WO2009064286A1

WO2009064286A1 - Multiple leaf spring assembly for foot support, and footwear and brace using same

Info

Publication number: WO2009064286A1
Application number: PCT/US2007/084488
Authority: WO
Inventors: Ian Engelman
Original assignee: Insightful Products
Priority date: 2007-11-13
Filing date: 2007-11-13
Publication date: 2009-05-22

Abstract

A spring assembly for footwear, the assembly comprising an upper support coupled to at least two lower leaf springs, each capable of individually engaging the ground, and each acting as individual suspension and energy absorber while being free to travel substantially independently from the other within a range. Optional aspects of the invention include the lower leaf springs being adjustable, and footwear and/or ankle-foot orthosis utilizing the spring assembly, locating the active spring area substantially under the midfoot region of a wearer.

Description

Multiple Leaf Spring Assembly for Foot Support, and Footwear, and Brace Using Same

Filed of the invention

[0001] This invention relates generally to footwear, and more particularly to footwear having a plurality of leaf springs for cushioning.

Background of the Invention

[0002] The human foot evolved over millions of years of walking primarily on surfaces that were not flat. It evolved for uneven soft terrain that was more forgiving like grass, dirt, and mud. Moreover, the human foot was not meant to last more than 40 years which was the average life span for millions of years. It is only in the recent century that humans regularly subjecting their feet to hard flat surfaces such as concrete. The shoe industry has not addressed that change well, and only recently do we see some new developments that divert from the basic shoe design.

[0003] The Z-coil® shoe (I need a Z-Coil Footwear, Albuquerque, NM) has improved the interface between the foot and the flat surface. This shoe utilizes a frustu-conical tubular still coil spring that is attached to the heel portion of the shoe, at the narrow side of the cone. The wider side of the cone is connected to a heel pad. The coil collapses within itself to provide for more excursion and shock absorption than one gets through a normal coil spring. The limitation of this design is the lack of good lateral stability. This instability has caused the company to deliver its product primarily through trained specialists that will set the spring in an orientation that matches the individuals side to side stability needs.

[0004] The efficiency of ambulation will be, in part, related to the up and down movement of the center of gravity of the human body, which will be related hereinafter as the vertical body mass movement. Efficiency requires minimizing that vertical body mass movement as this motion leads to poor endurance and increased fatigue.

[0005] US 6,782,639 to Mϋller discloses a shoe which provides good lateral stability by providing a rocker sole that is relatively flat in the coronal plane. The shoe also provides for shock absorption through the incorporation of a highly deformable and flexible material with good recovery effect. The limitation of this design is that it provides little if any assistance to the user, with respect to repositioning the user center of gravity. The user benefits from shock absorption at the heel strike, but is then left to climb out of that 'hole' with every step. The vertical mass movement is larger than normal. The coil spring is better at returning the center of gravity upwards to reduce the requirements of the body to bring the center of gravity to the desired height required for the next step.

[0006] Another consideration is the difference in requirements for standing and walking. In standing, posterior support is desired. During walking, that posterior support is not desired. The Mϋller rocker sole is adequate for walking, but does not provide the posterior support while standing. The spring like solutions solve that issue by making use of the fact that the ground reaction force is several times greater at impact. The spring will deflect while walking and functionally reduce that posterior support. However, the stiffness of the spring can be sufficient to provide posterior support while standing.

[0007] IN US 6,449,878, Lyden discloses an article of footwear having a single spring element to improve cushioning, stability, and running economy. The leaf spring element comprises a superior spring element and an inferior spring element affixed in function relationship to the superior spring element.

[0008] In US 5,875,567 Baylely discloses a shoe with a composite single leaf spring heel. The spring is a V-shaped composite assembly, including an upper plate underlying at least at the heel of the wearer's foot and lower plate integrally joined to the upper plate at the apex of the V-shaped spring assembly.

[0009] In US 5,437,1 10, Goldston et al. discloses an adjustable shoe heel single spring and stabilizer device, which provides the wearer of a shoe the ability to adjust the energy absorption and return characteristics of the shoe to suit their particular needs. An operable adjustment device is located on an exterior surface of the shoe. The wearer operates the adjustment device to selectively position a fulcrum at a desired location relative to upper and lower members of a spring mechanism disposed within the mid-sole of the shoe. The position of the fulcrum defines the energy absorption and return characteristics for the shoe. [0010] In US 4,566,206, Weber discloses an undamped spring having multi-spring rates in the heel support portion of a shoe, for resiliently compressing under heel pressure against the ground and returning a substantial portion of the energy of the pressure to the wearer's foot. The spring is formed of upper and lower leaf-like legs which are integrally joined together at an acute angle whose apex is directed forwardly relative to the shoe. An intermediate leaf-like leg is located between and integrally joined with one and extended towards the other of the upper and lower legs. Thus, heel pressure compresses the upper leg towards the lower leg until the intermediate leg is engaged and, thereafter, spring compression continues at an increased spring rate. However the springs in Weber, and in all leaf spring based solutions above, utilize a single spring loaded surface for substantially the width of the ground contact area.

[0011] In 4,492,046, Kosova discloses a running shoe with a longitudinal slot in the sole extending from its back edge into the arch region and dividing the shoe sole into upper and lower segments. A spring wire in this slot decreases the velocity of the heel impact and then, as the runner's weight shifts forward onto the ball and toes of the foot, launches the runner into a comfortable stride and reduces stress. At the heel and arch areas of the foot, the sole is at least as thick as in the ball area. This spring is a one- piece continuous wire of flexible and resilient spring metal having upper and lower halves. The rear end segments of the lower half of the spring are received snugly in corresponding bores formed in the lower section of the shoe sole a short distance forward from its rear edge. The bore which receives spring segment 18' is shown in FIG. 3. The rear end segments anchor the lower half of the spring in the lower section of the shoe sole. It will be apparent that the lower half of the spring moves in unison with the lower section 16 of the shoe sole, thus effecting a motion nearly equivalent to a single spring, due to the snug fit within the relatively thick sole. Clearly, both sides of the wire spring move in substantial unison.

[0012] In US 6,925,732 Clarke discloses an article of footwear with an upper and a sole structure. The primary components of the sole structure are a midsole and a frame element. The midsole is connected to the upper in a forefoot region of the footwear, but is unconnected to the upper in a rearfoot region of the footwear. The frame element is structured to extend onto a heel portion of the upper and around the heel portion to thereby stabilize the heel portion. The frame element may serve as a spring that provides cushioning in combination with the midsole. The configuration of the frame element, which extend onto the heel portion of the upper, leaves a lower surface of the upper exposed to permit direct contact with the midsole. The frame is shown to have a relief for the heel portion, to increase comfort.

[0013] Each person has a different requirement for redirecting the ground reaction force through the ankle and knee joints. Those requirements change according to personal step length, weight and activity level, as well as personal preferences. While there have been many solutions for shock absorption for a shoe, including utilizing resilient material, coil wire springs, tubular springs, and leaf springs, these existing solutions do not provide sufficient solution to solve the problem described above.

[0014] The term ground reaction force is well known to mean the direction and magnitude of the center of pressure in single or double limb stance phase. The location and direction of this force vector as it passes near the ankle and knee joints in single limb stance will determine the amount of energy it will take to stabilize that joint. For instance, if the ground reaction force vector goes near the ankle joint, little muscle activity is needed to resist plantarflexion. In a shoe that has a stiff heel or a more posterior placement of the spring mechanism, a more posterior location of the ground reaction force vector it produced. This will increase the moment of force on the ankle joint and more effort is needed for the walker to resist foot slap.

[0015] A single spring solution, or a solution that acts like a single spring in terms of the forces operating on the foot, is not preferred since it does not adequately address the side to side stability required for good support.

[0016] Furthermore, current Ankle Foot Orthosis (AFO hereinafter) design is forced to work with the structure of footwear that oftentimes does not address specific weaknesses of the individual. Even in footwear customized for a specific wearer, the limitation of the footwear design often dictate the AFO design. It would therefore be desirable to provide an AFO that may be incorporated to footwear, or otherwise coupled thereto, so as to provide easy adjustment to the wearer specific requirements while providing shock absorbing capacity and vertical mass movement assistance. [0017] Therefore, there is a yet unfulfilled need for a foot support spring assembly that will provide cushioning, energy absorption and pretension, and provide propulsion assistance during the phase of uplifting of the foot.

Summary of the invention

[0018] Thus it is an objective of an aspect of the present invention to overcome the shortcomings of the above described art, by providing a spring assembly for foot support, which provides cushioning, energy absorption and pretension, and provide vertical mass movement assistance.

[0019] It is a further objective of another aspect of the present invention to provide an AFO that may be incorporated to footwear or coupled thereto, so as to provide easy adjustment to the wearer specific requirements while providing shock absorbing capacity and vertical mass movement assistance.

[0020] It is yet another objective of an aspect of the present invention, to provide a spring assembly for foot support which may be incorporated into footwear, may be attached or otherwise coupled to footwear, or may be used with an AFO.

[0021] To that end, in a simple form, there are provided at least two leaf springs posteriorly extending substantially parallel to each other. The springs extend substantially along the longitudinal axis of the shoe, or at a slight angle thereof. At least the active regions of the lower springs are allowed to move substantially independently from each other, within a cushioning range. Stated differently, the active regions may individually engage the ground without connectively interacting with each other in a manner that will impede their independent cushioning action.

[0022] The term cushioning range means the range in which the springs can flex from a rest position, to the extent of flexing responsive to a downward pressure by the body weight. Directional terms such as horizontal, vertical, forward and aft should be considered to have their common and regular meaning, when the assembly is used by a wearer and relating to the common wearer standing or walking posture.

[0023] The independent dual action springs may be likened to an independent suspension on a car. Each spring can absorb impact with minimal effect on the other. Moreover, the wider base of support will naturally provide more stability. A good analogy is waterskiing. A skier with one ski has to have much more skill and balance than a water skier with two.

[0024] Thus, in a preferred embodiment of the invention, an upper support surface or surface is provided, forwardly extending from a posterior extent, preferably by the heel. The upper support surface is preferably a spring. In it's forward portion, the upper support surface is coupled to at least two generally longitudinally and rearwardly extending lower springs, wherein each of the posterior portions of the lower springs are able to move substantially independently from each other.

[0025] Therefore, in a first aspect of the invention, there is provided a spring assembly for foot support comprising an upper support having a posterior portion and an anterior portion, and a longitudinal and traverse axis. A plurality of lower leaf springs disposed below said upper support, generally extending rearwardly, and substantially parallel, in at least a portion thereof, to the longitudinal axis. At least one coupler couples at least one of said plurality of leaf springs to said upper support, however preferably each of the plurality of the leaf springs is coupled to the upper support by its own coupler. The lower springs extend at least in part of their length, substantially parallel to the longitudinal axis. At least two of the lower springs have an active region for engaging ground, and the active regions are free to move vertically, substantially independently from one another within a certain cushioning range. Thus if one considers two such lower leaf springs, each of the two springs is capable of substantially independently, resiliently resist the force applied thereto against the ground, in response to stepping or standing by the wearer's stepping or standing weight.

[0026] Optionally, the upper support comprises a leaf spring. Further optionally, the longitudinal position of at least one of said active regions is adjustable relative to at least an active region of at least one other of the plurality of lower springs.

[0027] A further option contemplated by the invention provides an opening in the posterior portion of the upper support. The opening is positioned to be below a wearer calcaneus, creating a calcaneus 'window', to provide relief for the calcaneus.

[0028] The lower springs are optionally replaceable. [0029] An optional embodiment of the invention extends to the spring assembly having an attachment for coupling said assembly onto an article of footwear. The selection of such attachment is a matter of technical choice. Many ways are known for such attachments, including but not limited to, straps, clips, glue, fasteners, and the like, and the invention is not limited to any specific coupling method but encompasses all appropriate methods.

[0030] Thus, it is also an aspect of the present invention to provide a footwear article incorporating the spring assembly, wherein at least a portion of the spring assembly, such as the upper support, is integrated at least partially within the sole of such footwear.

[0031] In an optional aspect of the invention, the footwear article described above further comprises at least one vertical support member extending upwardly from the footwear. A leg support member is coupled to said vertical member, so as to form an ankle-foot brace integrated into the footwear article.

[0032] In yet another aspect of the invention, there is provided an ankle foot orthosis (AFO), also known as ankle-foot brace, comprising a spring assembly as described above, the ankle foot brace comprising at least one vertical support member coupled to the upper support, and a leg support member coupled to the vertical support member. The AFO may further comprise an attachment operative to attach the brace to a footwear article.

[0033] Yet another aspect of the invention provides a method for redirecting the ground reaction force to fit individual requirements of a wearer, the method comprising the steps of:

providing a spring assembly as claimed in any of claims 3-5, said spring assembly being integrated into footwear or a brace, or being added on as attachment to a footwear article; individually adjusting the longitudinal location of at least one of said active regions of at least two of said lower springs, to redirect the ground reaction force to fit said requirements of said wearer. [0034] The most preferred embodiment of the invention has three leaf springs, two retaining collars, and two screws. The upper spring 6 in fig. 1 is curved so that is slightly higher than that of a normal shoe. Although most of the flexion will take place in the two lower leaf springs, the upper leaf spring may flex to a position that is of normal heel height when the wearer's weight is applied. The two lower springs will be able to slide through their respective collars 3, that will keep the two springs from separating in the front. Each spring will be secured at a second point behind the collar by a screw 51.

Short description of drawings

[0035] The summary above and the following detailed description will be better understood in view of the enclosed drawings which depict details of preferred embodiments. It should however be noted that the invention is not limited to the precise arrangement shown in the drawings and that the drawings are provided merely as examples.

[0036] Fig. 1 shows the side view of a preferred embodiment of the invention as applied to footwear.

[0037] Fig. 2 shows a rear view of the preferred embodiment of the invention.

[0038] Fig. 3a and 3b show optional embodiments of a coupler for coupling the upper and lower springs.

[0039] Fig. 4 shows a cut of the spring assembly integrated in footwear, the cut along line A-A of Fig. 1.

[0040] Fig. 5 shows a top view of a preferred embodiment.

[0041] Fig. 6 shows a bottom perspective view of yet another embodiment, showing an optional heel stress relief window, and offset adjustment type lower springs.

[0042] Fig. 7 shows a Ankle-Foot Orthosis (AFO) style brace utilizing the spring assembly.

[0043] Fig. 8 depicts a bottom view of the embodiment of Fig. 7, as applied to footwear. [0044] Fig. 9 is yet another embodiment of the invention used with an AFO. [0045] Fig. 10 is a bottom view of the embodiment of Fig. 9. Detailed Description

[0046] The following embodiments will be described in details by way of guidance and example to assist the skilled person in implementing certain aspects of the invention.

[0047] Different aspects of the present invention provide a unique system and approach which provides correction more effectively and more comfortably than solutions previously known in the art. Certain novel and unique feature, alone or in combination, create stable and more comfortable footwear or brace.

[0048] It is noted that the different aspects of the invention as described are appropriate for integration into footwear or an assembly thereon. Thus for example different aspects and embodiments of the invention may be incorporated into footwear during manufacturing, or attached thereto after manufacturing, into specially formed shapes, holes, and the like, to allow for easy integration. However those skilled in the art will recognize that many techniques exist to attach most if not all of the embodiments disclosed herein onto an existing shoe, by means of fasteners, straps, slots, and the like. It is also noted that while for convenience the different aspects of the invention are described or shown in relation to a shoe, that the invention is equally and easily adaptable for incorporation or attachment to any footwear such as, by way of a non- limiting example, to sneakers, boots, running shoes, bowling and other sport specific shoes, sandals, moccasins, work shoes and the like. The reference for shoe should therefore be construed as extending to all footwear.

[0049] As described above, the spring assembly described herein is suitable for use, either by direct attachment during manufacturing, or at a later stage, to an ankle foot orthosis.

[0050] Fig. 1 is a lateral depiction of an embodiment of the invention incorporated into a shoe 7. An upper support 6 is incorporated into the sole 2 to extend forwardly from a posterior extent about the heel. Preferably, the upper support 6 comprises a leaf spring, so as have some flexibility and add to the shock absorption quality of the invention. It is not necessary for this upper support to flex in order to achieve some of the benefits of this invention. [0051] Optionally, the upper support can also include an opening 91 that will create a relief for the calcaneus of the wearer hind foot.

[0052] At least one coupler 3 couples a plurality of lower springs 5 to the upper surface. Preferably a coupler 3 is provided for each lower spring. The coupler secures the lower spring and upper surface. The coupler preferably comprise a collar surrounding the spring, either completely or partially, but it may also comprise one or more fasteners, a glued, bonded, welded, or otherwise adhered area, and the like. Couplers 3 are preferably constructed of carbon fiber filaments wrapped around a form to create the tunnel dimensioned to accept both the upper support 6 and the lower leaf spring 5. The construction of the coupler 3 is a technical choice dictated by such choices as economy, material used, weight, required strength, and the like, and different couplers and/or coupling methods may be used and will be clear to the skilled in the art. In one embodiment, shown in Figs. 3A and 3B, coupler 3 is further used to affect spring adjustment.

[0053] The plurality of lower springs 5 extend substantially longitudinally and rearwardly, each terminating near an active region 5a. Lower springs 5 are leaf springs. Preferably the lower springs are parallel to each other and to the longitudinal axis of the spring assembly. A lower spring 5 operate to resiliency resist at least forces tending to bring the active region 5a of the lower spring 5 closer to the upper support in the vertical plane. The active region should be construed broadly as the region at, and, or near the posterior end of the lower springs, and may include the ends themselves and the spring region that engages the ground either directly or via a cushion or cover, during the wearer movement. The lower springs 5 are preferably separated in their active regions 5a, but may be connected in such a supple manner so as to allow the active region of one spring to act substantially independently from the active region of another spring, within the cushioning range. Thus, each active region 5a is free to move throughout its resilient cushioning range within the constraints of the structure, but with minimal, or preferably, no effect on the other spring active region. Furthermore, a bottom pad 88 may be placed on the active region to prevent floor scuffing, provide more traction, and the like. [0054] For clarity the rest of the specifications shall describe embodiments of the invention with two such longitudinal lower springs. The use of only two such lower springs is done merely for clarity and should not be interpreted as limiting the embodiments of the invention to any greater number of lower springs.

[0055] The term leaf spring relates generally to a spring having a width that is significantly larger than its thickness, and which generally comprises a plurality of layers of spring material laminated or otherwise bound together. The lower leaf springs 5 are preferably constructed with carbon fibers in a thermoset or thermoplastic arrangement. The leaf spring should have the flexibility and resiliency to withstand many step cycles.

[0056] Preferably, the lower springs 5 longitudinal location is adjustable, so as to allow adjustment of individual lower spring effective length adjustment. The effective length is the length of the active part of the lower spring that flexes under pressure during the movement of the wearer, between an anchor point and the end at or near the active region 5a. Such adjustability will allow obtaining an optional objective of the invention which provides a customized response and feel of the footwear to the wearer. Thus for example adjusting the medial lower spring forward, will compensate for a wearer tendency to step with an internally rotated foot. Conversely, an adjustment of the medial spring towards the rear, will compensate for a wearer who has a tendency to walk with a foot that is externally rotated.

[0057] Adjusting the lower springs longitudinal location may be established in a variety of ways known in the art. In its simplest method such adjustment may be achieved by replacing the lower springs with springs of varying lengths. Preferably, the lower spring location relative to the upper support is adjustable by moving the spring to a desired location and securing it in place. Two such methods shall be described herein by way of non-limiting examples. The skilled in the art shall recognize that many variations exist for fixing a leaf spring to the upper support, and the invention extends to the use of any suitable coupler, and to any common method of adjustment regardless of that technical choice.

[0058] The first method of providing adjustability to the lower springs 5 involve having a plurality of holes 52 in each spring. Alternatively, an elongated hole may be provided (not shown). The couplers 3 allow a sliding movement of the lower springs 5 along a substantially longitudinal axis. This may be achieved by having the couplers formed with a cavity oriented substantially along the longitudinal axis of the spring assembly, with the cavity being dimensioned to allow the spring longitudinal movement therein, thus forming a 'tunnel' 8 in which lower spring 5 can be moved so as to adjust the location of the active region 5a. One of the holes 52 is aligned with corresponding hole 41 on the lower structure. A holder 51 may then be inserted to fix the spring 5 in location. While the holder may be a pin, or any other fixing device, it is preferably a screw wherein hole 41 is internally threaded, and the screw engages those threads. When the spring assembly using this embodiment is integrated within a shoe, a cavity 4 is preferably provided in the sole 2, to allow easy adjustment. Preferably a cover (not shown) is also provided to prevent dirt from interfering with the adjustment mechanism.

[0059] Fig. 2 depicts a rear view of the spring assembly. The drawing shows the desired relationship between the spring assembly and the shoe, whereby the upper support 6 is embedded within the sole, below the shoe 7. The drawing depicts the right hand lower spring in the extended, down position, and the left hand spring removed to show the 'tunnel' 8 into which fits one of said leaf springs 5.

[0060] Figs. 3a and 3b depict an alternative manner of achieving adjustment, wherein the coupler is formed as a collar surrounding lower spring 5. A threaded bore 54 is provided in the collar, either on the side as shown in Fig. 3A or on the top or bottom as shown in Fig. 3B. A screw 53 engages the thread of threaded bore 54, so as to allow the lower spring 5 to move longitudinally within the tunnel 8 when the screw is slacked, and to hold the lower spring 5 securely when the screw 53 is tightened. While fig. 3B depicts the crew placed above the spring and going through a hole in forward arm 9 of upper support, the screw 53 may be inserted from below as well. It will also be clear that while the threading is shown in the coupler, threading may be present in the upper support, and achieve similar results. Preferably, the screws are set screw type that may blend well within the supporting structure. The above features will be clear to the skilled in the art and are thus not shown.

[0061] Fig. 4 is a cutaway view along the cut line A-A of Fig. 1. It depicts more clearly the first method of providing adjustability to the lower springs 5. Spring 5 has a plurality of holes 52 therein. At least one hole 41 in the upper support 6, or a forward arm 9 thereof, is threaded or otherwise constructed to hold a holder 51. The sole 2 has a cavity 4, which allows insertion and removal of a holder 51. Holder 51 is preferably a screw which screws into hole 41. Alternatively, holder 51 may be screwed into a threaded hole in the footwear 7. Further, a threaded nut may be affixed to the portion 9 of the upper support. Preferably a cover is provided to close cavity 4 from debris, dirt, and the like. Alternatively, a holder 55 may be inserted from the top of the assembly, preferably from inside the footwear when the assembly is integrated to it.

[0062] Fig. 5 is a top view of the spring assembly, showing the preferred embodiment of the upper support 6. As noted above, while the upper support 6 may be any simple support structure, it preferably comprises a leaf spring, and more preferably it comprises in its anterior portion a split structure with left and right forward arms 9, onto which the lower springs 5 couple via couplers 3. A calcaneus window 91 provides relief for the calcaneus of the wearer hind foot.

[0063] Fig. 6 is a bottom oblique view of the embodiment of fig. 5. While all the parts are shown for clarity of the relationship between the footwear 7 and the spring assembly, it is noted that the spring assembly may be incorporated partially or as a whole within the shoe. Further, Fig. 6 depicts optional pads 88 coupled to the active regions 5a of springs 5. The pads may be provided for improved traction, preventing scuffing, and the like. The pads are preferably made from common footwear sole material such as rubber, leather, and the like.

[0064] Figs. 7 and 8 depict another aspect of the invention as an Ankle Foot Orthosis (AFO), commonly known as a brace. The brace uses a spring assembly similar to the spring assembly provided for the footwear as described above, however it further includes two vertical supports 107, extending above the ankle, and terminating with a leg support 104. The leg support has a calf strap 1 1 to allow securing the leg support to a wearers calf. In the preferred embodiment shown, a cross-member 102 extends substantially transversely across the spring assembly, and couples the vertical members 107 to the spring assembly. A longitudinal member 101 extends forwardly from cross- member 102, and is coupled to upper support 6 with fasteners 32 and 33, thought holes 42 and 43 respectively. It is noted that other arrangements for attaching the upper brace structure to the spring assembly may be used, such as welding, riveting, and the like, and the example provided herein is provided by way of non-limiting example.

[0065] Fig. 7 is directed to a strap-on arrangement that may be strapped to any common footwear, using straps 74 and 75. It is noted that while straps 74 and 75 are used as footwear attachment, the skilled in the art will recognize a large number of ways for attaching the spring assembly to footwear. By way of example, such attachments may comprise screws extending into the sole, clips, cleats, various strapping arrangements, hook and loop attachments, gluing or bonding, and the like. As those attachments are considered equivalent to each other and judged by their function to attach the spring assembly to an article of footwear, and as those solutions are a matter of technical choice cleared to the skilled in the art, those methods are not detailed herein other than by the examples provided. Fig. 7 also depicts a supplemental rocker sole 77, which is desirous to provide smooth forward rolling motion.

[0066] Fig. 8 on the other hand, depicts a bottom view of a similar brace, but depicts yet another optional embodiment, wherein the spring assembly is incorporated within the footwear. One notes that all that is required to adapt a common footwear article which utilizes the spring assembly disclosed herein, is proving screw holes for attachment of the brace upper support to the upper support of the spring assembly. Threaded holes 99 show an alternative fastener positions to allow fore and aft adjustment of the spring 5 through the use of a top down orientation of screw 55 shown in Fig 4.

[0067] Figures 9 and 10 depict yet another embodiment of an AFO incorporating the spring assembly disclosed above. The primary differences between the embodiments of Figs. 9 and 10 are the replacement of vertical members 107 with a single vertical member 105, and the optional elimination of cross-member 102. The single vertical member 105 has a horizontal portion 201 , which couples to upper support 6 using fasteners which engage holes 42, 43.

[0068] Optionally, each of the lower springs may have a notch and/or may be keyed as to prevent the user from installing them the wrong way around.

[0069] Further optionally, the two leaf springs could be connected with crape or other sole material. [0070] Further optionally, the crape sole could extend rearwardly from the rocker section to provide a full length sole.

[0071] It will be appreciated that the invention is not limited to what has been described hereinabove merely by way of example. While there have been described what are at present considered to be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various other embodiments, changes, and modifications may be made therein without departing from the spirit or scope of this invention and that it is, therefore, aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention, for which letters patent is applied.

Claims

What is claimed is:

1. A spring assembly for foot support comprising an upper support having a posterior portion and an anterior portion, and a longitudinal and traverse axis; a plurality of lower leaf springs disposed below said upper support; at least one coupler for coupling at least one of said plurality of leaf springs to said upper support; wherein said lower springs extending generally rearwardly, and being at least in part of their length, disposed substantially parallel to said longitudinal axis; wherein at least two of said lower springs having an active region for engaging ground, said active regions being free to move vertically, substantially independently from one another within a cushioning range.

2. A spring assembly as claimed in claim 1 , wherein said upper support comprises a leaf spring.

3. A spring assembly as claimed in any of claims 1 or 2, wherein the longitudinal position of at least one of said active regions is adjustable relative to at least an active region of at least one other of said plurality of lower springs.

4. A spring assembly as claimed in any preceding claim, wherein said upper support further comprises an opening in said posterior portion, said opening positioned to be below a wearer calcaneus, to provide relief therefor.

5. A spring assembly as claimed in any of the preceding claims, wherein said lower springs are replaceable.

6. A spring assembly as claimed in any preceding claim further comprising an attachment for coupling said assembly onto an article of footwear.

7. a spring assembly as claimed in any preceding claim further comprising a flexible sole, having a rocker section disposed under a wearer forefoot region or a portion thereof, and extending rearwardly from the rocker section to provide a full length sole

8. A footwear article having a heel region and a forefoot region, comprising a spring assembly as claimed in any of claims 1-5, wherein said upper support is integrated at least partially within the sole of said footwear.

9. A footwear article as claimed in claim 8, further comprising at least one vertical support member extending upwardly from said footwear, and a leg support member coupled to said vertical member, to form an ankle-foot brace integrated into said footwear article.

10. An Ankle Foot Orthosis (AFO) comprising a spring assembly as claimed in claims 1-5, the ankle foot brace comprising at least one vertical support member coupled to said upper support, and a leg support member coupled to said vertical support member.

11. An Ankle Foot Orthosis as claimed in claim 10, further comprising an attachment operative to attach said brace to a footwear article.

12. A method of relocating the ground reaction force to fit individual requirements of a wearer, the method comprising the steps of: providing a spring assembly as claimed in any of claims 3-7, said spring assembly being integrated into footwear or a brace, or being added on as attachment to a footwear article;

Individually adjusting the longitudinal location of at least one of said active regions of at least two of said lower springs, to redirect the ground reaction force to fit said requirements of said wearer.