Abstract:
Disclosed is an ankle foot orthotic device for assisting a user during gait. The device comprises: a foot support having a shape and size configured to the plantar aspect of a user foot, the foot support having a forward portion and a rearward portion and a heel plate coupled to an upper surface of the rearward portion. The device further comprises: an upper rod having a longitudinal axis and a lower end connected to an offset and a lower rod having: a longitudinal axis; a lower end connected to the heel plate; and an upward end connected to the offset.

Description:
RELATED APPLICATION 
       [0001]    This application is a Continuation in Part of U.S. application Ser. No. 11/757,697, “An Ankle Foot Orthosis Device”, filed 4 Jun. 2007; the content of which is incorporated by reference as if fully set forth herein. 
     
    
     FIELD AND BACKGROUND OF THE INVENTION 
       [0002]    The present invention, in some embodiments thereof, relates to orthoses and, more particularly, but not exclusively, to an ankle foot orthosis. 
         [0003]    Drop foot, also known as steppage gait, is a condition in which there is a deficit in pivoting the foot upward toward the anterior of the tibia, herein dorsiflexion, due to neurologic and/or muscular malfunction. 
         [0004]    To prevent tripping during swinging forward, herein swing phase of gait, the affected leg must be lifted high off the ground and dropped into place in front of the other foot, referred to as a steppage gait. 
         [0005]    In “swing phase” of gait, the drop foot remains in the “dropped”, herein plantiflexed position and often barely clears the ground during the swing phase. As a result, the foot may catch on low lying debris, rocks or even an edge of a pavement stone, causing the person to trip and fall. 
         [0006]    A fall, particularly in an osteoporotic older person, can result in life-threatening bone fractures, immobility, and, due to the resultant sedentary life style, an early demise. 
         [0007]    Surgical treatment, when applicable, includes muscle transfers and/or nerve implantation; the latter presently limited to nerve lesions near the spinal nerve root. 
         [0008]    Conservative therapy includes fitting the user with an ankle foot orthosis (AFO); which lifts the foot with respect to the leg during swing phase of the gait, thereby substantially allowing the foot to clear the ground. 
         [0009]    There are aspects of the phases gait that may be beneficial to a user afflicted by drop foot when properly addressed by an AFO; for example pronation and supination of the foot. 
         [0010]    Pronation refers to inter alia, the forefoot assuming a substantially parallel position to the ground whereby the foot flexibly adapts to the angle and/or terrain of the ground. 
         [0011]    Supination refers to inter alia, the forefoot assuming an angled position to the rear foot in whereby the forefoot forms, what is referred to as a “locked position”. The locked position of the forefoot during supination allows the foot to act as a lever to aid in propulsion associated with the toe off phase of gait. 
         [0012]    In the drop foot condition, even with fully non-functional intrinsic and extrinsic foot muscles, the foot assumes “passive” positions of pronation and supination. 
         [0013]    For example, when the right leg is in swing phase and through heel contact, the right foot is in preparation to pronate upon contact with the ground. 
         [0014]    As the right foot becomes fully planted on the ground, in what is referred to as the “foot flat” position, the left leg is in swing phase while the left side of the pelvis circumducts toward the sagittal body plane. The left pelvic circumduction causes a supination in the right foot, with the supination continuing through right foot toe off. 
         [0015]    Following toe-off, the right foot again assumes a position of pronation in preparation for heel contact and foot flat phases of the gait cycle. 
         [0016]    To aid in the above-noted passive cycle of pronation and supination in a leg afflicted with drop foot, a natural tilt occurring between the foot plate and vertical support of a typical AFO could aid the affected foot in supination and pronation. 
         [0017]    For example, when the AFO connection between the foot plate and vertical support is rigid and unyielding, supination and pronation forces may be transferred to the foot rather than the ankle and/or mid tarsal joints that provide some of the movement required in pronation and supination. 
         [0018]    With the movement transferred to the foot, rather than the above-noted joints, the foot, and particularly the heel, may swing in the support plate and tend to become chaffed and sore. 
         [0019]    Such limitation of motion may reduce the ability of the foot to act as a shock absorber during heel-strike through foot flat portions of the gait cycle. With the decrease in foot shock absorption, the shock forces of heel strike are translated up the leg to the knee and hip joints, leading to osteoarthritis, pain, and possible limitation of range of motion in the knee and hip. 
         [0020]    Additionally, the shock forces absorbed may be translated to the lower back, resulting in lower back pain and possibly disc herniation, particularly in the lumbar spinal area. 
         [0021]    Further, during the swing phase of the above-noted left foot, the circumduction of the pelvis translates into rotatory forces on the right foot that is planted on the ground, thereby creating the above-noted supination, that should translate into a torque of the ankle joint and/or mid tarsal joint wherein the right foot tibia circumducts away from the sagittal body plane. 
         [0022]    If the foot plate maintains an intrinsic rigidity during gait, the midtarsal area of the foot may be forced to passively supinate against the rigid plate and/or rearfoot, creating undue stress on the midtarsal joint which can result in pain, arthritis and limitation of motion in the midtarsal joint. 
         [0023]    Background art, incorporated herein in their entirety by reference, include the following US Patents Numbers: 
         [0024]    1. U.S. Pat. No. 3,916,886, which teaches a preformed drop foot brace; 
         [0025]    2. U.S. Pat. No. 4,672,955, which teaches bands formed of curable composite material; 
         [0026]    3. U.S. Pat. No. 5,897,515, which teaches an ankle-foot orthosis made of a carbon fiber reinforced material; 
         [0027]    4. U.S. Pat. No. 6,102,881, which teaches an upper support bearing against the rear lower leg and a lower support bearing against the rear heel; 
         [0028]    5. U.S. Pat. No. 6,361,517, which teaches a foot lift assist comprising an elastic cord anchored at a person&#39;s hip by a belt; 
         [0029]    6. U.S. Pat. No. 6,790,193, which teaches a dorsal leg shell affixed to a user calf; 
         [0030]    7. U.S. Pat. No. 3,680,549 (Lehnels et al); 
         [0031]    8. U.S. Pat. No. 2,949,111 (Veikko Samuli Ruotoistenmaki, Vaasankatu); 
         [0032]    9. U.S. Pat. No. 6,945,947 B2 (Ingimundarson et al); 
         [0033]    Additional background art, incorporated herein in their entirety by reference, include the following US Patent Applications: 
         [0034]    1. Patent Publication No. WO/0135876, teaches a spring attached to the front side of a wearer&#39;s leg in a manner that allows sliding of the spring longitudinally; and 
         [0035]    2. U.S. Patent Application Publication No. 2007/0197948 A1. 
       SUMMARY OF THE INVENTION 
       [0036]    The present invention, in some embodiments thereof, relates to orthoses and, more particularly, but not exclusively, to an ankle foot orthosis. 
         [0037]    According to an aspect of some embodiments of the present invention there is provided an ankle foot orthotic device for assisting a user during gait. The device comprises: a foot support having a shape and size configured to the plantar aspect of a user foot, the foot support having a forward portion and a rearward portion and a heel plate coupled to an upper surface of the rearward portion. The device further comprises: an upper rod having a longitudinal axis and a lower end connected to an offset and a lower rod having: a longitudinal axis; a lower end connected to the heel plate; and an upward end connected to the offset. 
         [0038]    In some embodiments of the invention, the offset comprises a curved member. 
         [0039]    In some embodiments of the invention, the curved member curves substantially around a sagittal plane with respect to the foot support. 
         [0040]    In some embodiments of the invention, the offset is configured to allow relative movement along a coronal plane with respect to the foot support during user weight bearing. 
         [0041]    In some embodiments of the invention, the offset is configured to allow relative movement along a sagittal plane with respect to the foot support during user weight bearing. 
         [0042]    In some embodiments of the invention, the device includes a cuff connected to an upper end of the upper rod, the cuff configured to press against at least a portion of an anterior tibia. 
         [0043]    In some embodiments of the invention, the cuff is rotatably connected by a rotatable hinge to an upper end of the upper rod. 
         [0044]    In some embodiments of the invention, the rotatable hinge is configured to allow a swinging motion in the cuff along a sagittal plane with respect to the longitudinal axis of the upper rod. 
         [0045]    In some embodiments of the invention, the foot plate comprises a flexible material. 
         [0046]    In some embodiments of the invention, the heel plate is substantially rigid such that when the rear end of the rigid heel plate rises with respect to the foot support, and the forward portion is planted on a support surface, bending of the rigid heel plate is transferred beyond the front boundary of the heel plate. 
         [0047]    In some embodiments of the invention, when the forward portion is no longer in contact with the support surface, energy of the bending is transferred such that a sagittal axis passing through the forward portion becomes substantially aligned with a sagittal axis passing through the rearward position. 
         [0048]    According to another aspect of some embodiments of the present invention there is provided An ankle foot orthotic device for assisting gait, the device comprising: a rigid heel plate having a shape and size configured to encompass at least a portion of the plantar aspect of a user heel, the heel plate having a lower surface, a rod extending upward from the rigid heel plate, a cuff connected to an upper end of the rod, the cuff configured to press against at least a portion of an anterior tibia, a foot support having a shape and size configured to encompass at least a portion of the plantar aspect of a user foot, the foot support including: a forward flexible portion, a rearward portion having an upper surface rigidly connected to the lower surface of the rigid heel plate, such that when a rear end of the heel plate rises with respect to a sagittal axis of the foot support, and the forward portion is planted on a support surface, energy of bending is transferred to the forward flexible portion. 
         [0049]    In some embodiments of the invention, the rod includes a spring offset configured to transfer forces generated between the rod and the foot support to the foot support. 
         [0050]    In some embodiments of the invention, the ankle foot orthotic device is provided in a kit comprising modular components comprising different sizes comprising: the foot support, the rigid heel plate, the rod, and the cuff. 
         [0051]    In some embodiments of the invention, the lower surface of the rigid heel plate is configured to connect to an upper surface of a rearward portion of the foot support. 
         [0052]    In some embodiments of the invention, the rod is configured to connect to the rigid heel plate, the rod having an upper end configured to have a length sufficient to reach a mid to upper portion of a user tibia. 
         [0053]    In some embodiments of the invention, the rod includes: a portion extending upwardly from the heel plate and having an upward end connected to an offset, and an upper rod having a lower end connected to the offset such that the lower end is offset by a distance from the upper end. 
         [0054]    In some embodiments of the invention, the offset is configured to allow relative movement along a coronal plane with respect to the foot support. 
         [0055]    In some embodiments of the invention, the offset is configured to allow relative movement along a sagittal plane with respect to the foot support. 
         [0056]    According to still another aspect of some embodiments of the present invention there is provided ankle foot orthotic device for assisting gait, the device comprising: a foot support having a shape and size configured to the plantar aspect of a user foot, the foot support having a rearward portion and a flexible forward portion, a rigid heel plate coupled to an upper surface of the rearward portion, wherein: when a rear end of the heel plate rises with respect to the foot support, and the forward portion is planted on a support surface, energy of bending is transferred beyond the front boundary of the heel plate, and when the forward portion is no longer in contact with the support surface, the energy of the bending is transferred such that a sagittal axis passing through the forward portion becomes substantially aligned with a sagittal axis passing through the rearward portion, an upper rod having a longitudinal axis and a lower end connected to an offset, a cuff rotatably connected to an upper end of the upper rod with a rotatable hinge, the rotatable hinge configured to allow a swinging motion in the cuff along a sagittal plane with respect the longitudinal axis of the upper rod, a lower rod having a longitudinal axis extending upwardly from the heel plate and having an upward portion connected to the offset, wherein the offset is configured to allow at least one of: relative movement along a coronal plane with respect to the foot support, and relative movement along a sagittal plane with respect to the foot support. 
         [0057]    According to an additional aspect of some embodiments of the present invention there is provided a method of fabricating an ankle foot orthosis device for assisting gait, the method comprising: fabricating a foot support configured to at least partially encompass the plantar surface of a user foot, attaching to an upper surface of the foot support a rigid heel support configured to at least partially encompass the plantar surface of a user heel, bending an elongate bar to include an offset between an upper end and a lower end of the elongate bar, rigidly attaching a lower portion of the elongate bar to the rigid heel support, and rotatably attaching, to an upper portion of the elongate bar, a tibial support configured to at least partially encompass an anterior portion of a tibia of a user. 
         [0058]    In embodiments of the invention, the device optionally includes a foot support that is sized to fit into corresponding footwear of the user drop foot. 
         [0059]    In embodiments of the invention, the device optionally includes an elongate member that is mechanically coupled to the foot support. The elongate member optionally has a lower portion prolonging to an upper portion. The device optionally further includes a lower-leg-holder that is mechanically coupled to the elongate member. The lower-leg-holder optionally includes a support-brace that enables a corresponding shin to rest thereon. 
         [0060]    In embodiments of the invention, the lower portion of the elongate member optionally extend from a heel portion of the foot support upwards and rearwards towards a corresponding lower leg&#39;s calf, wherein the upper portion optionally further extend forwardly in a direction corresponding to the lower leg&#39;s shin. 
         [0061]    In embodiments of the invention, forward tilting of the lower leg against the support-brace causes the elongate member to bend forward in a direction corresponding to the user gait, wherein the forward bending causes the development of potential energy in the ankle foot orthosis device. At least some of the potential energy is optionally released during the toe-off phase of the gait cycle, thereby at least partially compensating for the energy lost due to the drop foot condition. 
         [0062]    In embodiments of the invention, some of the potential energy is optionally released during gait phases subsequent to the toe-off phase. 
         [0063]    In embodiments of the invention, the elongate member of the ankle foot orthosis device is optionally flexible. 
         [0064]    In embodiments of the invention, the foot support of the ankle foot orthosis device is flexible. 
         [0065]    In embodiments of the invention, the foot support optionally weighs, for example, approximately 70 grams, 60 grams, 50 grams, 40 grams or 30 grams. 
         [0066]    In embodiments of the invention, the elongate member optionally weighs, for example, approximately 100 grams, 90 grams, 80 grams, 70 grams or 60 grams. 
         [0067]    In embodiments of the invention, lower leg holder optionally weighs, for example, approximately 20 grams, 25 grams, 30 grams, 35 grams, 40 grams, 45 grams or 50 grams. 
         [0068]    In embodiments of the invention, the device weighs approximately, for example, 500 grams, 400 grams, 350 grams and the like. 
         [0069]    In embodiments of the invention, the foot support optionally includes at least one of the following first materials: carbon fibers, and graphite fibers. 
         [0070]    In embodiments of the invention, the first material is optionally disposed within at least one of the following second materials: epoxy resin, polydicyclopentadiene, and polyimide. 
         [0071]    In embodiments of the invention, the density and the structure of the first material and/or the second material optionally dictate the mechanical properties of the foot support. 
         [0072]    In embodiments of the invention, the foot support is optionally ergonomically designed to substantially fit the natural contour of a sole of the drop foot of the user. 
         [0073]    In embodiments of the invention, the foot support is optionally sized to fit easily, snugly and securely inside the user corresponding footwear. 
         [0074]    In embodiments of the invention, the mechanical properties of the foot support is optionally engineered as to enable substantial fitting of the foot support with the natural contour of a sole of a user drop foot during all phases of the user gait cycle. 
         [0075]    In embodiments of the invention, the elongate member is optionally integrally formed with the foot support. 
         [0076]    In embodiments of the invention, the elongate member is optionally fixedly coupled to the foot support with at least one elongate-member-fastener. 
         [0077]    In embodiments of the invention, the support-brace is optionally secured to some portion of the shin by straps. 
         [0078]    In embodiments of the invention, the elongate member is optionally made out of at least one of the following materials: high carbon steel, and very high carbon steel. However, the elongate member retains spring characteristics, i.e., elongate member is flexible. 
         [0079]    In embodiments of the invention at least some parts of the elongate member is optionally shaped and fixedly coupled to foot support via the at least one elongate-member-fastener such that elongate member is substantially aligned with the anatomic axis of ankle of the user drop foot. 
         [0080]    In embodiments of the invention, the lower portion of the elongate member extends from a heel portion substantially in alignment with the drop foot&#39;s ankle in a direction corresponding to a posterior position with regard to the drop foot&#39;s heel bone and ankle, wherein the posterior position is optionally substantially above the heel bone and the ankle. 
         [0081]    In embodiments of the invention, the at least one elongate-member-fastener and/or the elongate member and/or the foot support are replaceable. 
         [0082]    In embodiments of the invention, the at least one elongate-member-fastener includes a connector comprising of a base that is optionally integrally formed with a protruding plate. 
         [0083]    In embodiments of the invention, the protruding plate is optionally positioned adjacent to the inner side of drop foot, such to enable the fixedly coupling of the elongate member to the protruding plate by fastener means. 
         [0084]    In embodiments of the invention, padding elements are optionally fitted onto the foot support to provide comfortable cushioning for the drop foot&#39;s sole. 
         [0085]    The present invention further discloses a method of fabricating an ankle foot orthosis device for assisting a user having a drop foot. 
         [0086]    In embodiments of the invention, the method optionally includes, for example, the act of fabricating a foot support having a heel portion by, for example, laying up several layers of composite material. 
         [0087]    In embodiments of the invention, the method optionally includes, for example, the act of fabricating an elongate member that optionally have a lower and an upper portion that are bent relative to each other and wherein the upper portion is a prolongation of the lower portion. 
         [0088]    In embodiments of the invention, the method optionally includes, for example, the act of fabricating a lower-leg-holder, which optionally includes a U-shaped support-brace having an inner surface. 
         [0089]    In embodiments of the invention, the method optionally includes, for example, the act of mechanically coupling the elongate member to a heel portion of the foot support such that the lower portion extends rearwardly from the heel portion towards the drop foot&#39;s corresponding calf and such that the upper portion extends anteriorly towards the drop foot&#39;s corresponding shin. 
         [0090]    In embodiments of the invention, the method optionally includes, for example, the act of mechanically coupling the lower-leg-holder to the elongate member such that a curved part of the support-brace substantially points in a direction that corresponds to the user direction of gait, thereby enabling the user to rest his/her lower leg that corresponds to the drop foot against the inner surface of the support-brace. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0091]    The subject matter regarded as the invention will become more clearly understood in light of the ensuing description of embodiments thereof, given by way of example only, with reference to the accompanying Figures, wherein: 
           [0092]      FIG. 1  is a schematic isometric assembly view of an ankle foot orthosis device, according to some embodiments of the invention; 
           [0093]      FIG. 2  is a schematic isometric exploded view of the elongate member and lower-leg-holder of the ankle foot orthosis of  FIG. 1 , according to some embodiments of the invention; 
           [0094]      FIG. 3  is a schematic side view of the ankle foot orthosis device of  FIG. 1 , adjusted to a user drop foot, according to some embodiments of the invention; 
           [0095]      FIG. 4A  is a schematic isometric illustration of a foot support of the ankle foot orthosis of  FIG. 1 , according to some embodiments of the invention; 
           [0096]      FIG. 4B  is a schematic cross-sectional side view of the foot support of the ankle foot orthosis of  FIG. 1 , according to some embodiments of the invention; 
           [0097]      FIGS. 5-8  are schematic illustrations of a gait cycle during use of the ankle foot orthosis of  FIG. 1 , according to some embodiments of the invention; 
           [0098]      FIG. 9  is an exploded view of the lower portion of the ankle foot orthosis of  FIG. 1 , according to some embodiments of the invention; 
           [0099]      FIG. 10  is schematic flow-chart illustration of a method for fabricating the ankle foot orthosis device, according to some embodiments of the invention; 
           [0100]      FIG. 11  is an assembly view of a side spring ankle foot orthosis device, according to some embodiments of the invention; 
           [0101]      FIG. 12  is an exploded view of the side spring ankle foot orthosis of  FIG. 11 , according to some embodiments of the invention; 
           [0102]      FIGS. 13-15  are frontal views of the side spring ankle foot orthosis of  FIG. 11  during gait, according to some embodiments of the invention; 
           [0103]      FIGS. 14-19  are side views of the side spring ankle foot orthosis of  FIG. 11  during gait, according to some embodiments of the invention; 
           [0104]      FIG. 20  is a detail of a frontal hinge of the side spring ankle foot orthosis of  FIG. 11 , according to some embodiments of the invention; and 
           [0105]      FIG. 21  is chart showing a variety of modular components and sizes that are optionally used in creating side spring ankle foot orthosis of  FIG. 11  and the ankle foot orthosis of  FIG. 1 , according to some embodiments of the invention. 
       
    
    
       [0106]    The drawings taken with description make apparent to those skilled in the art how the invention is may be embodied in practice. 
         [0107]    It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate identical elements. 
       DESCRIPTION OF THE INVENTION 
       [0108]    The present invention, in some embodiments thereof, relates to orthoses and, more particularly, but not exclusively, to an ankle foot orthosis. 
         [0109]    According to some embodiments of the invention, the AFO includes a flexible foot support to which a flexible elongate member is substantially fixedly coupled. The AFO further includes a lower-leg-holder that is mechanically coupled to an upper part of the elongate member. The AFO is designed in a manner such that when it is suitably engaged with a user drop foot, the AFO stores potential energy during, for example, the transition from the mid-stance to the terminal-stance phase of the user gait cycle. At least some of the stored potential energy is optionally released during the subsequent toe-off phase of the user gait cycle, whereby the released potential energy may at least partially compensate for, e.g., the muscle weakness in the drop foot. Consequently, the AFO optionally causes ground clearance of the user drop foot during at least some of the gait cycle&#39;s swing phases. 
         [0110]    Additionally, in embodiments including a side spring, the side spring aids in storing energy associated with forward motion dorsiflexion of the foot. Furthermore, the AFO embodiment with the side spring facilitates pronation and supination associated with the gait cycle which is passive in a drop foot condition. Furthermore, the side spring aids in storing the energy associated with forward motion dorsiflexion of the foot. 
         [0111]    An embodiment is an example or implementation of the invention. The various appearances of “one embodiment,” “an embodiment” or “some embodiments” do not necessarily all refer to the same embodiments. 
         [0112]    Although various features of the invention may be described in the context of a single embodiment, the features may be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may be implemented in a single embodiment. 
         [0113]    Reference in the specification to “one embodiment”, “an embodiment”, “some embodiments” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment, but not necessarily all embodiments, of the invention. 
         [0114]    It is understood that the phraseology and terminology employed herein is not to be construed as limiting, and is for descriptive purpose only. 
         [0115]    The principles and uses of the teachings of the present invention may be better understood with reference to the accompanying description, figures and examples. 
         [0116]    It should be understood that the details set forth herein do not construe a limitation to an application of the invention. Furthermore, it should be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in embodiments other than the ones outlined in the description below. 
         [0117]    It should be understood that the terms “including”, “comprising”, “consisting” and grammatical variants thereof do not preclude the addition of one or more components, features, steps, integers or groups thereof and that the terms are not to be construed as specifying components, features, steps or integers. 
         [0118]    If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element. 
         [0119]    It should be understood that where the claims or specification refer to “a” or “an” element, such reference is not to be construed as there being only one of that element. 
         [0120]    It should be understood that where the specification states that a component, feature, structure, or characteristic “may”, “might”, “can” or “could” be included, that particular component, feature, structure, or characteristic is not required to be included. 
         [0121]    The descriptions, examples, methods and materials presented in the claims and the specification are not to be construed as limiting but rather as illustrative only. 
         [0122]    Meanings of technical and scientific terms used herein are to be commonly understood as by one of ordinary skill in the art to which the invention belongs, unless otherwise defined. 
         [0123]    The present invention can be implemented in the testing or practice with methods and materials equivalent or similar to those described herein. 
         [0124]    Any publications, including patents, patent applications and articles, referenced or mentioned in this specification are herein incorporated in their entirety into the specification, to the same extent as if each individual publication was specifically and individually indicated to be incorporated herein. In addition, citation or identification of any reference in the description of some embodiments of the invention shall not be construed as an admission that such reference is available as prior art to the present invention. 
         [0125]    The terms “bottom”, “below”, “top” and “above” and the like that may be specified herein do not necessarily indicate that a “bottom” component is below a “top” component, or that a component that is “below” is indeed “below” another component or that a component that is “above” is indeed “above” another component as such directions, components or both may be flipped, rotated, moved in space, placed in a diagonal orientation or position, placed horizontally or vertically, or similarly modified. Accordingly, it will be appreciated that the terms “bottom”, “below”, “top” and “above” may be used herein for exemplary purposes only, to illustrate the relative positioning or placement of certain components, to indicate a first and a second component, or to do both, such as when viewing them in the figures. 
         [0126]    It should be understood that, unless otherwise indicated, the term “couple”, “coupled”, “coupling”, and grammatical variations thereof as used herein, refers to the mechanical coupling between a plurality of elements, wherein the mechanical coupling between the plurality of elements may refer to an embodiment in which the different elements are substantially fixedly coupled to each other, as well as to another embodiment in which the plurality of elements may be integrally formed with each other. 
         [0127]    Where applicable, although state diagrams, flow diagrams or both may be used to describe embodiments, the invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described. 
         [0128]    With respect to the drawings, reference is now made to  FIGS. 1-3 : According to some embodiments of the invention, an AFO  100  is designed to provide a user drop foot  200  with stability and assistance to aid in duplicating normal gait pattern. 
         [0129]    According to some embodiments of the invention, AFO  100  includes an ergonomically designed foot support  110  that is sized to fit easily, snugly and securely inside a user footwear (not shown); such as footwear being, for example, a shoe, a sandal, or a boot. 
         [0130]    In addition, AFO  100  is designed to enable comfortable pulling out of the user foot from the user footwear. Furthermore, the ergonomics and/or the mechanical properties of foot support  110  is optionally designed and/or engineered, respectively, to enable substantial fitting of foot support  110  with the natural contour of a sole of user drop foot  200  during all phases of the user gait cycle. 
         [0131]    Referring now to  FIGS. 4A and 4B , the mechanical properties and/or the ergonomics of foot support  110  is optionally engineered, for example, by suitably structuring the materials out of which the foot support  110  is made, such that foot support  110  assists in compensating the user drop foot condition, which is optionally neurological and/or muscular and/or anatomic in origin. 
         [0132]    The material(s) out of which foot support  110  is made is optionally lightweight and strong, as well as flexible. Foot support  110  optionally weighs, for example, less than 2 kilograms. 
         [0133]    Foot support  110  is optionally made out of a composite material, e.g., as known in the art, or of any other suitable material. For example, foot support  110  optionally comprises a plurality of layers including a first material disposed within a second material, the first and the second materials making up a composite material, e.g., as known in the art. For example, the first material optionally comprises a plurality of layers of fiber (e.g., carbon fibers, graphite fibers). 
         [0134]    The fiber layers are optionally embedded within the second material that optionally comprises a thermoset such as, for example, epoxy resin, polydicyclopentadiene, polyimide or any other suitable material. 
         [0135]    According to some embodiments of the invention, the second material is optionally disposed relative to the first material of as to form a matrix-like structure, e.g., as known in the art, wherein the second material optionally serves as a bond material holding the first material together. Various parameters of the first and/or the second material such as, for example, orientation, thickness, density or other parameters optionally influence or dictate the mechanical properties of the composite material. 
         [0136]    For example, higher the density of the fibers within a layer or a certain portion of the layer, may contribute to the rigidity of the layer or portion of the layer. This effect is, for exemplary purposes only, schematically illustrated in  FIG. 4B , wherein a heel portion  111  of foot support  110  includes more layers of fibers  115  than a ball portion  112 . Consequently, heel portion  111  is optionally less flexible to bending than ball portion  112 , as is schematically illustrated by the more extensive bending of ball portion  112  compared to the bending of heel portion  111 . 
         [0137]    According to some embodiments of the invention, foot support  110  is optionally made of additional or alternative materials such as, for example; fiber reinforced polymers (e.g., carbon-fiber reinforced plastic, glass-fiber reinforced plastic); thermoplastic composite material; thermoplastic composites or any other suitable material(s). 
         [0138]    In some embodiments of the invention heel portion  111  is superimposed on foot support  110  and foot support includes flexible ball portion  112 . As will be explained below, super imposition of heel plate  151  serves to create a leaf spring that brings the foot of the user back to 90° with respect to the leg. 
         [0139]    Referring back to  FIGS. 1-3 , to use AFO  100 , the user places foot support  110  inside the footwear (not shown) that corresponds to the body side of the user drop foot  200 . For example, if drop foot  200  is the user left foot, the user adjusts foot support  110  to a left-sided footwear. 
         [0140]    The user then inserts his/her drop foot  200  into the corresponding footwear which he/she optionally dons substantially in the same manner as regular footwear on an unaffected foot. Once the foot support  110  and drop foot  200  are in place, the user optionally secures AFO  100  to his/her lower leg  210  by means of a lower-leg-holder  140 , as will be described hereinbelow. 
         [0141]    According to some embodiments of the invention, a vertical bar  130  is coupled to heel portion  111  of foot support  110  by means of a coupler  120 , which is optionally substantially semi-rigid. A number of elongate-member-fasteners  121  are described hereinbelow, with respect to  FIG. 9 . According to some other embodiments of the invention, vertical bar  130  is optionally integrally formed with heel portion  111  of foot support  110 . Vertical bar  130  is flexible as will be described below. 
         [0142]    In some embodiments vertical bar  130  comprises two portions; a lower portion  131  and an upper portion  132 . Lower portion  131  optionally extends rearwardly from heel portion  111  towards a calf  212 , and upper portion  132  optionally extends anteriorly towards a shin  211 . Accordingly, lower portion  131  is optionally bent relative to upper portion  132 . 
         [0143]    Furthermore, according to some embodiments of the invention, at least some parts of elongate member are optionally shaped and fixedly coupled to foot support  110  via elongate-member-fasteners  121  such that vertical bar  130  substantially intersects the anatomic axis of an ankle  207 . 
         [0144]    More specifically, lower portion  131  optionally extends from heel portion  111  in alignment with ankle  207  towards a posterior position with regard to a calcaneus  205  and ankle  207 , wherein the flexible portion of vertical bar  130  is optionally above ankle  207 . 
         [0145]    Consequently, AFO  100  is designed and adjustable to drop foot  200  as to possibly enable substantial imitation of the biomechanics of a healthy foot. Due to the alignment of vertical bar  130  with ankle  207  and calcaneus  205 , AFO  100  may facilitate the movement of foot  200  in proper anatomic function. 
         [0146]    According to some embodiments of the invention, vertical bar  130  is optionally made out of, for example, a resilient steel material such as, for example, high carbon steel, very high carbon steel or any other suitable material. 
         [0147]    According to some embodiments of the invention, lower-leg-holder  140  optionally includes a U-shaped support-brace  141  that is optionally mechanically coupled, e.g., via an outer front part  146 , to the end part of vertical bar  130  by leg-holder-fasteners  144  such that a curved part of U-shaped support-brace  141  substantially points in a direction that corresponds to the user gait. 
         [0148]    Leg-holder-fastener(s)  144  comprises, for example, a sleeve  145  that is fixedly coupled to outer front part  146  and into which the end part is tightly fitted. According to some embodiments of the invention, lower-leg-holder  140  optionally further include a securing end  147  ( FIG. 1 ) such as, for example, a rivet, for preventing the sliding out of the end part from sleeve  145 . 
         [0149]    According to some embodiments of the invention, lower-leg-holder  140  is optionally shaped to substantially fit onto at least some part of shin  211 , such that lower leg  210  can rest against an inner surface  143  of U-shaped support-brace  141 . Furthermore, according to some embodiments of the invention, AFO  100  is secured to user lower leg  210  by, for example, straps  142 . 
         [0150]      FIGS. 5-8  demonstrate AFO  100  assisting the user in overcoming the effects of the drop foot condition such that the user can walk while duplicating some of the biomechanics of normal gait; normal gait referring to the gait exhibited by the limbs of a person unaffected with a drop foot condition. 
         [0151]    It should be understood that angles α 1 , α 2 , α 3 , α 4 , as specified herein are not to be referred to as being angles of fixed size but rather as angles during the initial-contact, mid-stance, terminal-stance and toe-off phase of the gait cycle, respectively, wherein each of the angles optionally dynamically change during each of the phases. 
         [0152]    During the initial-contact phase ( FIG. 5 ), at least some of heel portion  111  of foot support  110  engages with floor  400 . The engagement of heel portion  111  with floor  400  causes drop foot  200  to apply a moment M 1  on foot support  110  around coupler  120  such that a tip  113  of drop foot  200  optionally pivots away from lower leg  210 , as schematically indicated with arrow M 1 ′. During the initial-contact phase, angle α 1  between tip  113  of drop foot  200  and shin  211  is optionally slightly larger than approximately 90°. For example, during initial-contact phase, angle α 1  may optionally have values of for example, approximately 93°, 95° and 97°. Angle α 1  optionally has other values during the initial-contact phase. 
         [0153]    Upon completion of the initial-contact phase ( FIG. 5 ), the user transitions to the mid-stance phase ( FIG. 6 ), wherein in the mid-stance phase, both heel portion  111  and ball portion  112  are engaged with floor  400 . During the mid-stance phase, lower leg  210  optionally rests against lower-leg-holder  140 , thereby applying a moment M 2  against inner surface  143  of support-brace  141  of lower-leg-holder  140 . As lower leg  210  moves towards drop foot  200 , as schematically indicated with arrow M 2 ′, angle α 2  between tip  113  of foot  200  and shin  211  decreases with respect to angle α 1  to by, for example, approximately 2°-5°, such that α 2  optionally attain a value of, for example, approximately 90° or approximately 88°. Angle α 2  optionally has other values during the mid-stance phase. 
         [0154]    Upon completion of the mid-stance phase ( FIG. 6 ), the user transitions to the terminal-stance phase of gait ( FIG. 7 ), wherein in the terminal-stance phase, heel portion  111  disengages from floor  400  due to the force and/or moment applied by lower leg  210  against inner surface  143  of U-shaped support-brace  141 . During the terminal-stance phase ( FIG. 7 ), angle α 3  between tip  113  of foot  200  and shin  211  optionally further decrease with respect to angle α 2  up to, for example, approximately 85°. Angle α 3  optionally has other values during the terminal-stance phase ( FIG. 7 ). 
         [0155]    It should be understood that AFO  100  is adjustable to meet individual user needs. For example, AFO  100  is individually adjustable to a user anatomy and biomechanical behavior. Accordingly, AFO  100  is optionally adjusted such that during the terminal stance phase ( FIG. 7 ) of a first user, angle α 3  optionally decrease up to approximately 83°, whereas during the terminal stance phase of a second user, angle α 3  optionally decrease only up to approximately 85°. 
         [0156]    In order to perform a transition from the mid-stance phase ( FIG. 6 ) to the terminal-stance phase ( FIG. 7 ), the user typically shifts his/her body weight to the gait&#39;s direction and towards the side of drop foot  200 , while tilting lower leg  210  downwards and forwards against inner surface  143  of support-brace  141 . Shifting his/her body weight forward in a direction that corresponds to the user gait, optionally result in a moment M 3  on inner surface  143  of support-brace  141 . Since vertical bar  130  has flexibility, moment M 3  causes vertical bar  130  to flex in a direction that is schematically indicated with arrow M 3 ′. Concurrent to the flexing of vertical bar  130 , drop foot  200  optionally pivot towards lower leg  210  to take up for the shortening of the distance between the extremities of vertical bar  130  occurring due to the bending thereof. 
         [0157]    In consequence, vertical bar  130  develops therein some potential energy of which some is optionally released during the subsequent toe-off phase ( FIG. 8 ) in form of, e.g., moment M 4  or other moments and/or forces. During the toe-off phase, both heel portion  111  and ball portion  112  disengage from floor  400 . The lower part of vertical bar  130  optionally exert, for example, moment M 4  on heel portion  111  of foot support  110 . 
         [0158]    Moment M 4  and/or other forces and/or moments optionally help compensating for the force lost due to, e.g., muscle weakness in drop foot  200  and thereof assists the user in performing the toe-off phase without dragging drop foot  200  along floor  400 . Correspondingly, AFO  100  optionally causes ground clearance of user drop foot  200  during the toe-off phase and during at least some of the subsequent swing phases. 
         [0159]    Further reference is now made to  FIG. 9 . According to some embodiments of the invention, coupler  120  optionally includes a connector  150  that optionally includes a base  151  that is optionally integrally formed with a protruding plate  152 . Plate  152  is optionally positioned adjacent to the inner side of drop foot  200 . According to some embodiments of the invention, plate  152  is optionally adapted to fixedly couple thereto vertical bar  130  by means of, e.g., clamps  129 , which optionally clamp vertical bar  130  therein. According to some embodiments of the invention, vertical bar  130  optionally has holes  128  suitable for receiving clamp securing fasteners  122 . Clamp securing fasteners  122  are optionally used for securing clamps  129  onto vertical bar  130 . Securing fasteners  122  are optionally, for example, bolts, nuts, rivets, and/or any other suitable fasteners. 
         [0160]    According to some embodiments of the invention, base  151  is optionally fixedly coupled to heel portion  111  of foot support  110  via, e.g., heel fasteners  123 , comprising, for example, bolts, nuts, rivets and the like. According to some embodiments of the invention, base  151  and heel portion  111  optionally receive heel fasteners  123  via holes  124  and  126 , respectively. The position of heel fasteners  123  is optionally secured by securing means  125 , comprising, for example, suitable stoppers. 
         [0161]    In some embodiments of the invention, padding elements  127   a,    127   b,    127   c,    127   d  and  127   e  are optionally fitted onto foot support  110  in a manner that substantially complements the shape of base  151 , thereby providing comfortable cushioning to the sole of drop foot  200 . 
         [0162]    According to some embodiments of the invention, all of the abovementioned elements of AFO  100  are optionally replaceable. 
         [0163]    In embodiments of the invention, foot support  110  optionally weighs, for example, approximately 70 grams, 60 grams, 50 grams, 40 grams or 30 grams. 
         [0164]    In embodiments of the invention, vertical bar  130  optionally weighs, for example, approximately 100 grams, 90 grams, 80 grams, 70 grams or 60 grams. 
         [0165]    In embodiments of the invention, lower leg holder  140  optionally weighs, for example, approximately 20 grams, 25 grams, 30 grams, 35 grams, 40 grams, 45 grams or 50 grams. 
         [0166]    In embodiments of the invention, AFO  100  weighs, for example, approximately 500 grams, 400 grams, 350 grams and the like. 
         [0167]    Reference is now made to  FIG. 10 . According to some embodiments of the invention, as indicated in stage  1100 , a method for fabricating an ankle foot orthosis device, optionally includes, for example, the act of fabricating foot support  110  by, for example, laying up several layers of, e.g., composite material. 
         [0168]    According to some embodiments of the invention, at a stage  1200 , the method optionally includes, for example, the act of fabricating vertical bar  130 . 
         [0169]    According to some embodiments of the invention, at a stage  1300 , the method optionally includes, for example, the act of fabricating lower-leg-holder  140 . 
         [0170]    According to some embodiments of the invention, at a stage  1400 , the method optionally include, for example, the act of mechanically coupling vertical bar  130  to heel portion  111  of foot support  110 . 
         [0171]    This is optionally accomplished in a manner such that lower portion  131  extends rearwardly from heel portion  111  towards drop foot&#39;s  200  corresponding calf  212  and such that upper portion  132  extends anteriorly towards the drop foot&#39;s  200  corresponding shin  211 . 
         [0172]    According to some embodiments of the invention, at a stage  1500 , the method optionally includes, for example, the act of mechanically coupling lower-leg-holder  140  to vertical bar  130 . 
         [0173]    This is optionally accomplished in a manner such that such that the curved part of support-brace  141  substantially points in a direction that corresponds to the user direction of gait, thereby enabling the user to rest his/her lower leg  210  that corresponds to the drop foot  200  against inner surface  143  of support-brace  141 . 
         [0174]      FIG. 11  shows a spiral spring AFO  300  in which elongated bar  130  includes a spiral spring  160  which creates flexibility between upper portion  132  and lower portion  131  in which heel portion  111  is superimposed on foot support  110 . 
         [0175]      FIG. 12  shows embodiment  300  in which (compared to  FIG. 9 ) heel portion  150  is attached to foot support  110  with sections  127   a,  b and c. Heel portion  150  comprises a main support  169  adapted to be fixedly coupled to vertical bar  130   
         [0176]      FIGS. 13-15  demonstrate that spiral spring  160  allows pronation and supination to be distributed between foot support  110  and vertical bar  130 . 
         [0177]    As seen in  FIG. 13  during swing phase an angle  174  is parallel between an axis  190  and an axis  192  which go through upper portion  132  and lower portion  131  respectively. 
         [0178]    As seen in  FIG. 14 , during heel strike and foot flat faces of gait, spiral spring  160  allows pronation such that angle  174  increases allowing footplate  110  pronate. Pronation is a portion of normal gait cycle in which the foot is substantially flexible and allows the foot to adapt to the terrain underneath. 
         [0179]    Upon toe-off, as seen in  FIG. 15 , angle  174  decreases such that heel plates  110  assumes a supination position. The position of supination allows the foot to become a rigid lever which aids in the toe off cycle of gait. Spiral spring  160  allows this supination to occur and is offset from the user leg. 
         [0180]    The inventor has discovered that providing spiral spring  160  not only allows pronation and supination of the foot, but allows this to occur without undue chaffing of the calf of the foot, because spring  160  is offset from the foot and tibia. 
         [0181]    Referring to  FIGS. 16-19 , spring  160  is shown to aid in the propulsive phases of gait such that the spring between portion  111  and  112  is aided and assisted by spring  160 . 
         [0182]    As seen in  FIG. 16 , foot support  110  is parallel to ground  400  and an angle  223  which represents the angle between axis  221  of upper portion  132  and  220  of lower portion  131 , is above 90°. 
         [0183]    In  FIG. 17  as the leg passes through foot flat, angle  223  becomes acute thereby reflecting the fact that spiral spring  160  has been put in tension that will later aid foot  200  in toe off. 
         [0184]    As seen in  FIG. 18 , in addition to acute angle  223 , foot support  110  has assumed that angle between axes  232  and  231  consisting of an angle  233 . As result forces are stored in both spiral spring  160  and footplate  110 . This creates a propulsion for the user and also allows foot  200  to clear the ground without tripping, as seen in  FIG. 19 . 
         [0185]      FIG. 19  shows that the energy in both angle  233  within foot support  110  and angle  223  controlled by spiral spring  160  have been released to ensure that foot  200  returns to a neutral position, thereby allowing foot  200  to effectively clear ground surface  400 . 
         [0186]    The inventor has discovered that by superimposing heel plate  151  on top of foot support  110 , that during toe off phase of gait the bending forces of foot support  110  are simply optimized toward the forefoot of the user such that ball portion  112  acts as a spring such that as the patient weight on foot support  110  changes, the energy stored is transferred from heel plate  151  toward ball portion  112 . The superimposition of heel plate  151  serves to create a leaf spring effect that brings the foot of the user quickly back to 90° with respect to the leg. Additionally the force of the propulsive portion of gait is divided between foot support  110  and spring  160 . 
         [0187]      FIG. 20  demonstrates the movement between upper portion  132  and U-shaped support-brace  141  in which axis  231  allows movement of plus or minus 10° such that the propulsive phase of gait does not cause chafing of the anterior tibia. 
         [0188]    The instant invention includes modular components that can be fit to a user that allow a variety of measurements to be incorporated in the AFO, including height of the brace, size of the foot support, and the size of the shin support. The modular components and measurements, seen in  FIG. 21 , are but a few of the many examples that can be incorporated in the instant invention. 
         [0189]    While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the embodiments. Those skilled in the art will envision other possible variations, modifications, and programs that are also within the scope of the invention. Accordingly, the scope of the invention should not be limited by what has thus far been described, but by the appended claims and their legal equivalents. Therefore, it is to be understood that alternatives, modifications, and variations of the present invention are to be construed as being within the scope and spirit of the appended claims.