US20050071018A1 - Universal prosthesis with cushioned ankle - Google Patents

Abstract

The invention provides a cushioned ankle prosthetic foot and a cosmesis having a slot between the big toe and adjacent toe to allow the amputee to wear thong sandals and the like. The cushioning desirably provides a smooth and more natural-feeling rollover from a heel-strike to a toe-off position and/or improved dynamic response characteristics. Advantageously, the prosthetic foot is configured so that it can be used as either a right or a left foot. Moreover, the cosmesis includes a toe reinforcement strap to desirably provide improved wear resistance to the cosmesis.

Description

RELATED APPLICATIONS
• This application is a continuation of U.S. patent application Ser. No. 09/586,666, filed Jun. 1, 2000, now U.S. Pat. No. 6,811,571, issue date Nov. 2, 2004, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/201,150, filed May 2, 2000, the entirety of each one of which is hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates generally to prosthetic feet and, more particularly, to a prosthetic foot having a cushioned ankle and a thong-receiving reinforced outer foot cosmesis.
• 2. Description of the Related Art
• In the prosthetics market, the conventional SACH foot has been the most widely prescribed artificial foot over the past several decades. The SACH foot generally includes a solid ankle and cushioned heel foot mounted to a limb along an approximate hinge axis taken through the ankle. The SACH foot has been popular precisely for its simplicity, and thus economy, but includes certain drawbacks in terms of dynamic response characteristics. Specifically, the low end SACH feet do not provide much energy storage and release, as do more sophisticated prosthetic feet.
• Some patients undergo what is known in the art as a Symes amputation, where the foot is severed from the leg near the ankle region. Because the Symes patient's calf and shin function as the stump for prosthetic purposes, prosthetic devices utilized by the patient must either be relatively compact, so as to be attachable below the point of amputation, or must be configured to accommodate the patient's shin and calf while attached thereto or higher up on the wearer's leg.
• Prior art prostheses available to Symes patients typically include an artificial foot bonded or bolted onto the bottom end of a socket worn on a patient's stump. These compact prosthetic feet can also attach below a downwardly depending pylon secured to a socket higher up on the amputee's leg. For such compact prostheses, it is difficult to provide the level of dynamic response approximating the original ankle and foot due to the lack of vertical space available.
• Some attempts at providing the appropriate response characteristics of the original ankle and foot in Symes foot prosthesis involve the use of rubber cushions, or bumpers, between a lower leg and the foot. Many of these require a pivotable bolt attachment between the leg and the foot. Unfortunately, many of these rubber cushion devices have limited durability due to the difficulty in bonding the rubber portions to the solid leg or foot portions, or are relatively complex, requiring several machined parts, which adds to the cost.
• U.S. Pat. Nos. 5,800,569 and 5,993,488, incorporated by reference herein, to Phillips disclose a resilient ankle block prosthesis that mitigates or overcomes some of the above disadvantages. But, there is still room for further improvements in providing a smooth and more natural-feeling rollover from a heel-strike to a toe-off position and/or of providing improved dynamic response characteristics, so as to provide a natural feeling foot during walking or running activities.
• There are also a number of foot cosmesis that are presently commercially available in the market. The cosmesis for an artificial foot serves as a cosmetic outer cover and provides the appearance of a relatively natural looking foot for the lower limb amputee.
• Conventional artificial feet and/or cosmesis can disadvantageously also be limited in terms of the flexibility and versatility they provide in allowing the amputee to don different types of conventional footwear. Moreover, the frictional contact between the artificial foot and the cosmesis can cause wear of the cosmesis, especially at the high stress contact points. This can not only result in inconvenient frequent replacement of the cosmesis but also further adds to the cost for the amputee. Additionally, many artificial feet are adapted to be used only as a left or right foot and not both, and this undesirably limits versatility and increases manufacturing and inventory costs.
• Consequently, there is a need for a relatively inexpensive, durable and versatile prosthetic foot assembly with improved performance characteristics.
SUMMARY OF THE INVENTION
• Accordingly, it is one object and advantage of the present invention to overcome some or all of the above limitations by providing a cushioned ankle prosthetic foot and an associated cosmesis having a slot between the big toe and adjacent toe to allow the amputee to wear thong sandals and the like. The cushioning desirably provides a smooth and more natural-feeling rollover from a heel-strike to a toe-off position and/or improved dynamic response characteristics. Advantageously, the prosthetic foot is configured so that it can be used as either a right or a left foot. Moreover, the cosmesis includes a toe reinforcement strap to desirably provide improved wear resistance to the cosmesis.
• In accordance with one preferred embodiment of the invention, a prosthetic foot assembly for a lower limb amputee is provided. The assembly generally comprises a prosthetic foot and an outer cosmesis. The prosthetic foot attaches to a socket or pylon of the lower limb amputee. The prosthetic foot generally comprises a lower foot plate and an upper ankle plate. The lower foot plate includes a symmetric toe configuration and a plurality of slots formed therebetween. The upper ankle plate has a length substantially shorter than the foot plate. The prosthetic foot further comprises an ankle block having a wedged configuration. The ankle block comprises a compressible material and is sandwiched between the foot plate and the ankle plate. The outer cosmesis has a length approximately equal to the length of a natural human foot and has an anterior toe region including a slot substantially aligned with one of the slots of the foot plate. Advantageously, the prosthetic foot assembly permits the lower limb amputee to wear thong sandals and the like and/or provides enhanced performance characteristics.
• In accordance with another preferred embodiment of the invention, an outer foot cosmesis is provided. The outer foot cosmesis has a length substantially the same as that of a natural human foot. The cosmesis comprises an inner cavity for receiving a prosthetic foot for attaching to a socket or pylon of a lower limb amputee. The cosmesis has a toe portion comprising at least one slot for receiving a thong of a sandal or other footwear. The cosmesis further comprises a reinforcement patch in the toe portion for improving the wear resistance of the cosmesis.
• For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
• All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a simplified partially sectional side elevation view of a prosthetic foot assembly having features in accordance with one preferred embodiment of the present invention.
• FIG. 2 is a simplified partially sectional top plan view of the prosthetic foot assembly ofFIG. 1.
• FIG. 3 is a simplified rear view of the prosthetic foot ofFIG. 1.
• FIG. 4 is a top plan view of a lower foot plate of the prosthetic foot assembly ofFIG. 1 having features in accordance with one preferred embodiment of the present invention.
• FIG. 5 is a side elevation view of the lower foot plate ofFIG. 4.
• FIG. 6 is a perspective view of an upper ankle plate of the prosthetic foot assembly ofFIG. 1 having features in accordance with one preferred embodiment of the present invention.
• FIG. 7 is a top plan view of the upper ankle plate ofFIG. 6.
• FIG. 8 is a sectional view along line8-8 ofFIG. 7.
• FIG. 9 is a sectional view along line9-9 ofFIG. 7.
• FIG. 10 is a perspective view of a compressible ankle block of the prosthetic foot assembly ofFIG. 1 having features in accordance with one preferred embodiment of the present invention.
• FIG. 11 is a top plan view of the compressible ankle block ofFIG. 10.
• FIG. 12 is a side elevation view of the compressible ankle block ofFIG. 10.
• FIG. 13 is a sectional view of an outer cosmesis (along substantially a longitudinal axis of the cosmesis) of the prosthetic foot assembly ofFIG. 1 having features in accordance with one preferred embodiment of the present invention.
• FIG. 14 is a sectional view along line14-14 ofFIG. 13.
• FIG. 15 is a perspective view of the outer cosmesis ofFIG. 13.
• FIG. 16 is a bottom plan view (showing some hidden lines) of the outer cosmesis ofFIG. 13.
• FIG. 17 is a perspective view of a reinforcement patch of the cosmesis ofFIG. 13.
• FIG. 18 is a top plan view of the reinforcement patch ofFIG. 17.
• FIG. 19 is a rear view of the reinforcement patch ofFIG. 17.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
• FIGS. 1 and 2 illustrate a prosthetic or artificial foot assembly orcombination10 having features in accordance with one preferred embodiment of the present invention. The prosthetic foot assembly orfoot prosthesis10 generally comprises a prosthetic orartificial foot12 and an outer foot cover orcosmesis14. For clarity, a sectional illustration of thecosmesis14 is shown inFIGS. 1 and 2.FIG. 3 is a rear view of theprosthetic foot12.
• The prosthetic foot orprosthesis12 generally comprises alower foot plate20, an upper,smaller ankle plate22, and a layer or block24 of resilient material sandwiched between and connecting thefoot plate20 to theankle plate22. In one preferred embodiment, thelower foot plate20 comprises a symmetric toe configuration, thereby desirably permitting theprosthetic foot12 to be used as either a left or right foot. Advantageously, this saves on manufacturing and inventory costs.
• Preferably, and as discussed in greater detail below, theintermediate ankle block24 is bonded to thefoot plate20 andankle plate22. Preferably, and as also discussed in greater detail below, thefoot plate20 and theankle plate22 comprise a strong, flexible material. Advantageously, during a walking and/or running stride, the combination of the resilient ankle block orkeel24 and theflexible plates20,22 provides a smooth rollover from a heel-strike to a toe-off position.
• In one preferred embodiment, alimit strap26 is used to further secure thefoot plate20, theankle block24 and theankle plate22. Thelimit strap26 controls or limits the maximum degree of displacement (expansion) of theankle block24 and the relative motion between thefoot plate20 and theankle plate22 proximate the heel portion of theprosthesis12.
• Preferably, the ankle orconnector plate22 is coupled to anattachment member28 for coupling theprosthetic foot12 to a downwardly depending leg such as a stump or lower-limb pylon of the amputee or wearer. Theankle plate22 is preferably connected to theattachment member28 utilizing abolt30 and awasher32. The center or longitudinal axis of thebolt30 defines anattachment axis34 which is generally aligned with the vertical centerline of an imaginary ankle so as to more faithfully simulate the location at which forces are transmitted between leg and foot.
• The cosmesis orfoot cover14 is generally shaped, sized and/or configured to generally emulate the appearance of a natural human foot. Thecosmesis14 is preferably constructed of a resilient material. Preferably, thecosmesis14 comprises aninner cavity40 shaped, sized and/or configured to receive theprosthetic foot12.
• In one preferred embodiment, thecosmesis14 comprises a slit or slot42 (FIG. 2) in the toe region to receive a thong or the like of a thong sandal or other footwear. Desirably, this adds to the versatility of the invention. Thecosmesis14 preferably further comprises a reinforcement patch orstrap44 in or near the toe region to provide durability.
• A supporting ground orfloor surface36 is also shown inFIG. 1. The spacing or gap between the cosmesis14 (or prosthetic foot assembly10) and thesurface36 and the orientation of thecosmesis14 relative to thesurface36 are indicative of an intermediate sole and/or heel of a shoe or other footwear worn by the amputee. Those of ordinary skill in the art will recognize that when the amputee is not wearing a shoe or other footwear, thecosmesis14 can be in direct contact with the ground orfloor surface36.
• As is known in the art, see for example U.S. Pat. Nos. 5,800,569 and 5,993,488, incorporated by reference herein, ambulation comprises several foot positions with respect to a supporting ground or floor surface. The several walking and/or running strides include a heel-strike position, a generally flat-foot position, a heel-off position and a toe-off position. Throughout these various stride positions, theprosthetic foot12 of the invention advantageously provides a smooth and generally life-like response to the wearer. During a walking and/or running stride, theankle block24 transmits the forces imparted thereon by thefoot plate20 and theankle plate22, and experiences a gradual rollover, or migration of the compressed region, from rear to front.
• Lower Foot Plate
• In one preferred embodiment, and referring in particular toFIGS. 4 and 5, the lower or bottom foot plate ormember20 generally comprises an anterior toe region orportion46, a medial arch region orportion48 and a posterior heel region orportion50. Preferably, thefoot plate20 has a curvilinear shape (FIG. 4), including a slight arch in thecenter section48 and a slightly upwardlycurved toe section46 andheel section50. Desirably, this generally simulates the natural curve of the sole of a human foot.
• The curvature(s) of the lower surface of thefoot plate20 generally corresponds to the profile of an associated contacting surface of thecosmesis14 and/or to the profile of an associated shoe sole. The curvature(s) of the upper surface of thefoot plate20 generally corresponds to selected ranges of human lengths. Optionally, thefoot plate20 can comprise a generally flat plate, as needed or desired.
• Preferably, thefoot plate20 has a thickness along its length that is tapered, and the tapered profile corresponds approximately to the weight of the amputee. That is, for a heavier weight group amputee, the thickness along the length of thefoot plate20 would be generally greater than that for a lighter weight group amputee.
• Thefoot plate20 preferably has a length and width roughly equal to or slightly smaller than the approximate length and width of the particular wearer's amputated foot and is sized, shaped and/or configured to fit within the outerflexible cosmesis14. Preferably, and as shown inFIG. 4, the width of thefoot plate20 is greater towards the front and follows a curved profile to define a maximum width (W) at or near the junction between thetoe region46 and thearch region48. Desirably, this simulates the approximate shape or contour of a natural foot. Optionally,foot plate20 may include a lower sole cushion to provide protection to the inner surfaces of thecosmesis14.
• In other preferred embodiments, thefoot plate20 can be shaped, sized and/or configured in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing a suitably strong and generally natural feeling prosthetic foot, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Thelower foot plate20 is preferably capable of flexing along its length. Desirably, the flexing of thefoot plate20 under the weight of the amputee tends to distribute and/or relieve shear stresses applied at the interface between thefoot plate20 andankle block24. Moreover, the flexing contributes to a more natural feeling walking and/or running stride for the wearer of theprosthetic foot12.
• In one preferred embodiment, the toe orfront section46 of thefoot plate20 comprises a plurality of generally elongated spaced toes52. Most preferably, thetoe section46 comprises three toes52 (labeled52a,52b,52c) and two corresponding slots54 (labeled54a,54b) formed therebetween. In other preferred embodiments, thetoe section46 can efficaciously comprise fewer or more toes, as required or desired, giving due consideration to the goals of achieving one or more of the advantages and benefits as taught or suggested herein. Optionally, thetoe section46 may not be slotted to form individual toes and/or thefoot plate20 may comprise a generally flat plate, as needed or desired.
• In one preferred embodiment, thetoes52a,52b,52c(and hence theslots54a,54b) are arranged to form a generally symmetric configuration about alongitudinal axis56 of thefoot plate20. Desirably, this allows thefoot plate20 to be used as part of a left or rightprosthetic foot12. In other preferred embodiments, the toes52 and slots54 can be efficaciously arranged in alternate configurations, as required or desired, giving due consideration to the goals of achieving one or more of the advantages and benefits as taught or suggested herein.
• The slots54 (and toes52) are sized, shaped and/or configured so that when thefoot plate20 is seated in thecosmesis14, a respective one of theslots54a,54bis substantially aligned with the thong-receiving slot42 (FIG. 2). Theparticular toe slot54aor54bthat is aligned with the cosmesis slot42 (and a corresponding slot of the reinforcement patch44) depends on whether thecosmesis14 is a right or left foot cosmesis. For illustration purposes, aright foot cosmesis14 is shown inFIG. 2 in which thetoe slot54ais aligned with thecosmesis slot42, though the skilled artisan will realize that a left foot cosmesis is substantially a mirror image of a right foot cosmesis in which thetoe slot54bwill be aligned with the corresponding cosmesis slot.
• Advantageously, the symmetric toe configuration of thefoot plate20 allows theprosthetic foot12 to be readily used in conjunction with acosmesis14 of a right or left foot. Desirably, this saves on manufacturing and inventory costs, and also adds to the versatility of the invention.
• Preferably, theouter toes52a,52bare slightly inwardly curved towards the foot platelongitudinal axis56 and the center ormiddle toe52cis substantially aligned with thelongitudinal axis56. In other preferred embodiments, the toes52 and slots54 can be efficaciously arranged in alternate configurations, as required or desired, giving due consideration to the goals of achieving one or more of the advantages and benefits as taught or suggested herein.
• Each one of the toes52 preferably includes a marker58 (labeled58a,58b,58cinFIG. 4) in the form of a slightly raised crosswise portion, rib or bump on each of the upper surfaces of the toes52. As discussed below, the location of themarkers58 generally corresponds to a smaller foot size. This allows the portion of the toes52 extending beyond thebumps58 to be trimmed down to form afoot plate20 for a smaller or intermediate foot size. Advantageously, this saves on manufacturing and inventory costs.
• In another preferred embodiment, the markers orindicators58 can comprise grooves. In yet another preferred embodiment, themarkers58 comprise bands which are colored to provide visual differentiation. In other preferred embodiments, as the skilled artisan will recognize, themarkers58 can be alternately formed and/or constructed with efficacy, as required or desired, giving due consideration to the goals of providing size indicating means, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Thetoe portion46 has atoe end60 and is preferably slightly uplifted or generally concave-upward relative to a generally horizontal plane P₁tangential to thetoe section46, as shown inFIG. 5. As indicated before, the curvature of thetoe portion46 generally simulates the natural curve of the toe region of the sole of a human foot. In other preferred embodiments, thetoe region46 can be efficaciously configured in alternate manners, as required or desired, giving due consideration to the goals of providing a generally natural feelingprosthetic foot12, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• The heel or rear section orportion50 has aheel end62 and is preferably slightly uplifted or generally concave-upward relative to a generally horizontal plane P₂. The plane P₂is substantially parallel to and slightly raised, offset or elevated by a predetermined distance (D₁₂) relative to the plane P₁. As indicated before, the curvature of theheel portion50 generally simulates the natural curve of the heel region of the sole of a human foot. In other preferred embodiments, theheel region50 can be efficaciously configured in alternate manners, as required or desired, giving due consideration to the goals of providing a generally natural feelingprosthetic foot12, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• It is understood that within the cosmesis14 (FIG. 1), the heel plane P₂is raised by a distance D₁₂relative to the toe plane P₁. The magnitude of D₁₂is largely determined by the particular configuration of thecosmesis14 and/or that of the sole and heel of the shoe or other footwear donned by the wearer. For example, for a higher shoe heel the distance D₁₂will be larger as compared to for a shorter shoe heel.
• The central or middlearch section48 is intermediate or between thetoe section46 and theheel section50 and is preferably generally concave downward. As indicated before, the curvature of thearch portion48 generally simulates the natural curve of the arch region of the sole of a human foot. The regions of thearch section48 proximate to thetoe section46 andheel section50 can be slightly concave upward. In other preferred embodiments, thecentral region48 can be efficaciously configured in alternate manners, as required or desired, giving due consideration to the goals of providing a generally natural feelingprosthetic foot12, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• In one preferred embodiment, thearch section48 comprises a substantially flatupper surface64 adjacent to theheel section50. In other preferred embodiments, thecentral region48 can be efficaciously configured in alternate manners, as required or desired, giving due consideration to the goals of providing a generally natural feelingprosthetic foot12, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• In general or on the average, thearch section48 of thefoot plate20 is thicker than the other sections of thefoot plate20. In other preferred embodiments, the centralarch region48 can be efficaciously dimensioned in alternate manners, as required or desired, giving due consideration to the goals of providing a generally natural feelingprosthetic foot12, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• In one preferred embodiment, the upper surface of thearch section48 comprises a location rib or bump66 for establishing the relative positioning between thefoot plate20 and theankle block24. Thelocation bump66 mates with or engages a corresponding groove on the lower surface of theankle block24. Therib66 may also provide added protection against separation, peeling or delamination between thefoot plate20 and theankle block24.
• Alternatively, the location rib may be provided on theankle block24 and the corresponding groove may be provided on thefoot plate20. Additionally, other positioning means such as location pins and the like may be efficaciously used, as required or desired, giving due consideration to the goals of establishing the desired positioning between thefoot plate20 and theankle block24, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Preferably, thelocation rib66 extends crosswise across the span of the upper surface of thefoot plate20. In other preferred embodiments, the rib66 (and corresponding groove) can be positioned and configured in alternate manners with efficacy, as required or desired, giving due consideration to the goals of establishing the desired positioning between thefoot plate20 and theankle block24, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Preferably, thefoot plate20 is fabricated from a vinyl ester based sheet molding compound, such as Quantum QC-8800, available from Quantum Composites of Midland, Mich. Thefoot plate20 preferably comprises a vinyl ester resin matrix with a substantially randomly arranged fiberglass fiber content. In another preferred embodiment, thefoot plate20 is constructed of fiberglass. Alternatively, thefoot plate20 may be formed by a plurality of lamina embedded in a hardened flexible polymer. Thefoot plate20 can also be formed of carbon fibers.
• In other arrangements, thefoot plate20 may be formed of alternate suitable materials, such as other composite materials, plastics, thermoplastic and thermosetting polymers, metals, alloys and ceramics among others, as required or desired, giving due consideration to the goals of achieving one or more of the advantages and benefits as taught or suggested herein. The desirable properties of thefoot plate20 are that it is relatively resilient so as to withstand cracking upon application of repeated bending stresses, yet has sufficient flexibility to enhance the performance characteristics felt by the wearer, in conjunction with the properties of theresilient ankle block24 and theankle plate22.
• Preferably, thefoot plate20 is formed by a molding process. More preferably, thefoot plate20 is formed by a compression molding process. Alternatively, thefoot plate20 can be formed by an injection molding process. In other preferred embodiments, thefoot plate20 can be fabricated using other techniques, for example, machining, welding, laminating, casting and forging among others, with efficacy, as required or desired, giving due consideration to the goals of providing enhanced performance, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• TABLES 1A-1B below, in accordance with one preferred embodiment, list various approximate dimensions of thefoot plate20 for various amputee foot and weight sizes. The number and letter in the “SIZE” column in TABLES 1A-1B respectively refer to the cosmesis size or overall length in centimeters and the weight group (L=Light, M=Medium, H=Heavy) of the amputee. The other column heading symbols in TABLES 1A-1B refer to dimensional labels as marked onFIGS. 4-5. T1 to T11 refer to thicknesses (in inches), A, B, L, N, O, P, X, Y refer to length scales (in inches), W refers to a width (in inches), R1, R2, R3, I, J, K refer to radii of curvature (in inches) and D refers to an angle in degrees (°). Note that the thicknesses T1 to T11 are taken at positions spaced by the corresponding value of Y, that is, the position at which T1 is taken is spaced from the position where T2 is taken by Y, and so on. It will be appreciated that other dimensions than those of TABLES 1A-1B may be used, as needed or desired.

  TABLE 1A
  FOOT PLATE DIMENSIONS FOR DIFFERENT AMPUTEE SIZES
  (CORRESPONDS TO FIGS. 4 AND 5)

  SIZE

  A

  B

  D

  R1

  R2

  R3

  I

  J

  K

  L

  N

  O

  P

  22L	2.75	3.00	18.0°	5.75	5.75	.19	.75	6.50	5.25	7.27	3.250	1.423	.94
  22H	2.75	3.00	18.0°	5.75	5.75	.19	.75	6.50	5.25	7.27	3.250	1.423	.94
  24L	3.00	3.25	16.0°	7.00	7.00	.19	.82	7.00	5.75	8.06	3.640	1.650	1.10
  24M	3.00	3.25	16.0°	7.00	7.00	.19	.82	7.00	5.75	8.06	3.640	1.650	1.10
  24H	3.00	3.25	16.0°	7.00	7.00	.19	.82	7.00	5.75	8.06	3.640	1.650	1.10
  26L	3.25	3.50	13.0°	8.75	8.75	.25	.88	7.63	6.25	8.85	4.000	1.860	1.26
  26M	3.25	3.50	13.0°	8.75	8.75	.25	.88	7.63	6.25	8.85	4.000	1.860	1.26
  26H	3.25	3.50	13.0°	8.75	8.75	.25	.88	7.63	6.25	8.85	4.000	1.860	1.26
  28L	3.50	3.75	13.5°	9.50	9.50	.25	.95	8.25	6.77	9.60	4.398	1.981	1.50
  28H	3.50	3.75	13.5°	9.50	9.50	.25	.95	8.25	6.77	9.60	4.398	1.981	1.50

• TABLE 1B
  FOOT PLATE DIMENSIONS FOR DIFFERENT AMPUTEE SIZES
  (CORRESPONDS TO FIGS. 4 AND 5)

  SIZE

  W

  X

  Y

  T1

  T2

  T3

  T4

  T5

  T6

  T7

  T8

  T9

  T10

  T11

  22L	2.082	2.60	.79	.064	.089	.169	.224	.233	.221	.207	.170	.146	.117	.107
  22H	2.082	2.60	.79	.078	.103	.183	.238	.247	.235	.221	.184	.160	.131	.121
  24L	2.250	2.70	.86	.066	.092	.175	.232	.241	.228	.214	.176	.151	.121	.111
  24M	2.250	2.70	.86	.080	.106	.189	.246	.255	.242	.228	.190	.165	.135	.125
  24H	2.250	2.70	.86	.095	.121	.204	.261	.270	.257	.243	.205	.180	.150	.140
  26L	2.417	2.75	.93	.083	.109	.195	.253	.262	.249	.235	.196	.170	.139	.129
  26M	2.417	2.75	.93	.098	.124	.210	.268	.277	.264	.250	.211	.185	.154	.144
  26H	2.417	2.75	.93	.119	.145	.231	.289	.298	.285	.271	.232	.206	.175	.165
  28L	2.600	2.60	1.00	.101	.127	.216	.275	.285	.271	.257	.217	.190	.158	.148
  28H	2.600	2.60	1.00	.122	.148	.237	.296	.306	.292	.278	.238	.211	.179	.169

• TABLE 2 below lists intermediate amputee foot sizes which can utilizefoot plates20 which are trimmed down from the standard sizes of TABLES 1A-1B. As discussed above,markers58 which are already formed on the foot plate toes52 facilitate this trim-down process. Advantageously, such a scheme saves on manufacturing and inventory costs.

  TABLE 2
  FOOT PLATE INTERMEDIATE TRIM DOWN SIZES

  		TRIM DOWN FROM FOOT
  	SIZE	PLATE FOR SIZE
  	21L	22L
  	21H	22H
  	23L	24L
  	23M	24M
  	23H	24H
  	25L	26L
  	25M	26M
  	25H	26H
  	27L	28L
  	27H	28H

• In one preferred embodiment, and referring toFIGS. 4 and 5, the distance S1 is about 0.40 inches, the radii of curvature R4 are about 0.12 inches, the angle θ_Fis about 8°, R5 is about 5 inches, the distance S2 is about 0.39 inches, themarker bump58 has a radius of curvature of about 0.03 inches and a height of about 0.015 inches, thelocation rib66 has a radius of curvature of about 0.19 inches and a height of about 0.06 inches, and the radius of curvature at the peripheral edge of the lower surface of thefoot plate20 is about 0.06 inches. Thefoot plate20 may be otherwise dimensioned, as needed or desired.
• Upper Ankle Plate
• Referring to the drawings, and in particular toFIGS. 1-3 and6-9, the upper ankle plate ormember22 is smaller in length than thefoot plate20 and has average and major widths smaller than the respective average and major widths of thefoot plate20. Theankle plate22 is preferably centered transversely with respect to thefoot plate20. Preferably, theankle plate22 is generally positioned over the back portion of thearch section48 of thelower foot plate20 and substantially above theankle block24. Theankle plate22 preferably extends substantially more forward of the attachment axis34 (FIG. 1) than rearwardly. The contour of the lower surface of the ankle plate generally conforms to the contour of the upper surface of theankle block24.
• In other preferred embodiments, theankle plate22 can be shaped, sized, configured and/or positioned in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing a suitably strong and generally natural feelingprosthetic foot12, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Theupper ankle plate22 is preferably capable of flexing along its length. Desirably, the flexing of theankle plate22 under the weight of the amputee tends to distribute and/or relieve shear stresses applied at the interface between theankle plate22 andankle block24. Moreover, the flexing contributes to a more natural feeling walking and/or running stride for the wearer of theprosthetic foot12.
• In one preferred embodiment, theankle plate22 generally comprises an anterior section orportion76, a medial section orportion78 and a posterior section orportion80. Thefront section76 generally extends towards thetoe region46 of thelower foot plate20 and therear section80 generally extends towards theheel region50 of thelower foot plate20. Preferably, theankle plate22 is generally sized, shaped and/or configured to approximately simulate the dynamics of the upper portion of a natural human foot. Optionally, theankle plate22 can comprise a generally flat plate, as needed or desired.
• Preferably, the ankleplate front section76 is generally inclined or noses in a downward direction relative to a plane P₃(FIG. 8) which is substantially perpendicular to a plane through theattachment axis34. This nosing of thefront section76 generally simulates the structure of the upper portion of a natural human foot. Moreover, the downwards inclination of thefront section76 preferably generally follows the underlying contour of the upper surface of thefoot plate20. Advantageously, this results in a generally uniform thickness of theankle block24 material underneath the ankleplate front section76. It has been determined that such a shape and/or configuration causes improved performance characteristics and longer durability with reduced chances of delamination, peeling or separation between theankle block24 and theplates20,22.
• Moreover, the downwards inclination of thefront section76 permits clearance space between the ankleplate front section76 and the surroundingcosmesis14 which can allow longer layers of theankle block24 to extend towards the footplate toe region46, as needed or desired. In other preferred embodiments, the ankleplate front section76 can be shaped, sized and/or configured in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing improved performance characteristics, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Preferably, the ankleplate front section76 has a tapered thickness with the smallest thickness substantially at or near afront end82 to allow more flexing of the ankleplate front section76 near the front region of theankle block24. In other preferred embodiments, the ankleplate front section76 can be shaped, sized and/or configured in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing improved performance characteristics, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Preferably, the ankleplate front section76 has a tapered width with the smallest width substantially at or near afront end82. This substantially conforms to the configuration of theunderlying ankle block24 and also more closely simulates the structure of the upper portion of a natural human foot. In other preferred embodiments, the ankleplate front section76 can be shaped, sized and/or configured in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing improved performance characteristics, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• In one preferred embodiment, the lower surface of the ankleplate front section76 comprises a location rib or bump86 for establishing the relative positioning between theankle plate22 and theankle block24. Thelocation bump86 mates with or engages a corresponding groove on the upper surface of theankle block24. Therib86 may also provide added protection against separation, peeling or delamination between theankle plate22 and theankle block24.
• Alternatively, the location rib may be provided on theankle block24 and the corresponding groove may be provided on theankle plate22. Additionally, other positioning means such as location pins and the like may be efficaciously used, as required or desired, giving due consideration to the goals of establishing the desired positioning between theankle plate22 and theankle block24, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Preferably, thelocation rib86 extends crosswise across the span of the lower surface of theankle plate22. In other preferred embodiments, the rib86 (and corresponding groove) can be positioned and configured in alternate manners with efficacy, as required or desired, giving due consideration to the goals of establishing the desired positioning between theankle plate22 and theankle block24, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• The ankle platemedial section78 is generally rectangular in shape and has top and bottom surfaces which are generally parallel to the plane P₃(FIG. 8). Preferably, themiddle section78 is generally positioned above the flatupper surface64 of the foot platearch section48. The width of themedial section78 is generally about the same as the width of thefoot plate20 below it. In other preferred embodiments, the ankle platemedial section78 can be shaped, sized, configured and/or positioned in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing improved performance characteristics, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• The ankle platemiddle section78 includes a through cavity orhole88 extending between the lower and upper surfaces of themiddle section78 to receive a bolt or screw30 and a washer32 (FIG. 1). Thefastening bolt30 is used to secure the attachment member28 (FIG. 1) to theankle plate22. Thecavity88 includes a lower cavity orhole90 and an upper cavity orhole92. Thelower cavity90 has a larger diameter compared to the diameter of theupper cavity92 to receive a head94 (FIG. 1) of thebolt30 and thewasher32. Theupper cavity92 receives a shank or threaded portion96 (FIG. 1) of thebolt30.
• Theattachment member28 connects theprosthetic foot12 to a stump or lower leg pylon (not shown) of a wearer. Theattachment member28 is adapted to be fastened to the upper surface of the ankle platemiddle section78. Preferably, the upper surface of the ankle platemiddle section78 has a pair of central lengthwise grooves98 (labeled98a,98binFIGS. 6-8) which engage or mate with corresponding protrusions on the lower surface of theattachment member28. Advantageously, this prevents or mitigates undesirable relative rotation and/or displacement between theankle plate22 and theattachment member28.
• Preferably, thegrooves98 are substantially V-shaped, though other shapes can be employed with equivalent efficacy. Alternatively, one or more grooves may be provided on the lower surface of theattachment member28 and the corresponding mating protrusions on the upper surface of the ankle platemiddle section78, as required or desired, giving due consideration to the goals of preventing or mitigating relative rotation and/or displacement between theankle plate22 and theattachment member28, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• In one preferred embodiment, theattachment member28 comprises a male pyramid connector and includes a coupling knob100 (FIG. 1) for mating with a coupling member on the pylon of the wearer. In the illustrated embodiment, the attachment member orpyramid connector28 comprises a base plate102 (FIG. 1), having theupstanding coupling knob100 formed integrally therewith. The attachment member further may include a pair of upstanding location pins which help transmit torsional forces between the pylon and thefoot prosthesis12 and/or theprosthetic foot assembly10.
• A central threaded bore104 (FIG. 1) in theknob100 threadably receives the threaded portion orshank96 of thefastening bolt30 extending upwardly through theaperture88 in the ankle platemiddle section78. Of course, other attachment members can be attached via the upwardly directedfastening bolt30, as will be readily apparent to those of skill in the art. Moreover, other fastening means such as pins, locks, clamps and the like may be efficaciously used, as needed or desired.
• Advantageously, thehead94 of the upwardly directedfastening bolt30 resides within theankle plate22 and thebolt30 does not traverse theankle block24 or thefoot plate20. Thus, bolt receiving cavities or holes are not needed in theankle block24 and thefoot plate20. This can be particularly important in the case of theankle block24 since such cavities or holes formed within theankle block24 may adversely affect the compressible or resilient properties of theankle block24, and hence affect the performance characteristics of theprosthetic foot12. Optionally, a downwardly directed bolt may be utilized so that thebolt head94 is seated within theattachment member28 and the threaded portion orshank96 is threadably engaged with theankle plate22.
• The ankle platerear section80 is generally rectangular in shape with generally curved side surfaces, and top and bottom surfaces which are generally parallel to the plane P₃(FIG. 8). Preferably, therear section80 is generally positioned above the flatupper surface64 of the foot platearch section48 and may also be positioned above part of the footplate heel region50. The major width of therear section80 is generally less than the width of the portions of theankle block24 andfoot plate20 below it. The major width of therear section80 is also generally less the width of the ankle platemedial section78. In other preferred embodiments, the ankleplate posterior section80 can be shaped, sized, configured and/or positioned in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing improved performance characteristics, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Preferably, the limit strap or extension delimiter26 (FIGS. 1-3) generally circumscribes portions of theankle plate22,ankle block24 andfoot plate20 at or near the rear or heel of theprosthetic foot12. Thelimit strap26 is in contact with the upper surface of the ankleplate posterior section80 and the lower surfaces of one or both of the foot platearch section48 and footplate heel section50. Thestrap26 preferably forms a generally snug fit around the sandwiched assembly of thefoot plate20,ankle plate22 andankle block24 though there are gaps orclearance spaces106 between thestrap26 and the curved sides of the ankle platerear section80, as seen inFIG. 3.
• Thelimit strap26 serves to contain or control the separation to prevent delamination between theankle block24 and theplates20,22 at or near the heel of theprosthetic foot12 during the heel-off portion of the amputee's stride, when the rear of thefoot12 undergoes maximum or high tension or stretching. Thelimit strap26 desirably has an overlap108 (FIG. 2) which is sewn using a cross-stitch of heavy thread. Although thestrap26 is shown with the overlappedportion108 above the top surface of theankle plate22, it is understood that theoverlap108 may be positioned otherwise.
• Preferably, theankle plate22 is fabricated from a vinyl ester based sheet molding compound, such as Quantum QC-8800, available from Quantum Composites of Midland, Mich. Theankle plate22 preferably comprises a vinyl ester resin matrix with a substantially randomly arranged fiberglass fiber content. In another preferred embodiment, theankle plate22 is constructed of fiberglass. Alternatively, theankle plate22 may be formed by a plurality of lamina embedded in a hardened flexible polymer. Theankle plate22 can also be formed of carbon fibers.
• In other arrangements, theankle plate22 may be formed of alternate suitable materials, such as other composite materials, plastics, thermoplastic and thermosetting polymers, metals, alloys and ceramics among others, as required or desired, giving due consideration to the goals of achieving one or more of the advantages and benefits as taught or suggested herein. The desirable properties of theankle plate22 are that it is relatively resilient so as to withstand cracking upon application of repeated bending stresses, yet has sufficient flexibility to enhance the performance characteristics felt by the wearer, in conjunction with the properties of theresilient ankle block24 and thefoot plate20.
• Preferably, theankle plate22 is formed by a molding process. More preferably, theankle plate22 is formed by a compression molding process. Alternatively, theankle plate22 can be formed by an injection molding process. In other preferred embodiments, theankle plate22 can be fabricated using other techniques, for example, machining, welding, laminating, casting and forging among others, with efficacy, as required or desired, giving due consideration to the goals of providing enhanced performance, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• TABLE 3 below, in accordance with one preferred embodiment, lists various approximate dimensions of theankle plate22 for various amputee foot sizes. The number in the “SIZE” column in TABLE 3 refers to the cosmesis size or overall length in centimeters. The other column heading symbols in TABLE 3 refer to dimensional labels as marked onFIGS. 7-8. A, B, D, F, K refer to lengths (in inches), H, I refer to widths (in inches), and C, E refer to thicknesses. It will be appreciated that other dimensions than those of TABLE 3 may be used, as needed or desired.

  TABLE 3
  ANKLE PLATE DIMENSIONS FOR DIFFERENT FOOT SIZES
  (CORRESPONDS TO FIGS. 7 AND 8)

  SIZE	A	B	C	D	E	F	H	I	K

  21-22	2.55	1.53	.300	.61	.950	4.080	1.50	1.10	2.55
  23-24	2.60	1.70	.300	.63	.960	4.300	1.64	1.20	2.60
  25-26	2.68	1.80	.340	.67	.997	4.480	1.76	1.30	2.68
  27-28	2.75	1.97	.340	.72	1.027	4.720	1.90	1.40	2.75

• In one preferred embodiment, and referring toFIGS. 7 and 8, the length G1 is about 0.85 inches, the length G2 is about 1.70 inches, the thickness G3 is about 0.35 inches, the thickness G4 is about 0.12 inches, the length G5 is about 1.70 inches, the radius of curvature R1 is about 0.22 inches, the radius of curvature R2 is about 0.50 inches, the angle θ_A1is about 5°, the angle θ_A2is about 170°, the angle θ_A3is about 6°, the diameter of thecavity92 is about 0.41 inches, the diameter of thecavity90 is about 1.00 inches, thelocation rib86 has a radius of curvature of about 0.19 inches and a height of about 0.06 inches, thegrooves98 have a depth of about 0.06 inches and a width of about 0.06 inches, the curved side surfaces of therear section80 have a radius of curvature of about 0.25 inches. Theankle plate22 may be otherwise dimensioned, as needed or desired.
• Thebolt30 is preferably a metric hex head bolt and preferably comprises stainless steel. Thebolt30 is cold formed with rolled threads and passivated. The minor diameter of thebolt head94 is about 16.85 mm. Thehead94 is about 6.30 mm thick. Theshank96 of thebolt30 is about 30 mm long and comprises threads (M10-1.5) along its whole length. Alternatively, a wide variety of other bolts may be used with equivalent efficacy, as needed or desired.
• Thewasher32 is preferably flat and round and is formed from stainless steel. Thewasher32 has a thickness of about 0.050 inches, an inner diameter of about 0.406 inches, and an outer diameter of about 0.875 inches. Alternatively, a wide variety of other washers may be used with equivalent efficacy, as needed or desired.
• The attachment member orpyramid connector28 is preferably formed from titanium or a titanium alloy such as TIMETAL 6S2, 6A1-4V titanium, or TI 3-1. The pyramid connector has a major diameter of about 1.614 inches and a height of about 0.758 inches. The central threaded bore104 of theconnector28 preferably comprises a M10-1.5 threaded through cavity. Alternatively, a wide variety of other attachment members may be used with equivalent efficacy, as needed or desired.
• Thelimit strap26 preferably comprises a thick natural tubular nylon webbing or a woven nylon having a thickness of about 0.078 inches and a width of about 0.75 inches. Theoverlap108 is sewn with a box stitch overlap with “X”, double back tack at both ends. A bonded polyester thread (Dabond) is used to create theoverlap108 with 8 stitches per inch. Alternatively, theoverlap108 can be stitched using a cross-stitch of heavy nylon thread. After cutting a strap of appropriate length from the raw material, the ends of the strap are melted.
• For a foot size of 21-22, thestrap26 has an open (ends not overlapped) span of about 6.70 inches, anoverlap108 of about 1.10 inches, and an internal diameter of about 1.65 inches. For a foot size of 23-24, thestrap26 has an open (ends not overlapped) span of about 7.20 inches, anoverlap108 of about 1.20 inches, and an internal diameter of about 1.81 inches. For a foot size of 25-26, thestrap26 has an open (ends not overlapped) span of about 7.70 inches, anoverlap108 of about 1.30 inches, and an internal diameter of about 1.93 inches. For a foot size of 27-28, thestrap26 has an open (ends not overlapped) span of about 8.10 inches, anoverlap108 of about 1.40 inches, and an internal diameter of about 2.02 inches. Thestrap26 can be dimensioned in alternate ways, as needed or required.
• Compressible Ankle Block
• Referring to the drawings, and in particular toFIGS. 1-3 and10-12, the ankle block or cushion24, is positioned intermediate thefoot plate20 and theankle plate22 and preferably comprises a monolithic element of material. Preferably, and as discussed in greater detail below, the lower surface of theankle block24 is bonded to thefoot plate20 and the upper surface of theankle block24 is bonded to theankle plate22 using an adhesive.
• The ankle block orkeel24 is smaller in length than thefoot plate20 and longer than theankle plate22. The average and major widths of theankle block24 are smaller than the respective average and major widths of thefoot plate20. The average width of theankle block24 is slightly greater than the average width of theankle plate22 while the major width of theankle block24 is about the same as the major width of theankle plate22.
• Theankle block24 is preferably centered transversely with respect to thefoot plate20 and theankle plate22. Preferably, theankle block24 is generally positioned over the back portion of thearch section48 of thelower foot plate20 and under the length of theupper ankle plate24. Theankle block24 preferably extends substantially more forward of the attachment axis34 (FIG. 1) than rearwardly. The contour of the lower surface of theankle block24 generally follows the contour of the portion of the upper surface of thefoot plate20 on which it is seated. The contour of the upper surface of theankle block24 generally follows the contour of the lower surface of theankle plate22.
• In other preferred embodiments, theankle block24 can be shaped, sized, configured and/or positioned in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing a smooth and life-like response during walking and/or running activities, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Advantageously, theankle block24 provides a cushioning effect and expands (stretches in tension), contracts (compresses) and/or distorts under the weight of the amputee during heel-strike, flat footed, heel-off and toe-off stages of walking and running activities. During walking and/or strides, the majority of the compressive forces imparted by the wearer is absorbed by theankle block24, with a small portion being absorbed by the flexiblelower foot plate20 and flexibleupper ankle plate22 of theprosthetic foot12.
• In one preferred embodiment, theankle block24 generally comprises an anterior section orportion116 and a posterior section orportion120. Thefront section116 generally extends towards thetoe region46 of thelower foot plate20 and therear section120 generally extends towards theheel region50 of thelower foot plate20.
• Preferably, anupper surface122 of the ankleblock front section116 is inclined in a downward direction relative to a plane P₄(FIG. 12) which is substantially perpendicular to a plane through theattachment axis34. This downwards inclination of theupper surface122 of the ankleblock front section116 generally corresponds to the downwards inclination of the lower surface of the ankle plate front section76 (FIG. 8) and has advantages and benefits as discussed above. In other preferred embodiments, the ankleblock front section116 can be shaped, sized and/or configured in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing a smooth and life-like response during walking and/or running activities, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Preferably, alower surface124 of the ankleblock front section116 is curved to generally follow the curvature of the portion of the foot platearch section48 below it. Desirably, this results in a generally uniform thickness of the ankleblock front section116. Functional testing has shown that such a shape and/or configuration causes improved performance characteristics and longer durability with reduced chances of delamination, peeling or separation between theankle block24 and theplates20,22.
• A downwardly slopingfront end126 of theankle block24 forms aface128 connecting the upper andlower surfaces122,124 of theankle block24. Theface128 is inclined relative to the vertical or to theattachment axis34 and extends downwardly from theankle plate22 to thefoot plate20. This particular shape of theankle block24 desirably contributes to a more uniform distribution and transfer of compression stress. The shorter length of theankle plate22 and the slopingfront face128 of theankle block24 tend to reduce shear stresses occurring near the front end ortip82 of theankle plate22 which could otherwise cause undesirable delamination of theprosthetic foot12.
• Preferably, the ankleblock front section116 has a tapered width with the smallest width substantially at or near afront end126. This tapered width generally conforms to the width of the overlying portion of theankle plate22. In other preferred embodiments, the ankleblock front section116 can be shaped, sized and/or configured in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing a smooth and life-like response during walking and/or running activities, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Preferably, theupper surface122 of the ankleblock front section116 comprises a crosswise location or positioning groove or notch130 which mates with thelocation rib86 of theankle plate22. As discussed above, thelocation groove130 and thelocation rib86 establish the desired relative positioning between theankle plate22 and theankle block24.
• The ankle blockrear section120 has atop surface132 and abottom surface134 which are generally parallel to the plane P₄(FIG. 12). Preferably, theupper surface132 is longer than thelower surface134. Therear section120 is generally positioned above the flatupper surface64 of the foot platearch section48 and may also be positioned above part of the footplate heel region50. The width of therear section120 is generally about the same as the width of thefoot plate20 below it. In other preferred embodiments, the ankle blockrear section120 can be shaped, sized, configured and/or positioned in alternate manners with efficacy, as required or desired, giving due consideration to the goals of providing a smooth and life-like response during walking and/or running activities, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Preferably, thelower surface134 of the ankle blockrear section120 comprises a crosswise location or positioning groove or notch140 which mates with thelocation rib66 of thefoot plate20. As discussed above, thelocation groove140 and thelocation rib66 establish the desired relative positioning between thefoot plate20 and theankle block24.
• Arear end142 of the ankle blockrear section120 has aface144 substantially parallel to the vertical or to theattachment axis34. Preferably, a downwardly and inwardly sloping rear/lower face146 of therear end142 connects theend face144 to thelower face134. This tapered orinclined face146 results in a substantially wedged configuration below and above theinclined face146. Advantageously, and as discussed below, such a configuration provides a high degree of “plantar flexion.”
• Preferably, theankle block24 is bonded to thefoot plate20 andankle plate22 using Loctite 4471 Instant Adhesive (Item# 44704) manufactured by Loctite, Inc. and as available from R. S. Hughs Co. of Anaheim, Calif. The Loctite adhesive is a medium viscosity, fast curing, single component Cyanoacrylate adhesive which is formulated for difficult to bond substrates. Preferably, before the use of the adhesive, the surfaces to be adhered are cleansed of any oils, degreased, abraded and cleaned. Alternatively, other suitable adhesives, glues, or adhering materials and techniques can be used with equivalent efficacy.
• A preferred material for theankle block24 is polyurethane foam such as Purcell Cellular Vulkollan Polyurethane, as available from Pleiger Plastics Company of Washington, Pa. Preferably, the polyurethane foam is a NDI/Polyester based polyurethane foam and has a high load capacity, is abrasion and tear resistant, and has a high elasticity with low permanent deformation. Alternatively, theankle block24 may comprise other suitable resilient materials such as natural or synthetic rubber, plastics, honeycomb structures or other materials.
• Cellular foam, however, provides a desirable viscoelastic springiness for a more natural feeling stride without the drawback of limited compression associated with solid elastomeric materials. Furthermore, the cellular nature of theankle block24 makes it lighter than solid elastomers. Foam densities between about 150 and 1500 kg/m³may be used to obtain the benefits of the invention taught herein.
• Theankle block24 provides a relatively stiff, yet flexible ankle region which may be customized for various wearers. Heavier wearers may require a denser and/or thicker resilient material for theankle block24, while lighter wearers may require a less dense material or less thickness. More detailed material specifications and dimensions are presented later herein.
• Preferably, theankle block24 is machined out of larger blocks or units of material which are formed by molding. The machining preferably comprises a water jet processing and can be performed by Pleiger Plastics Company of Washington, Pa. Preferably, any “molded skin” which is formed at the tool-block interface during the molding of the larger blocks or units and remains on theankle block24 is skived or sheared off theankle block24 while ensuring the correct dimensions.
• The “molded skin” can cause non-uniformity in the resilient and/or compressible characteristics of theankle block24. Moreover, it may make the adhesion of theankle block24 to theplates20,22 more difficult. In one preferred embodiment, molded skin is not allowed on any of the surfaces of theankle block24. In another preferred embodiment, molded skin is allowed on the side surfaces of theankle block24 but not on the top and bottom surfaces.
• In an alternative preferred embodiment, theankle block24 is formed by an injection molding process to achieve the desired shape, size and/or configuration. In other preferred embodiments, other techniques can be efficaciously utilized, as required or desired, giving due consideration to the goals of providing a smooth and life-like response during walking and/or running activities, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• Preferably, the surfaces of theankle block24 exposed to the atmosphere, that is, the side surfaces are treated or coated with a sealant to prevent moisture absorption over time due to the micro-cellular nature of the preferred material forming theankle block24. The absorption of moisture over time can change and/or cause unpredictability in the dynamic characteristics of theankle block24.
• Preferably, E-6000 MV Clear (Non-flammable) Sealant (Product Code 371000130) manufactured by Eclectic Products, Inc. and as available from Ellsworth Adhesive Systems of Tustin, Calif. is applied to the exposed surfaces of theankle block24. This sealant is preferably used in conjunction with a sealant thinner or solvent containing tetrachlorodethylene (perchloroethylene) manufactured by PPG Industries, Inc. and as available from Gallade Chemical, Inc. of Santa Ana, Calif. In other preferred embodiments, alternate sealants and/or thinners may be efficaciously used, as required or desired, giving due consideration to the goals of preventing or mitigating moisture absorption by theankle block24, and/or of achieving one or more of the advantages and benefits as taught or suggested herein.
• TABLE 4 below, in accordance with one preferred embodiment, lists various approximate dimensions of theankle block24 for various amputee foot and weight sizes. The number and letter in the “SIZE” column in TABLE 4 respectively refer to the cosmesis size or overall length in centimeters and the weight group (L=Light, M=Medium, H=Heavy) of the amputee. The “Manuf. ID” refers to the part identification for blocks of Purcell Cellular Vulkollan Polyurethane as available from Pleiger Plastics Company of Washington, Pa. and from which theankle block24 is fabricated to the required design. The other column heading symbols in TABLE 4 refer to dimensional labels as marked onFIGS. 11-12 and to the weight of theankle block24. B, C, D, E, H, J refer to length scales (in inches), A refers to a width (in inches), L refers to a thickness (in inches), and M refers to a radius of curvature (in inches). Note that the H dimension is tangent to the radius of curvature of thesurface124 and/or extends upto the beginning of the curvature of thesurface124. It will be appreciated that other dimensions and material specifications than those of TABLE 4 may be used, as needed or desired.

  TABLE 4
  ANKLE BLOCK DIMENSIONS AND WEIGHTS FOR
  DIFFERENT AMPUTEE SIZES (CORRESPONDS TO
  FIGS. 11 AND 12)

  											Ankle
  											Block
  	Manuf.										Weight
  SIZE	ID	A	B	C	D	E	H	J	L	M	(Grams)

  21-22L	15-40	1.50	4.32	2.55	1.55	.60	2.58	2.33	.92	5.75	25-30
  21-22H	15-45	1.50	4.32	2.55	1.55	.60	2.58	2.33	.92	5.75	31-36
  23-24L	15-40	1.64	4.57	2.60	1.73	.64	2.59	2.34	1.00	7.00	32-37
  23-24M	15-45	1.64	4.57	2.60	1.73	.64	2.59	2.34	1.00	7.00	38-42
  23-24H	15-50	1.64	4.57	2.60	1.73	.64	2.59	2.34	1.00	7.00	43-49
  25-26L	15-45	1.76	4.73	2.68	1.83	.70	2.75	2.50	1.00	8.75	41-46
  25-26M	15-50	1.76	4.73	2.68	1.83	.70	2.75	2.50	1.00	8.75	47-52
  25-26H	15-55	1.76	4.73	2.68	1.83	.70	2.75	2.50	1.00	8.75	53-59
  27-28L	15-45	1.90	4.97	2.75	2.00	.75	2.75	2.50	1.00	9.50	48-53
  27-28H	15-50	1.90	4.97	2.75	2.00	.75	2.75	2.50	1.00	9.50	54-60

• In one preferred embodiment, and referring toFIGS. 11 and 12, the thickness Q1 is about 0.25 inches, the angle θ_B1is about 5°, the angle θ_B2is about 10°, the angle θ_B3is about 15°, the angle θ_B4is about 60°, thelocation grooves130,140 have a radius of curvature of about 0.19 inches and a depth of about 0.06 inches. Theankle plate22 may be otherwise dimensioned, as needed or desired. For instance, other angles θ_B3ranging from about 5° to about 45° and other angles θ_B4ranging from about 45° to about 75° may be used to achieve the benefits taught herein.
• As indicated above, in one preferred embodiment, the ankle blocks24 are formed from larger blocks or block units of Purcell Cellular Vulkollan Polyurethane as available from Pleiger Plastics Company of Washington, Pa. One preferred block size has dimensions of 55 (+3/−2) mm×250 (±5) mm×500 (+10/−3) mm and is referred to as Block A in the TABLE 5 below. Another optional block size has dimensions of 55 (+3/−2) mm×250 (±5) mm×750 (+10/−3) mm and is referred to as Block B in the TABLE 5 below.
• TABLE 5 lists material and property specifications for Purcell Cellular Vulkollan Polyurethane as available from Pleiger Plastics Company of Washington, Pa.

  TABLE 5
  MATERIAL SPECIFICATION FOR PURCELL CELLULAR
  VULKOLLAN POLYURETHANE

  	Weight	Weight		Tensile
  Manuf.	Block A	Block B	Density	Strength	Elongation	Tear	Rebound	Hardness
  ID	(grams)	(grams)	(kg/m3)	(N/mm2)	(%)	(kN/m)	(%)	Shore A

  15-35	2179-2358	3269-3537	317-343	4.00	390	8	70	20-30
  15-40	2509-2716	3764-4073	365-395	4.50	410	10	70	25-35
  15-45	2839-3073	4259-4610	413-447	5.50	430	12	70	30-40
  15-50	3169-3431	4754-5146	461-499	6.50	450	14	70	35-45
  15-55	3499-3788	5249-5682	509-551	7.50	465	18	70	40-50
  15-60	3829-4146	5744-6218	557-603	8.00	470	20	70	45-55

  
  Prosthetic Foot Dynamics
• Theprosthetic foot12 of the invention provides a particularly smooth and life-like response during normal walking or running activities. The uniquely configuredankle block24 transmits the forces imparted thereon by thefoot plate20 and theankle plate22 such that the rollover or migration of the compressed region of theankle block24 is gradual and natural as felt by the amputee, as energy is cyclically stored and released theprosthetic foot12.
• During heel-strike, the weight of the amputee is initially transmitted to the heel of the leading foot, and the compressive stresses are absorbed by therear region120 of theankle block24 at or near therear end142. As the amputee continues through his/her stride, the compression of theankle block24 travels smoothly and continuously toward thefront portion116 or end126 of theankle block24 during the flat-foot position and leading to the heel-off position. In the toe-off position theankle block24 starts to resume its original (uncompressed) state as some of the weight of the amputee is being transferred to the opposite foot, which has now moved forward. Theankle block24 resumes its original shape as the amputee lifts his/her leading foot of the ground or supporting surface. Advantageously, the dynamics of such a stride give the foot a natural feel.
• During heel-strike, theheel section50 of thefoot plate20 bends to some degree and a slight amount of bending may occur at therear section80 of theankle plate22. In the heel-off position, thetoe section46 of thefoot plate20 bends to some degree and thefront section76 of theankle plate22 may bend slightly. In the toe-off position there is less bending if any of both the footplate toe section46 and the ankleplate front section76.
• It is important to note that although theankle block24 absorbs a majority of the compression generated by the wearer, theflexible foot plate20 and theflexible ankle plate22 are designed to work in conjunction with theresilient ankle block24 and provide enhanced dynamic performance.
• Another advantage is provided by the high degree of “plantar flexion” due to the wedged configuration of therear end142 of theankle block24. Referring in particular toFIGS. 1, 5 and12, this wedged configuration or inward taper of theface146 results in an increased and/or predetermined distance between the foot plate heel end62 (and heel region50) and acontact axis150 formed at the contact location between thetaper146 of theankle block24 and the upper surface of thelower foot plate20. Advantageously, during heel-strike, this effectively results in a longer moment, lever or cantilever arm between the heel end62 (and heel region50) and the effective fulcrum point or axis (which is at or close to the contact axis150). Desirably, this translates into more downward deflection of the toe end60 (and toe region46) caused by more upward deflection of the heel end62 (and heel region50) or “plantar flexion.”
• At heel-strike, theflexible heel member50 bends to absorb the amputee's walking or running energy. This energy is substantially uniformly transmitted to theflexible forefoot member46, causing it to deflect downward before the toe makes contact with the ground surface. Also, the subjection of the heel member orregion50 to bending moments causes transmission of spring stress through theheel region50 to the forefoot ortoe region46 whereby an energy return effect is achieved. This results in smoother rollover and a better overall feel as the amputee's weight more smoothly shifts forward from heel (heel-strike) to toe (heel-off). Absent such deflection of theforefoot region46, there is a greater delay between heel-strike and toe strike (heel-off), resulting in relatively unsmooth rollover.
• Thus, the high degree of plantar flexion achieved by theprosthetic foot12 of the present invention adds to providing a more smooth and life-like response during normal walking or running activities. The wedged or taper feature of theankle block24 can be adjusted or selectively dimensioned and configured, as required or desired, giving due consideration to the goals of providing a more natural walking and/or running feel and improved rebounding and responsiveness, and/or of achieving one or more of the advantages or benefits as taught or suggested herein.
• Although not illustrated, theprosthetic foot12 of the present invention can also provide enhanced performance for the wearer in inversion or eversion. The present invention allows the amputee to walk transversely upon sloped surfaces, for example, with thefoot plate20 generally conforming to the terrain while theankle plate22 remains relatively horizontal due to the sideways compression of theankle block24. Again, as the wearer lifts his or herfoot12, theankle block24 resumes its original shape, thus helping the wearer as energy is stored and then released.
• It can now be appreciated that the “feel” of the presentprosthetic foot12 is greatly enhanced by the cooperation betweenfoot plate20,ankle plate22, andankle block24. As the wearer continues through the walking stride, the dynamic response from theprosthetic foot12 is smooth as theankle block24 compresses in different regions and a high degree of plantar flexion is achieved. Further, the flexing of thefoot plate20 andankle plate22 also assist in smoothly transmitting the various bumps and jars found in uneven walking surfaces.
• Outer Cosmesis
• Referring to the drawings, and in particular toFIGS. 1-2 and13-16, theflexible cosmesis14 is an outer cover for a prosthetic foot, such as theprosthetic foot12, and is an approximate replicate of the appearance of a human anatomical foot.FIG. 13 shows animaginary plane36′ which is upwardly offset from the supportingground surface36 ofFIG. 1 and is tangential to the lower surface of thecosmesis14 near the toe region. The orientation of thecosmesis14 with respect to theplane36′ is indicative of a sole and/or heel of a shoe or other footwear worn by the amputee over thecosmesis14.
• Thecosmesis14 is preferably fabricated from a flexible material and provides an auxiliary or complementary cushioning effect. Thecosmesis14 generally comprises an anterior orfront toe region152, a posterior orrear heel region154 and theinner cavity40 which includes an inner sole156. Thecavity40 is adapted to receive a prosthetic foot, such as theprosthetic foot12. The sole156 is shaped, sized and configured to conform to the general shape, size and configuration of thelower foot plate20.
• Preferably, thecavity40 further comprises a slottedregion158 at thetoe portion152 of thecosmesis14 and a slotted region or slot160 at theheel portion154 of thecosmesis14. The slottedregion158 is formed under an extendingsection162 and is adapted to receive the footplate toe section46. The slottedregion160 is formed under an extending section orprotrusion164 and is adapted to receive the footplate heel section50.
• Thetoe region152 of thecosmesis14 comprises abig toe166, an adjacentsmall toe168 and three othersmall toes170,172,174. In one preferred embodiment, the slit orslot42 between thebig toe166 andadjacent toe168 is provided to receive a thong or the like of a thong sandal or other footwear. Optionally, slits or slots may also be provided between thesmall toes168,170,172,174, as needed or desired.
• The cosmesis inner sole156 comprises a pair oftoe seating portions176,178 at thetoe region152 of thecosmesis14. Thetoe seating portions176,178 are separated by an intermediate raisedportion184 and the thong-receivingslot42. Thesole toe portion176 is wider than thesole toe portion178 and is configured to seat one of the outer toes of thefoot plate20 and the central toe of thefoot plate20, such as the outer toe52aand thecentral toe52c. The smallersole toe portion178 is configured to receive an outer toe of thefoot plate20, such as theouter toe52b. The raised portion ormember184 is received in one of the slots54 between the toes52. Advantageously, because of the symmetric toe configuration of thefoot plate20, as the skilled artisan will recognize, theprosthetic foot12 may be used with either a left or aright foot cosmesis14. Desirably, this adds to the versatility of the invention.
• The inner slottedregion158 comprises a pair oftoe receiving slots180,182 at thetoe region152 of thecosmesis14. Thetoe receiving slots180,182 are separated by an intermediate raisedportion184 and the thong-receivingslot42. Theslot180 is wider than theslot182 and is configured to receive one of the outer toes of thefoot plate20 and the central toe of thefoot plate20, such as the outer toe52aand thecentral toe52c. Thesmaller slot182 is configured to receive an outer toe of thefoot plate20, such as theouter toe52b. The raised portion ormember184 is received in one of the slots54 between the toes52. Advantageously, because of the symmetric toe configuration of thefoot plate20, as the skilled artisan will recognize, theprosthetic foot12 may be used with either a left or aright foot cosmesis14. Desirably, this adds to the versatility of the invention.
• The thong-receivingslot42 of thecosmesis14 can be shaped, sized and/or configured in a wide variety of manners. In one preferred embodiment, theslot42 is substantially V-shaped. In another preferred embodiment, theslot42 is substantially U-shaped. Other suitable shapes may also be utilized with equivalent efficacy, as needed or desired.
• The reinforcement patch orstrap44 is provided in thetoe region152 of thecosmesis14. Thereinforcement patch44 provides a durable barrier between thefoot plate20 and thecosmesis14 and prevents or reduces wear of the sole156 of thecosmesis14 due to frictional contact and/or compression stresses. Thepatch44 may be directly exposed to the footplate toe region46 and/or thefoot plate20 and thus be part of the sole156, or it may be covered by a thin layer of the material forming thecosmesis14 and hence be slightly under the sole156. Alternatively, some portion(s) of thepatch44 may be directly exposed to the footplate toe region46 and/or thefoot plate20 and thus be part of the sole156 and some portion(s) may be covered by a thin layer of the material forming thecosmesis14 and hence be slightly under the sole156. Some or all of the edges of thepatch44 can be embedded in the material forming thecosmesis14.
• Thereinforcement patch44 preferably comprises a first supporting section orportion190 and a wider second supporting section orportion192 with a slit or slot194 formed therebetween. The narrower first supportingsection190 is generally aligned with thesole toe portion178 and lies below or is generally aligned with one outer foot plate toe52. The wider second supportingsection192 is generally aligned with thesole toe portion176 and lies below or is generally aligned with two adjacent foot plate toes52.
• Thepatch slot194 is substantially aligned with the thong-receivingslot42. Thepatch slot194 is also aligned with one of the slots54 formed between the foot plate toes52. Thepatch slot194 is further aligned with the raisedportion184 between thesole toe portions176,178.
• Theslot194 of thereinforcement patch44 can be shaped, sized and/or configured in a wide variety of manners. In one preferred embodiment, theslot194 is substantially U-shaped. In another preferred embodiment, theslot42 is substantially V-shaped. Other suitable shapes may also be utilized with equivalent efficacy, as needed or desired.
• Thereinforcement patch44 also includes a pair of spaced registration holes196 (labeled196a,196b) which assist in positioning thepatch44 in the desired position during fabrication of thecosmesis14. More than two registration holes196 may be used, as needed or desired. Also, other registration means such as registration pins may be used with equivalent efficacy.
• Preferably, thefoot plate20 is bonded to the cosmesis inner sole156 (which may include exposed portions of the reinforcement strap44) using Loctite 4471 Instant Adhesive (Item# 44704) manufactured by Loctite, Inc. and as available from R. S. Hughs Co. of Anaheim, Calif. The Loctite adhesive is a medium viscosity, fast curing, single component Cyanoacrylate adhesive which is formulated for difficult to bond substrates. Preferably, before the use of the adhesive, the surfaces to be adhered are cleansed of any oils, degreased, abraded and cleaned. Alternatively, other suitable adhesives, glues, or adhering materials and techniques can be used with equivalent efficacy.
• Thecosmesis14 is preferably fabricated from a urethane material such as urethane foam. Alternatively, thecosmesis14 may comprise other suitable resilient materials such as natural or synthetic rubber, plastics, honeycomb structures or other materials.
• Thecosmesis14 is preferably formed using a molding process such as injection molding or insert molding. The molding utilizes an anatomically sculpted foot shape or mold, with details and sizing based on a master pattern and/or digitized data representing typical foot sizes. The molded density is approximately 25 lb/ft³, though in other embodiments it may be less or more, as needed or desired.
• A core part or tooling mandrel198 (shown in phantom inFIG. 13) is preferably utilized during the fabrication/molding of thecosmesis14. After the molding process a predetermined length or quantity of material200 (FIG. 13) may be removed or cut off by machining to finalize the sizing of the cosmesis.
• The registration holes196 of thereinforcement patch44 are engaged by a suitable tool or molding cone to orient and/or position thepatch44 in the proper orientation and position during the molding process. Desirably, the molding process also causes thereinforcement patch44 to be firmly bonded in place. As indicated above, the surface of thepatch44 may be exposed, fully covered or partially covered after the molding is completed.
• Thereinforcement strap44 is preferably fabricated from a polyurethane impregnated belting (Supplier Part No. FN1-12E) as available from California Industrial Rubber Co. of Fresno, Calif. This material generally comprises a urethane or polyurethane core and a polyester casing, and has a tensile strength of 780 lb/in and undergoes 1% elongation under a tensile force of 68 lb/in. Alternatively, other suitably strong materials may be utilized, as needed or desired. Preferably, thestrap44 is formed by stamping and/or punching operations, though other techniques such as machining among others can be used, as needed or desired.
• TABLE 6 below, in accordance with one preferred embodiment, lists various approximate dimensions of the cosmesis14 (and other related dimensions that may be used during molding of the cosmesis14) for various amputee foot sizes. The number in the “SIZE” column in TABLE 6 refers to the cosmesis size or overall length in centimeters and the letter refers to the foot (L=Left, R=Right). The other column heading symbols in TABLE 6 refer to dimensional labels as marked on FIGS.13 AND16. All dimensions in TABLE 6 are in inches. Note that the dimensions T1 to T11 are taken at positions spaced by the corresponding value of Y, that is, the position at which T1 is taken is spaced from the position where T2 is taken by Y, and so on. It will be appreciated that other dimensions than those of TABLE 6 may be used, as needed or desired.

  TABLE 6
  COSMESIS DIMENSIONS FOR DIFFERENT FOOT SIZES
  (CORRESPONDS TO FIGS. 13 AND 16)

  SIZE

  TH

  A

  Y

  T1

  T2

  T3

  T4

  T5

  T6

  T7

  T8

  T9

  T10

  T11

  21L	.20	1.33	.79	.98	.85	.78	.73	.71	.63	.43	.29	.30	.33	—
  21R	.20	1.33	.79	.98	.85	.78	.73	.71	.63	.43	.29	.30	.33	—
  22L	.20	1.41	.79	.98	.85	.78	.73	.71	.63	.43	.29	.30	.33	.38
  22R	.20	1.41	.79	.98	.85	.78	.73	.71	.63	.43	.29	.30	.33	.38
  23L	.20	1.49	.86	1.04	.90	.82	.75	.75	.68	.51	.37	.32	.39	—
  23R	.20	1.49	.86	1.04	.90	.82	.75	.75	.68	.51	.37	.32	.39	—
  24L	.20	1.57	.86	1.04	.90	.82	.75	.75	.68	.51	.37	.32	.39	.44
  24R	.20	1.57	.86	1.04	.90	.82	.75	.75	.68	.51	.37	.32	.39	.44
  25L	.24	1.65	.93	.94	.83	.73	.69	.68	.58	.45	.34	.32	.40	—
  25R	.24	1.65	.93	.94	.83	.73	.69	.68	.58	.45	.34	.32	.40	—
  26L	.24	1.73	.93	.94	.83	.73	.69	.68	.58	.45	.34	.32	.40	.47
  26R	.24	1.73	.93	.94	.83	.73	.69	.68	.58	.45	.34	.32	.40	.47
  27L	.24	1.81	1.00	.90	.80	.72	.66	.62	.53	.36	.25	.25	.34	—
  27R	.24	1.81	1.00	.90	.80	.72	.66	.62	.53	.36	.25	.25	.34	—
  28L	.28	1.88	1.00	.90	.80	.72	.66	.62	.53	.36	.25	.25	.34	.40
  28R	.28	1.88	1.00	.90	.80	.72	.66	.62	.53	.36	.25	.25	.34	.40

• In one preferred embodiment, and referring toFIG. 13, X1 is about 0.40 inches, X2 is about 0.13 inches, X3 is about 0.40 inches, X4 is about 1.00 inches, X5 is about 0.375 inches, X6 is about 0.75 inches, X7 is about 3.10 inches, X8 is about 2.00 inches, X9 is about 4.93 inches, and X10 is about 2.40 inches. Thecosmesis14 and other length scales ofFIG. 13 may be otherwise dimensioned, as needed or desired.
• For foot sizes 21-24, thereinforcement patch44 has a thickness of about 0.060 inches, a major length of about 1.96 inches and a major width of about 2.21 inches. Thenarrow section190 has a width of about 0.49 inches and thewide section192 has a width of about 1.27 inches. Theslot194 has a length of about 1.37 inches and a width of about 0.45 inches. The registration holes196 have a diameter of about 0.19 inches and are spaced by about 1.76 inches. The spacing between the holes196 and the rear edge of thepatch44 is about 0.26 inches. The spacing between thehole196band the proximate side edge of thepatch44 is about 0.19 inches. The spacing between thehole196aand the proximate side edge of thepatch44 is about 0.26 inches. In other embodiments, thepatch44 can be alternately dimensioned, as needed or desired.
• For foot sizes 25-28, thereinforcement patch44 has a thickness of about 0.060 inches, a major length of about 1.96 inches and a major width of about 2.48 inches. Thenarrow section190 has a width of about 0.63 inches and thewide section192 has a width of about 1.40 inches. Theslot194 has a length of about 1.37 inches and a width of about 0.45 inches. The registration holes196 have a diameter of about 0.19 inches and are spaced by about 1.71 inches. The spacing between the holes196 and the rear edge of thepatch44 is about 0.35 inches. The spacing between thehole196band the proximate side edge of thepatch44 is about 0.34 inches. The spacing between thehole196aand the proximate side edge of thepatch44 is about 0.43 inches. In other embodiments, thepatch44 can be alternately dimensioned, as needed or desired.
• While the components and techniques of the present invention have been described with a certain degree of particularity, it is manifest that many changes may be made in the specific designs, constructions and methodology hereinabove described without departing from the spirit and scope of this disclosure. It should be understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification, but is to be defined only by a fair reading of the appended claims, including the full range of equivalency to which each element thereof is entitled.

Claims (41)

1. A prosthetic foot, comprising:

a foot element comprising a toe region comprising a toe and an adjacent slot that only extends within said toe region;

an ankle element positioned entirely above said foot element and spaced from said foot element; and

an ankle block comprising a compressible material and positioned intermediate said foot element and said ankle element such that said foot element and said ankle element do not directly contact one another.

2. The prosthetic foot ofclaim 1, wherein said toe and said slot have the same length.

3. The prosthetic foot ofclaim 1, wherein said foot element has an upper surface and said ankle element has a lower surface that is substantially parallel to said upper surface of said foot element.

4. The prosthetic foot ofclaim 1, wherein said ankle block comprises a monolithic element.

5. The prosthetic foot ofclaim 1, wherein said foot element comprises an integral unit.

6. The prosthetic foot ofclaim 1, wherein said foot element is generally curvilinear in shape.

7. The prosthetic foot ofclaim 1, wherein said ankle element is shorter than said foot element.

8. The prosthetic foot ofclaim 1, wherein said prosthetic foot further comprises a connector for facilitating attachment of said prosthetic foot to a socket or pylon.

9. The prosthetic foot ofclaim 1, wherein said prosthetic foot further comprises a cosmesis that includes a slot substantially aligned with said slot of said foot element.

10. The prosthetic foot ofclaim 1, wherein at least one of said foot element and said ankle element is flexible.

11. A prosthetic foot, comprising:

a foot element having a longitudinal axis and comprising a plurality of toes at an anterior toe region, said plurality of toes comprising two side toes and an intermediate central toe separated from said side toes by respective slots, said central toe being parallel to and aligned with said longitudinal axis, said toes having the same length and said slots extending entirely within said anterior toe region;

an ankle element spaced from said foot element and being connectable to a lower limb socket or pylon; and

a compressible ankle block sandwiched between said foot element and said ankle element.

12. The prosthetic foot ofclaim 11, wherein said ankle element is positioned entirely above said foot element.

13. The prosthetic foot ofclaim 11, wherein said foot element and said ankle element do not directly contact one another.

14. The prosthetic foot ofclaim 11, wherein said ankle block comprises a wedged configuration.

15. The prosthetic foot ofclaim 14, wherein said wedged configuration comprises a wedge shaped cut at a posterior section of said ankle block.

16. The prosthetic foot ofclaim 11, wherein said toes are slightly upwardly curved.

17. The prosthetic foot ofclaim 11, wherein said toes have a length of about 1.5 inches or less.

18. The prosthetic foot ofclaim 11, wherein said ankle block is in mechanical communication with an arch region of said foot element.

19. The prosthetic foot ofclaim 11, wherein said prosthetic foot further comprises an outer cosmesis that houses said foot element, said ankle element and said ankle block.

20. The prosthetic foot ofclaim 19, wherein said cosmesis comprises a toe region with a slot to form a big toe substantially aligned with one of said side toes of said foot element.

21. A prosthetic foot, comprising:

a foot element comprising an anterior toe region comprising a middle toe and a pair of flanking outer toes, each of said toes having geometrically substantially the same shape;

an ankle element positioned above said foot element and spaced from said foot plate over an entire length of said ankle plate;

at least one of said foot element and said ankle element being capable of flexing along their length; and

a resilient ankle block intermediate said foot element and said ankle element, said ankle block comprising a posterior section having a wedge shaped cut to form a generally vertical first rear face and a sloping second rear face downwardly inclined with respect to said first rear face.

22. The prosthetic foot ofclaim 21, wherein said toes only extend within said anterior toe region.

23. The prosthetic foot ofclaim 21, wherein said ankle element is positioned entirely above said foot element.

24. The prosthetic foot ofclaim 21, wherein said toes are symmetrically arranged.

25. The prosthetic foot ofclaim 21, wherein said foot element is generally curvilinear.

26. The prosthetic foot ofclaim 21, wherein said ankle block comprises an anterior section that has a sloping front face.

27. The prosthetic foot ofclaim 21, wherein said ankle block comprises an elastomer.

28. The prosthetic foot ofclaim 27, wherein said ankle block comprises polyurethane.

29. The prosthetic foot ofclaim 28, wherein said ankle block comprises polyurethane foam.

30. The prosthetic foot ofclaim 21, wherein said ankle block comprises cellular foam.

31. The prosthetic foot ofclaim 21, wherein said foot element and said ankle element do not directly contact one another.

32. A prosthetic foot, comprising:

a generally horizontal foot plate comprising a toe region comprising an asymmetric slot and an adjacent toe, said slot and said toe being positioned entirely within said toe region;

an ankle plate positioned entirely above said foot plate and spaced from said foot plate; and

a compressible ankle block positioned intermediate said foot plate and said ankle plate such that said foot plate and said ankle plate do not directly contact one another.

33. The prosthetic foot ofclaim 32, wherein said foot plate has a longitudinal axis and said slot is offset from said longitudinal axis.

34. The prosthetic foot ofclaim 33, wherein said toe is offset from said longitudinal axis.

35. The prosthetic foot ofclaim 32, wherein at least one of said foot plate and said ankle plate is flexible.

36. The prosthetic foot ofclaim 32, wherein said ankle block comprises substantially the sole means of support and connection between said foot plate and said ankle plate.

37. The prosthetic foot ofclaim 32, wherein said ankle block comprises a wedged configuration.

38. The prosthetic foot ofclaim 37, wherein said wedged configuration comprises a wedge shaped cut at a posterior section of said ankle block.

39. The prosthetic foot ofclaim 32, wherein said prosthetic foot further comprises a cosmesis that includes a slot substantially aligned with said slot of said foot plate.

40. The prosthetic foot ofclaim 32, wherein said ankle plate is generally horizontal.

41. The prosthetic foot ofclaim 32, wherein said foot plate extends a length substantially equal to that of a natural foot.

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