FOOTWEAR OUTSOLE HAVING ARCUATE INNER-STRUCTURE

Abstract

An outsole having a body member with an inner-structure including arcuately shaped channel members extending substantially from the medial to lateral sides thereof. The arcuately shaped channel members are spaced forwardly, rearwardly, and generally below the metatarsophalangeal joints of a wearer's foot inserted in footwear constructed from the outsole. The lower surface of the outsole has structure which provides formed areas of flexion to accommodate changes of anatomical position of the metatarsal joint axis of the wearer's foot during normal growth thereof and to permit the outsole to readily flex at areas which correspond to areas of the wearer's foot which normally flex as the foot passes through normal phases of gait, to thereby enhance the wearer's

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates generally to footwear and, more specifically, without limitation, to an outsole for footwear.

[0003] 2. Description of the Related Art

[0004] Various man-made products are generally imposed between a user's feet and supporting surfaces situated there beneath. Optimally, these man-made products should be designed to provide support and shock attenuation to protect the user's feet from structural injury. Unfortunately, man-made supporting surfaces tend to be detrimental to the human musculoskeletal structures.

[0005] As disclosed in U.S. Pat. No. 4,272,899, issued Jun. 16, 1981 to Jeffrey S. Brooks, the disclosures and teachings of which are incorporated herein by reference, a contoured insole structure may be provided in shoes to reduce abnormal stress from the heel to the metatarsals by properly supporting and stabilizing the feet during development. Proper support and stabilization reduces the associated stresses placed upon the medial column of the foot and distributes the body weight more evenly on the sole of the foot.

[0006] More specifically, when walking or running, the lateral (outside) portion of the human heel is generally the first part of the foot to strike the ground, with the foot then pivoting on the heel such that the lateral part of the forefoot bears against the underlying surface. In this position, the foot is supinated—inclined upwardly from the lateral to the medial side of the foot. The foot then pronates such that the metatarsal heads are in a substantially horizontal planar orientation relative to the underlying supporting surface (assuming the supporting surface is substantially horizontal) and the heel, ideally, is oriented perpendicularly to that underlying surface. As such, the foot is in a neutral position with the subtalar joint neither pronated nor supinated. Preferably, the bone structural alignment is firmly supported when the foot assumes such neutral position to prevent the ligaments, muscles and tendons of the foot from becoming over-stressed.

[0007] Various skeletal characteristics of the feet are pertinent to proper foot support, including: first, second, third, fourth and fifth metatarsal heads, indicated in phantom at M1 through M5 in FIG. 1; first, second, third, fourth and fifth metatarsal necks associated with the respective metatarsal heads M1-M5, indicated in phantom at N1 through N5; first, second, third, fourth and fifth proximal phalanges spaced distally outwardly from the respective metatarsal heads M1-M5, indicated in phantom at P1 through P5; and first, second, third, fourth and fifth metatarsal phalangeal joints spaced between the respective metatarsal heads M1-M5 and proximal phalanges P1-P5, indicated at J1 through J5 in FIG. 1. Further, various muscles and tendons interact to stabilize the foot during the sequence of progressive movements normally experienced in a walking or running gait in preparation for movement from the neutral position to a propulsive phase of the gait cycle, sometimes referred to as “toe-off” or “push-off”.

[0008] Thus, the progressive phases of gait are heel strike, when the heel hits the ground; midstance (or the neutral position), when stability of the arch is an essential necessity; and propulsive phase (or toe-off), as the heel lifts off the ground and the body weight shifts onto the ball of the foot. During the transition from the neutral position through toe-off, it is preferable that the second and third metatarsals be firmly supported, and that the first metatarsal head plantarflex (move downward) relative the second and third metatarsal heads. The toes preferably are firmly supported during toe-off so that they remain straight, and thus promote a stronger “pillar effect” by the phalanges.

[0009] Flexion of the first metatarsal phalangeal joint (i.e., the great toe joint) is normally approximately fifteen degrees to the associated metatarsal in a dorsiflexed position when standing, and increases to between sixty-five and ninety degrees, depending on the available motion and the activity required by the joint just prior to lifting off the underlying supporting surface. Proper foot care requires that the relationship among the foot bones comprising the metatarsophalangeal joints be maintained during flexure of the foot during walking, running, etc. A study of the normal length pattern of metatarsal bones at the metatarso-phalangeal joints, based on 279 radiographs and reported in Clinical Foot Roentgenology, by Gamble & Yale, Williams & Wilkins Publishers, Baltimore, 1966, disclosed that the relative spacing of those joints approximate an arcuate relationship that may be generally described as a parabolic curve, as suggested by the dashed line designated by “A” in FIG. 1.

[0010] In ideal foot posture for minimal stress, the position in which the feet would normally realize greatest weight-bearing efficiency (including an optimal ratio of supination and pronation) is one in which the subtalar joint is approximately forty-two degrees from the transverse plane, approximately sixteen degrees from the sagittal plane, and approximately forty-eight degrees from the frontal plane, sometimes referred to as the neutral position hereinbefore mentioned. In such neutral position, the leg and calcaneus are perpendicular to the weight-bearing surface, and the knee joint, ankle joint and forefoot, including the plane of the metatarsal heads, are substantially parallel to the subtalar joint and to the walking surface.

[0011] In view of the foregoing, it should be obvious that the user's feet should be placed in their individually most efficient position to function properly and to reduce excessive strain not only on the feet but also on the lower body structure supported by the feet. Throughout the progressive phases of gait, certain parts of the feet are generally subjected to higher stresses and that other parts of the feet require different degrees of support for maximum biomechanical efficiency, particularly since high impact forces to the foot are generally transferred to other skeletal structures, such as the shins, knees, and lower back region. Control of the user's foot must begin in the heel and progressively proceed to the more distally situated parts of the foot, including providing stability of the forefoot and proper flexure of the metatarsophalangeal joints, in order for the foot to function properly through the normal phases of gait.

[0012] As the thickness of the outsole of a shoe is increased, the inability of the shoe to allow appropriate arcuate flexure at the metatarsal joints of the wearer's foot confined to thick-soled footwear becomes more pronounced. For example, such thick-soled footwear may arise from platform-type outsoles utilized on selected footwear styles. Because of the inability of platform- or thick-soled shoes to allow appropriate flexure at the metatarsal joints, the normal functions of the wearer's foot—and the resulting increased stresses and strains on the wearer's musculo-skeletal structure—may also be substantially pronounced. In that event, proficiency of a wearer's foot may be greatly reduced in footwear utilizing platform- or thick-soled footwear.

[0013] Thus, what is needed is an outsole for footwear which, even when having a platform-type structure, provides appropriate flexure at the metatarsophalangeal joints, an appropriate amount of support and shock attenuation for different regions of the foot to thereby provide a proper environment that promotes a balanced foot position for healthy postural and skeletal structural support thus allowing the parts of the foot to function in a way which provides maximum efficiency, to prepare the body for stresses normally subjected thereto, and to protect those parts of the foot which are subjected to high impact forces.

SUMMARY OF THE INVENTION

[0014] In an outsole for footwear, there is provided a body member having a medial side, a lateral side, a toe end, a heel end, an upper surface and a lower surface; the upper surface of the body member has an inner-structure including a plurality of arcuately shaped channel members having a substantially uniform fore-to-aft width and extending substantially from the medial side to the lateral side. The plurality of arcuately shaped channel members are generally uniformly spaced apart and are configured such that at least one channel member is spaced forwardly from metatarsophalangeal joints of a wearer's foot inserted in footwear constructed with the body member, at least one channel member is spaced rearwardly from the metatarsophalangeal joints, and intermediate channel members are spaced generally below the metatarsophalangeal joints.

[0015] The lower surface of the body member has formed areas of flexion to accommodate changes of anatomical position of the metatarsal joint axis of the wearer's foot during normal growth thereof and to permit the outsole to readily flex at areas which correspond to areas of the wearer's foot which normally flex as the foot passes through normal phases of gait, to thereby enhance the wearer's foot comfort.

PRINCIPAL OBJECTS AND ADVANTAGES OF THE INVENTION

[0016] Principal objects and advantages of the present invention include: providing an outsole that promotes arcuate flexure of a wearer's metatarso-phalangeal joints when confined to footwear constructed with such an outsole; providing such an outsole having arcuately shaped channels formed on the upper surface of such outsole and extending substantially from medial to lateral sides thereof for promoting such flexure therebetween; providing such an outsole that utilizes spacing between the respective walls of the channels to provide an appropriate amount of flexure between such channels; and generally providing such a device that is efficient in operation, reliable in performance, and is particularly well adapted for the proposed usage thereof.

[0017] Other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, which constitute a part of this specification and wherein are set forth exemplary embodiments of the present invention to illustrate various objects and features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a perspective view of an outsole in accordance with the present invention showing the arcuate channels of the inner-structure for a user's right foot;

[0019] FIG. 2 is a bottom plan view of the outsole showing flexion channels formed in the bottom surface of the body member in accordance with the present invention;

[0020] FIG. 3 is a top plan view of the outsole showing the arcuate channel members of the inner-structure;

[0021] FIG. 4 is a cross-sectional view of the outsole of the present invention taken along line 4-4 of FIG. 3;

[0022] FIG. 5 is a cross-sectional view of the outsole of the present invention taken along line 4-4 of FIG. 3 showing the outsole in a flexed position during the propulsion phase of gait;

[0023] FIG. 6 is a schematic illustration, showing a top plan view of an insole of a left shoe and illustrating the approximate position of the metatarsal and related bone structure of a user's left foot in relation thereto;

[0024] FIG. 7 is a schematic illustration, bottom plan view, showing the bottom surface of an outsole (for a left shoe) constructed in accordance with the invention; and

[0025] FIG. 8 is a reduced schematic view of the outsole of FIG. 2, indicating specific angles for proper placement of the lines of weakness.

DETAILED DESCRIPTION OF THE INVENTION

[0026] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.

[0027] The reference numeral 1 generally refers to a footwear outsole having an arcuate inner-structure in accordance with the present invention, as shown in FIGS. 2 through 4. The outsole 1 comprises a body member 13 having a generally planar upper surface 15 for comfortable stable support for an insole and related structure of the footwear, known to those having skill in the pertinent art and a lower surface 17. The outsole 1 generally has a medial side 23, a lateral side 25, a toe end 27, and a heel end 29.

[0028] The upper surface 15 of body member 13 has an inner-structure 35 having at least one arcuately shaped transverse channel member 37 extending continuously substantially from medial side 23 to lateral side 25, as shown in FIG. 4. The channel member 37 is defined by fore and aft walls, 38 and 40, respectively, and has a substantially uniform fore-to-aft width. Preferably, the fore-to-aft width for the channel member is approximately 3 millimeters. For some applications, however, it is to be understood that the fore-to-aft width of each channel member 37 may be non-uniform and, further, that the fore-to-aft widths of the each respective channel 37 may vary between channels 37.

[0029] The plurality of channel members 37 are configured in a forwardly convex arcuate shape, such as the approximately parabolic shape as shown in FIG. 3, in a position on the body member appropriate for the relative positioning of the wearer's metatarsophalangeal joint based on the wearer's age, gender, foot size. In addition, the plurality of channel members 37 are generally substantially uniformly spaced apart, such as approximately 8 mm for example.

[0030] Preferably, sole 1 includes four channel members 37 and are configured such that one foremost channel members 50 is spaced forwardly from the metatarsophalangeal joints of a wearer's foot inserted in footwear constructed with the body member 13, one rearmost channel members 52 is spaced rearwardly from the metatarso-phalangeal joints, and intermediate channel members 54 and 56 are spaced generally below the metatarsophalangeal joints to thereby accommodate flexure thereof. For a growing foot, the intermediate channel members 37 are preferably formed such that one such channel member substantially underlies the metatarsophalangeal joints of the youth and forwardly positioned channel members 56 is generally spaced apart by the amount of foot growth that can be accommodated without replacing the footwear utilizing the outsole 1, such as one-half shoe size for example. The precise position of each channel member 37 will be discussed hereinafter.

[0031] The inner-structure 35 also includes a plurality of small weight-reduction bores, such as those indicated in FIG. 3 at 43 to reduce the overall weight of the outsole. Weight-reduction holes 13 may be varied as desired in shape, number and location, as is well known in the industry. The weight-reduction bores 43 have a diameter of approximately 5 mm., for example, and are preferably positioned at the forefoot of body member 13 both forwardly and rearwardly from each of the plurality of arcuately shaped channel members 37. More preferably, weight-reduction bores 43 are formed in an arcuate relationship between each channel member 37 and extend substantially from medial side 23 to lateral side 25. Bores 43 positioned between two channel members 37 are appropriately spaced apart to provide desired support and are preferably spaced apart approximately 8 to 10 millimeters on center.

[0032] A common sole perimeter 45 defines the limits of both the upper surface 15 and lower surface 17, taking any of the usual shoe sole shapes (although not limited thereto), and includes portions defined for purposes of reference herein as the toe edge 27, heel edge 29, medial side edge 23 and lateral side edge 25. A sole peripheral member 47 is spaced along the perimeter 45 inwardly thereof. The medial- and lateral-most portion of each channel member 37 terminates at the peripheral member 47 before the perimeter 45.

[0033] Body member 13 further includes a first relief area 53, and a second relief area 57, each of which is connected to the peripheral member 47. The upper surface of body member 13 of sole 1 permits the foot to be as secure and stable as is necessary for appropriate flexing and movement of the bone structure throughout the phases of gait. First relief area 53 is formed to have less resiliency than peripheral member 47 to permit the first metatarsophalangeal joint to move vertically downwardly in walking, in conjunction with the flex line action described to permit proper foot flexion in walking. First relief area 53 may be annular, as shown, or have an alternative, broad, relatively flat shape. For example, cutout 53 may be rectangular, triangular, oval, etc., as long as it is broad enough, in the distal to proximal (longitudinal) direction to accommodate the plantar grade, or downward and proximal shifting of the transverse axis of the first metatarsophalangeal joint, as the foot grows, and in normal walking.

[0034] The resiliency of the first relief area is lessened by forming the relief area such that it gives upon encountering force. As shown, relief area 53 includes at least one and preferably more than one concentric annular members 59 that are attached at several intervals to body member 13 or another concentric annular member 59, as shown in FIG. 3. As the first metatarsophalangeal joint moves vertically downwardly, the annular wall 61 of each concentric member 59 is able to buckle slightly and thus give relative to body member 13.

[0035] Likewise, second relief area 57 is also formed to have less resiliency than peripheral member 47 to provide shock attenuation for the high impact force encountered upon heel strike. Preferably, second relief area 57 may be circular, as shown, or have an alternative, broad, relatively flat shape. The resiliency of the second relief area is lessened by forming the relief area such that it gives upon encountering force. As shown in FIG. 3, second relief area 57 includes at least one and preferably more than one concentric annular members 63 that are attached at several intervals to body member 13 or another concentric member 63. During heel strike, the annular wall 65 of each concentric member 59 is able to buckle slightly and thus give relative to the body member 13. It is to be understood that second heel area 57 may be rectangular, triangular, etc. without departing from the scope of the invention.

[0036] The arch support includes a flexure-reducing structure 58, such as a diagonal crisscross type structure as shown in FIG. 3, configured to reduce flexure in an area defined by a rearmost arcuate channel 52, peripheral member 47 and heel support 57. It is to be understood that the flexure-reducing structure 58 may have any other configuration or combination of configurations. One of the purposes for the flexure-reducing structures 58 is to provide suitable support for the wearer's foot while preventing excessive lateral, forward, and rearward deflection of the respective spaces of the outsole 1 when subjected to the wearer's weight and while, at the same time, providing shock-absorbing characteristics for cushioning impacts directed at the wearer's foot during various walking, running, and other activities.

[0037] The arch support further includes a stabilizing member 60, which spans the entire length and width of the arch-support area of the outsole 1. The stabilizing member 62, as shown in FIG. 1, may include a rigid piece of material, such as a stiff cardboard, that prevents the arch area from deflecting or flexing downwardly upon bearing the user's weight. It is to be understood that the stabilizing member may be formed on the lower surface of the body member and may be formed integrally with the body member.

[0038] The outsole 1 also includes a tread member 75. For some applications, it may be desirable to utilize a pattern in the bottom surface 17 of body member 13, and in particular, forming a pattern in the tread member 75, which further enhances flexure of the metatarsophalangeal joints promoted by the inner-structure of body member 13 as hereinbefore described.

[0039] With reference to FIG. 2, it will be seen that the bottom or outsole surface 17 has incorporated therein preferably four spaced apart flexion channels 60, particularly indicated at A, B, C, D, in the order shown, from the distal or toe end 27 of outsole 1 toward the proximal or heel end 29 thereof. It will be noted in the figures that each channel A, B, C, D extends substantially transversely in a very gentle arc (convex side directed distally from heel edge 33) entirely from the medial edge 23 to the lateral edge 25 of sole 1. This is the preferred arrangement. For reasons that will become clear, it is especially preferred that the two central channels, indicated at B and C so extend across the sole. Channels A and D, however, may be discontinued prior to reaching perimeter 45. Channels A and D may be effectively ornamental, such as painted on the sole, actually engraved into bottom sole surface 17, or even omitted altogether, although this latter option is not preferred. With reference to FIG. 5 it can be seen that channels A and D when engraved into the sole at least serve to some extent to assist with sole flexion, which is primarily the function of central lines B and C.

[0040] Although channels B and C are shown in FIG. 2 to be continuous and unbroken, they can also be broken, as long as they extend entirely across the sole and interrupt perimeter edge 47, as indicated, at both the medial and lateral sides; for example, as in the side views shown in FIGS. 4 and 5. This feature, of breaking the perimeter, is necessary in order to provide the optimal degree of flexibility to sole 1 along flex channels B and C.

[0041] Also, although flex channels B and C are shown as being relatively thin, they can be broader than shown, especially if warranted for a large size shoe, and may in some cases be formed as broader flex “areas.” However, it is expected that, especially in small children's shoes, flex channels B and C, at least, will be narrow grooves or channels formed in bottom surface 17.

[0042] FIG. 6 illustrates a bottom shoe pattern for determining the precise angles and spaced-apart placement of flexion lines A, B, C and D on bottom surface 17. As will be further seen and described hereafter, the specific positions of the flex areas, or lines B and C, is critical for appropriate foot flexion in footwear having outsole 1. Four straight dashed lines A′, B′, C′ and D′ correspond respectively to flexion channels or areas A, B, C, and D. Positioning lines A′ and B′ extend medially and intersect at point X, medially of sole 1. Likewise, positioning lines C′ and D′ extend medially and intersect at point Y, also medially of sole 1.

[0043] Two other straight lines, shown in FIG. 6, the bottom pattern center line G and the heel tread center line H, both extend substantially longitudinally and pass through a central heel point Z. The angles between longitudinal line G and positioning lines A′- D′, and between line H and lines A′- D′ are used in determining the proper placement of flexion channels A, B, C and D. Although it is understood that the spacing between the lines will necessarily vary proportionately with increases or decreases in shoe size, as a specific example, in a children's size seven shoe having the sole 1 of the present invention, the angles shown in the figure are as follows:

[0044] Angel M, between lines G and A′ is 93 degrees, 30 minutes.

[0045] Angle N, between lines G and B′ is 100 degrees, 0 minutes.

[0046] Angle 0, between lines G and C′ is 106 degrees, 30 minutes.

[0047] Angle P, between lines G and D′ is 113 degrees, 0 minutes.

[0048] Angle Q, between lines H and A′ is 86 degrees, 30 seconds.

[0049] Angle R, between lines H and B′ is 92 degrees, 30 seconds.

[0050] Angle S, between lines H and C′ is 99 degrees, 30 seconds.

[0051] Angle T, between lines H and D′ is 106 degrees, 0 seconds.

[0052] As shown in FIGS. 2 and 4, the flexion channels 60 of the lower surface 17 of sole 1 and the channel members 37 of the inner structure of the upper surface 15 are cooperatively configured to provide optimum flexibility for the sole. It is to be noted that the flexion channel of the lower surface may have a smaller width than the associated channel member 37.

[0053] Although a children's boot outsole is shown here as one example of the type of sole, sole 1 can also be just as readily incorporated into sandals, sports shoes of all types, oxford-style shoes, etc. Conceivably, even women's pumps and other shoes with higher heels can also be modified with the new sole 1.

[0054] The body member 13 is generally integrally molded or otherwise formed or constructed from one or more pliable materials that provides the desired flexure, cushioning, light-weightiness, physical characteristics, wearability, slip resistance, durability for long use, and relative inertness. For example, the body member 13 may be formed of any suitable material, such as DPU sometimes referred to as blown thermoplastic rubber, polyurethane, TPR, PVC, EVA or other material well known to those of ordinary skill in the art of footwear.

[0055] It is to be understood that the length, width and vertical thickness of any particular outsole 1 may vary as is customary, depending upon the application and size of footwear for which that outsole 1 is intended. An example of outsole 1 may include a body member 13 having a thickness of approximately eight millimeters, a stabilizing member 62 having a thickness of approximately four millimeters, and a tread member 75 having a thickness of approximately six millimeters.

[0056] The arcuate structure of the channel members 37 and flexion channels 60 of the body member 13 provide the outsole 1 with the desired ability to permit a user's foot to be secure and stable as necessary while promoting appropriate flexing and movement of the metatarso-phalangeal joints throughout the supported phases of gait, even in platform footwear that would not otherwise provide such security, stability, and flexure. In addition, the outsole 1 comprises a structure configured to attenuate impact forces applied to the user's foot and other skeletal structures during standing, walking and running.

[0057] In an application of the present invention wherein the outsole 1 is appropriately fitted to a footwear upper and worn on a user's foot, some of the primary benefits provided thereby while walking and running begin at heel strike, when the heel of the user's footwear first hits the underlying supporting surface. After each such initial impact, the user's foot pivots distally about his heel, with the lateral sides of his arch and forefoot impacting against the underlying supporting surface and his foot pronating to a neutral position with the central vertical plane of his heel generally appropriately oriented perpendicularly to the underlying supporting surface. Resiliency of the herein-described components of the outsole 1 provides cushioning for the shocks arising from such secondary impacts.

[0058] the resiliency of the body member 13 beneath the user's metatarsal heads M1-M5 also serves to attenuate and/or redistribute weight-generated forces applied there against during mid-stance through propulsive phases of his gait cycle. The described motion places the user's foot in an appropriate biomechanical position for the propulsive phase of his gait cycle during midstance and toe-off phases.

[0059] As the user's foot rotates forwardly into the toe-off phase, the body member 13 promotes appropriate natural arcuate flexure of the metatarso-phalangeal joints while providing necessary support for the wearer's foot to remain stable as the user's heel lifts from the underlying supporting surface, and continuing to remain stable and appropriately flex up to the position in the user's gait whereat the metatarsophalangeal joints lift from the underlying supporting surface.

[0060] One of the primary reasons the user's foot remains stable throughout the supported phases of his gait is because the structure of the outsole 1 provides support and stability from before the user's foot rotates forwardly, during the lifting of the heel from the underlying supporting surface, to the point in the user's gait where the user's first metatarsal actually lifts from the underlying supporting surface. Thus, the outsole 1 appropriately allows the user's foot to function within the confines of his shoe.

[0061] It should be obvious from the foregoing that the material properties of the various regions of the outsole 1 appropriately flex, cushion, support and stabilize various parts of the user's foot as herein described. It should also now be obvious that the resiliencies may be altered, depending upon the intended use of the footwear for which the outsole 1 is intended without departing from the scope of the present invention. Further, it will be appreciated that the present invention is not limited necessarily to any particular type of footwear and may be equally desirable for use in shoes and boots, particularly those having thick- or platform-type soles.

[0062] It is to be understood that the invention described herein is equally applicable to outsoles for footwear for infants, toddlers, and youth as well as adults and that, while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts as described and shown.

Claims

1. An outsole for footwear, the outsole comprising a body member having a medial side, a lateral side, an upper surface and a lower surface,

(a) the upper surface comprising an inner-structure having at least one arcuately shaped transverse channel member extending substantially from said medial side to said lateral side, wherein said at least one arcuately shaped transverse channel member is configured to be spaced approximately below the metatarso-phalangeal joints of a wearer's foot inserted in footwear constructed with said body member; and

(b) the lower surface having structure providing formed areas of flexion to accommodate changes of anatomical position of the metatarsal joint axis of the wearer's foot during normal growth thereof and to permit the outsole to readily flex at areas which correspond to areas of the wearer's foot which normally flex as the foot passes through normal phases of gait, to thereby enhance the wearer's foot comfort.

2. The outsole of

claim 1 wherein the inner structure of the upper surface provides a stable structure for receiving an insole.

3. The outsole of

claim 1, wherein the structure providing formed areas of flexion comprises at least first and second paired channels formed into the lower surface of the outsole.

4. The outsole of

claim 3 wherein said at least one arcuately shaped transverse channel member extending substantially from said medial side to said lateral side comprises at least first and second paired arcuate shaped channel members.

5. The outsole of

claim 4 wherein said at least first and second paired channels formed into the lower surface of the outsole and the at least first and second paired channels formed in the upper surface are cooperatively configured such that a proximal wall member of each of said paired channels of the lower surface and said paired channel members of the upper surface are in planar relation.

6. The outsole of

claim 2 wherein the inner-structure of the upper surface further comprises a first relief area formed into the upper surface at a position beneath the ball of the wearer's foot to accommodate downward and proximal movement of the user's first metatarsal to thereby cooperatively enhance flexion of said outsole.

7. The outsole of

claim 6 wherein the first relief area comprises a plurality of spaced-apart, concentric annular members formed into the upper surface at a position beneath the ball of the wearer's foot.

8. The outsole of

claim 6 wherein the inner-structure of the upper surface further comprises a second relief area formed into the upper surface at a position beneath the heel of the wearer's foot.

9. The outsole of

claim 8 wherein the second relief area comprises a plurality of spaced-apart, concentric annular members formed into the upper surface at a position beneath the heel of the wearer's foot.

10. An outsole as provided in

claim 1, wherein said at least one arcuately shaped of the upper surface has a substantially uniform fore-to-aft width.

11. An outsole as provided in

claim 10, wherein said fore-to-aft width of said arcuately shaped rib is approximately three millimeters.

12. An outsole as provided in

claim 4, wherein said at least first and second paired arcuately shaped channel members are approximately spaced apart by the amount of generally acceptable grown of the wearer's foot without replacement of the footwear utilizing said outsole.

13. An outsole as provided in

claim 4, wherein said at least two arcuately shaped channel members are spaced relative to said body member such that at least one of said at least two arcuately shaped channel members is spaced forwardly from the metatarsophalangeal joints of the wearer and at least one of said at least two arcuately shaped channel member underlies the metatarsophalangeal joints of the wearer.