows a quadrant embodiment as in Fig. 31 wherein the density of the sole varies. Fig. 33 shows embodiments like Figs. 24 through 26 but wherein a portion of the shoe sole thickness is decreased to less than the theoretically ideal stability plane. Fig. 34 εhow embodimentε with εideε both greater and leεser than the theoretically ideal stability plane. Figε. 35-44 are from the '302 application. Fig. 35 iε a perεpective view of a typical athletic shoe for running known to the prior art to which the invention is applicable. Fig. 36 illustrates in a close-up frontal plane cross section of the heel at the ankle joint the typical shoe of existing art, undeformed by body weight, when tilted sideways on the bottom edge. Fig. 37 shows, in the same close-up crosε sec¬ tion as Fig. 2, the applicant's prior invention of a naturally contoured shoe sole design, also tilted out. Fig. 38 shows a rear view of a barefoot heel tilted laterally 20 degrees. Fig. 39 εhowε, in a frontal plane croεε section at the ankle joint area of the heel, the applicant's new invention of tension stabilized εideε applied to his prior naturally contoured shoe sole. Fig. 40 showε, in a frontal plane croεε section close-up, the Fig. 5 deεign when tilted to itε edge, but undeformed by load. Fig. 41 shows, in frontal plane cross section at the ankle joint area of the heel, the Fig. 5 design when tilted to its edge and naturally deformed by body weight, though constant shoe sole thicknesε is maintained undeformed. Fig. 42 is a εequential εerieε of frontal plane cross sectionε of the barefoot heel at the ankle joint area. Fig. 8A is unloaded and upright; Fig. 8B is moder¬ ately loaded by full body weight and upright; Fig. 8C is heavily loaded at peak landing force while running and upright; and Fig. 8D is heavily loaded and tilted out laterally to its about 20 degree maximum. Fig. 43 is the applicant's new shoe εole deεign in a εequential εerieε of frontal plane croεs sectionε of the heel at the ankle joint area that corresponds exactly to the Fig. 8 εerieε above. Fig. 44 is two perspective views and a close-up view of the structure of fibrouε connective tissue of the groups of fat cells of the human heel. Fig. 10A shows a quartered section of the calcaneuε and the fat pad cham¬ berε below it; Fig. 10B εhowε a horizontal plane cloεe-up of the inner εtructureε of an individual chamber; and Fig. 10D εhowε a horizontal εection of the whorl arrange¬ ment of fat pad underneath the calcaneus. Figs. 45 - 58 were new to the continuation-in- part applications, Serial No. 462,531 filed June 5, 1995, and Serial No. 472,979 filed June 7, 1995. Fig. 45 is similar to Fig. 4, but showε more extreme thickness increase variations. Fig. 46 is similar to Fig. 5, but showε more extreme thickneεs increase variations. Fig. 47 iε similar to Fig. 6, but showε more extreme density variations. Fig. 48 is similar to Fig. 7, but εhowε more extreme thickneεs decrease variationε. Fig. 49 iε εimilar to Fig. 8, but shows more extreme bottom sole tread pattern variations. Fig. 50 iε similar to Fig. 10, but showε more extreme thickneεε increaεe variationε Fig. 51 is similar to Fig. 11, but shows more extreme density variations. Fig. 52 is similar to Fig. IA, but showε on the right side an upper shoe sole surface of the contoured side that is complementary to the shape of the wearer's foot sole; on the left side Fig. 52 shows an upper sur¬ face between complementary and parallel to the flat ground and a lower surface of the contoured shoe sole side that is not in contact with the ground. Fig. 53 is like Fig. 27 of the '819 patent, but with angular measurements of the contoured shoe sole sides indicated from zero degrees to 180 degrees. Fig. 54 iε similar to Fig. 19 of the '819 pat¬ ent, but without contoured stability sides. Figs. 55-56 are similar to Figs. 20-21 of the '819 patent, but without contoured stability sideε. Fig. 57 iε εimilar to Fig. 34, which is Fig. 15 of the '478 application showing the applicant's design with the outer surface defined by a part of a quadrant, but with more extreme thickneεε variations. Fig. 58 is based on Fig. IB but alεo shows, for purposes of illustration, on the right side a relative thicknesε increase of the contoured shoe sole side for that portion of the contoured shoe sole side beyond the limit of the full range of normal sideways foot inversion and eversion motion, and on the left side, a similar relative density increase; Figs. 59 - 63 are new to this continuation-in- part application; Fig. 59 is Fig. 25 of the applicant's '819 patent and illustrates an alternate embodiment of the invention wherein the sole structure deforms in use to follow a theoretically ideal stability plane according to the invention during deformation; Fig. 60 is Fig. 26 of the '819 patent and shows an embodiment wherein the contour of the εole according to the invention iε approximated by a plurality of line εegmentε; Fig. 61 iε new and εimilar to Fig. 52 above, but shows the uεe of εoft material or voids between the upper side surface of the contoured shoe sole sideε and contoured εides of the wearer's foot sole; Fig. 62A-B is new and similar to Fig. 45A-B above, but showε the uεe of soft material or voids within the contoured sides of the shoe sole; Fig. 63 is Fig. 8 from the applicant's '748 application and shows a footprints 37 and 17, like Fig. 5 of the '748 application, of a right barefoot upright and tilted out 20 degrees, showing the actual relative posi¬ tions to each other as a low arched foot rolls outward from upright to tilted out 20 degrees. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Figs. 1A-C illustrate, in frontal or transverse plane cross sections in the heel area, the applicant's concept of the theoretically ideal stability plane applied to shoe εoleε. Figε. 1A-1C illuεtrate clearly the principle of natural deformation as it applies to the applicant's design, even though design diagrams like those preceding (and in his previous applications already referenced) are normally shown in an ideal state, without any functional deformation, obviously to show their exact shape for proper construction. That natural structural shape, with its contour paralleling the foot, enables the shoe sole to deform naturally like the foot. In the applicant's invention, the natural deformation feature creates such an important functional advantage it will be illustrated and discussed here fully. Note in the figures that even when the shoe sole shape is deformed, the constant shoe sole thicknesε in the frontal plane feature of the inven¬ tion is maintained. Fig. IA is Fig. 8A in the applicant's U.S. Patent Application 07/400,714 and Fig. 15 in his 07/239,667 Application. Fig. IA shows a fully contoured shoe sole design that follows the natural contour of all of the foot εole, the bottom as well as the sides. The fully contoured shoe εole assumes that the resulting slightly rounded bottom when unloaded will deform under load aε shown in Fig. IB and flatten just as the human foot bottom is slightly round unloaded but flattens under load. Therefore, the 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 of the shoe sole as well. By pro- viding the closeε match to the natural εhape of the foot, the fully contoured design allows the foot to function as naturally as posεible. Under load. Fig. IA would deform by flattening to look eεεentially like Fig. IB. Figε. IA and IB show in frontal plane cross section the essential concept underlying this invention, the theoretically ideal stability plane which is alεo theoretically ideal for efficient natural motion of all kindε, including running, jogging or walking. For any given individual, the theoretically ideal stability plane 51 is determined, first, by the desired shoe sole thick¬ neεε (s) in a frontal plane cross section, and, second, by the natural shape of the individual's foot surface 29. For the case shown in Fig. IB, the theoreti¬ cally ideal stability plane for any particular individual (or size average of individuals) is determined, first, by the given frontal plane crosε section shoe sole thicknesε (ε) ; 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 which is defined as the supper surface of the shoe sole that is in physical contact with and supports the human foot sole. Fig. IB is Fig. 8B of the '714 application and shows the same fully contoured design when upright, under normal load (body weight) and therefore deformed natu¬ rally in a manner very closely paralleling the natural deformation under the same load of the foot. An almost identical portion of the foot sole that is flattened in deformation is also flatten in deformation in the shoe sole. Fig. IC is Fig. 8C of the '714 application and shows the same design when tilted outward 20 degrees laterally, the normal barefoot limit; with virtually equal accuracy it shows the opposite foot tilted 20 degrees inward, in fairly severe pronation. As shown, the deformation of the shoe sole 28 again very closely parallels that of the foot, even as it tilts. Just as the area of foot contact iε almoεt as great when tilted 20 degrees, the flattened area of the deformed εhoe εole iε also nearly the same as when upright. Consequently, the barefoot fully supported εtructurally and itε natural εtability iε maintained undiminished, regardless of shoe tilt. In marked contrast, a conventional shoe, εhown in Fig. 12, akeε contact with the ground with only its relatively sharp edge when tilted and is therefore inher¬ ently unstable. The capability to deform naturally is a design feature of the applicant's naturally contoured shoe sole designε, whether fully contoured or contoured only at the sides, though the fully contoured design is moεt optimal and is the most natural, general case, aε note in the referenced September 2, 1988, application, assuming shoe sole material such as to allow natural deformation. It is an important feature because, by following the natural deformation of the human foot, the naturally deforming shoe sole can avoid interfering with the natural biome- chanics of the foot and ankle. Fig. IC also represents with reasonable accu¬ racy a shoe sole design corresponding to Fig. IB, a natu¬ rally contoured εhoe sole with a conventional built-in flattening deformation, as in Fig. 14 of the above refer- enced September 2, 1988, application, except that design would have a slight crimp at 145. Seen in this light, the naturally contoured side deεign in Fig. IB is a more conventional, conservative design that is a special case of the more generally fully contoured design in Fig. IA, which is the closest to the natural form of the foot, but the least conventional. In its simplest conceptual form, the appli¬ cant's Fig. 1 invention is the structure of a conven¬ tional shoe sole that has been modified by having its sides bent up so that their inner surface conforms to the shape of the outer surface of the foot sole of the wearer (instead of the shoe sole sides being flat on the ground, as is conventional) ; this concept is like that described in Fig. 3 of the applicant's 07/239,667 application. For the applicant's fully contoured design, the entire shoe sole — including both the sides and the portion directly underneath the foot — is bent up to conform to the shape of the unloaded foot sole of the wearer, rather than the partially flattened load-bearing foot sole shown in Fig. 3. This theoretical or conceptual bending up must be accomplished in practical manufacturing without any of the puckering distortion or deformation that would neces¬ sarily occur if such a conventional shoe sole were actu- ally bent up simultaneously along all of itε the sides; consequently, manufacturing techniques that do not require any bending up of shoe sole material, such as injection molding manufacturing of the shoe sole, would be required for optimal results and therefore is prefera¬ ble. It is critical to the novelty of this fundamen¬ tal concept that all layers of the shoe sole are bent up around the foot sole. A small number of both street and athletic shoe soles that are commercially available are naturally contoured to a limited extent in that only their bottom soles, which are about one quarter to one third of the total thickness of the entire shoe sole, are wrapped up around portions of the wearer's foot soleε; the remaining sole layers, including the inεole, the midsole and the heel lift (or heel) of such shoe soles, constituting over half of the thickness of the entire shoe sole, remains flat, conforming to the ground rather than the wearers' feet. Consequently, in existing contoured shoe εoles, the shoe sole thicknesε of the contoured εide portionε iε much leεε than the thickneεs of the sole portion directly underneath the foot, whereas in the applicant's shoe sole inventions in the '819 patent the shoe εole thickneεs of the contoured εide portionε are the εame as the thicknesε of the sole portion directly underneath the foot. This major and conspicuouε εtructural differ¬ ence between the applicant'ε underlying concept and the existing shoe sole art is paralleled by a similarly dra¬ matic functional difference between the two: the afore¬ mentioned equivalent or similar thicknesε of the appli¬ cant'ε εhoe sole invention maintains intact the firm lateral stability of the wearer's foot, as demonstrated when the foot is unshod and tilted out laterally in inversion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a similar dem¬ onstration in a conventional shoe sole, the wearer's foot and ankle are unstable. The sides of the applicant's shoe sole invention extend sufficiently far up the sideε of the wearer's foot εole to maintain the lateral stabil¬ ity of the wearer's foot when bare. In addition, the applicant's shoe sole inven¬ tion maintains the natural stability and natural, unin¬ terrupted motion of the wearer's foot when bare through¬ out its normal range of sideways pronation and supination motion occurring during all load-bearing phases of loco¬ motion of the wearer, including when said wearer is standing, walking, jogging and running, even when said foot is tilted to the extreme limit of that normal range, in contrast to unstable and inflexible conventional shoe soleε, including the partially contoured exiεting art deεcribed above. The εideε of the applicant'ε εhoe εole invention extend εufficiently far up the sides of the wearer's foot sole to maintain that natural εtability and uninterrupted motion. For the Fig. 1 εhoe εole invention, the amount of any εhoe εole εide portionε coplanar with the theore¬ tically ideal stability plane 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 εaid shoe sole being εufficient to maintain intact the firm εtability of the wearer's foot throughout the range of foot inversion and eversion motion typical of the use for which the shoe is intended and alεo typical of the kind of wearer — εuch aε normal or exceεsive pronator — for which said shoe is intended. As mentioned earlier. Fig. IA is Fig. 15 in the applicant's 07/239,667 application; however, it does not show the heel lift 38 which iε included in the original Fig. 15. That heel lift iε εhown with conεtant frontal or transverse plane thicknesε, εince it is oriented con¬ ventionally in alignment with the frontal or transverεe plane and perpendicular to the long axiε of the εhoe εole; consequently, the thickness of the heel lift decreases uniformly in the frontal or transverεe plane between the heel and the forefoot when moving forward along the long axis of the shoe εole. However, the con¬ ventional heel wedge, or toe taper or other εhoe sole thickness variations in the sagittal plane along the long axis of the shoe sole, can be located at an angle to the conventional alignment. For example, the heel wedge can be rotated inward in the horizontal plane so that it is located perpendicular to the subtalar axis, which is located in the heel area generally about 20 to 25 degrees medially, although a different angle can be used base on individual or group testing; such a orientation may provide better, more natural support to the subtalar joint, through which critical pronation and supination motion occur. The applicant's theoretically ideal εtability plane concept would teach that such a heel wedge orientation would require constant shoe sole thicknesε in a vertical plane perpendicular to the choεen εubtalar joint axis, instead of the frontal plane. Fig. 2 is Fig. 9 of the '714 application and shows, in frontal or transverεe plane croεs section in the heel area, the preferred relative density of the shoe sole, including the insole aε a part, order to maximize the εhoe εole's ability to deform naturally following the natural deformation of the foot sole. Regardless of how many shoe sole layers (including insole) or laminations of differing material densities and flexibility are used in total, the softest and most flexible material 147 should be closest to the foot sole, with a progresεion through leεε soft 148 to the firmest and least flexible 149 at the outermost shoe sole layer, the bottom sole. This arrangement helps to avoid the unnatural εide lever arm/torque problem mentioned in the previouε several figures. Fig. 3, which is a frontal or transverse plane crosε section at the heel, is Fig. 10 from the appli¬ cant's copending U.S. Patent Application 07/400,714, filed August 30, 1989. Fig. 3 illustrates that the applicant's naturally contoured shoe sole sides can be made to provide a fit so close as to approximate a custom fit. By molding each masε-produced εhoe εize with sides that are bent in somewhat from the position 29 they would normally be in to conform to that standard size shoe last, the shoe soles so produced will very gently hold the sideε of each individual foot exactly. Since the shoe sole is designed as described in connection with Fig. 2 (Fig. 9 of the applicant's copending application No. 07/400,714) to deform easily and naturally like that of the bare foot, it will deform easily to provide this designed-in custom fit. The greater the flexibility of the shoe sole sideε, the greater the range of individual foot εize. This approach applies to the fully contoured deεign deεcribed here in Fig. IA (Fig. 8A of the '714 application) and in Fig. 15, United Stateε Patent Appli¬ cation 07/239,667 (filed 02 September 1988), aε well, which would be even more effective than the naturally contoured εides design shown in Fig. 3. Besideε providing a better fit, the intentional undersizing of the flexible shoe sole εides allows for simplified design of shoe sole lasts, since they can be designed according to the simple geometric methodology described in the textual specification of Fig. 27, United States Application 07/239,667 (filed 02 September 1988). That geometric approximation of the true actual contour of the human is close enough to provide a virtual cuεtom fit, when compensated for by the flexible undersizing from standard shoe lastε described above. Expanding on the '714 application, a flexible undersized version of the fully contoured design described in Fig. IA (and 8A of the '714 application) can also be provided by a similar geometric approximation. Aε a result, the undersized flexible shoe sole sides allow the applicant's εhoe εole inventionε baεed on the theoretically ideal εtability plane to be manufactured in relatively εtandard εizeε in the same manner as are shoe uppers, since the flexible shoe sole sides can be built on standard shoe lasts, even though conceptually those sideε conform cloεely to the specific εhape of the indi- vidual wearer's foot sole, because the flexible sides bend to conform when on the wearer's foot sole. Fig. 3 showε the shoe sole structure when not on the foot of the wearer; the dashed line 29 indicates the position of the shoe last, which is assumed to be a reasonably accurate approximation of the shape of the outer surface of the wearer's foot sole, which determines the shape of the theoretically ideal stability plane 51. Thus, the dashed lines 29 and 51 show what the positionε of the inner εurface 30 and outer surface 31 of the shoe sole would be when the shoe is put on the foot of the wearer. Numbering with the figures in this application is conεiεtent with the numbering uεed in prior applica¬ tion of the applicant. The Fig. 3 invention provideε a way make the inner εurface 30 of the contoured εhoe sole, especially its sides, conform very closely to the outer surface 29 of the foot sole of a wearer. It thuε makes much more practical the applicant's earlier underlying naturally contoured designs shown in Figs. 1A-C. The shoe sole structures shown in Fig. 1, then, are what the Fig. 3 shoe εole εtructure would be when on the wearer's foot, where the inner surface 30 of the εhoe upper iε bent out to virtually coincide with the outer εurface of the foot sole of the wearer 29 (the figures in this and prior applications show one line to emphasize the conceptual coincidence of what in fact are two lines; in real world embodiments, some divergence of the surface, especially under load and during locomotion would be unavoidable) . In its simplest conceptual form, the appli¬ cant's invention is the structure of a conventional εhoe sole that has been modified by having itε sides bent up so that their inner surface conforms to a shape nearly identical but εlightly εmaller than the εhape of the outer εurface of the foot sole of the wearer (instead of the εhoe εole εides being flat on the ground, as is con¬ ventional) ; this concept is like that described in Fig. 3 of the applicant's 07/239,667 application. For the appl- icant'ε fully contoured deεign deεcribed in Fig. 15 of the '667 application, the entire εhoe sole — including both the sideε and the portion directly underneath the foot — is bent up to conform to a shape nearly identical but slightly smaller than the contoured shape of the unloaded foot sole of the wearer, rather than the par¬ tially flattened load-bearing foot εole shown in Fig. 3. This theoretical or conceptual bending up must be accomplished in practical manufacturing without any of the puckering distortion or deformation that would neces¬ sarily occur if such a conventional shoe sole were actu¬ ally bent up simultaneouεly along all of itε the sides; conεequently, manufacturing techniqueε that do not require any bending up of εhoe εole material, εuch aε injection molding manufacturing of the εhoe εole, would be required for optimal reεultε and therefore is prefera¬ ble. It is critical to the novelty of this fundamen¬ tal concept that all layers of the εhoe sole are bent up around the foot sole. A small number of both street and athletic shoe soleε that are commercially available are naturally contoured to a limited extent in that only their bottom soles, which are about one quarter to one third of the total thickness of the entire shoe εole, are wrapped up around portions of the wearers' foot soles; the midsole and heel lift (or heel) of such εhoe soles, constituting over half of the thicknesε of the entire shoe sole, remains flat, conforming to the ground rather than the wearers' feet. (At the other extreme, some shoeε in the exiεting art have flat midεoleε and bottom soles, but have insoleε that conform to the wearer's foot sole.) Consequently, in existing contoured shoe soles, the shoe sole thickness of the contoured side portions is much less than the thickness of the sole portion directly underneath the foot, whereas in the applicant's εhoe εole inventionε the εhoe sole thicknesε of the contoured side portionε are the same as the thicknesε of the εole por¬ tion directly underneath the foot. Thiε major and conεpicuouε structural differ¬ ence between the applicant's underlying concept and the existing shoe sole art is paralleled by a similarly dra¬ matic functional difference between the two: the afore¬ mentioned equivalent thicknesε of the applicant'ε εhoe εole invention maintainε intact the firm lateral εtabil¬ ity of the wearer's foot, as demonstrated when the foot is unshod and tilted out laterally in inversion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a similar demonstration in a con¬ ventional εhoe sole, the wearer's foot and ankle are unstable. The sides of the applicant's shoe sole inven- tion extend sufficiently far up the sides of the wearer's foot sole to maintain the lateral stability of the wear¬ er's foot when bare. In addition, the applicant'ε εhoe εole inven¬ tion maintainε the natural εtability and natural, unin- terrupted motion of the wearer's foot when bare through¬ out itε normal range of εideways pronation and supination motion occurring during all load-bearing phases of loco¬ motion of the wearer, including when the wearer is stand¬ ing, walking, jogging and running, even when εaid foot is tilted to the extreme limit of that normal range, in contrast to unstable and inflexible conventional shoe εoleε, including the partially contoured existing art described above. The sides of the applicant's shoe εole invention extend sufficiently far up the sides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. For the Fig. 3 shoe εole invention, the amount of any shoe sole side portions coplanar with the theore¬ tically ideal stability plane iε determined by the degree of εhoe εole εtability 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 intact the firm stability of the wearer's foot throughout the range of foot inversion and everεion motion typical of the uεe for which the εhoe iε intended and alεo typical of the kind of wearer — εuch as normal or excessive pronator — for which said shoe iε intended. The shoe sole sides of the Fig. 3 invention are sufficiently flexible to bend out easily when the shoeε are put on the wearer's feet and therefore the shoe soleε gently hold the εideε of the wearer's foot sole when on, providing the equivalent of custom fit in a masε-produced εhoe εole. In general, the applicant'ε preferred εhoe εole embodiments include the structural and material flexibility to deform in parallel to the natural deforma¬ tion of the wearer's foot εole as if it were bare and unaffected by any of the abnormal foot biomechanics cre¬ ated by rigid conventional shoe sole. At the same time, the applicant's preferred shoe sole embodiments are sufficiently firm to provide the wearer's foot with the structural support necessary to maintain normal pronation and supination, as if the wearer's foot were bare; in contrast, the excessive soft¬ ness of many of the shoe sole materials used in shoe soles in the existing art cause abnormal foot pronation and supination. Fig. 3 iε a frontal or transverse plane cross section at the heel, so the structure is shown at one of the essential structural support and propulsion elements, as specified by applicant in his copending 07/239,667 application in its Fig. 21 specification. The essential structural support elements are the base and lateral tuberosity of the calcaneus 95, the heads of the metatar- sals 96, and the base of the fifth metatarsal 97; the esεential propulsion element iε the head of the first distal phalange 98. The Fig. 3 shoe sole structure can be abbreviated along its sides to only the esεential εtructural εupport and propulsion elements, like Fig. 21 of the '667 application. The Fig. 3 design can also be abbreviated underneath the shoe sole to the εame eεsen- tial structural support and propulsion elementε, aε shown in Fig. 28 of the '667 application. As mentioned earlier regarding Fig. IA, the applicant has previously shown heel lifts with constant frontal or transverse plane thicknesε, since it is ori¬ ented conventionally in alignment with the frontal or transverse plane and perpendicular to the long axis of the shoe sole. However, the heel wedge (or toe taper or other shoe sole thickness variations in the sagittal plane along the long axis of the shoe sole) can be loca¬ ted at an angle to the conventional alignment in the Fig. 3 design. For example, the heel wedge can be rotated inward in the horizontal plane so that it is located per- pendicular to the subtalar axis, which iε located in the heel area generally about 20 to 25 degrees medially, although a different angle can be used base on individual or group testing; such a orientation may provide better, more natural εupport to the εubtalar joint, through which critical pronation and supination motion occur. The applicant's theoretically ideal stability plane concept would teach that such a heel wedge orientation would require constant εhoe sole thickness in a vertical plane perpendicular to the chosen subtalar joint axis, instead of the frontal plane. The sideε of the εhoe sole structure described under Fig. 3 can also be used to form a slightly leεs optimal structure: a conventional shoe sole that has been modified by having its sideε bent up εo that their inner εurface conformε to εhape nearly identical but slightly larger than the shape of the outer surface of the foot sole of the wearer, instead of the shoe sole sides being flat on the ground, as is conventional. Clearly, the closer the sides are to the shape of the wearer's foot sole, the better as a general rule, but any side position between flat on the ground and conforming like Fig. 3 to a shape slightly smaller than the wearer's shape is both possible and more effective than conventional flat shoe εole sides. And in εome cases, such as for diabetic patients, it may be optimal to have relatively looεe εhoe εole εides providing no conforming presεure of the shoe sole on the tender foot sole; in such caseε, the εhape of the flexible εhoe upperε, which can even be made with very elaεtic materials such as lycra and spandex, can provide the capability for the shoe, including the shoe sole, to conform to the shape of the foot. As discusεed earlier by the applicant, the critical functional feature of a εhoe εole is that it deforms under a weight-bearing load to conform to the foot sole just as the foot sole deforms to conform to the ground under a weight-bearing load. So, even though the foot sole and the shoe sole may start in different loca¬ tions — the shoe sole sides can even be conventionally flat on the ground — the critical functional feature of both is that they both conform under load to parallel the shape of the ground, which conventional shoes do not, except when exactly upright. Consequently, the appli- cant's shoe sole invention, εtated most broadly, includes any shoe εole — whether conforming to the wearer's foot sole or to the ground or εome intermediate poεition, including a εhape much εmaller than the wearer's foot εole — that deformε to conform to the theoretically ideal stability plane, which by definition itself deforms in parallel with the deformation of the wearer's foot sole under weight-bearing load. Of course, it is optimal in terms of preserving natural foot biomechanics, which is the primary goal of the applicant, for the shoe sole to conform to the foot sole when on the foot, not just when under a weight-bear¬ ing load. And, in any case, all of the essential struc¬ tural support and propulsion elements previously identi¬ fied by the applicant in discusεing Fig. 3 muεt be εup- ported by the foot sole. To the extent the shoe sole sides are easily flexible, aε haε already been εpecified as desirable, the position of the shoe sole sides before the wearer puts on the shoe is leεε important, εince the sides will easily conform to the shape of the wearer's foot when the shoe is put on that foot. In view of that, even shoe sole sideε that conform to a εhape more than slightly smaller than the shape of the outer surface of the wearer's foot sole would function in accordance with the applicant's general invention, since the flexible sides could bend out easily a considerable relative distance and still conform to the wearer's foot sole when on the wearer's foot. Fig. 4 is Fig. 4 from the applicant's copending U.S. Patent Application 07/416,478, filed October 3, 1989. Fig. 4 illustrateε, in frontal or transverse plane crosε εection in the heel area, the applicant's new invention of shoe sole side thickness increasing beyond the theoretically ideal stability plane to increase sta¬ bility somewhat beyond its natural level. The unavoid¬ able trade-off reεulting is that natural motion would be restricted somewhat and the weight of the shoe sole would increase somewhat. Fig. 4 shows a situation wherein the thicknesε of the sole at each of the opposed sideε iε thicker at the portionε of the εole 31a by a thickness which gradu¬ ally varies continuously from a thicknesε (ε) through a thickneεε (s+sl) , to a thickneεε (ε+ε2) . Theεe designs recognize that lifetime use of existing shoes, the design of which has an inherent flaw that continually diεruptε natural human biomechanicε, has produced thereby actual structural changes in a human foot and ankle to an extent that must be compensated for. Specifically, one of the most common of the abnormal effects of the inherent exiεting flaw iε a weakening of the long arch of the foot, increaεing pronation. Theεe designs therefore modify the applicant's preceding designs to provide greater than natural stability and should be particularly useful to individuals, generally with low arches, prone to pronate excesεively, and could be used only on the medial side. Similarly, individuals with high arches and a tendency to over supinate and lateral ankle sprains would also benefit, and the design could be used only on the lateral side. A shoe for the general population that compensates for both weaknesεes in the same shoe would incorporate the enhanced stability of the deεign compenεation on both sides. The new design in Fig. 4 (like Figs. 1 and 2 of the '478 application) allows the εhoe sole to deform naturally closely paralleling the natural deformation of the barefoot under load; in addition, shoe sole material must be of such composition as to allow the natural deformation following that of the foot. The new designε retain the eεεential novel aεpect of the earlier deεignε; namely, contouring the shape of the shoe sole to the shape of the human foot. The difference is that the shoe sole thicknesε in the frontal plane iε allowed to vary rather than remain uni¬ formly conεtant. More εpecifically, Fig. 4 (and Figε. 5, 6, 7, and 11 of the '478 application) εhow, in frontal plane cross sections at the heel, that the shoe sole thickness can increase beyond the theoretically ideal stability plane 51, in order to provide greater than natural stability. Such variations (and the following variations) can be consiεtent through all frontal plane croεε εections, so that there are proportionately equal increaεeε to the theoretically ideal stability plane 51 from the front of the shoe sole to the back, or that the thicknesε can vary, preferably continuously, from one frontal plane to the next. The exact amount of the increase in shoe sole thicknesε beyond the theoretically ideal stability plane is to be determined empirically. Ideally, right and left εhoe εoleε would be custom designed for each individual based on an biomechanical analysis of the extent of his or her foot and ankle disfunction in order to provide an optimal individual correction. If epidemiological εtud- ieε indicate general corrective patternε for specific categories of individuals or the population as a whole, then mass-produced corrective shoeε with εoles incorpo¬ rating contoured εides exceeding the theoretically ideal stability plane would be possible. It is expected that any such mass-produced corrective shoes for the general population would have contoured side portion thicknesεeε exceeding the theoretically ideal εtability plane by an amount of 5 percent to 10 percent, preferably at least in that part of the contoured side which becomes wearer's body weight load-bearing during the full range of inver- sion and eversion, which is sideways or lateral foot motion. More specific groups or individuals with more severe disfunction could have an empirically demonstrated need for greater corrective thicknesses of the contoured side portion on the order of 11 to 25 percent more than the theoretically ideal stability plane, again, prefera¬ bly at least in that part of the contoured side which becomes wearer's body weight load-bearing during the full range of inversion and eversion, which is sidewayε or lateral foot motion. The optimal contour for the increaεed contoured side thickness may also be determined empirically. As described in the '478 application, in its simplest conceptual form, the applicant's Fig. 4 inven¬ tion is the structure of a conventional shoe sole that has been modified by having its sides bent up so that their inner surface conforms to a shape of the outer surface of the foot sole of the wearer (instead of the shoe sole sideε conforming to the ground by paralleling it, aε is conventional) ; this concept is like that described in Fig. 3 of the applicant's 07/239,667 appli¬ cation. For the applicant's fully contoured design described in Fig. 15 of the '667 application, the entire shoe sole — including both the sides and the portion directly underneath the foot — is bent up to conform to a shape nearly identical but slightly smaller than the contoured shape of the unloaded foot sole of the wearer, rather than the partially flattened load-bearing foot sole shown in Fig. 4. This theoretical or conceptual bending up must be accomplished in practical manufacturing without any of the puckering diεtortion or deformation that would neceε¬ εarily occur if εuch a conventional εhoe εole were actu- ally bent up εimultaneously along all of its the sides; consequently, manufacturing techniques that do not require any bending up of shoe sole material, such as injection molding manufacturing of the shoe sole, would be required for optimal resultε and therefore is prefera- ble. It is critical to the novelty of this fundamen¬ tal concept that all layers of the shoe sole in Fig. 4 are bent up around the foot sole. A small number of both street and athletic shoe soles that are commercially available are naturally contoured to a limited extent in that only their bottom εoles, which are about one quarter to one third of the total thicknesε of the entire εhoe εole, are wrapped up around portionε of the wearers' foot soles; the midsole and heel lift (or heel) of such shoe soles, constituting over half of the thicknesε of the entire εhoe εole, remainε flat, conforming to the ground rather than the wearers' feet. (At the other extreme, εome εhoes in the existing art have flat midsoleε and bottom εoles, but have insoleε that conform to the wear- er'ε foot εole.) Consequently, in existing contoured shoe soleε, the total εhoe εole thickneεε of the contoured εide por¬ tionε, including every layer or portion, is much lesε than the total thickneεε of the εole portion directly underneath the foot, whereas in the applicant's '478 shoe sole invention the shoe sole thickness of the contoured side portions are at least similar to the thickness of the sole portion directly underneath the foot, meaning a thickness variation of up to 25 percent, as measured in frontal or transverεe plane cross sections. This major and conspicuouε εtructural differ¬ ence between the applicant's underlying concept and the existing shoe sole art is paralleled by a similarly dra- matic functional difference between the two: the afore¬ mentioned εimilar thickneεε of the applicant'ε εhoe εole invention maintainε intact the firm lateral stability of the wearer's foot, as demonstrated when the foot is unshod and tilted out laterally in inversion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a similar demonstration in a con¬ ventional shoe sole, the wearer's foot and ankle are unεtable. The sides of the applicant's shoe sole inven- tion extend sufficiently far up the sides of the wearer's foot sole to maintain the lateral stability of the wear¬ er's foot when bare. In addition, the applicant's shoe sole inven¬ tion maintains the natural stability and natural, unin- terrupted motion of the wearer's foot when bare through¬ out its normal range of sidewayε pronation and εupination motion occurring during all load-bearing phaεeε of loco¬ motion of the wearer, including when the wearer iε εtand- ing, walking, jogging and running, even when εaid foot is tilted to the extreme limit of that normal range, in con¬ trast to unstable and inflexible conventional shoe soleε, including the partially contoured exiεting art described above. The sides of the applicant's shoe sole invention extend sufficiently far up the sides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact thick¬ ness of the shoe sole sideε and their εpecific contour will be determined empirically for individuals and groups using standard biomechanical techniqueε of gait analyεis to determine thoεe combinationε that best provide the barefoot stability described above. For the Fig. 4 shoe sole invention, the amount of any shoe sole side portions coplanar with the theore¬ tically ideal stability plane is determined by the degree of shoe sole stability desired and the shoe sole weight and bulk required to provide said εtability; the amount of εaid coplanar contoured sides that is provided said shoe sole being εufficient to maintain intact the firm εtability of the wearer's foot throughout the range of foot inversion and eversion motion typical of the use for which the shoe is intended and also typical of the kind of wearer — such as normal or excesεive pronator — for which εaid εhoe iε intended. In general, the applicant'ε preferred εhoe εole embodiments include the structural and material flexibil¬ ity to deform in parallel to the natural deformation of the wearer's foot sole as if it were bare and unaffected by any of the abnormal foot biomechanics created by rigid conventional shoe sole. At the same time, the applicant's preferred shoe sole embodiments are sufficiently firm to provide the wearer's foot with the structural support necessary to maintain normal pronation and supination, as if the wearer's foot were bare; in contrast, the exceεsive soft¬ neεε of many of the εhoe εole materials used in shoe soles in the existing art cause abnormal foot pronation and supination. As mentioned earlier regarding Fig. IA, the applicant has previously shown heel lifts with constant frontal or transverεe plane thickness, since it is ori¬ ented conventionally in alignment with the frontal or tranεverse plane and perpendicular to the long axis of the shoe sole. However, the heel wedge (or toe taper or other shoe εole thickneεε variationε in the εagittal plane along the long axiε of the εhoe εole) can be loca¬ ted at an angle to the conventional alignment in the Fig. 4 deεign. For example, the heel wedge can be located perpendicular to the εubtalar axis, which is located in the heel area generally about 20 to 25 degrees medially, although a different angle can be used base on individual or group testing; such a orientation may provide better, more natural support to the subtalar joint, through which critical pronation and supination motion occur. The applicant's theoretically ideal stability plane concept would teach that such a heel wedge orientation would require constant shoe sole thicknesε in a vertical plane perpendicular to the choεen subtalar joint axis, instead of the frontal plane. Fig. 5 is Fig. 5 in the applicant's copending U.S. Patent Application 07/416,478 and shows, in frontal or transverεe plane croεε εection in the heel area, a variation of the enhanced fully contoured deεign wherein the εhoe εole begins to thicken beyond the theoretically ideal stability plane 51 at the contoured sideε portion, preferably at leaεt in that part of the contoured εide which becomeε wearer's body weight load-bearing during the full range of inversion and eversion, which is εide¬ ways or lateral foot motion. Fig. 6 is Fig. 10 in the applicant's copending '478 application and showε, in frontal or tranεverse plane croεε section in the heel area, that similar varia¬ tionε in shoe midsole (other portions of the shoe sole area not shown) density can provide similar but reduced effects to the variations in shoe sole thickness described previously in Figs. 4 and 5. The major advan¬ tage of this approach is that the structural theoreti¬ cally ideal stability plane is retained, so that natu¬ rally optimal stability and efficient motion are retained to the maximum extent poεεible. These conεtructive den- sity variations are most typically meaεured in durometerε on a Shore A εcale, to include from 5 percent to 10 per¬ cent and from 11 percent up to 25 percent. The denεity variationε are located preferably at leaεt in that part of the contoured εide which becomeε wearer's body weight load-bearing during the full range of inversion and ever¬ sion, which is sideways or lateral foot motion. The '478 application showed midsole only, since that iε where material denεity variation has historically been most common. Denεity variations can and do, of course, also occur in other layers of the shoe sole, such as the bottom sole and the inner sole, and can occur in any combination and in symmetrical or asymmetrical pat- terns between layers or between frontal or transverse plane cross sections. The major and conspicuouε structural difference between the applicant's underlying concept and the exist- ing εhoe εole art iε paralleled by a εimilarly dramatic functional difference between the two: the aforementioned εimilar thickness of the applicant's shoe sole invention maintains intact the firm lateral stability of the wear¬ er's foot, as demonstrated when the foot is unshod and tilted out laterally in inversion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a similar demonstration in a conventional shoe sole, the wearer's foot and ankle are unεtable. The sides of the applicant's shoe εole invention extend εuf- ficiently far up the εides of the wearer's foot sole to maintain the lateral stability of the wearer's foot when bare. In addition, the applicant's shoe sole inven¬ tion maintains the natural stability and natural, unin- terrupted motion of the wearer's foot when bare through¬ out its normal range of εideways pronation and supination motion occurring during all load-bearing phases of loco¬ motion of the wearer, including when the wearer is stand¬ ing, walking, jogging and running, even when said foot is tilted to the extreme limit of that normal range, in contraεt to unεtable and inflexible conventional εhoe εoles, including the partially contoured existing art described above. The sides of the applicant'ε shoe sole invention extend sufficiently far up the sides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact material density of the εhoe εole sides will be determined empirically for individuals and groups using standard biomechanical techniques of gait analyεis to determine those combinationε that beεt provide the bare¬ foot εtability deεcribed above. For the Fig. 6 εhoe εole invention, the amount of any εhoe εole εide portionε coplanar with the theore- tically ideal stability plane is determined by the degree of εhoe εole 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 intact the firm stability of the wearer's foot throughout the range of foot inversion and eversion motion typical of the use for which the shoe is intended and also typical of the kind of wearer — such as normal or excesεive pronator — for which εaid εhoe iε intended. In general, the applicant's preferred shoe sole embodiments include the structural and material flexibil¬ ity to deform in parallel to the natural deformation of the wearer's foot sole as if it were bare and unaffected by any of the abnormal foot biomechanics created by rigid conventional shoe sole. At the same time, the applicant's preferred shoe sole embodiments are sufficiently firm to provide the wearer's foot with the structural support necesεary to maintain normal pronation and εupination, aε if the wearer's foot were bare; in contrast, the excessive soft¬ neεε of many of the shoe sole materials used in shoe soleε in the existing art cause abnormal foot pronation and supination. As mentioned earlier regarding Fig. IA, the applicant has previously shown heel lifts with constant frontal or transverse plane thickness, since it is ori¬ ented conventionally in alignment with the frontal or transverse plane and perpendicular to the long axis of the εhoe εole. However, the heel wedge (or toe taper or other shoe sole thicknesε variations in the sagittal plane along the long axis of the shoe sole) can be loca¬ ted at an angle to the conventional alignment in the Fig. 4 deεign. For example, the heel wedge can be located perpendicular to the subtalar axis, which is located in the heel area generally about 20 to 25 degrees medially, although a different angle can be used base on individual or group testing; such a orientation may provide better, more natural support to the subtalar joint, through which critical pronation and supination motion occur. The applicant's theoretically ideal stability plane concept would teach that such a heel wedge orientation would require constant shoe sole thickness in a vertical plane perpendicular to the chosen subtalar joint axis, instead of the frontal plane. Fig. 7 is Fig. 14B of the applicant's '478 application and shows, in frontal or transverse plane crosε sections in the heel area, embodiments like those in Fig. 4 through 6 but wherein a portion of the shoe sole thickneεε iε decreaεed to leεε than the theoreti¬ cally ideal stability plane, the amount of the thicknesε variation as defined for Fig. 4 and 5 above, preferably at least in that part of the contoured side which becomeε wearer's body weight load-bearing during the full range of inversion and eversion, which is sideways or lateral foot motion. It is anticipated that some individuals with foot and ankle biomechanics that have been degraded by existing shoeε may benefit from εuch embodimentε, which would provide leεε than natural εtability but greater freedom and motion, and leεs εhoe sole weight and bulk. Fig. 7 showε a embodiment like the fully contoured design in Fig. 5, but with a show sole thicknesε decreas¬ ing with increasing distance from the center portion of the sole. Fig. 8 is Fig. 13 of the '478 application and shows, in frontal or transverεe plane crosε εection, a bottom εole tread design that provides about the same overall shoe sole density variation as that provided in Fig. 6 by midsole density variation. The less supporting tread there is under any particular portion of the shoe sole, the less effective overall shoe density there is, since the midsole above that portion will deform more easily than if it were fully supported. Fig. 8 from the '478 is illuεtrative of the applicant's point that bottom sole tread patterns, just like midsole or bottom sole or inner sole density, directly affect the actual structural support the foot receives from the shoe sole. Not shown, but a typical example in the real world, is the popular "center of pressure" tread pattern, which is like a backward horse¬ shoe attached to the heel that leaves the heel area directly under the calcaneus unsupported by tread, so that all of the weight bearing load in the heel area is transmitted to outside edge treads. Variations of this pattern are extremely common in athletic shoes and are nearly universal in running shoeε, of which the 1991 Nike 180 model and the Avia "cantilever" εeries are examples. The applicant's '478 shoe sole invention can, therefore, utilize bottom sole tread patterns like any these common exampleε, together or even in the absence of any other shoe sole thicknesε or denεity variation, to achieve an effective thickneεε greater than the theoreti¬ cally ideal εtability plane, in order to achieve greater stability than the shoe sole would otherwise provide, as discusεed earlier under Figε. 4-6. Since εhoe bottom or outer sole tread patterns can be fairly irregular and/or complex and can thus make difficult the measurement of the outer load-bearing sur¬ face of the shoe sole. Conεequently, thickneεε varia- tionε in εmall portionε of the shoe sole that will deform or compress without εignificant overall resistance under a wearer's body weight load to the thickness of the over¬ all load-bearing plane of the shoe out sole should be ignored during measurement, whether such easy deformation is made posεible by very high point preεsure or by the use of relatively compresεible outεole (or underlying midεole) materials. Portions of the outsole bottom surface composed of materials (or made of a delicate structure, much like the small raised markers on new tire treads to prove the tire is brand new and unused) that wear relatively quickly, εo that thickness variations that exist when the shoe sole is new and unused, but disappear quickly in uεe, should also be ignored when measuring shoe sole thickneεε in frontal or transverse plane crosε sections. Similarly, midsole thickness variations of unused shoe soleε due to the uεe of materialε or εtructureε that compact or expand quickly after uεe εhould alεo be ignore when measuring shoe sole thicknesε in frontal or tranε- verεe plane cross sectionε. The applicant's shoe sole invention maintains intact the firm lateral stability of the wearer's foot, that stability as demonstrated when the foot iε unεhod and tilted out laterally in inverεion to the extreme limit of the normal range of motion of the ankle joint of the foot. The εideε of the applicant'ε εhoe εole inven¬ tion extend εufficiently far up the εideε of the wearer's foot sole to maintain the lateral stability of the wear¬ er's foot when bare. In addition, the applicant's shoe sole inven¬ tion maintains the natural stability and natural, unin¬ terrupted motion of the wearer's foot when bare through- out its normal range of sidewayε pronation and εupination motion occurring during all load-bearing phases of loco¬ motion of the wearer, including when the wearer is stand¬ ing, walking, jogging and running, even when the foot is tilted to the extreme limit of that normal range, in con- trast to unεtable and inflexible conventional shoe soleε, including the partially contoured exiεting art deεcribed above. The sides of the applicant's shoe sole invention extend sufficiently far up the sides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact thick¬ nesε and material density of the bottom sole tread, as well as the shoe sole sides and their specific contour, will be determined empirically for individuals and groups using standard biomechanical techniqueε of gait analyεis to determine those combinations that best provide the barefoot stability described above. Fig. 9 is Fig. 9A from the applicant's copend¬ ing U.S. Patent Application 07/463,302, filed January 10, 1990. Fig. 9A shows, also in croεε εections at the heel, a naturally contoured shoe sole design that parallels as closely as possible the overall natural cushioning and stability system of the barefoot (described in Fig. 8 of the '302 application) , including a cushioning compartment 161 under support structures of the foot containing a pressure-transmitting medium like gas, gel, or liquid, like the subcalcaneal fat pad under the calcaneus and other bones of the foot; consequently, Figs. 9A-D from '302, shown completely in Figs. 43A-D in this applica¬ tion, directly correspond to Figs. 8A-D of '302, shown as Figs. 42A-D in this application. The optimal presεure- tranεmitting medium iε that which moεt closely approxi¬ mates the fat pads of the foot; εilicone gel is probably most optimal of materials currently readily available, but future improvements are probable; since it transmits pressure indirectly, in that it compresses in volume under pressure, gas is significantly leεε optimal. The gaε, gel, or liquid, or any other effective material, can be further encapεulated itεelf, in addition to the sides of the εhoe sole, to control leakage and maintain unifor¬ mity, as is common conventionally, and can be subdivided into any practical number of encapsulated areas within a compartment, again as iε common conventionally. The relative thickness of the cushioning compartment 161 can vary, as can the bottom sole 149 and the upper midsole 147, and can be consistent or differ in various areas of the shoe εole; the optimal relative εizes should be those that approximate most closely those of the average human foot, which suggeεtε both εmaller upper and lower εoles and a larger cushioning compartment than shown in Fig. 9. And the cushioning compartments or pads 161 can be placed anywhere from directly underneath the foot, like an insole, to directly above the bottom sole. Optimally, the amount of compression created by a given load in any cushioning compartment 161 should be tuned to approximate as closely as possible the compresεion under the corre¬ sponding fat pad of the foot. The function of the subcalcaneal fat pad iε not met satisfactorily with existing proprietary cuεhioning εystems, even those featuring gas, gel or liquid as a pressure transmitting medium. In contrast to those arti- ficial syεtemε, the new deεign shown is Fig. 9 conforms to the natural contour of the foot and to the natural method of transmitting bottom presεure into side tension in the flexible but relatively non-stretching (the actual optimal elasticity will require empirical studieε) sides of the shoe sole. Existing cushioning syεtems like Nike Air or Asics Gel do not bottom out under moderate loads and rarely if ever do so even partially under extreme loads; the upper surface of the cushioning device remains sus- pended above the lower surface. In contrast, the new design in Fig. 9 provideε firm εupport to foot εupport structures by providing for actual contact between the lower surface 165 of the upper midsole 147 and the upper surface 166 of the bottom sole 149 when fully loaded under moderate body weight presεure, as indicated in Fig. 9B, or under maximum normal peak landing force during running, as indicated in Fig. 9C, just as the human foot does in Figs. 42B and 42C. The greater the downward force transmitted through the foot to the shoe, the greater the compression pressure in the cushioning com¬ partment 161 and the greater the reεulting tension of the shoe sole sides. Fig. 9D shows the same shoe sole design when fully loaded and tilted to the natural 20 degree lateral limit, like Fig. 4ID. Fig. 9D εhowε that an added εtability benefit of the natural cuεhioning εystem for εhoe soles is that the effective thicknesε of the εhoe εole is reduced by compression on the side so that the potential destabilizing lever arm repreεented by the shoe εole thickneεs is also reduced, so foot and ankle stabil¬ ity is increased. Another benefit of the Fig. 9 design is that the upper midsole shoe surface can move in any horizontal direction, either sideways or front to back in order to absorb shearing forces; that shearing motion is controlled by tension in the sides. Note that the right side of Figs. 9A-D is modified to provide a natural crease or upward taper 162, which allows complete side compression without binding or bunching between the upper and lower shoe sole layers 147, 148, and 149; the shoe sole crease 162 parallels exactly a similar crease or taper 163 in the human foot. Another posεible variation of joining shoe upper to shoe bottom sole is on the right (lateral) side of Figs. 9A-D, which makes use of the fact that it is optimal for the tension absorbing shoe sole sides, whether shoe upper or bottom sole, to coincide with the Theoretically Ideal Stability Plane along the side of the shoe sole beyond that point reached when the shoe is tilted to the foot's natural limit, so that no destabil¬ izing shoe sole lever arm is created when the shoe is tilted fully, as in Fig. 9D. The joint may be moved up slightly so that the fabric side does not come in contact with the ground, or it may be cover with a coating to provide both traction and fabric protection. It should be noted that the Fig. 9 design pro¬ vides a structural baεiε for the εhoe sole to conform very easily to the natural εhape of the human foot and to parallel eaεily the natural deformation flattening of the foot during load-bearing motion on the ground. Thiε is true even if the shoe sole is made conventionally with a flat sole, as long as rigid structures such as heel coun¬ ters and motion control devices are not used; though not optimal, such a conventional flat shoe made like Fig. 9 would provide the esεential features of the new invention resulting in significantly improved cushioning and sta¬ bility. The Fig. 9 design could also be applied to intermediate-shaped shoe εoles that neither conform to the flat ground or the naturally contoured foot. In addition, the Fig. 9 deεign can be applied to the appli¬ cant'ε other designs, such as those described in his pending U.S. Patent Application 07/416,478, filed on October 3, 1989. In summary, the Fig. 9 design εhowε a shoe con¬ struction for a shoe, including: a shoe sole with a com- partment or compartments under the structural elements of the human foot, including at least the heel; the compart¬ ment or compartments contains a presεure-tranε itting medium like liquid, gas, or gel; a portion of the upper surface of the shoe sole compartment firmly contacts the lower surface of said compartment during normal load- bearing; and pressure from the load-bearing is transmit¬ ted progreεεively at least in part to the relatively inelastic sides, top and bottom of the shoe sole compart¬ ment or compartments, producing tension. The applicant's Fig. 9 invention can be com¬ bined with the Fig. 3 invention, although the combination is not shown; the Fig. 9 invention can be combined with Figs. 10 and 11 below. Alεo not εhown, but uεeful combi- nationε, is the applicant's Figs. 3, 10 and 11 inventionε with all of the applicant's deformation sipeε inventions, the first of a sequence of applications on various embodiments of that sipes invention is U.S. Patent Appli¬ cation 07/424,509, filed October 20, 1989, and with hiε inventionε based on other sagittal plane or long axis shoe sole thickness variations described in U.S. Patent Application 07/469,313, filed January 24, 1990. All of the applicant's shoe sole invention mentioned immediately above maintain intact the firm lateral stability of the wearer's foot, that stability as demonstrated when the wearer's foot is unshod and tilted out laterally in inversion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a similar demonstration in a conventional shoe sole, the wearer's foot and ankle are unstable. The sides of the applicant's shoe sole invention extend sufficiently far up the sides of the wearer's foot sole to maintain the lateral stability of the wearer's foot when bare. In addition, the applicant's invention main¬ tains the natural stability and natural, uninterrupted motion of the foot when bare throughout its normal range of sideways pronation and supination motion occurring during all load-bearing phases of locomotion of the wear¬ er, including when said wearer is standing, walking, jogging and running, even when the foot is tilted to the extreme limit of that normal range, in contrast to unsta¬ ble and inflexible conventional shoe soles, including the partially contoured existing art described above. The sides of the applicant's shoe sole invention extend suf¬ ficiently far up the sides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact material den- sity of the εhoe εole sides will be determined empiric¬ ally for individuals and groups using standard biomechan¬ ical techniques of gait analyεiε to determine those com¬ binations that best provide the barefoot stability described above. For the shoe sole combination inventions list immediately above, the amount of any shoe sole side por¬ tions coplanar with the theoretically ideal stability plane iε 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 con¬ toured sides that is provided said shoe sole being suffi¬ cient to maintain intact the firm stability of the wear¬ er's foot throughout the range of foot inversion and everεion motion typical of the uεe for which the εhoe is intended and also typical of the kind of wearer — such as normal or as excessive pronator — for which said εhoe iε intended. Finally, the εhoe εole εides are sufficiently flexible to bend out easily when the shoeε are put on the wearer's feet and therefore the shoe soles gently hold the sideε of the wearer's foot sole when on, providing the equivalent of custom fit in a mass-produced shoe sole. In general, the applicant's preferred εhoe εole embodiments include the structural and material flexibil¬ ity to deform in parallel to the natural deformation of the wearer's foot sole as if it were bare and unaffected by any of the abnormal foot biomechanics created by rigid conventional shoe sole. At the same time, the applicant's preferred shoe sole embodiments are sufficiently firm to provide the wearer's foot with the structural support necessary to maintain normal pronation and supination, as if the wearer's foot were bare; in contrast, the exceεεive soft- neεε of many of the shoe sole materials used in shoe soles in the existing art cause abnormal foot pronation and supination. Fig. 10 was new with this '598 application and is a combination of the shoe sole structure concepts of Fig. 3 and Fig. 4; it combines the custom fit design with the contoured sideε greater than the theoretically ideal stability plane. It would apply as well to the Fig. 7 design with contoured sideε less than the theoretically ideal stability plane, but that combination is not shown. It would alεo apply to the Fig. 8 deεign, which shows a bottom sole tread design, but that combination is also not shown. While the Fig. 3 custom fit invention is novel for shoe sole structures as defined by the theoretically ideal stability plane, which specifies constant shoe εole thickness in frontal or transverεe plane, the Fig. 3 cuεtom fit invention is also novel for shoe sole struc¬ tureε with sideε that exceed the theoretically ideal εtability plane: that iε, a εhoe εole with thickneεs greater in the sides than underneath the foot. It would also be novel for shoe sole structures with sideε that are leεs than the theoretically ideal stability plane, within the parameters defined in the '714 application. And it would be novel for a shoe sole structure that provides stability like the barefoot, as described in Figs. 1 and 2 of the '714 application. In its simplest conceptual form, the appli¬ cant's invention is the structure of a conventional shoe sole that has been modified by having its sideε bent up so that their inner surface conforms to a shape nearly identical but slightly smaller than the shape of the outer surface of the foot sole of the wearer (instead of the shoe sole sides conforming to the ground by parallel¬ ing it, as is conventional) ; this concept is like that described in Fig. 3 of the applicant's 07/239,667 appli- cation. For the applicant's fully contoured design described in Fig. 15 of the '667 application, the entire shoe sole — including both the sides and the portion directly underneath the foot — is bent up to conform to a shape nearly identical but slightly smaller than the contoured shape of the unloaded foot sole of the wearer, rather than the partially flattened load-bearing foot sole shown in Fig. 3. This theoretical or conceptual bending up must be accomplished in practical manufacturing without any of the puckering distortion or deformation that would neces¬ sarily occur if εuch a conventional εhoe sole were actu¬ ally bent up simultaneously along all of its the sides; consequently, manufacturing techniques that do not require any bending up of shoe sole material, such as injection molding manufacturing of the shoe sole, would be required for optimal results and therefore is prefer¬ able. It is critical to the novelty of this fundamen¬ tal concept that all layers of the shoe sole are bent up around the foot sole. A small number of both street and athletic shoe εoleε that are commercially available are naturally contoured to a limited extent in that only their bottom soles, which are about one quarter to one third of the total thicknesε of the entire shoe sole, are wrapped up around portions of the wearers' foot soles; the midsole and heel lift (or heel) of such shoe soles, constituting over half of the thickneεε of the entire shoe sole, remains flat, conforming to the ground rather than the wearers' feet. (At the other extreme, εome shoes in the existing art have flat midsoles and bottom soles, but have insoleε that conform to the wearer's foot sole.) Consequently, in existing contoured shoe soles, the total shoe sole thickness of the contoured side por¬ tions, including every layer or portion, is much leεε than the total thickness of the sole portion directly underneath the foot, whereas in the applicant's prior shoe sole inventions the shoe εole thickness of the con¬ toured side portions are at least similar to the thick¬ ness of the sole portion directly underneath the foot, meaning a thickness variation of up to 25 percent, as measured in frontal or transverse plane crosε εectionε. Thiε major and conεpicuous structural differ¬ ence between the applicant's underlying concept and the existing shoe sole art is paralleled by a similarly dra¬ matic functional difference between the two: the afore¬ mentioned similar thicknesε of the applicant'ε εhoe sole invention maintains intact the firm lateral stability of the wearer's foot, that stability aε demonεtrated when the wearer's foot is unεhod and tilted out laterally in inverεion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a εimilar dem- onεtration in a conventional εhoe sole, the wearer's foot and ankle are unstable. The sides of the applicant's shoe sole invention extend sufficiently far up the sides of the wearer's foot sole to maintain the lateral stabil¬ ity of the wearer's foot when bare. In addition, the applicant's invention main¬ tains the natural εtability and natural, uninterrupted motion of the foot when bare throughout itε normal range of εidewayε pronation and supination motion occurring during all load-bearing phaseε of locomotion of the wearer, including when εaid wearer iε εtanding, walking, jogging and running, even when the foot iε tilted to the extreme limit of that normal range, in contraεt to unεta¬ ble and inflexible conventional εhoe εoles, including the partially contoured exiεting art described above. The sides of the applicant's shoe sole invention extend suf¬ ficiently far up the sides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact thickneεε and material density of the shoe sole sides and their spe¬ cific contour will be determined empirically for individ¬ uals and groups using standard biomechanical techniques of gait analysis to determine thoεe combinationε that beεt provide the barefoot stability described above. For the Fig. 10 shoe sole invention, the amount of any shoe sole side portionε coplanar with the theore¬ tically ideal εtability plane iε determined by the degree of εhoe εole εtability deεired and the εhoe 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 intact the firm stability of the wearer's foot throughout the range of foot inversion and eversion motion typical of the uεe for which the shoe is intended and also typical of the kind of wearer — such as normal or as excesεive pronator — for which said shoe is intended. Finally, the shoe sole sideε are εufficiently flexible to bend out eaεily when the εhoeε are put on the wearer's feet and therefore the shoe soles gently hold the sideε of the wearer's foot sole when on, providing the equivalent of custom fit in a mass-produced shoe sole. In general, the applicant's preferred shoe sole embodiments include the structural and material flexibil- ity to deform in parallel to the natural deformation of the wearer's foot sole as if it were bare and unaffected by any of the abnormal foot biomechanics created by rigid conventional shoe sole. At the same time, the applicant'ε preferred shoe sole embodiments are sufficiently firm to provide the wearer's foot with the structural support necessary to maintain normal pronation and supination, as if the wearer's foot were bare; in contrast, the excessive soft- neεε of many of the shoe sole materials uεed in shoe soles in the existing art cause abnormal foot pronation and supination. As mentioned earlier regarding Fig. IA and Fig. 3, the applicant has previously shown heel lift with con¬ stant frontal or transverεe plane thickneεε, εince it is oriented conventionally in alignment with the frontal or transverse plane and perpendicular to the long axis of the shoe sole. However, the heel wedge (or toe taper or other shoe sole thicknesε variations in the sagittal plane along the long axis of the shoe sole) can be loca¬ ted at an angle to the conventional alignment in the Fig. 10 design. For example, the heel wedge can be located perpendicular to the subtalar axis, which iε located in the heel area generally about 20 to 25 degreeε medially, although a different angle can be used base on individual or group testing; such a orientation may provide better, more natural support to the subtalar joint, through which critical pronation and supination motion occur. The applicant's theoretically ideal stability plane concept would teach that such a heel wedge orientation would require conεtant εhoe εole thickneεε in a vertical plane perpendicular to the choεen subtalar joint axis, instead of the frontal plane. Besides providing a better fit, the intentional undersizing of the flexible shoe sole sideε allowε for simplified design of shoe sole lastε, since the shoe last needs only to be approximate to provide a virtual cuεto fit, due to the flexible εides. As a result, the under¬ sized flexible shoe sole sideε allow the applicant's Fig. 10 shoe εole invention based on the theoretically ideal stability plane to be manufactured in relatively standard εizes in the same manner as are shoe uppers, since the flexible shoe sole εideε can be built on εtandard εhoe lasts, even though conceptually those εideε conform to the specific shape of the individual wearer's foot εole, becauεe the flexible εideε bend to so conform when on the wearer's foot sole. Fig. 10 shows the shoe sole structure when not on the foot of the wearer; the dashed line 29 indicates the position of the shoe last, which is assumed to be a reasonably accurate approximation of the shape of the outer surface of the wearer's foot sole, which determines the shape of the theoretically ideal stability plane 51. Thus, the dashed lineε 29 and 51 show what the positionε of the inner surface 30 and outer surface 31 of the shoe sole would be when the shoe is put on the foot of the wearer. The Fig. 10 invention provides a way make the inner surface 30 of the contoured shoe sole, especially itε εideε, conform very cloεely to the outer surface 29 of the foot sole of a wearer. It thus makes much more practical the applicant'ε earlier underlying naturally contoured designs shown in Figs. 4 and 5. The shoe sole structures shown in Fig. 4 and 5, then, are what the Fig. 10 shoe sole structure would be when on the wearer's load-bearing foot, where the inner surface 30 of the shoe upper is bent out to virtually coincide with the outer surface of the foot sole of the wearer 29 (the figures in this and prior applications show one line to emphasize the conceptual coincidence of what in fact are two lines; in real world embodiments, εome divergence of the εur¬ face, eεpecially under load and during locomotion would be unavoidable) . The εideε of the εhoe sole structure described under Fig. 10 can also be uεed to form a εlightly less optimal structure: a conventional shoe sole that has been modified by having its sides bent up so that their inner surface conforms to shape nearly identical but εlightly larger than the shape of the outer surface of the foot sole of the wearer, instead of the shoe sole sides being flat on the ground, as is conventional. Clearly, the closer the sideε are to the shape of the wearer's foot sole, the better as a general rule, but any side position between flat on the ground and conforming like Fig. 10 to a shape slightly εmaller than the wearer's εhape is both possible and more effective than conventional flat shoe sole εides. And in some cases, such as for diabetic patients, it may be optimal to have relatively loose shoe sole εides providing no conforming pressure of the shoe sole on the tender foot sole; in such cases, the shape of the flexible shoe uppers, which can even be made with very elaεtic materialε such as lycra and spandex, can provide the capability for the shoe, including the shoe sole, to conform to the shape of the foot. As diεcuεεed earlier by the applicant, the critical functional feature of a εhoe sole is that it deforms under a weight-bearing load to conform to the foot sole just as the foot sole deforms to conform to the ground under a weight-bearing load. So, even though the foot sole and the εhoe εole may start in different loca¬ tions — the shoe sole sides can even be conventionally flat on the ground — the critical functional feature of both is that they both conform under load to parallel the shape of the ground, which conventional shoes do not, except when exactly upright. Consequently, the appli¬ cant's shoe sole invention, stated most broadly, includes any shoe sole — whether conforming to the wearer's foot sole or to the ground or εome intermediate position, including a shape much smaller than the wearer's foot sole — that deformε to conform to a εhape at leaεt simi¬ lar to the theoretically ideal stability plane, which by definition itself deforms in parallel with the defor a- tion of the wearer's foot sole under weight-bearing load. Of course, it is optimal in terms of preserving natural foot biomechanics, which is the primary goal of the applicant, for the shoe sole to conform to the foot sole when on the foot, not just when under a weight-bear- ing load. And, in any case, all of the essential struc¬ tural support and propulsion elements previously identi¬ fied by the applicant earlier in discuεεing Fig. 3 must be supported by the foot sole. To the extent the shoe sole sides are easily flexible, as has already been specified as desirable, the position of the shoe sole sides before the wearer puts on the shoe is less important, since the sides will easily conform to the shape of the wearer's foot when the shoe is put on that foot. In view of that, even shoe sole sides that conform to a shape more than slightly smaller than the shape of the outer surface of the wearer's foot sole would function in accordance with the applicant's general invention, since the flexible sides could bend out easily a considerable relative distance and still conform to the wearer's foot sole when on the wearer's foot. Fig. 11 is new with this application and is a combination of the shoe sole structure concepts of Fig. 3 and Fig. 6; it combines the custom fit design with the contoured sideε having material denεity variationε that produce an effect εimilar to variations in shoe sole thickness shown in Figε. 4, 5, and 7; only the midεole iε shown. The density variation pattern shown in Fig. 2 can be combined with the type shown in Fig. 11. The density pattern can be constant in all crosε sections taken along the long the long axis of the shoe sole or the pattern can vary. The applicant's Fig. 11 shoe sole invention maintains intact the firm lateral εtability of the wear¬ er's foot, that stability as demonstrated when the wear¬ er's foot is unεhod and tilted out laterally in inverεion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a εimilar demonεtration in a conventional εhoe εole, the wearer's foot and ankle are unstable. The sideε of the applicant's shoe sole inven¬ tion extend sufficiently far up the sides of the wearer's foot sole to maintain the lateral stability of the wear- er's foot when bare. In addition, the applicant's invention main¬ tains the natural stability and natural, uninterrupted motion of the foot when bare throughout its normal range of sideways pronation and supination motion occurring during all load-bearing phases of locomotion of the wearer, including when said wearer is standing, walking, jogging and running, even when the foot is tilted to the extreme limit of that normal range, in contrast to unsta¬ ble and inflexible conventional shoe soles, including the partially contoured existing art described above. The εideε of the applicant'ε shoe sole invention extend suf¬ ficiently far up the sides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact material den¬ sity of the shoe sole sideε will be determined empir¬ ically for individuals and groups using standard biomech¬ anical techniques of gait analysis to determine thoεe combinationε that beεt provide the barefoot εtability described above. For the Fig. 11 shoe sole invention, the amount of any shoe εole side portions coplanar with the theore¬ tically ideal stability plane 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 εideε that is provided said shoe sole being sufficient to maintain intact the firm stability of the wearer's foot throughout the range of foot inversion and eversion motion typical of the use for which the shoe is intended and alεo typical of the kind of wearer — such as normal or as excessive pronator — for which said shoe is intended. Finally, the shoe sole sides are sufficiently flexible to bend out easily when the shoes are put on the wearer's feet and therefore the shoe soles gently hold the sides of the wearer's foot sole when on, providing the equivalent of custom fit in a maεε-produced shoe sole. In general, the applicant's preferred εhoe sole embodimentε include the structural and material flexibil¬ ity to deform in parallel to the natural deformation of the wearer's foot sole as if it were bare and unaffected by any of the abnormal foot biomechanics created by rigid conventional shoe sole. At the same time, the applicant's preferred shoe sole embodimentε are sufficiently firm to provide the wearer's foot with the structural support necessary to maintain normal pronation and supination, as if the wearer's foot were bare; in contrast, the exceεεive εoft- ness of many of the shoe sole materials used in shoe soles in the existing art cause abnormal foot pronation and supination. As mentioned earlier regarding Fig. IA and Fig. 3, the applicant has previously shown heel lift with con¬ stant frontal or transverse plane thicknesε, since it is oriented conventionally in alignment with the frontal or transverse plane and perpendicular to the long axis of the shoe sole. However, the heel wedge (or toe taper or other shoe sole thicknesε variationε in the sagittal plane along the long axis of the shoe sole) can be loca¬ ted at an angle to the conventional alignment in the Fig. IA design. For example, the heel wedge can be located per¬ pendicular to the subtalar axis, which is located in the heel area generally about 20 to 25 degreeε medially, although a different angle can be used base on individual or group testing; such a orientation may provide better, more natural support to the subtalar joint, through which critical pronation and supination motion occur. The applicant's theoretically ideal stability plane concept would teach that such a heel wedge orientation would require constant shoe sole thickness in a vertical plane perpendicular to the chosen subtalar joint axis, instead of the frontal plane. Besides providing a better fit, the intentional undersizing of the flexible shoe sole sides allows for simplified design of shoe sole lasts, εince the shoe last needs only to be approximate to provide a virtual custom fit, due to the flexible sideε. As a result, the under¬ sized flexible shoe εole εideε allow the applicant'ε Fig. 10 shoe sole invention based on the theoretically ideal stability plane to be manufactured in relatively standard εizes in the same manner as are shoe uppers, since the flexible shoe sole sides can be built on standard shoe lasts, even though conceptually those sides conform to the specific shape of the individual wearer's foot sole, becauεe the flexible εideε bend to so conform when on the wearer's foot sole. Besides providing a better fit, the intentional undersizing of the flexible shoe sole sides allows for εimplified deεign of shoe sole lasts, since they can be designed according to the εimple geometric methodology described in the textual εpecification of Fig. 27, United States Patent Application 07/239,667, filed 02 September 1988. That geometric approximation of the true actual contour of the human is close enough to provide a virtual custom fit, when compensated for by the flexible under¬ sizing from εtandard εhoe laεtε deεcribed above. A flexible underεized version of the fully contoured design described in Fig. 11 can also be pro¬ vided by a similar geometric approximation. As a result, the undersized flexible shoe εole εideε allow the appli¬ cant'ε εhoe εole inventions based on the theoretically ideal stability plane to be manufactured in relatively standard εizeε in the εame manner as are shoe uppers, since the flexible shoe sole sides can be built on stan¬ dard shoe lasts, even though conceptually thoεe sides conform closely to the specific shape of the individual wearer's foot εole, because the flexible sides bend to conform when on the wearer's foot sole. Fig. 11 shows the shoe sole structure when not on the foot of the wearer; the dashed line 29 indicates the poεition of the εhoe laεt, which is assumed to be a reasonably accurate approximation of the shape of the outer surface of the wearer's foot sole, which determines the shape of the theoretically ideal stability plane 51. Thus, the daεhed lineε 29 and 51 εhow what the positions of the inner surface 30 and outer surface 31 of the εhoe sole would be when the shoe is put on the foot of the wearer. The Fig. 11 invention provides a way make the inner surface 30 of the contoured shoe sole, especially its sides, conform very closely to the outer surface 29 of the foot sole of a wearer. It thus makes much more practical the applicant's earlier underlying naturally contoured designs shown in Fig. 1A-C and Fig. 6. The shoe sole structure shown in Fig. 61, then, is what the Fig. 11 shoe sole structure would be when on the wearer's foot, where the inner surface 30 of the shoe upper is bent out to virtually coincide with the outer surface of the foot sole of the wearer 29 (the figures in this and prior applications show one line to emphasize the concep- tual coincidence of what in fact are two lines; in real world embodiments, some divergence of the surface, espe¬ cially under load and during locomotion would be unavoid¬ able) . The sides of the shoe sole structure described under Fig. 11 can alεo be uεed to form a slightly less optimal structure: a conventional shoe sole that has been modified by having its εides bent up εo that their inner surface conforms to shape nearly identical but slightly larger than the shape of the outer surface of the foot εole of the wearer, inεtead of the εhoe εole εides being flat on the ground, aε iε conventional. Clearly, the cloεer the εides are to the εhape of the wearer's foot sole, the better as a general rule, but any side position between flat on the ground and conforming like Fig. 11 to a shape slightly smaller than the wearer's shape is both possible and more effective than conventional flat shoe εole sides. And in some cases, such as for diabetic patients, it may be optimal to have relatively looεe shoe sole sides providing no conforming presεure of the εhoe sole on the tender foot sole; in such caεeε, the shape of the flexible shoe uppers, which can even be made with very elaεtic materials such as lycra and εpandex, can provide the capability for the shoe, including the shoe sole, to conform to the shape of the foot. As discussed earlier by the applicant, the critical functional feature of a shoe sole is that it deforms under a weight-bearing load to conform to the foot sole just as the foot sole deforms to conform to the ground under a weight-bearing load. So, even though the foot sole and the shoe sole may start in different loca¬ tions — the shoe sole sides can even be conventionally flat on the ground — the critical functional feature of both is that they both conform under load to parallel the shape of the ground, which conventional shoes do not, except when exactly upright. Consequently, the appli¬ cant's εhoe εole invention, εtated most broadly, includes any shoe sole — whether conforming to the wearer's foot sole or to the ground or some intermediate position, including a shape much smaller than the wearer's foot sole — that deforms to conform to the theoretically ideal stability plane, which by definition itself deforms in parallel with the deformation of the wearer's foot sole under weight-bearing load. Of courεe, it is optimal in terms of preserving natural foot biomechanics, which is the primary goal of the applicant, for the shoe sole to conform to the foot sole when on the foot, not just when under a weight-bear¬ ing load. And, in any case, all of the esεential εtruc- tural εupport and propulεion elementε previously identi¬ fied by the applicant earlier in discussing Fig. 3 must be supported by the foot εole. To the extent the εhoe εole εideε are eaεily flexible, aε has already been specified as desirable, the position of the shoe sole sides before the wearer puts on the εhoe iε leεs important, since the sideε will eaεily conform to the shape of the wearer's foot when the shoe is put on that foot. In view of that, even shoe sole sides that conform to a shape more than slightly smaller than the shape of the outer surface of the wearer's foot sole would function in accordance with the applicant's general invention, since the flexible sideε could bend out easily a considerable relative distance and still conform to the wearer's foot sole when on the wearer's foot. The applicant's shoe sole inventions described in Figs. 4, 10 and 11 all attempt to provide structural compensation for actual structural changes in the feet of wearers that have occurred from a lifetime of use of existing shoeε, which have a major flaw that has been identified and described earlier by the applicant. As a result, the biomechanical motion of even the wearer's bare feet have been degraded from what they would be if the wearer's feet had not been structurally changed. Conεequently, the ultimate design goal of the applicant's inventions is to provide un-degraded barefoot motion. That means to provide wearerε with shoe soleε that com¬ pensate for their flawed barefoot structure to an extent εufficient to provide foot and ankle motion equivalent to that of their bare feet if never εhod and therefore not flawed. Determining the biomechanical characteristics of such un-flawed bare feet will be difficult, either on an individual or group basiε. The difficulty for many groups of wearers will be in finding un-flawed, never- shod barefoot from similar genetic groups, asεuming εig- nificant genetic differenceε exiεt, as seems at least possible if not probable. The ultimate goal of the applicant's invention is to provide shoe sole structureε that maintain the natural εtability and natural, uninterrupted motion of the foot when bare throughout itε normal range of side¬ ways pronation and supination motion occurring during all load-bearing phases of locomotion of a wearer who has never been shod in conventional shoes, including when said wearer is εtanding, walking, jogging and running, even when the foot is tilted to the extreme limit of that normal range, in contrast to unstable and inflexible conventional shoe soles. Figs. 12-23 are Figs. 1-7 and 11-15, respec¬ tively, from the '714 application. Fig. 12 showε in a real illustration a foot 27 in position for a new biomechanical teεt that is the basiε for the discovery that ankle sprainε are in fact unnatural for the bare foot. The teεt εimulates a lateral ankle sprain, where the foot 27 — on the ground 43 — rolls or tiltε to the outεide, to the extreme end of itε normal range of motion, which iε usually about 20 degrees at the heel 29, as εhown in a rear view of a bare (right) heel in Fig. 12. Lateral (inverεion) sprains are the most common ankle sprainε, accounting for about three-fourthε of all. The especially novel aspect of the testing approach is to perform the ankle spraining simulation while standing stationary. The absence of forward motion is the key to the dramatic εucceεε of the teεt becauεe otherwiεe it iε impoεsible to recreate for testing pur¬ poseε the actual foot and ankle motion that occurε during a lateral ankle εprain, and εimultaneously to do it in a controlled manner, while at normal running speed or even jogging slowly, or walking. Without the critical control achieved by slowing forward motion all the way down to zero, any teεt subject would end up with a sprained ankle. That is because actual running in the real world is dynamic and involves a repetitive force maximum of three times one's full body weight for each footstep, with sudden peaks up to roughly five or six timeε for quick stops, missteps, and direction changes, as might be experienced when spraining an ankle. In contrast, in the static simulation test, the forces are tightly controlled and moderate, ranging from no force at all up to whatever maximum amount that is comfortable. The Stationary Sprain Simulation Test (SSST) consists simply of standing stationary with one foot bare and the other shod with any shoe. Each foot alternately is carefully tilted to the outside up to the extreme end of its range of motion, simulating a lateral ankle sprain. The Stationary Sprain Simulation Test clearly identifies what can be no less than a fundamental flaw in existing shoe design. It demonstrateε concluεively that nature's biomechanical system, the bare foot, is far superior in stability to man's artificial shoe design. Unfortunately, it also demonstrateε that the shoe's severe instability overpowers the natural stability of the human foot and synthetically creates a combined bio¬ mechanical system that is artificially unstable. The shoe is the weak link. The test shows that the bare foot is inherently stable at the approximate 20 degree end of normal joint range because of the wide, steady foundation the bare heel 29 provides the ankle joint, as seen in Fig. 12. In fact, the area of physical contact of the bare heel 29 with the ground 43 is not much lesε when tilted all the way out to 20 degreeε aε when upright at 0 degrees. The new Stationary Sprain Simulation Test pro¬ vides a natural yardstick, totally missing until now, to determine whether any given shoe allows the foot within it to function naturally. If a shoe cannot pasε this simple litmus test, it is positive proof that a particu- lar shoe is interfering with natural foot and ankle bio¬ mechanicε. The only queεtion iε the exact extent of the interference beyond that demonεtrated by the new test. Conversely, the applicant's designs are the only designs with shoe soles thick enough to provide cuεhioning (thin-εoled and heel-less moccasins do pasε the test, but do not provide cushioning and only moderate protection) that will provide naturally stable perfor¬ mance, like the bare foot, in the Stationary Sprain Simu¬ lation Test. Fig. 13 shows that, in complete contrast the foot equipped with a conventional running shoe, desig¬ nated generally by the reference numeral 20 and having an upper 21, though initially very stable while resting com- pletely flat on the ground, becomeε immediately unεtable when the shoe sole 22 is tilted to the outside. The tilting motion lifts from contact with the ground all of the shoe sole 22 except the artificially sharp edge of the bottom outside corner. The shoe sole instability increases the farther the foot is rolled laterally. Eventually, the instability induced by the shoe itself is so great that the normal load-bearing pressure of full body weight would actively force an ankle sprain .if not controlled. The abnormal tilting motion of the shoe does not stop at the barefoot's natural 20 degree limit, as you can see from the 45 degree tilt of the shoe heel in Fig. 13. That continued outward rotation of the shoe past 20 degrees cauεeε the foot to slip within the shoe, shifting its position within the shoe to the outside edge, further increaεing the εhoe's structural instabil¬ ity. The slipping of the foot within the shoe iε cauεed by the natural tendency of the foot to εlide down the typically flat surface of the tilted shoe sole; the more the tilt, the stronger the tendency. The heel is εhown in Fig. 13 becauεe of itε primary importance in sprains due to its direct physical connection to the ankle liga¬ ments that are torn in an ankle sprain and also because of the heel'ε predominant role within the foot in bearing body weight. It iε eaεy to εee in the two figureε how totally different the physical shape of the natural bare foot iε compared to the shape of the artificial shoe sole. It is strikingly odd that the two objects, which apparently both have the εame biomechanical function, have completely different physical shapes. Moreover, the shoe sole clearly does not deform the same way the human foot εole doeε, primarily aε a conεequence of its dissim- ilar shape. Fig. 14A illustrateε that the underlying prob¬ lem with exiεting εhoe deεignε iε fairly easy to under¬ stand by looking closely at the principal forceε acting on the physical structure of the shoe sole. When the shoe is tilted outwardly, the weight of the body held in the shoe upper 21 shifts automatically to the outside edge of the shoe sole 22. But, εtrictly due to itε unnatural shape, the tilted εhoe sole 22 provides abso¬ lutely no supporting physical εtructure directly under¬ neath the εhifted body weight where it iε critically needed to εupport that weight. An eεsential part of the supporting foundation is missing. The only actual struc- tural εupport comeε from the sharp corner edge 23 of the shoe sole 22, which unfortunately is not directly under the force of the body weight after the shoe is tilted. Instead, the corner edge 23 is offset well to the inside. As a result of that unnatural misalignment, a lever arm 23a is set up through the shoe sole 22 between two interacting forces (called a force couple) : the force of gravity on the body (usually known as body weight 133) applied at the point 24 in the upper 21 and the reaction force 134 of the ground, equal to and opposite to body weight when the shoe iε upright. The force couple cre¬ ates a force moment, commonly called torque, that forces the shoe 20 to rotate to the outside around the sharp corner edge 23 of the bottom sole 22, which serves as a stationary pivoting point 23 or center of rotation. Unbalanced by the unnatural geometry of the shoe sole when tilted, the opposing two forceε produce torque, causing the shoe 20 to tilt even more. As the shoe 20 tilts further, the torque forcing the rotation becomes even more powerful, εo the tilting process becomes a self-reenforcing cycle. The more the shoe tiltε, the more destabilizing torque is produced to fur¬ ther increaεe the tilt. The problem may be eaεier to understand by looking at the diagram of the force components of body weight shown in Fig. 14A. When the shoe sole 22 is tilted out 45 degrees, as shown, only half of the downward force of body weight 133 is physically supported by the shoe sole 22; the εupported force component 135 is 71% of full body weight 133. The other half of the body weight at the 45 degree tilt is unsupported physically by any shoe sole struc¬ ture; the unsupported component is also 71% of full body weight 133. It therefore produces εtrong deεtabilizing outward tilting rotation, which iε reεiεted by nothing structural except the lateral ligaments of the ankle. Fig. 14B show that the full force of body weight 133 is split at 45 degrees of tilt into two equal components: supported 135 and unεupported 136, each equal to .707 of full body weight 133. The two vertical compo¬ nents 137 and 138 of body weight 133 are both equal to .50 of full body weight. The ground reaction force 134 is equal to the vertical component 137 of the supported component 135. Fig. 15 show a summary of the force componentε at εhoe εole tiltε of 0, 45 and 90 degreeε. Fig. 15, which uses the same reference numerals as in Fig. 14, showε that, aε the outward rotation continueε to 90 degreeε, and the foot εlipε within the εhoe while liga¬ ments stretch and/or break, the destabilizing unsupported force component 136 continues to grow. When the shoe sole has tilted all the way out to 90 degreeε (which unfortunately doeε happen in the real world) , the sole 22 is providing no structural support and there is no sup¬ ported force component 135 of the full body weight 133. The ground reaction force at the pivoting point 23 is zero, since it would move to the upper edge 24 of the shoe sole. At that point of 90 degree tilt, all of the full body weight 133 iε directed into the unreεiεted and unεupported force component 136, which iε destabilizing the shoe sole very powerfully. In other words, the full weight of the body is physically unsupported and there- fore powering the outward rotation of the shoe sole that produces an ankle sprain. Insidiouεly, the farther ankle ligamentε are εtretched, the greater the force on them. In stark contrast, untilted at 0 degrees, when the shoe sole is upright, resting flat on the ground, all of the force of body weight 133 is physically supported directly by the shoe sole and therefore exactly equals the supported force component 135, as also shown in Fig. 15. In the untilted position, there is no destabilizing unsupported force component 136. Fig. 16 illustrates that the extremely rigid heel counter 141 typical of existing athletic shoes, together with the motion control device 142 that are often used to strongly reinforce those heel counters (and sometimes also the sides of the mid- and forefoot) , are ironically counterproductive. Though they are intended to increase stability, in fact they decrease it. Fig. 16 shows that when the shoe 20 is tilted out, the foot iε shifted within the upper 21 naturally against the rigid structure of the typical motion control device 142, instead of only the outside edge of the shoe sole 22 itself. The motion control support 142 increaεeε by almoεt twice the effective lever arm 132 (compared to 23a) between the force couple of body weight and the ground reaction force at the pivot point 23. It doubles the destabilizing torque and alεo increases the effective angle of tilt so that the destabilizing force component 136 becomes greater compared to the supported component 135, also increaεing the deεtabilizing torque. To the extent the foot εhifts further to the outside, the prob¬ lem becomes worse. Only by removing the heel counter 141 and the motion control deviceε 142 can the extenεion of the deεtabilizing lever arm be avoided. Such an approach would primarily rely on the applicant'ε contoured εhoe sole to "cup" the foot (especially the heel) , and to a much leεser extent the non-rigid fabric or other flexible material of the upper 21, to poεition the foot, including the heel, on the εhoe. Eεsentially, the naturally con¬ toured sides of the applicant's shoe sole replace the counter-productive existing heel counters and motion control deviceε, including thoεe which extend around virtually all of the edge of the foot. Fig. 17 εhows that the εame kind of torεional problem, though to a much more moderate extent, can be produced in the applicant'ε naturally contoured deεign of the applicant'ε earlier filed applicationε. There, the concept of a theoretically-ideal εtability plane was developed in terms of a sole 28 having a lower surface 31 and an upper surface 30 which are spaced apart by a pre- determined distance which remains constant throughout the sagittal frontal planes. The outer surface 27 of the foot is in contact with the upper surface 30 of the sole 28. Though it might εeem desirable to extend the inner surface 30 of the shoe sole 28 up around the sides of the foot 27 to further support it (especially in creating anthropomorphic designs) , Fig. 17 indicates that only that portion of the inner shoe sole 28 that is directly supported structurally underneath by the rest of the shoe sole is effective in providing natural support and sta- bility. Any point on the upper εurface 30 of the εhoe sole 28 that is not εupported directly by the constant shoe sole thickness (as meaεured by a perpendicular to a tangent at that point and εhown in the εhaded area 143) will tend to produce a moderate deεtabilizing torque. To avoid creating a deεtabilizing lever arm 132, only the εupported contour sides and non-rigid fabric or other material can be used to poεition the foot on the εhoe sole 28. Fig. 18 illustrates an approach to minimize structurally the destabilizing lever arm 32 and therefore the potential torque problem. After the last point where the constant shoe sole thickness (s) is maintained, the finishing edge of the shoe εole 28 εhould be tapered gradually inward from both the top εurface 30 and the bottom εurface 31, in order to provide matching rounded or semi-rounded edges. In that way, the upper εurface 30 does not provide an unsupported portion that creates a destabilizing torque and the bottom surface 31 does not provide an unnatural pivoting edge. The gap 144 between shoe sole 28 and foot sole 29 at the edge of the shoe sole can be "caulked" with exceptionally soft sole mate¬ rial as indicated in Fig. 18 that, in the aggregate (i.e. all the way around the edge of the εhoe sole) , will help position the foot in the shoe sole. However, at any point of presεure when the εhoe tiltε, it will deform easily so as not to form an unnatural lever causing a destabilizing torque. Fig. 19 illustrates a fully contoured design, but abbreviated along the sideε to only essential struc¬ tural εtability and propulεion shoe sole elements as shown in Fig. 21 of United States Patent Application 07/239,667 (filed 02 September 1988) combined with the freely articulating structural elements underneath the foot as shown in Fig. 28 of the εame patent application. The unifying concept is that, on both the sideε and underneath the main load-bearing portionε of the εhoe εole, only the important εtructural (i.e., bone) elementε of the foot εhould be εupported by the εhoe εole, if the natural flexibility of the foot iε to be paralleled accu¬ rately in εhoe εole flexibility, so that the shoe εole does not interfere with the foot's natural motion. In a sense, the shoe sole should be composed of the same main structural elements as the foot and they should articu¬ late with each other just as do the main joints of the foot. Fig. 19E shows the horizontal plane bottom view of the right foot corresponding to the fully contoured design previously described, but abbreviated along the sides to only essential structural support and propulεion elementε. Shoe sole material density can be increaεed in the unabbreviated eεεential elements to compensate for increased pressure loading there. The essential struc- tural εupport elementε are the baεe and lateral tuberoε- ity of the calcaneuε 95, the headε of the etatarsals 96, and the baεe of the fifth metatarεal 97 (and the adjoin¬ ing cuboid in some individuals) . They must be supported both underneath and to the outside edge of the foot for stability. The essential propulsion element is the head of the first distal phalange 98. Fig. 19 shows that the naturally contoured stability sideε need not be used except in the identified esεential areaε. Weight savings and flexibility improvements can be made by omitting the non-essential stability sides. The design of the portion of the shoe sole directly underneath the foot shown in Fig. 19 allows for unobstructed natural inversion/everεion motion of the calcaneus by providing maximum shoe sole flexibility particularly between the base of the calcaneus 125 (heel) and the metatarsal heads 126 (forefoot) along an axis 120. An unnatural torεion occurε about that axiε 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 inversion and eversion) calca- neuε to articulate freely and independently from the relatively more fixed forefoot inεtead of the fixed or fuεed εtructure or lack of stable structure between the two in conventional designs. In a sense, freely articu¬ lating 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 the fifth meta¬ tarsal 97. An optional support for the main longitudinal arch 121 may also be retained for runners with subεtan- tial foot pronation, although would not be neceεεary for many runnerε. The forefoot can be subdivided (not shown) into its component essential structural support and propulsion elements, the individual heads of the metatarsal and the heads of the distal phalanges, so that each major articu¬ lating joint set of the foot is paralleled by a freely articulating shoe sole support propulsion element, an anthropomorphic design; various aggregations of the sub¬ division are also possible. The design in Fig. 19 features an enlarged structural support at the base of the fifth metatarsal in order to include the cuboid, which can also come into contact with the ground under arch comPrEsεion in some individuals. In addition, the design can provide general side support in the heel area, as in Fig. 19E or alterna¬ tively can carefully orient the stability sideε in the heel area to the exact positions of the lateral calcaneal tuberosity 108 and the main baεe of the calcaneus 109, as in Fig. 19E' (showing heel area only of the right foot) . Figs. 19A-D show frontal plane cross sections of the left shoe and Fig. 19E shows a bottom view of the right foot, with flexibility axes 120, 122, 111, 112 and 113 indica¬ ted. Fig. 19F shows a sagittal plane cross section show¬ ing the structural elements joined by very thin and rela¬ tively soft upper midsole layer. Figs. 19G and 19H show similar cross sectionε with εlightly different deεignε featuring durable fabric only (slip-lasted shoe) , or a structurally sound arch design, respectively. Fig. 191 εhowε a side medial view of the shoe sole. Fig. 19J shows a simple interim or low cost construction for the articulating shoe εole support ele- ment 95 for the heel (showing the heel area only of the right foot) ; while it is most critical and effective for the heel support element 95, it can also be used with the other elements, such as the baεe of the fifth metatarεal 97 and the long arch 121. The heel sole element 95 shown can be a single flexible layer or a lamination of layers. When cut from a flat sheet or molded in the general pat¬ tern shown, the outer edges can be easily bent to follow the contours of the foot, particularly the sideε. The shape shown allows a flat or slightly contoured heel ele- ment 95 to be attached to a highly contoured shoe upper or very thin upper sole layer like that shown in Fig. 19F. Thus, a very simple construction technique can yield a highly sophisticated shoe εole design. The size of the center section 119 can be εmall to conform to a fully or nearly fully contoured design or larger to con¬ form to a contoured sides design, where there is a large flattened sole area under the heel. The flexibility is provided by the removed diagonal sections, the exact proportion of size and shape can vary. Fig. 20 illuεtrates an expanded explanation of the correct approach for measuring shoe sole thicknesε according to the naturally contoured design, as described previously in Figs. 23 and 24 of United States Patent Application 07/239,667, filed 02 September 1988. The tangent described in thoεe figureε would be parallel to the ground when the shoe sole is tilted out sideways, so that meaεuring εhoe εole thickness along the perpendicu- lar will provide the least distance between the point on the upper shoe sole εurface cloεest to the ground and the closeεt point to it on the lower surface of the shoe sole (asεuming no load deformation) . Fig. 21 shows 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 bot¬ tom or outer εole 128 includeε moεt or all of the special contours of the new design. Not only would that com¬ pletely or mostly limit the special contours to the bot¬ tom 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 sur¬ faces, as would be the case otherwiεe. The advantage of this approach is seen in the naturally contoured deεign example illuεtrated in Fig. 21A, which shows some con¬ tours on the relatively softer midsole sides, which are subject to lesε wear but benefit from greater traction for stability and ease of deformation, while the rela¬ tively harder contoured bottom sole provides good wear for the load-bearing areas. Fig. 2IB εhows in a quadrant side design the 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. 21C showε in frontal plane cross section the concept applied to the quadrant sided or single plane design and indicating in Fig. 2ID in the shaded area 129 of 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 denεity. Fig. 2IE εhowε in bottom view the outline of a bottom sole 128 made from flat material which can 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 esεential support areas diεcussed in Fig. 21 of the '667 application; by that method, the contoured mids¬ ole and flat bottom sole surfaces can be made to join satiεfactorily by coinciding cloεely, which would be topologically impoεsible if all of the side areas were retained on the bottom sole. Figs. 22A-22C, frontal plane cross sections, show an enhancement to the previously described embodi¬ ments of the shoe sole side stability quadrant invention of the '349 Patent. As stated earlier, one major purpose of that design is to allow the shoe sole to pivot eaεily from side to side with the foot 90, thereby following the foot's natural inversion and eversion motion; in conven¬ tional designε εhown in Fig. 22a, εuch 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 facili¬ tates the shoe sole's responsivenesε in following the foot's natural motion. Correct positioning is essential to the invention, especially when the very narrow or "hard tisεue" definition of heel width iε used. Incor¬ rect or shifting relative position will reduce the inher¬ ent efficiency and stability of the side quadrant design, by reducing the effective thickneεε of the quadrant εide 26 to leεs than that of the εhoe sole 28b. As shown in Fig. 22B and 22C, naturally contoured inner stability sideε 131 hold the pivoting edge 31 of the load-bearing foot εole in the correct poεition for direct contact with the flat upper surface of the conventional εhoe εole 22, so that the shoe sole thickness (s) is maintained at a constant thicknesε (ε) in the εtability quadrant sides 26 when the shoe is everted or inverted, following the theo- retically ideal stability plane 51. The form of the enhancement is inner shoe sole stability sideε 131 that follow the natural contour of the εideε 91 of the heel of the foot 90, thereby cupping the heel of the foot. The inner stability sideε 131 can be located directly on the top εurface of the εhoe εole 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 soft like the insole. The difference is that because of their higher relative density, preferably like that of the uppermost midsole, the inner stability sideε function as part of the shoe sole, which provides structural support to the foot, not just gentle cushioning and abraεion protection of a εhoe inεole. In the broadest sense, though, insoles should be conεidered εtructurally and functionally aε part of the εhoe εole, aε εhould any shoe material between foot and ground, like the bottom of the shoe upper in a slip- lasted shoe or the board in a board-lasted shoe. The inner stability side enhancement is par¬ ticularly useful in converting existing conventional shoe sole design embodiments 22, as conεtructed within prior art, to an effective embodiment of the εide εtability quadrant 26 invention. Thiε feature iε important in constructing prototypes and initial production of the invention, as well as an ongoing method of low cost pro- duction, εince such production would be very close to exiεting art. The inner stability sideε enhancement iε moεt essential in cupping the sides and back of the heel of the foot and therefore is esεential on the upper edge of the heel of the εhoe sole 27, but may also be extended around all or any portion of the remaining εhoe εole upper edge. The size of the inner stability sides should, however, taper down in proportion to any reduc- tion in shoe sole thickness in the sagittal plane. Figs. 23A-23C, 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 sideε '667 appli- cation design. The enhancement positionε and stabilizes the foot relative to the shoe sole, and maintains the constant shoe sole thickness (s) of the naturally con¬ toured sides 28a design, as shown in Figs. 23B and 23C; Fig. 23A shows a conventional design. The inner shoe sole stability sideε 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 εole εideε embodiment 28 are the εame as described previously under Figs. 22A-22C for the side stability quadrant embodiment. It iε clear from comparing Figs. 23C and 22C that the two different approaches, that with quadrant sideε and that with natu¬ rally contoured sides, can yield some similar resulting shoe sole embodimentε through the uεe of inner εtability εides 131. In esεence, both approaches provide a low cost or interim method of adapting existing conventional "flat sheet" shoe manufacturing to the naturally con¬ toured design described in previous figures. Figs. 24-34 are Figs. 1-3, 6-9, 11-12, and 14- 15, respectively, from the '478 application. Figs. 24, 25, and 26 show frontal plane cross sectional views of a shoe sole according to the appli- cant's prior inventions based on the theoretically ideal stability plane, taken at about the ankle joint to show the heel section of the shoe. Figs. 4, 5, 8, and 27-32 show the same view of the applicant's enhancement of that invention. The reference numerals are like those used in the prior pending applications of the applicant mentioned above and which are incorporated by reference for the sake of completenesε of diεcloεure, if neceεsary. In the figures, a foot 27 is positioned in a naturally contoured shoe having an upper 21 and a sole 28. The shoe sole normally contactε the ground 43 at about the lower cen¬ tral heel portion thereof, aε εhown in Fig. 4. The con¬ cept of the theoretically ideal stability plane, as developed in the prior applicationε as noted, defines the plane 51 in terms of a locus of points determined by the thickness(es) of the sole. Fig. 24 shows, in a rear cross sectional view, the application of the prior invention εhowing the inner surface of the shoe sole conforming to the natural con- tour of the foot and the thickness of the shoe sole remaining constant in the frontal plane, so that the outer surface coincideε with the theoretically ideal stability plane. Fig. 25 showε a fully contoured εhoe εole deεign of the applicant'ε prior invention that follows the natural contour of all of the foot, the bottom as well as the εideε, while retaining a conεtant shoe sole thickness in the frontal plane. The fully contoured shoe sole asεumeε that the resulting slightly rounded 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 com¬ position as to allow the natural deformation following that of the foot. The design applies particularly to the heel, but to the rest of the shoe sole as well. By pro¬ viding the closeεt match to the natural εhape of the foot, the fully contoured deεign allows the foot to func- tion as naturally as possible. Under load, Fig. 2 would deform by flattening to look essentially like Fig. 24. Seen in this light, the naturally contoured side design in Fig. 24 is a more conventional, conservative design that is a special case of the more general fully con¬ toured design in Fig. 25, which is the closest to the natural form of the foot, but the least conventional. The amount of deformation flattening used in the Fig. 24 design, which obviously varies under different loads, is not an essential element of the applicant's invention. Figs. 24 and 25 both show in frontal plane cross sections the esεential concept underlying thiε invention, the theoretically ideal stability plane, which is also theoretically ideal for efficient natural motion of all kinds, including running, jogging or walking. Fig. 25 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 thicknesε(es) in a fron¬ tal plane cross section, and, second, by the natural shape of the individual's foot surface 29. For the special case shown in Fig. 24, the theoretically ideal stability plane for any particular individual (or size average of individuals) is deter¬ mined, first, by the given frontal plane crosε εection shoe sole thickness(es) ; second, by the natural shape of the individual's foot; and, third, by the frontal plane crosε εection width of the individual'ε load-bearing footprint 30b, which iε defined as the upper surface of the shoe sole that is in physical contact with and εup- ports the human foot sole. The theoretically ideal stability plane for the special case iε compoεed conceptually of two partε. Shown in Fig. 24, the firεt part iε a line segment 31b of equal length and parallel to line 30b at a constant dis¬ tance(s) equal to shoe sole thickness. This corresponds to a conventional shoe sole directly underneath the human foot, and also corresponds to the flattened portion of the bottom of the load-bearing foot sole 28b. 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 thick¬ ness(es) from the closest point on the contoured side inner edge 30a. In summary, the theoretically ideal stability plane is the essence of this invention because it is uεed to determine a geometrically precise 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 εtated unequivocally that any εhoe 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. The theoretical ideal was taken to be that which is closeεt to natural. Fig. 26 illustrates in frontal plane croεε εec¬ tion another variation of the applicant'ε prior invention that uεes stabilizing quadrants 26 at the outer edge of a conventional shoe sole 28b illustrated generally at the reference numeral 28. The stabilizing quadrants would be abbreviated in actual embodiments. Fig. 28 showε that the thickneεε can also increase and then decreaεe; other thickneεε variation εequenceε are alεo poεεible. The variation in εide con¬ tour thickness in the new invention can be either symme¬ trical on both sides or asymmetrical, particularly with the medial side providing more stability than the lateral side, although many other asymmetrical variations are posεible, and the pattern of the right foot can vary from that of the left foot. Figε. 29, 30, 6 and 32 εhow that εimilar varia¬ tions in shoe midsole (other portions of the shoe sole area not shown) density can provide similar but reduced effects to the variations in shoe sole thickness described previously in Figs. 4, 5, 27 and 28. The major advantage of this approach iε that the structural theore¬ tically ideal stability plane is retained, so that natu¬ rally optimal stability and efficient motion are retained to the maximum extent possible. The forms of dual and tri-density midsoles shown in the figures are extremely common in the current art of running shoes, and any number of densities are theoretically possible, although an angled alternation of just two densities like that shown in Fig. 29 provides continually changing composite density. However, the applicant's prior invention did not prefer multi-densi- tieε in the midsole, since only a uniform denεity pro¬ videε a neutral εhoe εole deεign that doeε not interfere with natural foot and ankle biomechanics in the way that multi-density shoe soles do, which is by providing dif¬ ferent amounts of support to different parts of the foot; it did not, of course, preclude such multi-density mid- εoleε. In theεe figures, the density of the sole mater¬ ial designated by the legend (dl) is firmer than (d) while (d2) iε the firmest of the three representative densities shown. In Fig. 29, a dual density εole iε shown, with (d) having the lesε firm density. It should be noted that shoe soles using a combination both of sole thicknesses greater than the theoretically ideal stability plane and of midsole den¬ sities variations like those just described are also possible but not shown. In particular, it is anticipated that individu¬ als with overly rigid feet, those with restricted range of motion, and those tending to over-supinate may benefit from the Fig. 33 embodiments. Even more particularly, it is expected that the invention will benefit individualε with significant bilateral foot function asymmetry: namely, a tendency toward pronation on one foot and supination on the other foot. Consequently, it is antici¬ pated that this embodiment would be used only on the εhoe εole of the εupinating foot, and on the inεide portion only, possibly only a portion thereof. It is expected that the range less than the theoretically ideal stabil¬ ity plane would be a maximum of about five to ten per¬ cent, though a maximum of up to twenty-five percent may be beneficial to some individualε. Fig. 33A shows an embodiment like Figs. 4 and 28, but with naturally contoured sides less than the theoretically ideal stability plane. Fig. 33B showε an embodiment like the fully contoured deεign in Figs. 5 and 6, but with a shoe εole thickness decreasing with increasing diεtance from the center portion of the sole. Fig. 33C shows an embodiment like the quadrant-sided deεign of Fig. 31, but with the quadrant sides increas¬ ingly reduced from the theoretically ideal stability plane. The lesser-sided design of Fig. 33 would also apply to the Figs. 29, 30, 6 and 32 density variation approach and to the Fig. 8 approach using tread design to approximate density variation. Fig. 34 A-C show, in cross sections similar to those in pending U.S. Patent '349, that with the quad¬ rant-sided design of Figs. 26, 31, 32 and 33C that it is possible to have shoe sole sideε that are both greater and leεεer than the theoretically ideal εtability plane in the same shoe. The radius of an intermediate shoe sole thicknesε, taken at (S 2 ) at the base of the fifth metatarsal in Fig. 34B, is maintained constant throughout the quadrant sides of the shoe εole, including both the heel, Fig. 34C, and the forefoot, Fig. 34A, so that the side thickness is leεε than the theoretically ideal εta- bility plane at the heel and more at the forefoot. Though poεsible, this is not a preferred approach. The same approach can be applied to the naturally contoured sides or fully contoured designε deεcribed in Figε. 24, 25, 4, 5, 6, 8, and 27-30, but it iε also not preferred. In addition, is εhown in Figε. 34 D-F, in cross sectionε similar to those in pending U.S. Patent Application 07/239,667, it is possible to have shoe sole sides that are both greater and lesεer than the theoretically ideal stability plane in the same shoe, like Figs. 34A-C, but wherein the side thickness (or radius) is neither con¬ stant like Figs. 34A-C or varying directly with shoe sole thickness, like in the applicant's pending applications, but instead varying quite indirectly with shoe sole thicknesε. Aε εhown in Figs. 34D-F, the shoe sole side thickneεs varies from somewhat less than shoe sole thick¬ nesε at the heel to somewhat more at the forefoot. This approach, though possible, is again not preferred, and can be applied to the quadrant sided design, but is not preferred there either. Figs. 35-44 are Figs. 1-10 from the '302 appli¬ cation. Fig. 35 showε a perεpective view of a εhoe, εuch aε a typical athletic εhoe specifically for running, according to the prior art, wherein the running shoe 20 includes an upper portion 21 and a sole 22. Fig. 36 illustrateε, in a close-up crosε εec¬ tion of a typical εhoe of existing art (undeformed by body weight) on the ground 43 when tilted on the bottom outside edge 23 of the shoe sole 22, that an inherent stability problem remains in existing designε, even when the abnormal torque producing rigid heel counter and other motion deviceε are removed, as illustrated in Fig. 5 of pending U.S. Patent Application 07/400,714, filed on August 30, 1989, shown as Fig. 16 in this application. The problem is that the remaining εhoe upper 21 (εhown in the thickened and darkened line) , while providing no lever arm extension, since it is flexible instead of rigid, nonetheless creates unnatural destabilizing torque on the εhoe εole. The torque is due to the tension force 155a along the top surface of the shoe sole 22 caused by a compreεsion force 150 (a composite of the force of gravity on the body and a sidewayε motion force) to the side by the foot 27, due simply to the shoe being tilted to the side, for example. The resulting destabilizing force acts to pull the shoe sole in rotation around a lever arm 23a that is the width of the shoe sole at the edge. Roughly speaking, the force of the foot on the shoe upper pulls the shoe over on its side when the shoe is tilted sideways. The compression force 150 also cre¬ ates a tenεion force 155b, which is the mirror image of tension force 155a Fig. 37 shows, in a close-up cross section of a naturally contoured design shoe sole 28, described in pending U.S. Patent Application 07/239,667, filed on September 2, 1988, (also shown undeformed by body weight) when tilted on the bottom edge, that the same inherent stability problem remainε in the naturally contoured shoe sole design, though to a reduced degree. The problem iε lesε since the direction of the force vector 155 along the lower surface of the shoe upper 21 is parallel to the ground 43 at the outer sole edge 32 edge, instead of angled toward the ground as in a conventional design like that εhown in Fig. 36, εo the reεulting torque produced by lever arm created by the outer sole edge 32 would be less, and the contoured shoe εole 28 provides direct structural support when tilted, unlike conventional designs. Fig. 38 shows (in a rear view) that, in con¬ trast, the barefoot is naturally stable because, when deformed by body weight and tilted to its natural lateral limit of about 20 degrees, it does not create any desta¬ bilizing torque due to tension force. Even though ten¬ sion paralleling that on the shoe upper iε created on the outer εurface 29, both bottom and εides, of the bare foot by the compreεεion force of weight-bearing, no deεtabil- izing torque is created because the lower εurface under tension (i.e., the foot's bottom sole, shown in the dark¬ ened line) is resting directly in contact with the ground. Consequently, there is no unnatural lever arm artificially created against which to pull. The weight of the body firmly anchors the outer surface of the foot underneath the foot so that even considerable pressure against the outer surface 29 of the side of the foot resultε in no deεtabilizing motion. When the foot iε tilted, the supporting structures of the foot, like the calcaneus, slide against the side of the strong but flex¬ ible outer surface of the foot and create very substan¬ tial pressure on that outer surface at the sides of the foot. But that presεure iε precisely resisted and bal¬ anced by tension along the outer surface of the foot, resulting in a stable equilibrium. Fig. 39 εhows, in cross section of the upright heel deformed by body weight, the principle of the ten- sion stabilized sideε of the barefoot applied to the naturally contoured εhoe sole design; the same principle can be applied to conventional εhoeε, but iε not shown. The key change from the existing art of shoes is that the sideε of the shoe upper 21 (shown as darkened lines) muεt wrap around the outside edges 32 of the shoe sole 28, instead of attaching underneath the foot to the upper surface 30 of the shoe sole, as done conventionally. The shoe upper sideε can overlap and be attached to either the inner (εhown on the left) or outer surface (shown on the right) of the bottom sole, since those sides are not unusually load-bearing, as shown; or the bottom sole, optimally thin and tapering as shown, can extend upward around the outside edges 32 of the shoe sole to overlap and attach to the shoe upper sides (shown Fig. 39B) ; their optimal position coincides with the Theoretically Ideal Stability Plane, so that the tenεion force on the shoe sideε iε transmitted directly all the way down to the bottom shoe, which anchors it on the ground with virtually no intervening artificial lever arm. For shoes with only one sole layer, the attachment of the shoe upper sideε should be at or near the lower or bottom surface of the shoe εole. The design shown in Fig. 39 is based on a fun¬ damentally different conception: that the εhoe upper iε integrated into the εhoe εole, inεtead of attached on top of it, and the shoe sole is treated as a natural exten- sion of the foot sole, not attached to it separately. The fabric (or other flexible material, like leather) of the shoe uppers would preferably be non- stretch or relatively so, εo aε not to be deformed exces¬ sively by the tension place upon its sides when com- pressed as the foot and shoe tilt. The fabric can be reinforced in areas of particularly high tension, like the eεsential structural support and propulsion elements defined in the applicant's earlier applications (the base and lateral tuberoεity of the calcaneus, the base of the fifth metatarsal, the heads of the metatarsalε, and the first distal phalange) ; the reinforcement can take many forms, such as like that of corners of the jib sail of a racing sailboat or more simple strapε. Aε cloεely as possible, it should have the same performance character- isticε aε the heavily callouεed εkin of the sole of an habitually bare foot. The relative density of the shoe sole is preferred as indicated in Fig. 9 of pending U.S. Patent Application 07/400,714, filed on Auguεt 30, 1989, with the εofteεt denεity neareεt the foot εole, εo that the conforming sides of the shoe sole do not provide a rigid destabilizing lever arm. The change from existing art of the tension stabilized sides shown in Fig. 39 is that the shoe upper is directly integrated functionally with the εhoe εole, inεtead of εimply being attached on top of it. The advantage of the tenεion εtabilized εideε design is that it provides natural stability as close to that of the barefoot as possible, and does so economically, with the minimum shoe εole side width possible. The result is a shoe sole that is naturally stabilized in the same way that the barefoot is stabil¬ ized, as seen in Fig. 40, which shows a close-up cross section of a naturally contoured design shoe sole 28 (undeformed by body weight) when tilted to the edge. The same destabilizing force against the side of the shoe shown in Fig. 36 is now stably resisted by offsetting tension in the surface of the shoe upper 21 extended down the side of the εhoe sole so that it is anchored by the weight of the body when the shoe and foot are tilted. In order to avoid creating unnatural torque on the shoe sole, the shoe uppers may be joined or bonded only to the bottom sole, not the midsole, so that pres- sure shown on the side of the shoe upper produceε εide tenεion only and not the deεtabilizing torque from pull¬ ing εimilar to that deεcribed in Fig. 36. However, to avoid unnatural torque, the upper areaε 147 of the εhoe midεole, which forms a sharp corner, should be composed of relatively soft midsole material; in this caεe, bond¬ ing the εhoe uppers to the midsole would not create very much destabilizing torque. The bottom sole is preferably thin, at least on the stability sideε, so that its attachment overlap with the εhoe upper εideε coincide aε cloεe as possible to the Theoretically Ideal Stability Plane, so that force is tranεmitted on the outer shoe sole surface to the ground. In summary, the Fig. 39 design is for a shoe conεtruction, including: a εhoe upper that iε compoεed of material that is flexible and relatively inelastic at least where the shoe upper contacts the areas of the structural bone elements of the human foot, and a shoe sole that has relatively flexible sideε; and at leaεt a portion of the sides of the shoe upper being attached directly to the bottom sole, while enveloping on the outside the other sole portionε of εaid shoe sole. This construction can either be applied to convention shoe sole structures or to the applicant's prior shoe sole inventions, such aε the naturally contoured εhoe sole conforming to the theoretically ideal stability plane. Fig. 41 shows, in cross section at the heel, the tension stabilized sideε concept applied to naturally contoured deεign shoe sole when the shoe and foot are tilted out fully and naturally deformed by body weight (although constant shoe sole thickness is shown unde¬ formed) . The figure showε that the εhape and εtability function of the shoe sole and shoe uppers mirror almost exactly that of the human foot. Figs. 42A-42D show the natural cushioning of the human barefoot, in crosε εectionε at the heel. Fig. 42A shows the bare heel upright and unloaded, with little pressure on the subcalcaneal fat pad 158, which is evenly distributed between the calcaneus 159, which is the heel bone, and the bottom sole 160 of the foot. Fig. 42B shows the bare heel upright but under the moderate presεure of full body weight. The compres¬ εion of the calcaneus against the subcalcaneal fat pad produces evenly balanced presεure within the subcalcaneal fat pad because it is contained and surrounded by a rela¬ tively unstretchable fibrous capsule, the bottom εole of the foot. Underneath the foot, where the bottom εole iε in direct contact with the ground, the preεsure cauεed by the calcaneuε on the compreεεed εubcalcaneal fat pad iε tranεmitted directly to the ground. Simultaneouεly, substantial tension is created on the sides of the bottom sole of the foot because of the surrounding relatively tough fibrous capsule. That combination of bottom preε- εure and εide tension is the foot's natural shock absorp¬ tion system for support structures like the calcaneus and the other boneε of the foot that come in contact with the ground. Of equal functional importance iε that lower εurface 167 of thoεe εupport εtructures of the foot like the calcaneus and other bones make firm contact with the upper surface 168 of the foot's bottom sole underneath, with relatively little uncompresεed fat pad intervening. In effect, the εupport εtructureε of the foot land on the ground and are firmly εupported; they are not εuspended on top of springy material in a buoyant manner analogous to a water bed or pneumatic tire, like the existing pro¬ prietary shoe sole cushioning εyεtems like Nike Air or Asics Gel. This simultaneously firm and yet cushioned support provided by the foot sole must have a signifi¬ cantly beneficial impact on energy efficiency, also called energy return, and is not paralleled by existing shoe designs to provide cushioning, all of which provide shock absorption cushioning during the landing and sup¬ port phases of locomotion at the expense of firm support during the take-off phase. The incredible and unique feature of the foot's natural system is that, once the calcaneus is in fairly direct contact with the bottom εole and therefore provid¬ ing firm support and stability, increaεed pressure pro¬ duces a more rigid fibrous capsule that protects the calcaneuε and greater tenεion at the εideε to abεorb shock. So, in a senεe, even when the foot'ε suspension system would seem in a conventional way to have bottomed out under normal body weight pressure, it continues to react with a mechanism to protect and cushion the foot even under very much more extreme preεεure. Thiε iε εeen in Fig. 42C, which εhowε the human heel under the heavy pressure of roughly three times body weight force of landing during routine running. This can be easily veri¬ fied: when one stands barefoot on a hard floor, the heel feels very firmly supported and yet can be lifted and virtually slammed onto the floor with little increase in the feeling of firmnesε; the heel simply becomes harder as the pressure increaseε. In addition, it εhould be noted that thiε εys¬ tem allowε the relatively narrow baεe of the calcaneus to pivot from side to side freely in normal pronation/ supination motion, without any obstructing torsion on it, despite the very much greater width of compressed foot sole providing protection and cushioning; this is cru¬ cially important in maintaining natural alignment of joints above the ankle joint such as the knee, hip and back, particularly in the horizontal plane, εo that the entire body is properly adjusted to absorb shock cor¬ rectly. In contrast, existing shoe sole deεignε, which are generally relatively wide to provide stability, pro¬ duce unnatural frontal plane torsion on the calcaneus, restricting its natural motion, and causing misalignment of the joints operating above it, resulting in the over- use injuries unusually common with such shoeε. Instead of flexible sideε that harden under tenεion cauεed by pressure like that of the foot, existing shoe sole designs are forced by lack of other alternatives to use relatively rigid sideε in an attempt to provide εuffi- cient εtability to offεet the otherwise uncontrollable buoyancy and lack of firm support of air or gel cushions. Fig. 42D shows the barefoot deformed under full body weight and tilted laterally to the roughly 20 degree limit of normal range. Again it is clear that the natu- ral system provides both firm lateral support and stabil¬ ity by providing relatively direct contact with the ground, while at the same time providing a cushioning mechaniεm through side tension and subcalcaneal fat pad preεsure. Figs. 43A-D show Figs. 9B-D of the '302 appli¬ cation, in addition to Fig. 9 of this application. While the Fig. 9 and Fig. 43 design copies in a simplified way the macro structure of the foot. Figs. 44 [10] A-C focus on a more on the exact detail of the natu- ral structures, including at the micro level. Figs. 44A and 44C are perspective views of cross εectionε of the human heel εhowing the matrix of elastic fibrous connec¬ tive tissue arranged into chambers 164 holding closely packed fat cells; the chambers are structured aε whorlε radiating out from the calcaneuε. Theεe fibrouε-tissue strands are firmly attached to the undersurface of the calcaneus and extend to the εubcutaneouε tissues. They are usually in the form of the letter U, with the open end of the U pointing toward the calcaneus. As the most natural, an approximation of this specific chamber structure would appear to be the most optimal as an accurate model for the εtructure of the εhoe εole cuεhioning compartmentε 161, at leaεt in an ultimate sense, although the complicated nature of the design will require some time to overcome exact design and construction difficulties; however, the description of the structure of calcaneal padding provided by Erich Blechschmidt in Foot and Ankle. March 1982 (translated from the original 1933 article in German) , is so detailed and comprehensive that copying the same structure as a model in shoe sole design is not difficult technically, once the crucial connection is made that such copying of this natural syεtem is necessary to overcome inherent weaknesses in the design of existing shoeε. Other arrangementε and orientationε of the whorlε are possible, but would probably be leεε optimal. Purεuing thiε nearly exact deεign analogy, the lower εurface 165 of the upper midεole 147 would corre¬ spond to the outer surface 167 of the calcaneus 159 and would be the origin of the U shaped whorl chamberε 164 noted above. Fig. 44B shows a cloεe-up of the interior structure of the large chambers shown in Fig. 44A and 44C. It is clear from the fine interior structure and compression characteristics of the mini-chambers 165 that those directly under the calcaneus become very hard quite easily, due to the high local presεure on them and the limited degree of their elaεticity, so they are able to provide very firm support to the calcaneus or other bones of the foot εole; by being fairly inelaεtic, the compreε¬ sion forceε on thoεe compartmentε are dissipated to other areas of the network of fat pads under any given support structure of the foot, like the calcaneus. Consequently, if a cushioning compartment 161, such aε the compartment under the heel εhown in Figs. 9 & 43, is subdivided into εmaller chambers, like those εhown in Fig. 44, then actual contact between the upper εurface 165 and the lower εurface 166 would no longer be required to provide firm εupport, εo long as those compartments and the pres¬ sure-transmitting medium contained in them have material characteristicε similar to thoεe of the foot, aε described above; the use of gas may not be satisfactory in this approach, εince its compresεibility may not allow adequate firmness. In summary, the Fig. 44 design showε a shoe construction including: a shoe sole with a compartments under the structural elements of the human foot, includ¬ ing at least the heel; the compartments containing a pressure-transmitting medium like liquid, gas, or gel; the compartments having a whorled structure like that of the fat pads of the human foot εole; load-bearing preε¬ εure being transmitted progresεively at leaεt in part to the relatively inelastic sides, top and bottom of the shoe sole compartments, producing tension therein; the elasticity of the material of the compartmentε and the preεεure-tranεmitting medium are εuch that normal weight- bearing loadε produce εufficient tenεion within the εtructure of the compartmentε to provide adequate struc- tural rigidity to allow firm natural εupport to the foot εtructural elementε, like that provided the barefoot by itε fat pads. That shoe sole construction can have shoe εole compartments that are subdivided into micro chambers like those of the fat pads of the foot sole. Since the bare foot that is never shod is pro¬ tected by very hard callouses (called a "seri boot") which the εhod foot lacks, it seemε reasonable to infer that natural protection and shock absorption system of the shod foot is adversely affected by its unnaturally undeveloped fibrous capsuleε (εurrounding the εubcalcan- eal and other fat padε under foot bone εupport struc- tures) . A solution would be to produce a shoe intended for uεe without socks (i.e., with smooth surfaceε above the foot bottom sole) that uses insoles that coincide with the foot bottom sole, including its sideε. The upper εurface of thoεe inεoleε, which would be in contact with the bottom εole of the foot (and itε εides) , would be coarse enough to stimulate the production of natural barefoot callouses. The insoles would be removable and available in different uniform grades of coarseness, as is sandpaper, so that the user can progress from finer grades to coarser grades as his foot soles toughen with use. Similarly, socks could be produced to serve the same function, with the area of the sock that corresponds to the foot bottom sole (and εideε of the bottom εole) made of a material coarse enough to stimulate the produc¬ tion of callouses on the bottom sole of the foot, with different grades of coarseness available, from fine to coarse, corresponding to feet from soft to naturally tough. Using a tube sock design with uniform coarseness, rather than conventional sock design assumed above, would allow the user to rotate the sock on his foot to elimi¬ nate any "hot spot" irritation points that might develop. Also, since the toes are most prone to bliεtering and the heel is most important in shock absorption, the toe area of the sock could be relatively lesε abrasive than the heel area. The following Figures 45-58 were new with the continuation-in-part applications Serial No. 462,531 filed June 5, 1995, and Serial No. 472,979 filed June 7, 1995. Fig. 45 iε new in the continuation-in-part application, but iε εimilar to Fig. 4 from the appli- cant'ε copending U.S. Patent Application 07/416,478, filed October 3, 1989, and deεcribed above. Fig. 45A illuεtrateε, in frontal or transverse plane crosε section in the heel area, the applicant's new invention of shoe sole side thickness increasing beyond the theoretically ideal stability plane to increase stability εomewhat beyond itε natural level. The unavoidable trade-off reεulting iε that natural motion would be reεtricted εomewhat and the weight of the εhoe εole would increaεe εomewhat. For purpoεeε of illustration, the right side of Fig. 45A shows roughly a 50 percent thickness increase over the theoretically ideal stability plane 51 and the left side showε roughly a 100 percent increaεe. Fig. 45B εhows the same modifications to a forefoot εection of the shoe sole, where such extreme thickness variations are considered more practical and effective. Fig. 45 shows a situation wherein the thicknesε of the sole at each of the opposed εideε iε thicker at the portionε of the sole 31a by a thickness which gradu¬ ally varies continuously from a thickness (s) through a thickness (s+sl) , to a thickneεs (s+s2) . Theεe deεigns recognize that lifetime use of existing shoes, the design of which has an inherent flaw that continually disrupts natural human biomechanics, has produced thereby actual structural changes in a human foot and ankle to an extent that must be compensated for. Specifically, one of the most common of the abnormal effects of the inherent existing flaw is a weakening of the long arch of the foot, increasing pronation. These designs therefore modify the applicant's preceding designs to provide greater than natural stability and should be particularly useful to individuals, generally with low arches, prone to pronate excesεively, and could be used only on the medial side. Similarly, individuals with high arches and a tendency to over supinate and lateral ankle sprainε would alεo benefit, and the deεign could be uεed only on the lateral side. A shoe for the general population that compenεateε for both weaknesses in the same εhoe would incorporate the enhanced εtability of the deεign compenεation on both εideε. The new design in Fig. 45 (like Figs. 1 and 2 of the '478 application) allows the shoe sole to deform naturally closely paralleling the natural deformation of the barefoot under load; in addition, shoe sole material muεt be of εuch compoεition as to allow the natural deformation following that of the foot. The new designs retain the essential novel aspect of the earlier designε; namely, contouring the εhape of the εhoe εole to the εhape of the human foot. The difference iε that the εhoe εole thickneεε in the frontal plane is allowed to vary rather than remain uni¬ formly constant. More specifically, Fig. 45 (and Figs. 5, 6, 7, and 11 of the '478 application) show, in frontal plane cross sections at the heel, that the shoe sole thicknesε can increaεe beyond the theoretically ideal stability plane 51, in order to provide greater than natural stability. Such variations (and the following variations) can be consistent through all frontal plane cross εectionε, εo that there are proportionately equal increases to the theoretically ideal stability plane 51 from the front of the shoe sole to the back, or that the thicknesε can vary, preferably continuously, from one frontal plane to the next. The exact amount of the increase in shoe sole thicknesε beyond the theoretically ideal εtability plane is to be determined empirically. Ideally, right and left shoe soleε would be cuεtom designed for each individual based on an biomechanical analysiε of the extent of his or her foot and ankle disfunction in order to provide an optimal individual correction. If epidemiological stud¬ ies indicate general corrective patterns for εpecific categorieε of individuals or the population as a whole, then masε-produced corrective εhoeε with εoleε incorpo¬ rating contoured sides exceeding the theoretically ideal εtability plane would be poεεible. Reεearch in the a newly developing εcientific field, theoretical human anatomy, indicates unexpected results that the extent of human anatomical structural deformity due to the adverse biomechanical performance of existing footwear is εignificantly more substantial than might be expected and extends to skeletal, muscular, and other human structures beyond the foot and ankle joint. It appears that knee, hip, and lower back are directly affected, with the entire spinal column thus also affected, and therefore indeed most of the rest of the human body affected as well. As a consequence of careful review of the implications for shoe sole design based on this surpriε- ing discovery, maεs-produced corrective shoes for the general population, in some caεeε, would require unex¬ pectedly the use of contoured side portion thicknesεeε exceeding the theoretically ideal εtability plane by an amount aε much as 26 percent to 50 percent, preferably at least in that part of the contoured side which becomes load-bearing under a wearer's body weight during the full range of foot inversion and eversion, which is sideways or lateral foot motion. It is also apparent that some more specific groups or individuals with more severe disfunction could have an empirically demonεtrated need for greater corrective thicknesseε of the contoured εide portion on the order of 51 to 100 percent more than the theoretically ideal stability plane, again, preferably at least in that part of the contoured side which becomes wearer's body weight load-bearing during the full range of inversion and eversion, which is sideways or lateral foot motion. The optimal contour for the increased con¬ toured side thickness may also be determined empirically. In addition, these extreme modificationε of the theoretically ideal εtability plane result in shoe εole embodimentε with better biomechanical performance in termε of εtability and freedom of motion, and comfort, than existing shoeε, even for individual wearerε with completely normal anatomical εtructure. Aε described in the earlier '478 Application, in its simplest conceptual form, the applicant's Fig. 4 and this new Fig. 45 invention are the structure of a conventional shoe sole that has been modified by having its sides bent up so that their inner surface conforms to a shape of the outer surface of the foot sole of the wearer (instead of the shoe sole sides conforming to the ground by paralleling it, as iε conventional) ; thiε con¬ cept is like that described in Fig. 3 of the applicant's 07/239,667 application. For the applicant's fully con¬ toured design described in Fig. 15 of the '667 applica¬ tion, the entire shoe sole — including both the sideε and the portion directly underneath the foot — is bent up to conform to a shape nearly identical but slightly smaller than the contoured shape of the unloaded foot sole of the wearer, rather than the partially flattened load-bearing foot sole shown in Fig. 45. This theoretical or conceptual bending up must be accomplished in practical manufacturing without any of the puckering distortion or deformation that would neces¬ sarily occur if such a conventional shoe sole were actu¬ ally bent up simultaneously along all of itε the sides; consequently, manufacturing techniques that do not require any bending up of shoe εole material, εuch aε injection molding manufacturing of the εhoe sole, would be required for optimal resultε and therefore iε prefera¬ ble. It is critical to the novelty of this funda¬ mental concept that all layers of the shoe sole in Fig. 45 are bent up around the foot sole. A small number of both street and athletic εhoe εoleε that are commercially available are naturally contoured to a limited extent in that only their bottom εoles, which are about one quarter to one third of the total thickneεε of the entire εhoe εole, are wrapped up around portionε of the wearers' foot soleε; the midsole and heel lift (or heel) of such shoe soles, constituting over half of the thickneεε of the entire shoe sole, remains flat, conforming to the ground rather than the wearers' feet. (At the other extreme, some shoes in the existing art have flat midsoles and bottom soles, but have insoles that conform to the wear¬ er's foot sole. ) Consequently, in existing contoured shoe soles, the total shoe sole thickness of the contoured side por¬ tions, including every layer or portion, is much lesε than the total thickness of the sole portion directly underneath the foot, whereas in the applicant's '478 shoe sole invention the shoe εole thickneεε of the contoured εide portionε are at leaεt εimilar to the thickneεε of the sole portion directly underneath the foot, meaning a thicknesε variation of up to 25 percent, as measured in frontal or transverεe plane croεε sections. New Fig. 45 of thiε continuation-in-part appli¬ cation explicitly defineε thoεe thickneεε variationε, as measured in frontal or transverse plane crosε sections, of the applicant's shoe soles from 26 percent up to 50 percent, which distinguishes over all known prior art. In addition, for εhoe sole thickness deviating outwardly in a constructive way from the theoretically ideal stability plane, the shoe sole thicknesε variation of the applicant'ε εhoe soles is increased in this appli¬ cation from 51 percent to 100 percent, as measured in frontal or transverse plane crosε sections. The Fig. 45 invention, and all previous and following figures included in this application, can be used at any one, or combination including all, of the essential structural support and propulεion elements defined in the '819 patent. Those elements are the base and lateral tuberosity of the calcaneus, the heads of the metatarsalε, and the base of the fifth metatarsal, and the head of the first diεtal phalange, reεpectively. Of the metatarsal heads, only the first and fifth metatarsal heads are proximate to the contoured shoe εole sides. This major and conspicuous structural differ- ence between the applicant's underlying concept and the existing shoe εole art is paralleled by a similarly dra¬ matic functional difference between the two: the afore¬ mentioned εimilar thickness of the applicant's shoe sole invention maintains intact the firm lateral stability of the wearer's foot, as demonεtrated when the foot iε unεhod and tilted out laterally in inverεion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a εimilar demonεtration in a con¬ ventional εhoe sole, the wearer's foot and ankle are unstable. The sides of the applicant's shoe sole inven¬ tion extend sufficiently far up the εides of the wearer's foot sole to maintain the lateral stability of the wear¬ er's foot when bare. In addition, the applicant's shoe sole inven¬ tion maintains the natural stability and natural, unin¬ terrupted motion of the wearer's foot when bare through¬ out its normal range of sideways pronation and supination motion occurring during all load-bearing phases of loco¬ motion of the wearer, including when the wearer is stand¬ ing, walking, jogging and running, even when said foot is tilted to the extreme limit of that normal range, in con¬ trast to unεtable and inflexible conventional shoe soleε, including the partially contoured existing art described above. The εideε of the applicant'ε shoe sole invention extend εufficiently far up the εides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact thick- ness of the shoe sole sides and their specific contour will be determined empirically for individuals and groups using εtandard biomechanical techniques of gait analysis to determine those combinationε that beεt provide the barefoot εtability described above. For the Fig. 45 shoe sole invention, the amount of any shoe sole side portions coplanar with the theore¬ tically ideal stability plane 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 intact the firm stability of the wearer's foot throughout the range of foot inversion and eversion motion typical of the uεe for which the εhoe iε intended and also typical of the kind of wearer — such as normal or excessive pronator — for which said shoe is intended. In general, the applicant's preferred shoe εole embodimentε include the structural and material flexibil¬ ity to deform in parallel to the natural deformation of the wearer's foot sole as if it were bare and unaffected by any of the abnormal foot biomechanics created by rigid conventional shoe sole. At the same time, the applicant's preferred shoe sole embodiments are sufficiently firm to provide the wearer's foot with the structural support necesεary to maintain normal pronation and supination, as if the wearer's foot were bare; in contrast, the excessive soft- neεε of many of the shoe sole materials used in shoe soleε in the existing art cauεe abnormal foot pronation and εupination. Aε mentioned earlier regarding Fig. IA, the applicant has previously shown heel lifts with constant frontal or transverεe plane thickneεε, since it is ori¬ ented conventionally in alignment with the frontal or transverse plane and perpendicular to the long axis of the shoe sole. However, the heel wedge (or toe taper or other shoe sole thickness variations in the sagittal plane along the long axis of the shoe sole) can be loca¬ ted at an angle to the conventional alignment in the Fig. 45 design. For example, the heel wedge can be located perpendicular to the subtalar axis, which iε located in the heel area generally about 20 to 25 degreeε medially, although a different angle can be uεed baεe on individual or group teεting; such a orientation may provide better, more natural support to the εubtalar joint, through which critical pronation and εupination motion occur. The applicant's theoretically ideal stability plane concept would teach that such a heel wedge orientation would require constant shoe sole thickneεs in a vertical plane perpendicular to the chosen subtalar joint axiε, inεtead of the frontal plane. In addition, any of the above described thick¬ nesε variations from a theoretically ideal stability plane can be used together with any of the below described density or bottom sole design variations. All portionε of the εhoe εole are included in thickneεε and density measurement, including the εockliner or insole, the midsole (including heel lift or other thickness vari- ation measured in the sagittal plane) and bottom or outer sole. The above described thickness of Fig. 45 and below described thickness and density variations apply to the load-bearing portions of the contoured sideε of the applicant's shoe sole inventions, the side portion being identified in Fig. 4 of the '819 patent. Thicknesε and density variations described above are measured along the contoured side portion. The side portion of the fully contoured design introduced in the '819 patent in Fig. 15 cannot be defined as explicitly, since the bottom portion is contoured like the sides, but should be meaεured by estimating the equivalent Fig. 4 figure; generally, like Figs. 14 and Fig. 15 of the '819 patent, assuming the flattened sole portion shown in Fig. 14 corresponds to a load-bearing equivalent of Fig. 15, so that the contoured sides of Figs. 14 and Fig. 15 are esεentially the same. Alternately, the thickness and density varia¬ tions described above can be measured from the center of the esεential structural support and propulεion elementε defined in the '819 patent. Thoεe elements are the base and lateral tuberosity of the calcaneus, the heads of the metatarsalε, and the baεe of the fifth metatarεal, and the head of the first distal phalange, respectively. Of the metatarsal heads, only the first and fifth metatarsal heads are used for such measurement, since only those two are located on lateral portions of the foot and thuε proximate to contoured εtability εideε of the applicant'ε εhoe εole. Fig. 46 iε εimilar to Fig. 5 in the applicant'ε copending U.S. Patent Application 07/416,478, but includ¬ ing the shoe sole thickness variations as described in Fig. 45 above. Fig. 46 showε, in frontal or tranεverεe plane croεε εection in the heel area, a variation of the enhanced fully contoured design wherein the shoe sole begins to thicken beyond the theoretically ideal stabil¬ ity plane 51 at the contoured sides portion, preferably at least in that part of the contoured side which becomes wearer's body weight load-bearing during the full range of inversion and eversion, which is εideways or lateral foot motion. For purposeε of illuεtration, the right εide of Fig. 46 εhows roughly a 50 percent thickneεε increaεe over the theoretically ideal stability plane 51 and the left side showε roughly a 100 percent increase. Fig. 47 is similar to Fig. 6 of the parent '598 application, which is Fig. 10 in the applicant's copendi¬ ng '478 application and shows, in frontal or transverεe plane crosε section in the heel area, that similar varia¬ tions in shoe midεole (other portions of the shoe sole area not shown) density can provide similar but reduced effects to the variations in shoe sole thickness described previously in Figε. 4 and 5. The major advan- tage of thiε approach iε that the structural theoreti¬ cally ideal stability plane is retained, so that natu¬ rally optimal εtability and efficient motion are retained to the maximum extent possible. The more extreme con¬ structive density variations of Fig. 47 are, as most typically measured in durometers on a Shore A scale, to include from 26 percent to 50 percent and from 51 percent up to 200 percent. The denεity variations are located preferably at least in that part of the contoured side which becomes wearer's body weight load-bearing during the full range of inversion and everεion, which iε εide¬ wayε or lateral foot motion. The '478 application εhowed midεole only, since that is where material density variation has historically been most common. Denεity variations can and do, of course, also occur in other layers of the shoe sole, such as the bottom sole and the inner sole, and can occur in any combination and in symmetrical or asymmetrical pat¬ terns between layerε or between frontal or tranεverεe plane cross sectionε. The major and conεpicuous structural difference between the applicant'ε underlying concept and the exiεt¬ ing shoe sole art is paralleled by a εimilarly dramatic functional difference between the two: the aforementioned similar thicknesε of the applicant's shoe sole invention maintains intact the firm lateral stability of the wear¬ er's foot, as demonstrated when the foot is unεhod and tilted out laterally in inverεion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a similar demonstration in a conventional shoe sole, the wearer's foot and ankle are unstable. The sides of the applicant's shoe sole invention extend suf¬ ficiently far up the sides of the wearer's foot sole to maintain the lateral stability of the wearer's foot when bare. In addition, the applicant's shoe sole inven¬ tion maintains the natural εtability and natural, unin¬ terrupted motion of the wearer'ε foot when bare through- out its normal range of sideways pronation and supination motion occurring during all load-bearing phases of loco¬ motion of the wearer, including when the wearer is stand¬ ing, walking, jogging and running, even when said foot is tilted to the extreme limit of that normal range, in con- trast to unstable and inflexible conventional shoe εoleε, including the partially contoured exiεting art deεcribed above. The sides of the applicant'ε εhoe εole invention extend εufficiently far up the sides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact mate¬ rial density of the shoe sole sides will be determined empirically for individuals and groupε using standard biomechanical techniques of gait analysis to determine those combinations that beεt provide the barefoot stabil- ity deεcribed above. For the Fig. 47 εhoe εole invention, the amount of any εhoe εole side portions coplanar with the theore¬ tically ideal εtability plane iε determined by the degree of εhoe εole stability desired and the shoe sole weight and bulk required to provide said stability; the amount of said coplanar contoured sideε that is provided said shoe sole being sufficient to maintain intact the firm stability of the wearer's foot throughout the range of - Ill - foot inversion and eversion motion typical of the use for which the shoe is intended and alεo typical of the kind of wearer — such as normal or excesεive pronator — for which said shoe is intended. In general, the applicant's preferred shoe sole embodiments include the structural and material flexibil¬ ity to deform in parallel to the natural deformation of the wearer's foot sole as if it were bare and unaffected by any of the abnormal foot biomechanics created by rigid conventional shoe sole. At the same time, the applicant's preferred shoe sole embodiments are sufficiently firm to provide the wearer's foot with the structural support necesεary to maintain normal pronation and εupination, aε if the wearer's foot were bare; in contrast, the excessive soft¬ neεε of many of the εhoe sole materials used in shoe soles in the existing art cause abnormal foot pronation and supination. As mentioned earlier regarding Fig. IA, the applicant has previously shown heel lifts with constant frontal or transverse plane thickness, since it iε ori¬ ented conventionally in alignment with the frontal or tranεverεe plane and perpendicular to the long axis of the shoe sole. However, the heel wedge (or toe taper or other shoe sole thicknesε variationε in the sagittal plane along the long axis of the shoe sole) can be loca¬ ted at an angle to the conventional alignment in the Fig. 4 design. For example, the heel wedge can be located perpendicular to the subtalar axiε, which iε located in the heel area generally about 20 to 25 degrees medially, although a different angle can be used base on individual or group testing; εuch a orientation may provide better, more natural εupport to the εubtalar joint, through which critical pronation and εupination motion occur. The applicant'ε theoretically ideal εtability plane concept would teach that εuch a heel wedge orientation would require constant shoe sole thickness in a vertical plane perpendicular to the chosen subtalar joint axis, instead of the frontal plane. Fig. 48 is similar to Fig. 7 of the parent '598 application, but with more the extreme thicknesε varia- tion similar to Fig. 45 above. Fig. 48 is like Fig. 7, which is Fig. 14B of the applicant's '478 application and shows, in frontal or transverse plane cross sections in the heel area, embodiments like those in Fig. 4 through 6 but wherein a portion of the shoe sole thickness is decreased to less than the theoretically ideal stability plane, the amount of the thicknesε variation aε defined for Fig. 45 above, except that the moεt extreme maximum inwardly variation is 41 to 50 percent, and the more typical maximum inwardly thickness variation would be 26 to 40 percent, preferably at least in that part of the contoured side which becomes wearer's body weight load- bearing during the full range of inversion and eversion, which is sideways or lateral foot motion. For purposeε of illustration, the right side of Fig. 48 εhowε a thick- neεε reduction of approximately 40 percent and the left side a reduction of approximately 50 percent. It is anticipated that some individuals with foot and ankle biomechanics that have been degraded by existing shoes may benefit from εuch embodimentε, which would provide leεε than natural εtability but greater freedom and motion, and leεε εhoe εole weight and bulk. Fig. 7 εhowε a embodiment like the fully contoured deεign in Fig. 5, but with a show sole thicknesε decreaεing with increasing distance from the center portion of the sole. Fig. 49 iε similar to Fig. 8 of the parent '598 application which was Fig. 13 of the '478 application and shows, in frontal or transverεe plane cross section, a bottom sole tread design that provides about the same overall shoe εole denεity variation as that provided in Fig. 6 by midsole density variation. The less supporting tread there iε under any particular portion of the shoe sole, the less effective overall shoe density there is, since the midsole above that portion will deform more easily than if it were fully supported. Fig. 49 shows more extreme shoe sole tread design, roughly equivalent to the structural changes in shoe sole thicknesε and/or denεity deεcribed in Figs. 45-48 above. Fig. 49, like Fig. 8 from the '478, is illus¬ trative of the applicant's point that bottom sole tread patterns, just like midεole or bottom sole or inner sole density, directly affect the actual structural support the foot receives from the shoe sole. Not εhown, but a typical example in the real world, is the popular "center of presεure" tread pattern, which iε like a backward horεeshoe attached to the heel that leaves the heel area directly under the calcaneus unsupported by tread, so that all of the weight bearing load in the heel area is transmitted to outside edge treads. Variationε of thiε pattern are extremely common in athletic shoes and are nearly universal in running shoes, of which the 1991 Nike 180 model and the Avia "cantilever" serieε are exampleε. Like the applicant'ε '478 shoe sole invention, the Fig. 49 invention can, therefore, utilize bottom sole tread patterns like any these common examples, together or even in the absence of any other shoe sole thickness or density variation, to achieve an effective thickneεε greater than the theoretically ideal stability plane, in order to achieve greater stability than the shoe sole would otherwiεe provide, aε diεcussed earlier under Figε. 4-6. Since shoe bottom or outer sole tread patternε can be fairly irregular and/or complex and can thus make difficult the measurement of the outer load-bearing sur¬ face of the shoe sole. Consequently, thicknesε varia¬ tionε in εmall portions of the shoe sole that will deform or compreεs without significant overall resistance under a wearer's body weight load to the thicknesε of the over- all load-bearing plane of the shoe out sole should be ignored during measurement, whether εuch eaεy deformation iε made poεεible by very high point preεεure or by the use of relatively compresεible outsole (or underlying midsole) materials. Portions of the outsole bottom surface composed of materials (or made of a delicate structure, much like the small raised markers on new tire treads to prove the tire is brand new and unuεed) that wear relatively quickly, so that thickness variations that exist when the shoe sole is new and unused, but disappear quickly in use, should also be ignored when measuring shoe sole thickness in frontal or transverse plane cross sectionε. Similarly, midεole thickneεs variations of unused εhoe εoles due to the use of materials or structures that compact or expand quickly after use should also be ignore when meaεuring εhoe sole thicknesε in frontal or tranε- verse plane crosε sectionε. The applicant's shoe εole invention maintains intact the firm lateral stability of the wearer's foot, that stability as demonstrated when the foot is unshod and tilted out laterally in inversion to the extreme limit of the normal range of motion of the ankle joint of the foot. The sides of the applicant's shoe sole inven¬ tion extend sufficiently far up the sideε of the wearer's foot sole to maintain the lateral εtability of the wear¬ er's foot when bare. In addition, the applicant's shoe sole inven¬ tion maintains the natural stability and natural, unin¬ terrupted motion of the wearer's foot when bare through¬ out its normal range of εidewayε pronation and supination motion occurring during all load-bearing phases of loco- motion of the wearer, including when the wearer is stand¬ ing, walking, jogging and running, even when the foot is tilted to the extreme limit of that normal range, in contrast to unstable and inflexible conventional εhoe soles, including the partially contoured existing art described above. The εides of the applicant's shoe εole invention extend εufficiently far up the εides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact thickness and material density of the bottom sole tread, as well as the shoe sole sides and their specific contour, will be determined empirically for individuals and groups uεing standard biomechanical techniques of gait analysiε to determine those combinations that best provide the barefoot stability described above. Fig. 50 iε similar to Fig. 10, which was new with the '598 application and which was a combination of the shoe sole structure concepts of Fig. 3 and Fig. 4; it combines the custom fit design with the contoured sideε greater than the theoretically ideal εtability plane. It would apply aε well to the Fig. 7 design with contoured sideε leεs than the theoretically ideal stability plane, but that combination is not εhown. It would alεo apply to the Fig. 8 design, which shows one of a typical bottom sole tread designε, but that combination iε alεo not εhown. In the continuation-in-part applicationε Serial No. 462,531 filed June 5, 1995, and Serial No. 472,979 filed June 7, 1995, the uεe of thiε invention with other¬ wise conventional shoes with a side sole portion of any thickness, including contoured sides with uniform or any other thicknesε variation or density variation, including bottom sole tread variation, especially including those defined above and below by the applicant, is further clarified. For purposes of illustration, the right side of Fig. 50 shows a shoe εole thickneεε increase variation of nearly 50 percent, while the left side showε a thick¬ neεs reduction of about over 60 percent. While the Fig. 3 custom fit invention iε novel for shoe sole structures as defined by the theoretically ideal stability plane, which specifies constant shoe sole thickness in frontal or transverse plane, the Fig. 3 cus¬ tom fit invention is also novel for shoe sole structures with sides that exceed the theoretically ideal stability plane: that is, a εhoe sole with thicknesε greater in the εides than underneath the foot. It would also be novel for shoe sole structures with sides that are less than the theoretically ideal stability plane, within the para¬ meters defined in the '714 application. And it would be novel for a shoe sole structure that provides stability like the barefoot, as described in Figs. 1 and 2 of the '714 application. In its simplest conceptual form, the appli¬ cant's invention is the structure of a conventional shoe sole that has been modified by having its sides bent up so that their inner surface conforms to a shape nearly identical but slightly smaller than the shape of the outer surface of the foot sole of the wearer (instead of the shoe sole sides conforming to the ground by parallel¬ ing it, as is conventional) ; this concept is like that described in Fig. 3 of the applicant's 07/239,667 appli- cation. For the applicant'ε fully contoured design described in Fig. 15 of the '667 application, the entire shoe sole — including both the sideε and the portion directly underneath the foot — iε bent up to conform to a shape nearly identical but slightly smaller than the contoured shape of the unloaded foot sole of the wearer, rather than the partially flattened load-bearing foot sole shown in Fig. 3. This theoretical or conceptual bending up must be accomplished in practical manufacturing without any of the puckering distortion or deformation that would neces¬ sarily occur if such a conventional shoe sole were actu¬ ally bent up simultaneously along all of its the sides; consequently, manufacturing techniques that do not require any bending up of shoe sole material, such as injection molding manufacturing of the shoe sole, would be required for optimal reεultε and therefore iε prefer¬ able. It iε critical to the novelty of thiε fundamen¬ tal concept that all layers of the shoe sole are bent up around the foot εole. A εmall number of both street and athletic shoe soleε that are commercially available are naturally contoured to a limited extent in that only their bottom εoles, which are about one quarter to one third of the total thicknesε of the entire εhoe εole, are wrapped up around portionε of the wearers' foot soleε; the midεole and heel lift (or heel) of such shoe soles, constituting over half of the thickness of the entire shoe sole, remains flat, conforming to the ground rather than the wearers' feet. (At the other extreme, some shoes in the existing art have flat midsoleε and bottom soles, but have insoles that conform to the wearer's foot sole.) Consequently, in existing contoured shoe soles, the total shoe sole thicknesε of the contoured εide por¬ tions, including every layer or portion, is much less than the total thickness of the sole portion directly underneath the foot, whereas in the applicant's prior shoe sole inventions the shoe sole thickness of the con¬ toured side portions are at least similar to the thick¬ neεε of the εole portion directly underneath the foot, meaning a thickneεs variation of up to either 50 percent or 100 percent or regardleεε of contoured εide thickneεε εo long aε side of some thicknesε conforms or is at least complementary to the shape of the wearer's foot sole when the εhoe εole is on the wearer's foot sole, as measured in frontal or transverεe plane cross sectionε. This major and conspicuous structural differ- ence between the applicant's underlying concept and the existing shoe εole art iε paralleled by a similarly dra¬ matic functional difference between the two: the afore¬ mentioned similar thicknesε of the applicant'ε εhoe εole invention maintains intact the firm lateral stability of the wearer's foot, that stability as demonstrated when the wearer's foot is unshod and tilted out laterally in inversion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a similar dem¬ onstration in a conventional shoe sole, the wearer's foot and ankle are unstable. The sides of the applicant's shoe εole invention extend εufficiently far up the εideε of the wearer's foot sole to maintain the lateral stabil¬ ity of the wearer's foot when bare. In addition, the applicant's invention main¬ tains the natural stability and natural, uninterrupted motion of the foot when bare throughout its normal range of sideways pronation and supination motion occurring during all load-bearing phases of locomotion of the wear¬ er, including when said wearer is standing, walking, jogging and running, even when the foot is tilted to the extreme limit of that normal range, in contrast to unsta¬ ble and inflexible conventional shoe soles, including the partially contoured existing art described above. The sides of the applicant's shoe εole invention extend εuf¬ ficiently far up the sides of the wearer's foot εole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact thickness and material density of the shoe sole sideε and their εpe¬ cific contour will be determined empirically for indi- vidualε and groupε uεing εtandard biomechanical tech¬ niqueε of gait analyεiε to determine thoεe combinations that best provide the barefoot εtability described above. For the Fig. 50 shoe sole invention, the amount of any shoe sole side portions coplanar with the theore¬ tically ideal stability plane is determined by the degree of shoe εole εtability deεired and the εhoe εole weight and bulk required to provide said stability; the amount of said coplanar contoured sides that is provided εaid shoe sole being sufficient to maintain intact the firm stability of the wearer's foot throughout the range of foot inversion and eversion motion typical of the use for which the shoe is intended and alεo typical of the kind of wearer — such as normal or as excessive pronator — for which said shoe is intended. Finally, the shoe sole sides are sufficiently flexible to bend out easily when the shoes are put on the wearer's feet and therefore the shoe εoles gently hold the εides of the wearer's foot sole when on, providing the equivalent of custom fit in a masε-produced εhoe εole. In general, the applicant'ε preferred εhoe εole embodimentε include the εtructural and material flexibil- ity to deform in parallel to the natural deformation of the wearer's foot sole aε if it were bare and unaffected by any of the abnormal foot biomechanicε created by rigid conventional εhoe εole. At the εame time, the applicant's preferred shoe sole embodiments are sufficiently firm to provide the wearer's foot with the structural support necesεary to maintain normal pronation and supination, as if the wearer's foot were bare; in contrast, the excessive soft- ness of many of the shoe sole materials used in shoe εoleε in the existing art cause abnormal foot pronation and εupination. Aε mentioned earlier regarding Fig. IA and Fig. 3, the applicant has previously shown heel lift with con- stant frontal or transverse plane thicknesε, εince it is oriented conventionally in alignment with the frontal or transverse plane and perpendicular to the long axis of the shoe sole. However, the heel wedge (or toe taper or other shoe sole thickness variations in the sagittal plane along the long axis of the shoe sole) can be loca¬ ted at an angle to the conventional alignment in the Fig. 45 invention. For example, the heel wedge can be located perpendicular to the εubtalar axis, which is located in the heel area generally about 20 to 25 degrees medially, although a different angle can be used base on individual or group testing; such a orientation may provide better, more natural support to the εubtalar joint, through which critical pronation and supination motion occur. The applicant's theoretically ideal stability plane concept would teach that such a heel wedge orientation would require conεtant εhoe εole thickneεs in a vertical plane perpendicular to the chosen subtalar joint axis, instead of the frontal plane. Besides providing a better fit, the intentional undersizing of the flexible shoe sole sides allows for simplified design of shoe sole lastε, since the shoe last needs only to be approximate to provide a virtual custom fit, due to the flexible sides. As a result, the under¬ sized flexible shoe sole sides allow the applicant's Fig. 50 shoe sole invention based on the theoretically ideal stability plane to be manufactured in relatively standard sizes in the same manner as are shoe uppers, since the flexible shoe sole sideε can be built on εtandard εhoe lasts, even though conceptually those sides conform to the specific shape of the individual wearer's foot sole, because the flexible sides bend to so conform when on the wearer's foot εole. Fig. 50 εhowε the εhoe εole εtructure when not on the foot of the wearer; the dashed line 29 indicates the position of the shoe last, which is asεumed to be a reaεonably accurate approximation of the shape of the outer surface of the wearer's foot sole, which determines the shape of the theoretically ideal stability plane 51. Thus, the dashed lines 29 and 51 show what the positionε of the inner εurface 30 and outer εurface 31 of the shoe sole would be when the εhoe iε put on the foot of the wearer. The Fig. 50 invention provideε a way make the inner surface 30 of the contoured shoe sole, especially its sideε, conform very closely to the outer surface 29 of the foot εole of a wearer. It thuε makeε much more practical the applicant's earlier underlying naturally contoured designs shown in Figs. 4 and 5. The shoe sole structures shown in Fig. 4 and 5, then, are similar to what the Fig. 50 shoe sole structure would be when on the wearer's load-bearing foot, where the inner surface 30 of the εhoe upper is bent out to virtually coincide with the outer surface of the foot sole of the wearer 29 (the figures in this and prior applications show one line to emphaεize the conceptual coincidence of what in fact are two lineε; in real world embodimentε, some divergence of the surface, especially under load and during locomotion would be unavoidable) . The sides of the shoe sole structure deεcribed under Fig. 50 can alεo be used to form a slightly leεs optimal structure: a conventional εhoe sole that has been modified by having its sideε bent up εo that their inner surface conforms to shape nearly identical but slightly larger than the shape of the outer surface of the foot sole of the wearer, instead of the shoe sole sides being flat on the ground, as is conventional. Clearly, the cloεer the sides are to the shape of the wearer's foot sole, the better as a general rule, but any side position between flat on the ground and conforming like Fig. 50 to a εhape εlightly εmaller than the wearer's shape is both posεible and more effective than conventional flat shoe sole sideε. And in εome cases, such as for diabetic patients, it may be optimal to have relatively loose shoe sole sides providing no conforming presεure of the shoe sole on the tender foot sole; in such cases, the shape of the flexible shoe uppers, which can even be made with very elastic materials such as lycra and spandex, can provide the capability for the shoe, including the shoe sole, to conform to the shape of the foot. As discuεεed earlier by the applicant, the critical functional feature of a εhoe εole iε that it deformε under a weight-bearing load to conform to the foot εole juεt as the foot sole deforms to conform to the ground under a weight-bearing load. So, even though the foot sole and the shoe sole may start in different loca¬ tions — the shoe sole sides can even be conventionally flat on the ground — the critical functional feature of both is that they both conform under load to parallel the shape of the ground, which conventional shoeε do not, except when exactly upright. Consequently, the appli¬ cant's εhoe sole invention, stated most broadly, includeε any εhoe sole — whether conforming to the wearer's foot sole or to the ground or some intermediate position, including a shape much smaller than the wearer's foot sole — that deforms to conform to a shape at least simi¬ lar to the theoretically ideal stability plane, which by definition itself deforms in parallel with the deforma¬ tion of the wearer's foot sole under weight-bearing load. Of courεe, it iε optimal in termε of preεerving natural foot biomechanics, which is the primary goal of the applicant, for the shoe sole to conform to the foot sole when on the foot, not just when under a weight-bear- ing load. And, in any case, all of the essential struc¬ tural support and propulsion elements previously identi¬ fied by the applicant earlier in discussing Fig. 3 must be supported by the foot sole. To the extent the shoe sole sides are easily flexible, as has already been εpecified as desirable, the position of the shoe sole sideε before the wearer putε on the shoe is lesε important, εince the εideε will eaεily conform to the εhape of the wearer's foot when the shoe is put on that foot. In view of that, even shoe sole sideε that conform to a εhape more than slightly smaller than the shape of the outer surface of the wearer's foot sole would function in accordance with the applicant's general invention, since the flexible sides could bend out easily a considerable relative distance and still conform to the wearer's foot sole when on the wearer's foot. Fig. 51 was new in Serial No. 462,531 filed June 5, 1995, and Serial No. 472,979 filed June 7, 1995, and similar to Fig. 11, which was new with the '598 ap- plication and which was is a combination of the shoe εole structure concepts of Fig. 3 and Fig. 6; it combines the cuεtom fit design with the contoured sides having mate¬ rial density variations that produce an effect similar to variations in shoe sole thickness shown in Figε. 4, 5, and 7; only the midsole is shown. The density variation pattern shown in Fig. 2 can be combined with the type shown in Fig. 11 or Fig. 51. The density pattern can be constant in all crosε εectionε taken along the long the long axis of the shoe sole or the pattern can vary. The applicant's Fig. 51 shoe sole invention maintains intact the firm lateral stability of the wear¬ er's foot, that stability as demonstrated when the wear¬ er's foot is unshod and tilted out laterally in inversion to the extreme limit of the normal range of motion of the ankle joint of the foot; in a similar demonstration in a conventional shoe sole, the wearer's foot and ankle are unεtable. The εideε of the applicant'ε shoe sole inven- tion extend sufficiently far up the sides of the wearer's foot sole to maintain the lateral stability of the wear¬ er's foot when bare. In addition, the applicant's invention main¬ tains the natural stability and natural, uninterrupted motion of the foot when bare throughout itε normal range of εidewayε pronation and εupination motion occurring during all load-bearing phaεes of locomotion of the wearer, including when said wearer is standing, walking, jogging and running, even when the foot is tilted to the extreme limit of that normal range, in contrast to unsta¬ ble and inflexible conventional shoe soleε, including the partially contoured existing art deεcribed above. The εideε of the applicant's εhoe sole invention extend suf¬ ficiently far up the sides of the wearer's foot sole to maintain the natural stability and uninterrupted motion of the wearer's foot when bare. The exact material den¬ εity of the εhoe εole εides will be determined empir¬ ically for individualε and groupε uεing εtandard biomech¬ anical techniques of gait analyεis to determine those combinations that best provide the barefoot stability described above. For the Fig. 51 shoe sole invention, the amount of any shoe sole side portions coplanar with the theore¬ tically ideal stability plane 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 εaid coplanar contoured εideε that iε provided εaid shoe sole being sufficient to maintain intact the firm stability of the wearer's foot throughout the range of foot inversion and eversion motion typical of the use for which the shoe is intended and alεo typical of the kind of wearer — such as normal or as excesεive pronator — for which εaid εhoe iε intended. Finally, the shoe sole εides are sufficiently flexible to bend out easily when the shoes are put on the wearer's feet and therefore the shoe soles gently hold the sides of the wearer's foot sole when on, providing the equivalent of cuεtom fit in a mass-produced shoe sole. In general, the applicant's preferred shoe sole embodiments include the structural and material flexibil¬ ity to deform in parallel to the natural deformation of the wearer's foot sole as if it were bare and unaffected by any of the abnormal foot biomechanics created by rigid conventional shoe sole. At the same time, the applicant's preferred shoe sole embodiments are sufficiently firm to provide the wearer's foot with the structural support necessary to maintain normal pronation and supination, as if the wearer's foot were bare; in contrast, the excessive soft¬ ness of many of the shoe sole materials used in shoe soles in the existing art cause abnormal foot pronation and supination. As mentioned earlier regarding Fig. IA and Fig. 3, the applicant has previouεly εhown heel lift with conεtant frontal or transverse plane thickness, since it is oriented conventionally in alignment with the frontal or transverεe plane and perpendicular to the long axis of the shoe sole. However, the heel wedge (or toe taper or other shoe sole thickness variations in the sagittal plane along the long axis of the shoe sole) can be loca¬ ted at an angle to the conventional alignment in the Fig. IA design. For example, the heel wedge can be located perpendicular to the subtalar axis, which is located in the heel area generally about 20 to 25 degreeε medially, although a different angle can be uεed base on individual or group testing; such a orientation may provide better, more natural support to the subtalar joint, through which critical pronation and supination motion occur. The applicant's theoretically ideal stability plane concept would teach that such a heel wedge orientation would require conεtant εhoe εole thickneεε in a vertical plane perpendicular to the choεen εubtalar joint axiε, inεtead of the frontal plane. Beεideε providing a better fit, the intentional underεizing of the flexible εhoe εole sides allows for εimplified deεign of εhoe εole laεtε, εince the shoe last needs only to be approximate to provide a virtual custom fit, due to the flexible sides. As a result, the under¬ sized flexible shoe sole sides allow the applicant's Fig. 50 shoe sole invention based on the theoretically ideal stability plane to be manufactured in relatively standard sizes in the same manner as are shoe uppers, since the flexible shoe sole sides can be built on standard shoe lasts, even though conceptually those sides conform to the specific shape of the individual wearer's foot sole, because the flexible εideε bend to εo conform when on the wearer's foot sole. Besideε providing a better fit, the intentional underεizing of the flexible εhoe εole εideε allows for simplified deεign of shoe sole lasts, since they can be deεigned according to the simple geometric methodology described in the textual specification of Fig. 27, United Stateε Patent Application 07/239,667, filed 02 September 1988. That geometric approximation of the true actual contour of the human is close enough to provide a virtual custom fit, when compensated for by the flexible under¬ εizing from standard shoe lastε deεcribed above. A flexible undersized version of the fully contoured design described in Fig. 51 can also be pro- vided by a similar geometric approximation. Aε a reεult, the underεized flexible εhoe εole εides allow the appli¬ cant's shoe sole inventions based on the theoretically ideal stability plane to be manufactured in relatively εtandard εizeε in the εame manner aε are εhoe uppers, since the flexible shoe sole sideε can be built on εtan¬ dard εhoe laεts, even though conceptually those εideε conform cloεely to the εpecific εhape of the individual wearer'ε foot sole, because the flexible sideε bend to conform when on the wearer's foot sole. Fig. 51 shows the shoe sole structure when not on the foot of the wearer; the dashed line 29 indicates the position of the shoe last, which is aεεumed to be a reasonably accurate approximation of the shape of the outer εurface of the wearer'ε foot sole, which determines the shape of the theoretically ideal stability plane 51. Thus, the dashed lines 29 and 51 show what the positions of the inner surface 30 and outer surface 31 of the shoe sole would be when the shoe is put on the foot of the wearer. The Fig. 51 invention provideε a way make the inner εurface 30 of the contoured εhoe εole, eεpecially its sides, conform very closely to the outer surface 29 of the foot sole of a wearer. It thus makes much more practical the applicant's earlier underlying naturally contoured deεigns shown in Fig. 1A-C and Fig. 6. The shoe sole structure shown in Fig. 51, then, is what the Fig. 11 shoe εole structure would be when on the wearer's foot, where the inner surface 30 of the shoe upper iε bent out to virtually coincide with the outer surface of the foot sole of the wearer 29 (the figureε in thiε and prior applicationε show one line to emphasize the concep- tual coincidence of what in fact are two lines; in real world embodiments, some divergence of the surface, espe¬ cially under load and during locomotion would be unavoid¬ able) . The sides of the shoe sole structure described under Fig. 51 can also be used to form a slightly lesε optimal structure: a conventional shoe sole that has been modified by having its sides bent up so that their inner surface conforms to shape nearly identical but slightly larger than the shape of the outer surface of the foot sole of the wearer, instead of the shoe sole sides being flat on the ground, as is conventional. Clearly, the closer the sides are to the shape of the wearer's foot sole, the better as a general rule, but any εide position between flat on the ground and conforming like Fig. 11 to a shape slightly εmaller than the wearer's shape is both possible and more effective than conventional flat shoe sole sideε. And in some cases, such as for diabetic patients, it may be optimal to have relatively loose shoe sole sides providing no conforming pressure of the shoe sole on the tender foot sole; in such caseε, the shape of the flexible shoe uppers, which can even be made with very elastic materials such as lycra and spandex, can provide the capability for the shoe, including the shoe sole, to conform to the shape of the foot. Aε diεcuεεed earlier by the applicant, the critical functional feature of a shoe sole is that it deforms under a weight-bearing load to conform to the foot sole just as the foot sole deforms to conform to the ground under a weight-bearing load. So, even though the foot sole and the shoe sole may start in different loca¬ tionε — the εhoe εole εideε can even be conventionally flat on the ground — the critical functional feature of both is that they both conform under load to parallel the shape of the ground, which conventional shoes do not, except when exactly upright. Consequently, the appli¬ cant's shoe εole invention, εtated moεt broadly, includes any shoe sole — whether conforming to the wearer's foot sole or to the ground or some intermediate position, including a shape much smaller than the wearer's foot sole — that deforms to conform to the theoretically ideal stability plane, which by definition itεelf deformε in parallel with the deformation of the wearer's foot sole under weight-bearing load. Of course, it is optimal in terms of preserving natural foot biomechanics, which is the primary goal of the applicant, for the shoe sole to conform to the foot sole when on the foot, not just when under a weight-bear- ing load. And, in any case, all of the esεential struc¬ tural support and propulsion elements previously identi¬ fied by the applicant earlier in discusεing Fig. 3 must be supported by the foot sole. To the extent the shoe sole sides are easily flexible, as has already been specified as desirable, the position of the shoe sole sides before the wearer puts on the shoe is less important, since the sides will easily conform to the shape of the wearer's foot when the shoe is put on that foot. In view of that, even shoe sole sides that conform to a shape more than slightly smaller than the shape of the outer surface of the wearer's foot sole would function in accordance with the applicant's general invention, since the flexible sides could bend out easily a considerable relative distance and still conform to the wearer's foot εole when on the wearer's foot. The applicant's shoe sole inventionε deεcribed in Figε. 4, 10, 11 and 51 all attempt to provide struc- tural compenεation for actual structural changes in the feet of wearers that have occurred from a lifetime of use of existing shoes, which have a major flaw that has been identified and described earlier by the applicant. As a result, the biomechanical motion of even the wearer's bare feet have been degraded from what they would be if the wearer's feet had not been structurally changed. Consequently, the ultimate design goal of the applicant'ε inventions is to provide un-degraded barefoot motion. That means to provide wearers with shoe soles that com¬ pensate for their flawed barefoot structure to an extent sufficient to provide foot and ankle motion equivalent to that of their bare feet if never shod and therefore not flawed. Determining the biomechanical characteristicε of εuch un-flawed bare feet will be difficult, either on an individual or group baεiε. The difficulty for many groupε of wearerε will be in finding un-flawed, never- shod barefoot from similar genetic groups, asεuming εig¬ nificant genetic differences exist, as seemε at least poεεible if not probable. The ultimate goal of the applicant'ε invention iε to provide εhoe εole εtructureε that maintain the natural stability and natural, uninterrupted motion of the foot when bare throughout its normal range of side¬ ways pronation and supination motion occurring during all load-bearing phaseε of locomotion of a wearer who haε never been shod in conventional shoes, including when said wearer is standing, walking, jogging and running, even when the foot is tilted to the extreme limit of that normal range, in contrast to unstable and inflexible conventional shoe soles. Fig. 51, like Fig. 47, increases constructive density variations, as most typically measured in duro- meterε on a Shore A εcale, to include 26 percent up to 50 percent and from 51 percent to 200 percent. The εame variationε in shoe bottom sole deεign can provide εimilar effectε to the variation in shoe sole denεity deεcribed above. In addition, any of the above deεcribed thick¬ neεε variationε from a theoretically ideal εtability plane can be uεed together with any of the above described density or bottom εole deεign variationε. Fig. 51 show such a combination; for illuεtration purpoεeε, it showε a thickness increase greater than the theoretically ideal stability plane on the right εide and a leεεer thickness on the left side — both sides illustrate the density variations described above. All portionε of the shoe sole are included in thickness and density measure- ment, including the εockliner or insole, the midsole (including heel lift or other thickness variation mea¬ sured in the sagittal plane) and bottom or outer εole. In addition the Fig. 51 invention and the Fig. 11 invention can be combined with the invention εhown in Fig. 12 of the '870 application, which can alεo be com¬ bined with the other figures of this application, as can Fig. 9A-9D of the '870 application. Any of these figures can also be combined alone or together with Fig. 9 of this application, which is Fig. 9 of the '302 application or Fig. 10 of that application, or with Figs. 11-15, 19- 28, 30, and 33A-33M of the '523 application, or with Figs.7-9 of the '313 application, or Fig. 8 of the '748 application, with or without stability sipe 11. The above described thickness and density vari¬ ations apply to the load-bearing portions of the con- toured sides of the applicant's shoe sole inventions, the side portion being identified in Fig. 4 of the '819 pat¬ ent. Thickness and density variations described above are measured along the contoured side portion. The side portion of the fully contoured design introduced in the '819 patent in Fig. 15 cannot be defined as explicitly, since the bottom portion is contoured like the sides, but should be measured by eεtimating the equivalent Fig. 4 figure; generally, like Figs. 14 and Fig. 15 of the '819 patent, assuming the flattened sole portion shown in Fig. 14 correspondε to a load-bearing equivalent of Fig. 15, so that the contoured sideε of Figs. 14 and Fig. 15 are esεentially the same. Alternately, the thickness and density varia¬ tions described above can be measured from the center of the essential structural support and propulεion elementε defined in the '819 patent. Those elements are the base and lateral tuberosity of the calcaneus, the heads of the metatarsals, and the baεe of the fifth metatarsal, and the head of the first distal phalange, reεpectively. Of the metatarεal headε, only the first and fifth metatarsal heads are used for such measurement, since only those two are located on lateral portions of the foot and thuε proximate to contoured εtability sides of the applicant's shoe sole. Fig. 52A-B was new with the continuation-in- part applications Serial No. 462,531 filed June 5, 1995, and Serial No. 472,979 filed June 7, 1995; it broadens the definition of the theoretically ideal stability plane, as defined in the '786 and all prior applicationε filed by the applicant. The '819 patent and subsequent applications have defined the inner surface of the theo¬ retically ideal stability plane as conforming to the shape of the wearer's foot, especially its εideε, so that the inner surface of the applicant's shoe sole invention conforms to the outer surface of the wearer's foot sole, especially it sides, when measured in frontal plane or transverse plane cross sections. For illustration purposes, the right side of Fig. 52 explicitly includes an upper shoe sole surface that is complementary to the shape of all or a portion the wearer's foot sole. In addition, this application describes shoe contoured sole side designs wherein the inner surface of the theoretically ideal εtability plane lieε at εome point between conforming or complementary to the shape of the wearer's foot sole, that is — roughly paralleling the foot sole including its side — and par¬ alleling the flat ground; that inner surface of the theo- retically ideal stability plane becomes load-bearing in contact with the foot sole during foot inversion and everεion, which iε normal sideways or lateral motion. The basiε of thiε deεign was introduced in the appli¬ cant's '302 application relative to Fig. 9 of that appli- cation. Again, for illustration purpoεeε, the left side of Fig. 52B describes shoe sole side designs wherein the lower surface of the theoretically ideal stability plane, which equates to the load-bearing surface of the bottom or outer shoe sole, of the shoe sole side portions is above the plane of the underneath portion of the shoe sole, when measured in frontal or transverεe plane croεε sections; that lower εurface of the theoretically ideal stability plane becomes load-bearing in contact with the ground during foot inversion and everεion, which iε nor¬ mal sideways or lateral motion. Although the inventions described in this application may in many cases be less optimal than thoεe previously described by the applicant in earlier applica- tions, they nonethelesε diεtinguish over all prior art and still do provide a εignificant εtability improvement over exiεting footwear and thuε provide significantly increaεed injury prevention benefit compared to exiεting footwear. Fig. 53 waε new in the continuation-in-part applications Serial No. 462,531 filed June 5, 1995, and Serial No. 472,979 filed June 7, 1995, and provides a means to measure the contoured shoe sole sides incorpo¬ rated in the applicant's inventions described above. Fig. 53 iε Fig. 27 of the '819 patent modified to corre¬ late the height or extent of the contoured side portions of the εhoe εole with a preciεe angular measurement from zero to 180 degrees. That angular measurement corre¬ sponds roughly with the support for sidewayε tilting provided by the contoured shoe sole sides of any angular amount from zero degrees to 180 degrees, at least for such contoured sides proximate to any one or more or all of the esεential stability or propulsion εtructures of the foot, as defined above and previously, including in the '523 patent application. The contoured shoe sole sides as described in this application can have any angu- lar measurement from zero degrees to 180 degrees. Figs. 54A-54F, Fig.55A-E, and Fig. 56 were new to the continuation-in-part applications Serial No. 462,531 filed June 5, 1995, and Serial No. 472,979 filed June 7, 1995, and describe shoe sole structural inven- tions that are formed with an upper surface to conform, or at least be complementary, to the all or most or at least part of the shape of the wearer's foot sole, whether under a body weight load or unloaded, but without contoured stability sides as defined by the applicant. Aε such, Figs. 54-56 are similar to Figs. 19-21 of the '819 patent, but without the contoured stability sideε 28a defined in Fig. 4 of the '819 patent at the eεεential εtructural εupport and propulεion elementε, which are the base and lateral tuberosity of the calcaneus, the heads of the firεt and fifth metatarεalε, the baεe of the fifth metatarεal, and the firεt diεtal phalange, and with εhoe sole contoured side thickneεs variations, as measured in frontal or transverse plane crosε εectionε aε defined in thiε and earlier applications. Those contoured side thickness variations from the theoretically ideal stability plane, as previously defined, are uniform thicknesε, variationε of 5 to 10 percent, variationε of 11 to 25 percent, variationε of 26 to 40 percent and 41 to 50 for thickneεses decreaεing from the theoretically ideal εtability plane, thickneεε variationε of 26 to 50 percent and 51 percent to 100 percent for thickneεε variationε increasing from the theoretically ideal stability plane. Figs. 54A-54F, Fig.55A-E, and Fig. 56, like the many other variationε of the applicant'ε naturally con¬ toured deεign described in this and earlier applications, shown a shoe εole invention wherein both the upper, foot εole-contacting εurface of the εhoe εole and the bottom, ground-contacting εurface of the εhoe εole mirror the contourε of the bottom εurface of the wearer's foot sole, forming in effect a flexible three dimensional mirror of the load-bearing portionε of that foot sole when bare. The shoe εole εhown in Figε. 54-56 preferably include an insole layer, a midsole layer, and bottom sole layer, and variation in the thicknesε of the εhoe εole, aε meaεured in εagittal plane croεε εectionε, like the heel lift common to most shoes, as well as a shoe upper. Fig. 55D shows somewhat more conventional contoured εhoe εole εideε, but which are not load-bearing, like the roughly vertical sides shown in Figε. 55A-C. Fig. 57A-57C is similar to Fig. 34A-34C, which show, in cross sectionε εimilar to thoεe in pending U.S. Patent '349, that with the quadrant-εided deεign of Figs. 26, 31, 32 and 33C that it is posεible to have εhoe εole εideε that are both greater and leεεer than the theoreti¬ cally ideal stability plane in the same shoe. Fig. 57A-C shows the same range of thickness variation in contoured shoe side as Fig. 45 and used to show εimultaneously the general case for both extreme increases and extreme decreases. The quadrant design determines the shape of the load-bearing portion of outer surface of the bottom or outer sole, which is coincident with the theoretically ideal stability plane; the finishing edge 53 or 53a is optional, not a mandatory part of the invention. The relationship between the applicant's two different contoured shoe sole side designε, the quadrant sided design and the naturally contoured design are dis¬ cuεεed in publiεhed PCT Application PCT/US89/03076, from which iε quoted the following three paragraphs. A corrected shoe sole design, however, avoids such unnatural interference by neutrally maintaining a constant distance between foot and ground, even when the εhoe is tilted sidewayε, aε if in effect the εhoe εole were not there except to cushion and protect. Unlike existing shoeε, the corrected εhoe 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 side¬ wayε motion, there are two poεsible geometric solutions, depending upon whether just the lower horizontal plane of the shoe sole surface varies to achieve natural contour or both upper and lower surface planeε vary. In the two plane solution, the naturally con¬ toured deεign, which will be deεcribed in Figureε 1-28, both upper and lower εurfaceε or planes of the shoe sole vary to conform to the natural contour of the human foot. The two plane solution iε the most fundamental concept and naturally most effective. It is the only pure geo¬ metric solution to the mathematical problem of maintain- ing conεtant distance between foot and ground, and the most optimal, in the same εenεe that round iε only εhape for a wheel and perfectly round is most optimal. On the other hand, it is the least similar to exiεting deεigns of the two posεible solutions and 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 formed by varia- tionε in the bottom surface alone. The upper surface or plane of the shoe sole remains unvaryingly flat in fron¬ tal plane crosε sections, like most existing shoes, while the plane of the bottom shoe sole varies on the sides to provide a contour that preεerveε 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 prob¬ lem of avoiding disruption of natural human biomechanics. The one plane solution is the closeεt to exiεting shoe sole design, and therefore the easieεt and cheapeεt to manufacture with existing equipment. Since it is more conventional in appearance than the two plane solution, but lesε biomechanically effective, the one plane quad- rant contour εide deεign is preferable for dress or street shoeε and for light exerciεe, like caεual walking. Fig. 57A-C, and Fig. 34A-34F, shows a general embodiment of the applicant's invention for thicknesε or denεity variationε, whether quadrant εided or naturally contoured εides: that whatever the εhoe εole εide thick¬ neεε variation defined for a particular embodiment, that thickness variation definition is maintained as measured in two different frontal or transverse plane crosε sec¬ tions and those two crosε sections must be taken from sectionε of the εhoe εole that have different thick- neεεeε, aε measured in sagittal plane crosε εections or cross sections along the long axis of the shoe εole. Fig. 57A-C also εhows the special case of the radius of an intermediate shoe εole thickneεε, taken at (S 2 ) at the baεe of the fifth metatarsal in Fig. 34B, is maintained constant throughout the quadrant sides of the shoe sole, including both the heel, Fig. 34C, and the forefoot, Fig. 34A, so that the side thickness is lesε than the theoretically ideal εtability plane at the heel and more at the forefoot. Though poεεible, thiε iε not a preferred approach. Fig. 58 iε based on Fig. IB but also εhowε, for purposes of illustration, on the right side of Fig. 58 a relative thickness increase of the contoured shoe sole side for that portion of the contoured shoe sole side beyond the limit of the full range of normal sideways foot inversion and eversion motion, while uniform thick- ness existε for the load-bearing portions of the con¬ toured shoe sole side. Alternately, the same relative thicknesε increase of the contoured shoe sole side could exist for that portion of the contoured shoe sole side beyond the limit of the full range of foot inversion and eversion, relatively more uniform or smaller thickness variations exiεtε for the load-bearing portionε of the contoured εhoe sole side; thiε deεign could apply to Fig. 4, 5, 8, 45, 46, and 49 and otherε. For purpoεes of illustration, the left side of Fig. 58 shows a density increase used for the same purpoεe aε the thickneεs increase. And the same design can be used for embodi¬ ments with decreasing thickness variations, like Fig. 7 and Fig. 48. That normal range of foot inversion or ever- sion, and its corresponding limitε of load-bearing outer or bottom εole εurface 211, noted above and elsewhere in this application can be determined either by individual measurement by means known in the art or by using general existing ranges or ranges developed by statistically meaningful studies, including using new, more dynamically based teεting procedureε; such ranges may also include a extra margin for error to protect the individual wearer. The following Figures 59-62 are new with thiε continuation-in-part application, although Figs. 59 and 60 are from a prior application, now an issued patent. Figs. 59 and 60 are Figs. 25 and 26 from the applicant's '819 patent. The shoe sole according to the invention can be made by approximating the contours, aε indicated in Figε. 59A, 59B, and 60. Fig. 59A shows a frontal plane cross section of a design wherein the sole material in areas 107 is so relatively soft that it deforms easily to the contour of shoe sole 28 of the pro¬ posed invention. In the proposed approximation as seen in Fig. 59B, the heel cross section includes a sole upper surface 101 and a bottom sole edge εurface 102 following when deformed an inεet theoretically ideal stability plane 51. The sole edge surface 102 terminates in a laterally extending portion 103 joined to the heel of the εole 28. The laterally-extending portion 103 iε made from a flexible material and εtructured to cauεe itε lower εurface 102 to terminate during deformation to parallel the inεet theoretically ideal εtability plane 51. 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 theoretically 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 contour of the foot as deεcribed by lineε 30a and 30b shown in Fig. 4 of the applicant's '819 patent. It is presently contemplated that the con¬ trolled 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 fash¬ ion or grooved so that the bottom sole bends inwardly under presεure to the correct contour. The second useε an easily deformable material 107 in a tapered manner on the εideε to deform under preεsure to the correct contour. While such techniques produce stability and natural motion reεultε which are a significant improvement over conventional designε, they are inherently inferior to contourε produced by simple geometric shaping. First, the actual deformation muεt be produced by preεεure which iε unnatural and does not occur with a bare foot and sec¬ ond, only approximations are possible by deformation, even with sophiεticated design and manufacturing tech¬ niques, given an individual's particular running gait or body weight. Thus, the deformation procesε iε limited to a minor effort to correct the contours from surfaces approximating the ideal curve in the first instance. The theoretically ideal εtability plane can also be approximated by a plurality of line segments 110, such as tangents, chords, or other lines, as shown in Fig. 60. 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 approxima¬ tion may 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 stability plane 51, the single plane approximation iε presently not preferred, since it is the leaεt optimal. By increaεing the number of flat planar εurfaces formed, the curve more closely approximates the ideal exact design contours, as previ¬ ously described. Single and double plane approximations are shown as line εegmentε in the croεs section illus¬ trated in Fig. 60. Both Figs. 59A and 59B are relatively hybrid embodimentε of a more general invention, the uεe of εoft, easily deformable materials 107 in any embodiment so that, first, the upper surface 30 of the shoe sole con¬ forms, or is at least complementary, to some or all of the shape of the wearer's foot sole when that upper sur- face 30 would not otherwise so conform; in other words, the soft, deformable material enables the conformance. This enabling structure is shown in Fig. 61, which is εimilar to Fig. 52 above; Fig. 61 iε shown in the undeformed state. Fig. 61 shows, on the left side, a side upper surface 30a which does not conform to the side of the wearer's foot sole, but will easily deform to con¬ form during lateral motion if the material 107 used between the upper surface 30a and the wearer's foot sole 29 is sufficiently soft, compared to the material of the adjoining shoe sole portions. Instead of soft or very soft material 107, the enclosed or partially enclosed space 108 between surfaceε 30a and 29 can also be devoid of material; the outermost side can be contained by shoe sole 28 material or by the shoe sole upper 21, as shown. Second, the use of soft, deformable materials may alεo compress sufficiently so as to enable the thick- ness of the shoe sole, as measured in frontal or trans¬ verεe plane crosε εectionε, to be uniform or to have a thickneεε that varieε within the parameters established in other earlier applications or above in earlier contin¬ uation-in-part applications of the '598 parent of this application, even if εuch thickneεε would not otherwiεe be uniform or vary with the applicant'ε eεtablished parameters. This enabling εtructures is shown in Fig. 62A- B, which is similar to Fig. 45A-B above. Fig. 62A-B is εhown in a uncompreεεed εtate, but with sufficiently soft material 107, the Fig. 62A εtructure on the left side of the shoe sole shown could compresε to roughly the thick¬ neεε equivalent to the right εide of the Fig. 62A εhoe εole. The soft materials 107 can be located in one con- tinuous section of soft material 107, as shown in Fig. 62A, or in more than one section. Such soft material 107 can be located anywhere between the wearer's foot sole 29 and the ground 43, including anywhere between the upper surface of the shoe sole 30 and the bottom surface 31. The soft material 107 can form all or a portion of those upper or lower surfaces 30 and 31, or can be enclosed fully or in part by εhoe εole material of generally typi¬ cal firmneεε, εuch as from 30 to 80 durometers on the Shore A scale. Such enclosed or partially enclosed sections 108 can also be devoid of any shoe sole material, as εhown in Fig. 62B, εo that all or a portion of the upper surface 30* of the enclosed section or sections is in contact with all or a portion of the lower surface 31 of the enclosed section or εectionε, or the material 107 can be extraordinarily εoft so that such contact is virtually made. The right side of the Fig. 62B shoe sole structure would compreεε to coincide roughly with the theoretically ideal stability plane 51; and the left εide would com¬ press in thickness to the original outer surface of the right side of Fig. 45B above. A large number of poten¬ tial embodiments exist for the Fig. 61-62 invention. The shoe sole structureε shown in Figs. 61-62 can be combined with Fig. 58 above. Under normal body weight load-bearing forces, the upper portion of the contoured shoe sole side can not fully compress into contact between upper and lower surfaces 30* and 31 % , since 31 x is longer; therefore, that upper portion can coincide with the non-load-bearing portion of the shoe sole, aε in Fig. 58, with the εame functional utility. In conclusion, it is critical to note that, although many of the applicant's figures in thiε and prior applications are shown in static, unloaded εtates, the very core of all his shoe sole inventionε iε that thoεe shoe sole structureε support the wearer's foot sole while standing or during locomotion including walking and running, providing the same stability as the wearer's foot when bare. Consequently, the true test of all of the applicant's inventions is in their dynamic, load- bearing εtate, like that shown approximately in Figs. 1A- F above, although as noted there those Figs, are shown undeformed or compressed, since the unloaded portion maintains the εame shoe sole thicknesε to illuεtrate proper conεtruction of the preferred mode. When compressed or deformed under body weight bearing loads, both normal and peak, the thickness of the flattened, load-bearing portion of the applicant's shoe soles should be substantially uniform, as shown by the vertically oriented dashed lines labeled "S" in Figε. 1B- 1F, or within the variation parameters established in this and the applicant's prior applications. As measured in frontal plane cross sections, uniform thickness is generally considered the best or most optimal mode, but thickness variations within εtated parameters for the reasonε deεcribed previouεly and above may be optimal for individuals or groups, and are subεtantially superior in stability to the prior art. As meaεured in frontal or tranεverεe plane cross εectionε, the thickneεs of the applicant's shoe εole invention aε defined in thiε and prior applicationε, and in the '819 patent, should preferably be maintained over the full range of the wearer's subtalar ankle joint, from extreme pronation to extreme supination, as shown by Fig. 63 below, the extended width of which, compared to convention shoes, corresponds to the applicant's conform¬ ing sideε invention when flattened under a wearer's body weight load measured when standing, as described in Figs. 12-13 above, where the load is roughly one half the wear¬ er's body weight. The εame type of meaεurement εhould be made for the dynamic peak forceε that occur during all formε of locomotion, εince thoεe higher forces will increase the width of the dynamic load-bearing footprint and thus will require higher conforming shoe sole sides. The forms of locomotion that should be included, but not limited to, are at least walking, which has a peak force of about one wearer's body weight (conventionally called 1 G) ; run¬ ning, which haε a peak force of about three wearer's body weights (or 3 G's) ; and leaping, which has a peak force of about five to seven wearer's body weights (5 to 7 G'ε) . The moεt critical measurement, to ensure that the applicant's invention has been constructed properly and with sufficiently high conforming sideε, εhould be made in a manner deεcribed in Figs. 12-13 above, but with the wearer leaping onto a force platform with the wear¬ er's single landing foot fully inverted in supination, simulating the ankle sprain position. The applicant's invention, properly constructed in its preferred modes, is stable when so tested, whereas conventional shoeε can¬ not be tested in this manner without the wearer spraining or fracturing the wearer's ankle while doing so, given the inherent instability of conventional shoeε in thiε fully inverted position, as described above in Fig. 13. Fig. 63 is Fig. 8 from the applicant's '748 application and showε a footprints 37 and 17, like Fig. 5 of the '748 application, of a right barefoot upright and tilted out 20 degreeε, showing the actual relative posi¬ tionε to each other aε a low arched foot rolls outward from upright to tilted out 20 degrees. Fig. 63 shows footprints 37 and 17, like Fig. 5, of a right barefoot upright and tilted out 20 degrees, showing the actual relative positions to each other as a low arched foot rolls outward from upright to tilted out 20 degrees. The low arched foot is particularly notewor¬ thy because it exhibits a wider range of motion than the Fig. 5 high arched foot, εo the 20 degree lateral tilt footprint 17 iε farther to the outεide of upright foot¬ print 37. In addition, the low arched foot pronateε inward to inner footprint borderε 18; the hatched area 19 is the increased area of the footprint due to the prona- tion, whereaε the hatched area 16 iε the decreaεed area due to pronation. In Fig. 63, the lateral stability sipe 11 is clearly located on the shoe εole along the inner margin of the lateral footprint 17 superimposed on top of the shoe sole and is straight to maximize ease of flexibil¬ ity. A shoe sole of extreme width iε neceεsitated by the common foot tendency toward excessive pronation, as shown in Fig. 63, in order to provide structural support for the full range of natural foot motion, including both pronation and εupination. Extremely wide shoe soleε are most practical if the sides of the shoe sole are not flat as is conventional but rather are bent up to conform to the natural shape of the shoe wearer's foot sole in accordance with the applicant's '819 patent and later pending applications. As noted above, the Fig. 63 shoe εole 28 can be used with or without lateral sipe 11 and iε shown here primarily to indicate the full range of the load-bearing portion of a wearer's foot sole. Thus, it will clearly be understood by those skilled in the art that the foregoing description haε been made in termε of the preferred embodiment and vari¬ ous changes and modifications may be made without depart¬ ing from the εcope of the present invention which is to be defined by the appended claims.

Claims: WHAT IS CLAIMED IS: 1. A shoe sole for a shoe and other footwear, such as athletic and street shoes, comprising: a shoe sole with an upper, foot sole-contacting surface that is at least complementary to the shape of a wearer's foot sole, at least in a forefoot and heel area, including a portion complementary to at least a part of a curved side of the foot sole; and the shoe sole having at least one εection void that, under a wearer's body weight load-bearing compresεion, enables the load-bearing portions of the at leaεt one εide portion of the shoe sole to have a thick- nesε which varieε from a uniform thickneεs by not more than 50 percent, when measured in transverse plane cross sections; said shoe εole thickneεs 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 εole, when mea- εured in frontal plane cross sectionε; εaid thickness varying when measured in the sagittal plane and being greater in a heel area than a forefoot area; the compressed thickness which varies from a uniform thickneεε by not more than 50 percent of the shoe sole extends through a side portion of at least 10 degreeε. 2. The εhoe εole aε set forth in claim 1, wherein said at leaεt one εection void iε located at leaεt in a forefoot area of the εhoe εole; the εhoe εole haε at leaεt another εide por- tion, which adjoins said side portion in the forefoot, that iε less thick than said conforming side portion, in order to εave weight and to increase flexibility. 3. The εhoe εole as set forth in claim 2, wherein the thicknesε of the shoe sole, which varieε from a uniform thickneεs by not more than 50 percent as mea- sured in transverεe plane croεε εectionε, extendε from the underneath εole portion through the εide portion at the forefoot at leaεt through a εidewayε tilt angle of 45 degrees. 4. The shoe sole as εet forth in claim 2, wherein the thickneεε of the shoe sole, which varies from a uniform thickness by not more than 50 percent as mea- sured in transverse plane cross sections, extends from the underneath sole portion through the side portion at the forefoot at least through a sideways tilt angle of 90 degrees. 5. The shoe sole as set forth in claim 2, wherein the thickneεε of the εhoe εole, which varieε from a uniform thickness by not more than 50 percent as mea- sured in transverεe plane cross sectionε, extendε from the underneath sole portion through the side portion at the forefoot at least through a sideways tilt angle of 135 degrees. 6. The shoe sole as set forth in claim 2, wherein the thickneεε of the εhoe sole, which varies from a uniform thickneεε by not more than 50 percent as mea- sured in transverεe plane croεs sections, extends from the underneath sole portion through the side portion at the forefoot at least through a εideways tilt angle of 180 degrees. 7. The shoe sole as set forth in claim 3, wherein the ground-contacting portion of said side por- tion includes at least a midsole. 8. The shoe sole as set forth in claim 3, wherein the ground-contacting portion of said side por- tion includes at least a midsole and an outer sole. 9. The shoe sole as set forth in claim 3, wherein the ground-contacting portion of said εide por- tion includes at least a inεole and an outer εole. 10. The shoe sole as set forth in claim 3, wherein said side portion iε proximate to a head of a fifth metatarεal of a wearer's foot. 11. The shoe sole as set forth in claim 3, wherein said side portion is proximate to a head of a first metatarsal of a wearer's foot. 12. The shoe sole as set forth in claim 3, wherein said side portion is proximate to a head of a first distal phalange of a wearer's foot. 13. A shoe sole for a shoe and other footwear, including athletic shoes and street shoeε, compriεing: an upper, foot sole-contacting surface of the shoe sole that is εhaped to a contour at least complemen- tary to the shape of at least part of a sole of a heel of a wearer's foot, including at leaεt part of an underneath εole portion and at leaεt one εide portion of the foot sole; and the shoe sole having at least one section void that, under a wearer's body weight load-bearing compression, enables the load-bearing portions of the at least one side portion of the shoe sole to have a thick- neεs and density, each of which varies from a uniform thicknesε by not more than 50 percent, when measured in transverεe plane croεε εectionε; the thickness and density of the shoe sole, each of which varies from a uniform thicknesε by not more than 50 percent aε measured in transverεe plane cross sections, extends from the underneath sole portion through the side portion at the heel at least through a sideways tilt angle of 20 degrees. 14. The shoe sole as set forth in claim 13, wherein the shoe sole has at least another side portion, which adjoins said side portion in the heel, that is leεε thick than εaid εide portion, in order to save weight and to increase flexibility. 15. The εhoe εole aε εet forth in claim 14, wherein the thickneεε of the shoe sole, which varies from a uniform thickness by not lesε than 26 percent nor more than 50 percent aε meaεured in tranεverεe plane cross sectionε, extends from the underneath sole portion through the side portion at the heel at least through a sideways tilt angle of 45 degrees. 16. The shoe sole as set forth in claim 14, wherein the thickneεε of the εhoe εole, which varieε from a uniform thickneεε by not less than 26 percent nor more than 50 percent aε meaεured in transverse plane cross sections, extends from the underneath sole portion through the side portion at the heel at leaεt through a εideways tilt angle of 90 degreeε. 17. The shoe sole as set forth in claim 14, wherein the thicknesε of the εhoe sole, which varies from a uniform thicknesε by not leεs than 26 percent nor more than 50 percent as measured in transverse plane crosε εectionε, extendε from the underneath sole portion through the side portion at the heel at least through a sidewayε tilt angle of 135 degrees. 18. The shoe sole as set forth in claim 14, wherein the thickneεs of the shoe sole, which varies from a uniform thicknesε by not leεs than 26 percent nor more than 50 percent as measured in transverse plane crosε sectionε, extends from the underneath sole portion through the side portion at the heel at least through a sideways tilt angle of 180 degrees. 19. The shoe sole as set forth in claim 15, wherein the ground-contacting portion of said side por- tion includes at leaεt a midεole. 20. The εhoe εole as set forth in claim 15, wherein the ground-contacting portion of said side por- tion includes at least a midsole and an outer sole. 21. The shoe εole as set forth in claim 15, wherein the ground-contacting portion of said side por- tion includes at leaεt a insole and an outer sole. 22. The shoe sole as set forth in claim 15, wherein the ground-contacting portion of said side por- tion includes at least a heel lift. 23. The εhoe sole as set forth in claim 15, wherein said side portion is proximate to a base of a calcaneus of a wearer's foot. 24. The shoe sole as set forth in claim 15, wherein said side portion is proximate to a lateral tuberosity of a wearer's foot. 25. The shoe sole as set forth in claim 15, wherein εaid side portion is proximate to a base of a fifth metatarεal of a wearer's foot. 26. A shoe sole construction for a shoe and other footwear, εuch as athletic and street εhoeε, com- priεing: a εhoe εole with an upper, foot sole-contacting surface that is at least complementary to the shape of a wearer's foot εole, at leaεt in a forefoot and heel area, including a portion complementary to at leaεt a part of a curved εide of the foot sole; and the shoe sole having at least one section void that, under a wearer's body weight load-bearing compression, enables the load-bearing portions of the at least one side portion of the shoe sole to have a thick- neεε and density, each of which varies from a uniform thickness by not more than 50 percent, when measured in transverεe plane crosε εections; said shoe sole thickness being defined aε the εhortest distance between any point on an upper, foot sole-contacting εurface of εaid εhoe εole and a lower, ground-contacting εurface of said shoe εole, when mea- εured in frontal plane croεs sections; the thickness which varies from a uniform thicknesε by not more than 50 percent of the shoe sole extends through a side portion of at least 10 degreeε. 27. The εhoe sole as set forth in claim 26, wherein the shoe sole has at least another side portion, which adjoins said side portion, that iε less thick than said side portion, in order to save weight and to increase flexibility. 28. The shoe sole as set forth in claim 27, wherein the thicknesε of the εhoe sole, which varies from a uniform thickness by not less than 26 percent nor more than 50 percent as measured in transverεe plane croεs sections, extends from the underneath sole portion through the side portion at the heel at least through a sidewayε tilt angle of 45 degrees. 29. The shoe sole aε εet forth in claim 27, wherein the thickness of the shoe sole, which varies from a uniform thickness by not less than 26 percent nor more than 50 percent as measured in transverse plane crosε sections, extends from the underneath sole portion through the side portion at the heel at least through a sideways tilt angle of 90 degrees. 30. The shoe sole as set forth in claim 27, wherein the thickness of the shoe sole, which varies from a uniform thickness by not lesε than 26 percent nor more than 50 percent as measured in tranεverse plane crosε sections, extends from the underneath sole portion through the side portion at the forefoot at least through a sideways tilt angle of 135 degrees. 31. The εhoe εole as set forth in claim 27, wherein the thickness of the shoe sole, which varies from a uniform thickness by not lesε than 26 percent nor more than 50 percent as measured in tranεverse plane croεε εections, extends from the underneath sole portion through the side portion at the forefoot at least through a sideways tilt angle of 180 degrees. 32. The shoe sole as set forth in claim 27, wherein the ground-contacting portion of said εide por- tion includes at leaεt a midεole. 33. The εhoe εole aε set forth in claim 27, wherein the ground-contacting portion of said side por- tion includes at least a midsole and an outer sole. 34. The shoe sole as εet forth in claim 27, wherein the ground-contacting portion of said side por- tion includes at least a inεole and an outer sole. 35. The shoe sole as set forth in claim 27, wherein the ground-contacting portion of said side por- tion includes at least a heel lift. 36. The shoe sole as set forth in claim 27, wherein said side portion iε proximate to a base of a calcaneus of a wearer's foot. 37. The shoe sole as set forth in claim 27, wherein said side portion is proximate to a lateral tuberoεity of a wearer's foot. 38. The shoe εole aε εet forth in claim 27, wherein εaid εide portion iε proximate to a baεe of a fifth metatarεal of a wearer's foot. 39. The shoe sole as set forth in claim 27, wherein said side portion is proximate to a head of a fifth metatarsal of a wearer's foot. 40. The shoe sole as set forth in claim 27, wherein said side portion is proximate to a head of a first metatarsal of a wearer's foot. 41. The εhoe εole as set forth in claim 27, wherein εaid side portion is proximate to a head of a first diεtal phalange of a wearer's foot. 42. A shoe sole for a εhoe and other footwear, particularly athletic εhoes and including street shoes, comprising: an upper, foot sole-contacting surface of the shoe sole that is shaped to a contour at least complemen- tary to the shape of at least part of a sole of a fore- foot of a wearer'ε foot, including at leaεt part of an underneath εole portion and at leaεt one side portion of the foot sole; and the shoe sole having at least one section void that, under a wearer's body weight load-bearing compression, enables the load-bearing portions of the at least one side portion of the shoe sole to have a thick- nesε and density, each of which varies from a uniform thicknesε by not more than 100 percent, when measured in transverse plane cross sections; the thickness of the shoe sole, which varies from a uniform thickness by not more than 100 percent as measured in transverεe plane cross sectionε, extends from the underneath sole portion through the conforming side portion at the forefoot at least through a sidewayε tilt angle of 20 degreeε.

Inventors: ELLIS FRAMPTON ERROLL III, ELLIS, FRAMPTON, ERROLL, III
Applicants: ELLIS FRAMPTON ERROLL III, ELLIS, FRAMPTON, ERROLL, III
Application year: 1996
Main classification: A43B13
IPC codes: A43B13