Abstract:
The present invention relates to a vertical shock absorbing prosthetic foot that has a forefoot having a toe spring and a toe plate and a heel having a heel spring and a heel strike. The heel spring and toe spring comprise a foot spring. The toe spring can be forward opening and the heel spring can be rearward opening. The toe spring can be located rearward of the heel spring. The foot spring can be generally loop shaped. A connector is used to connect the foot to a residual limb or other prosthetic components. The connector can have a top piece and a bottom piece, and the connector has a shape that is complementary to the foot spring. The connector can be adjustably connected to the foot spring by rotating the connector around the foot spring to adjust the location of the heel strike.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a prosthetic foot, and more particularly to a vertical shock absorbing prosthetic foot comprising a foot spring for absorbing energy, that is flexible about many axis, that is efficient at storing and returning energy during use and that is angularly adjustably connectable to a residual limb.  
         [0003]     2. Description of the Related Art  
         [0004]     People frequently are in need of prosthetic limbs as a result of accidents, disease or birth defects. The need for quality prosthetic feet is high. There have been many attempts to make suitable prosthetic feet, each desiring to reach goals of safety, functionality and comfort, among other qualities. The existing prosthetic feet have achieved varying levels of success at attaining each of these stated goals. Further, many strategies have been utilized in designing prosthetic feet. Some designs are relatively noncomplicated, and seek to use a simple design. Other designs are complex, and seek to simulate or copy the structure of the human foot.  
         [0005]     One prosthetic foot in particular is made by Freedom Innovations and sold under the name Renegade LP. This foot has an uninterrupted component spanning from the ankle to the toe. A second component extends from the heel to the front of the foot. While this foot may work well for its intended purpose, it is not without some limitations. For example, there is not a heel spring incorporated into the design. Another limitation of this foot is that there is no way to adjust the location of the heel with respect to the residual limb.  
         [0006]     Another existing prosthetic foot is sold by Ossur under the name Modular III. This foot has one uninterrupted component forming the ankle and spanning to the toe area. A heel component depends rearward from the major component to the heel. This heel component connects to the bottom surface of the major component. A primary advantage of this foot resides in its simplicity. However, there are drawbacks also associated therewith. One limitation is the lack of adjustability of the location of the heel with respect to the residual limb. A further limitation of this foot is the lack of a heel spring.  
         [0007]     A third prosthetic foot is an assembly that is shown in U.S. Pat. No. 6,129,766 to Johnson et al. This patent discloses an ankle member, a heel member pivotally connected to the ankle member, and an elongate metatarsal-toe member having a rear portion underlying a forward portion of the heel member and projecting forwardly from the heel member. This foot has compressible elements incorporated between the pivotally connected members. This foot, being an assembly, is relatively complicated when compared to the previously described prosthetic feet. A further limitation of this foot is that there may be inherent noise problems incorporated into the design of the compressible elements. This is evidenced by the presence of, and the need for, noise abatement features being described in the disclosure.  
         [0008]     A fourth prosthetic foot is sold by Otto Bock under the name LuXon Max. This foot shows a relatively flat and uninterrupted component spanning from the ankle location forward to a location above and rearward of the toe location. Distinct heel and toe components are connected to the bottom of the flat component. One limitation of this foot is that there is no way to adjust the location of the heel with respect to the residual limb. Another limitation of this foot is that there is no heel spring incorporated into the design.  
         [0009]     Yet another prosthetic foot is shown in U.S. Pat. No. 6,602,295 to Doddroe et al. The foot shown in this patent has a foot plate, which is an uninterrupted plate spanning from heal to toe. A toe spring and a heel spring are provided. The toe spring is forward of the heel spring. The toe spring and heel spring are independently connected to a top plate. Further, the heel spring is rotatably connectable to the top plate and the foot plate.  
         [0010]     Another prosthetic foot is shown in U.S. Pat. No. 6,241,776 to Christensen. The foot shown in this patent has a forefoot reinforcement member extending from an attachment section, through a curvilinear spring and arch section, to a toe end. A heel member extends from the arch section to the heel end. The strength and energy return in this foot is due to the flexing of the members. A limitation of this foot is that it is lacking is adjustability. A further limitation is that it does not have a heel spring.  
         [0011]     Another prosthetic foot is shown in U.S. Pat. No. 5,037,444 to Phillips. That patent shows a foot with a forefoot portion and a demountably connected heel portion. At toe-off, the energy return is created from energy stored during the flexing of the forefoot member. One limitation is that the foot of this invention does not have a heel spring. A further limitation is the lack of adjustability of the location of the heel.  
         [0012]     Thus there exists a need for a prosthetic foot that solves these and other problems.  
       SUMMARY OF THE INVENTION  
       [0013]     The present invention relates to a vertical shock absorbing prosthetic foot that has a forefoot having a toe spring and a toe plate and a heel having a heel spring and a heel strike. Advantageously, the heel spring and toe spring comprise a foot spring. These components can be made of carbon epoxy composite material and can be integral, or can be assembled from multiple components. A connector is used to connect the foot to a residual limb or other prosthetic components. The connector can have a top piece and a bottom piece.  
         [0014]     According to one aspect of the present invention, the toe spring can be a forward opening, or forward facing, toe spring, and the heel spring can be a rearward opening heel spring. The toe spring can have a rear that is rearward of the front of the heel spring. The foot spring, being comprised of the toe spring and heel spring, can be generally loop shaped. The connector has a shape that is complementary to the foot spring.  
         [0015]     According to another aspect of the present invention, the connector can be adjustably connected to the foot spring by rotating the connector around the foot spring. This results in the practitioner being able to adjustably select the location of the heel with respect to the residual limb.  
         [0016]     One advantage of the prosthetic foot of the present invention is that the connector is adjustably connectable to the foot, allowing the practitioner to adjust the location of the heel with respect to the connector. The location of the heel with respect to the connector contributes to overall length of the prosthetic limb, and can affect gate. Further, varying the location of the heel will affect the amount of flexing and deflection of the heel strike and compression of the heel spring at heel-strike. This adjustability results in the foot being more properly positioned given the needs and uses of a particular person.  
         [0017]     Another advantage of the prosthetic foot of the present invention is that the foot spring is comprised of the toe spring and the heel spring. In this regard, the toe spring and heel spring are coacting springs that are not entirely independent of each other. Further, the toe spring, or at least a portion thereof, is located rearward of at least a portion of the heel spring. This advantageously allows for increased space for spring compression of the toe spring and heel spring in the limited space of the prosthetic foot.  
         [0018]     Related, a further advantage of the prosthetic foot of the present invention is that the present invention provides support to the person at mid-stance. This is accomplished by flexing of the heel strike and toe plate, and of compression of the heel spring and toe spring. This flexing and compression relieve problems that may normally be associated with flat foot. Further, the energy in the heel strike and heel spring is useful in propelling the foot towards toe-off, and, alternatively, the energy in the toe plate and toe spring can be useful in assisting the person onto the heel strike if the person chooses to rock backwards.  
         [0019]     Also related, a further advantage yet of the prosthetic foot of the present invention is that the present invention is free of sharp angles. Sharp angles in a prosthetic foot can lead to stress concentrations. Avoiding stress concentrations decreases the likelihood of failure of the foot.  
         [0020]     A still further advantage yet of the present invention is that it is customizable to suit the specific needs of a given person. This is initially accomplished by selecting an appropriate blank foot from a given number of sizes of blank feet. The prosthetic foot can then be reduced in size from the initial size to a desired size.  
         [0021]     A still further advantage yet of the prosthetic foot of the present invention is that it incorporates a split toe design. The toes can deflect and flex independent of each other, such as when an object is under only one of the two toes. This is advantageous for stability on terrain that is not completely flat. The split toe design is also advantageous during inversion and eversion to maximize the amount to forefoot that is in contact with the ground.  
         [0022]     A still further advantage yet of the prosthetic foot of the present invention is that the foot can be tapered. The tapered design is advantageous in as much as it allows for the pre-selection of the flexural characteristics of the prosthetic foot.  
         [0023]     A still further advantage yet of the prosthetic foot of the present invention is that there are no moving or rotatably connected parts that may fail over time. Further, none of the parts of the present invention are in a rubbing engagement. The present invention is therefore free from undesired noises and is free from the need of noise abatement features.  
         [0024]     Other advantages, benefits, and features of the present invention will become apparent to those skilled in the art upon reading the detailed description of the invention and studying the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]      FIG. 1  is a side view of a preferred embodiment of the prosthetic foot of the present invention showing a connector connected to the foot.  
         [0026]      FIG. 2  is a partial side view of a preferred embodiment of the prosthetic foot of the present invention showing a connector connected to the foot.  
         [0027]      FIG. 3  is an exploded side view of a preferred embodiment of the prosthetic foot of the present invention showing a connector connected to the foot.  
         [0028]      FIG. 4  is a side view of a preferred embodiment of the prosthetic foot of the present invention without a connector connected to the foot.  
         [0029]      FIG. 5  is a top view of the prosthetic foot shown in  FIG. 4   
         [0030]      FIG. 6  is a rear view of the prosthetic foot shown in  FIG. 4   
         [0031]      FIG. 7  is a front view of the prosthetic foot shown in  FIG. 4   
         [0032]      FIG. 8  is an exploded side view of a preferred connector.  
         [0033]      FIG. 9  is a top view of the connector shown in  FIG. 8 .  
         [0034]      FIG. 10  is a top view of an alternative preferred connector.  
         [0035]      FIG. 11  is a top view of an alternative preferred connector.  
         [0036]      FIG. 12  is a side view of a preferred embodiment of the present invention showing the connector in a forward position on the foot.  
         [0037]      FIG. 13  is a side view of a preferred embodiment of the present invention showing the connector in a rearward position on the foot.  
         [0038]      FIG. 14  is a side view of the operation of a preferred embodiment of the prosthetic foot of the present invention at heel-strike.  
         [0039]      FIG. 15  is a side view of the operation of a preferred embodiment of the prosthetic foot of the present invention at mid-stance.  
         [0040]      FIG. 16  is a side view of the operation of a preferred embodiment of the prosthetic foot of the present invention at toe-off.  
         [0041]      FIG. 17  is a side view of a preferred embodiment of the prosthetic foot of the present invention showing an object under a toe.  
         [0042]      FIG. 18  is a cross-sectional side view of a preferred embodiment of the prosthetic foot of the present invention in an intended environment. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0043]     While the invention will be described in connection with several preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.  
         [0044]     The prosthetic foot  10  of the present invention is preferably made from a carbon epoxy composite material. It will be understood that the present invention is not limited to being constructed of carbon epoxy composite material, and that other resilient materials can be used without departing from the broad aspects of the present invention.  
         [0045]     The foot  10  is preferably made in blanks that can be reduced in length, or shortened, to meet the requirements of a particular person. Several size blanks can be made so that practitioners can select an appropriate blank for a starting point. Also, the blanks can be made to several heights or have features with varying sizes depending on the intended applications.  
         [0046]     The prosthetic foot  10  of the present invention can be made to any desired thickness. Given that the thickness of the material is related to the flexural strength and amount of deflection of any given component of the foot, it is understood that blanks can be constructed having various thicknesses, and that each component within any given foot may be made with a different thickness. Further, it is understood that the thickness of material within any given part of the foot  10  can be tapered to achieve a desired flexural characteristic.  
         [0047]     Calling attention now to  FIGS. 1 and 18 , it is shown that the prosthetic foot  10  of the present invention is intended for use with a connector  80  in order to be connected to another prosthetic component (not shown). The prosthetic foot  10  can be inserted into a shell  7  or cosmetic cover that resembles natural foot. The shell  7  can be used for direct contact with the ground  5  or for insertion into a shoe (not shown). It will be understood for the sake of clarity, the prosthetic foot  10  of the present invention is hereafter described in some circumstances as being in direct relation to the ground  5  or a surface without showing the shell  7 .  
         [0048]     A foot  10  is provided that is generally comprised of a rear portion  11  and a front portion  12 . A foot spring  13  is provided between the front and rear of the foot  10 . In the preferred embodiment, the foot spring  13  generally has a loop or circular shape. However, it will be understood that the foot spring  13  could have other shapes without departing from the broad aspects of the present invention. Further, the foot spring  13  preferably has a radius of approximately one inch. However, the foot spring  13  could have a larger or smaller radius without departing from the broad aspects of the present invention. The prosthetic foot  10  of the present invention has a longitudinal axis  15  spanning the length of the foot. The longitudinal axis  15  is generally parallel with the ground  5  when the foot rests on the ground during zero load conditions. When viewed from above, the prosthetic foot has a right side  16  and a left side  17 .  
         [0049]     Referring now to  FIGS. 4-7 , several parts of a preferred embodiment of the prosthetic foot  10  of the present invention are more clearly shown. One part of the prosthetic foot  10  is the forefoot  20 . The forefoot  20  has a first end  21  and a second end  22 . The forefoot also has a first surface  23  and a second surface  24 . The first surface  23  is on the bottom of the foot  10  at the first end  21 , and is on the top at the second end  22 . The second surface  24  is the opposite surface from the first surface  23  throughout the length of the forefoot  20 . A plate  25  is at the second end  22  of the forefoot. The plate  25  has a mating surface  26 . The plate  25  is preferably about a half as thick as the thickness of the forefoot  20  at the second end  22  of the forefoot.  
         [0050]     A toe spring  30  is at the second end  22  of the forefoot  20 . The toe spring  30  has a top  31 , a bottom  32 , a front  33  and a rear  34 . The toe spring  30  generally has an undeflected shape of a semicircle. Toe spring  30  is a forward opening toe spring, or forward facing toe spring. The toe spring  30  could have a different shape without departing from the broad aspects of the present invention. During a downward load condition, the toe spring compresses and deforms from its nondeflected semicircular shape in response to the applied force. Conversely, during an upward load condition, the toe spring  30  expands and deforms in response to the applied force. The toe spring  30  can twist during inversion and eversion.  
         [0051]     A toe plate  40  is at the first end  21  of the forefoot. The toe plate  40  has a front end  41  and a rear end  42 . The front end  41  of the toe plate is the foremost portion of the prosthetic foot  10 . The toe plate  40  has a top surface  43  and a bottom surface  44 . The top surface  43  of the toe plate  40  coincides with the first surface  23  of the forefoot  20 , and the bottom surface  44  of the toe plate coincides with the second surface  24  of the forefoot. The rear end  42  is preferably integral with the bottom front end of the toe spring  30 . The body of the toe plate  40  flexibly depends forward and downwardly from the toe spring  30 . The toe plate slightly curves upwardly along its length. During a downward load condition, the toe plate  40  flexes and deflects upwards in response to the applied force.  
         [0052]     Looking now at  FIG. 5  in particular and also  FIG. 17 , the toe plate  40  preferably has two toes  46  and  47 , and are preferably separated by a slit  45  in the toe plate  40  having a selected width. Toe  46  is preferably on the left side  17  of the foot  10 , and toe  47  is preferably on the right side  16  of the foot. The toes are shown to be approximately equal in width, and equally spaced from the longitudinal axis  15 . However, the widths of the toes or their respective orientations could vary without departing from the broad aspects of the present invention. Toes  46  and  47  can flexibly deflect different amounts, or have independent deflection characteristics, depending on what terrain the person encounters. This is illustrated in  FIG. 17 , wherein an object is located under toe  47 . Toe  47  correspondingly is upwardly flexibly deflected. Meanwhile, toe  46  is not flexibly deflected and contacts the ground  5 . Both toes  46  and  47  will, however, deflect similarly when the load is not offset (such as during inversion or eversion) and when the person is on flat ground. During inversion and eversion condition (not shown), one side of each of the two toes  46  and  47  can remain in contact with the ground, while the opposite side or each respective toe is lifted off the ground.  
         [0053]     Returning now to  FIGS. 4-7 , several preferred aspects of a heel  50  are illustrated. The heel  50  has a first end  51  and a second end  52 . The heel  50  also has a first surface  53  and a second surface  54 . The first surface  53  is on the bottom of the foot  10  at the second end  52 , and is on the top at the first end  51 . The second surface  54  is the opposite surface from the first surface  53  throughout the length of the heel  50 . A plate  55  is at the first end  51  of the heel  50 . The plate  55  has a mating surface  56 . The plate  55  is preferably about a half as thick as the thickness of the heel  50  at the first end  51  of the heel  50 .  
         [0054]     The mating surface  56  of the plate  55  of the heel can be adhesively connected to the mating surface  26  of the plate  25  of the forefoot  20 . Such a connection is preferably permanent.  
         [0055]     A heel spring  60  is at the first end  51  of the heel  50 . The heel spring  60  has a top  61 , a bottom  62 , a front  63  and a rear  64 . The heel spring  60  generally has an undeflected shape of a semicircle. Heel spring  60  is a rearward opening heel spring, or rearward facing heel spring. The heel spring  60  could have a different shape without departing from the broad aspects of the present invention. During a downward load condition, the heel spring  60  compresses and deforms from its nondeflected semicircular shape in response to the applied force. Conversely, during an upward load condition, the heel spring  60  expands and deforms in response to the applied force. The heel spring can twist during inversion and eversion.  
         [0056]     A heel strike is at the second end  52  of the heel. The heel strike  70  has a front end  71  and a rear end  72 . The rear  72  of the heel strike comprises a lip  75 . The rear end  72  of the heel strike is the rearmost portion of the prosthetic foot  10 . The heel strike  70  has a top surface  74  and a bottom surface  75 . The top surface  74  of the heel strike  70  coincides with the first surface  53  of the heel  50 , and the bottom surface  75  of the heel strike  70  coincides with the second surface  54  of the heel  50 . The front  71  of the heel strike  70  is preferably integral with the bottom rear end of the heel spring  60 . The body of the heel strike  70  flexibly depends rearward and downwardly from the heel spring  60 . The heel strike is generally flat except for the lip during a zero load condition. The lip  73  is generally bent upwards in relation to the remainder of the heel strike  70 . During a downward load condition, the heel strike  70  flexes and deflects upwards in response to the applied force.  
         [0057]     In the preferred embodiment, the toe spring is located rearward of the heel spring. Further, looking again as  FIGS. 5-7 , it is shown that either the front  71  of the heel strike or the back bottom end of the heel spring  60  has a width that is narrower than the width of the slit  45  in the toe plate  40 . In this regard, the heel  50  passes or extends through the forefoot  20 . It will be understood that in an alternative embodiment (not shown) the heel could have a slit and the toe plate could pass through the slit in the heel without departing from the broad aspects of the present invention.  
         [0058]     Turning now to  FIGS. 8 and 9 , a preferred connector  80  is provided. The connector  80  has a top piece  90  and a bottom piece  100 . The top piece  90  has a base  91  with a bottom  92  and a top  93 . The bottom  92  is preferably concave and complementary shaped to the generally loop shaped foot spring  13 . According to one preferred embodiment, the top  93  can have a pyramidal adapter  94  thereon. A first tab  95  with a first hole  96  there through is on one side of the top  90 . A second tab  97  with a second hole  98  there through is on the side of the top  90  that is opposite of the side with the first tab  95 .  
         [0059]     A bottom piece  100  is also provided. The bottom piece  100  has a bottom surface  101  and a top surface  102 . The bottom surface  101  is preferably flat. The top surface is preferably convex and complementary to the generally loop shaped toe spring  13 . Holes  103  are provided for receiving bolts  105 . The holes  103  are spaced apart a distance equal to the distance between holes  96  and  98  of the top piece  90 . In this regard, the top and bottom pieces  90  and  100  can be aligned and bolted together using bolts  105 . The connector  80  has an alignment axis  106 . The bolts  105  are inserted into holes  103  generally parallel to the alignment axis  106 .  
         [0060]     Looking now to  FIG. 10 , an alternative preferred embodiment of the connector top  110  is provided. While not shown, it will be understood how to modify the connector bottom to coact with this preferred connector top. In this regard, the connector  110  has a top piece  120  with a base  121  that is complementary to the foot spring  13 . The top piece  120  further has a pyramidal adapter  124  on its top. A first tab  125  having two holes  126  there through is on one side of the top  120 . A second tab  127  with a two additional holes  128  there through is on the side of the top  120  that is opposite of the side with the first tab  125 .  
         [0061]     Looking now to  FIG. 11 , a further alternative preferred embodiment of the connector top  130  is provided. Connector  130  can preferably be bolted to bottom piece  100 . The connector  130  has a top piece  140  with a base  141  that is complementary to the foot spring  13 . The top piece  140  further has a receiver adapter  144  on its top. A first tab  145  having a hole  146  there through is on one side of the top  140 . A second tab  147  with a second hole  148  there through is on the side of the top  140  that is opposite of the side with the first tab  145 .  
         [0062]     Turning now to  FIGS. 2 and 3 , it is shown that the connector  80  is complementarily connected to the foot spring  13  of the prosthetic foot  10  of the present invention. In this regard, the bolts  105  are used to clamp the connector  80  onto a selected position on the foot spring  13 . The connector is frictionally held in its selected position on the foot spring  13 .  
         [0063]     The connector can be selectively positioned on the foot spring  13  to selectively adjust the location of the heel strike  70  with respect to the connector  80 . One result is that the overall length of the prosthetic limb can be adjusted by adjusting the orientation of the alignment axis  106  of the connector on the foot spring  13 . Two examples are provided, and are shown in  FIGS. 12 and 13 . In  FIG. 12 , the connector is adjusted to a forward position. In the forward position, the heel strike  70  is lowered in relation to the remainder of the foot  10 . Also, the distance between the heel strike  70  and the connector  80  is increased when the connector  80  is rotated forward on the foot spring  13 . Conversely, as shown in  FIG. 13 , the connector  80  can be adjusted rearward to a rearward position. In the rearward position, the heel strike  70  is raised in relation to the remainder of the foot  10 . Also, the distance between the heel strike  70  and the connector  80  is decreased when the connector  80  is rotated rearward on the foot spring  13 . It will be understood that the connector  80  can be adjusted to any desired location on the foot spring  13 .  
         [0064]     Operation of the present invention is illustrated in  FIGS. 14-16 .  FIG. 14  is illustrative of loading conditions at heel-strike. At heel-strike, the heel strike  70  makes initial contact with the ground  5 , and the front foot portion  12  is off the ground completely. The heel strike  70  flexibly deflects upward and the heel spring  60  compresses. The deflection of the heel strike  70  is severe, especially when the person is heavy or when the person runs or jumps, or otherwise has a lot of momentum that needs to be absorbed by the foot  10 . Energy is stored in the deflected heel strike  70  and heel spring  60 . The toe plate  40  is not deflected during in heel-strike, but may be moved slightly. The person&#39;s weight acting rearward against the connector  80  applies a force that tends to pull the toe plate  40  upwards. The amount of force being transmitted to the foot spring  13  will tend to pull the tow plate  40  downwards. The toe plate  40  will move up or down depending on which force is greater.  
         [0065]     As the person moves toward mid-stance, the heel strike  70  releases some of its stored energy to assist in propelling the foot  10  to the mid-stance position. Also, the heel spring  60  releases some of its stored energy to assist in raising the person upwards.  
         [0066]     An operational view at mid-stance is provided in  FIG. 15 . At mid-stance, the heel strike  70  and the toe plate  40  both contact the ground, and are both moderately deflected. Further, the foot spring  13  is moderately compressed. If the person chooses to rock back onto the heel strike  70 , the toe spring  30  portion of the foot spring  13  decompresses, or expands, and the toe plate deflexes to assist the person in rocking backwards. Conversely, if the person chooses to move towards toe-off, the heel strike  70  and the heel spring  60  portion of the foot spring  13  release energy to assist the person towards toe-off.  
         [0067]     It is noteworthy, that if the person happens to land in a flat foot orientation, the toe plate  40  and the heel strike  70  may deflect severely, and the foot spring  13  may compress severely, while absorbing the shock, and then release some energy to return the foot to mid-stance equilibrium.  
         [0068]      FIG. 16  shows an operational view of the present invention at toe-off. At toe-off, the front end  41  of the toe plate  40  is the only part of the foot that is contacting the ground  5 . The toe plate  40  is severely deflected and foot spring  30  is compressed. The entire rear foot portion  11  is slightly moved forward with respect to the toe plate  40  at toe-off, due to the compression of the foot spring  13 . The heel strike  70  is not deflected during toe-off. The toe plate  40  releases energy during toe-off that pushes the foot in a direction generally perpendicular to the bottom surface  44  of the toe plate  40 .  
         [0069]     Thus it is apparent that there has been provided, in accordance with the invention, a prosthetic foot that fully satisfies the objects, aims and advantages as set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.