Patent Description:
United States Patent Publication <CIT> relates to a rotator for a prosthetic ankle joint comprising a resilient body comprising an outer perimeter, a first surface, a second surface opposite the first surface, and an interior opening there between, a shaft, the shaft comprising a bore interface with at least one contact surface, a first prosthesis body coupled to the longitudinal shaft and a second prosthesis body comprising a longitudinal lumen and a flange located on an upper surface of the second prosthesis body.

US Patent Publication <CIT> relates to an impact reducing prosthetic pylon. UK Patent Application Publication <CIT> relates to a telescopic shin prosthesis. US Patent Publication <CIT> relates to a coupling for a prosthetic device.

Multi-axial prosthesis assemblies that include a resilient closed undulating member are used to provide vertical and rotational movement for lower limb prostheses. A shaft is located through a resilient bumper, with a first prosthetic member fixedly attached to the shaft and engages a first surface of the undulating member, and a second prosthetic member comprises a lumen to movably receive the shaft. The prosthetic members are engaged to the resilient bumper with projections that are located in the recesses of the resilient bumper and the prosthetic members and the bumper are configured so that the projections from each member are offset from the projections of the other member, which results in an undulating appearance to the outer surface of the resilient bumper.

In one embodiment, a prosthetic assembly is provided, comprising a resilient undulating body comprising an outer perimeter, a first surface, a second surface opposite the first surface, and an interior opening therebetween, a longitudinal shaft located in the interior opening of the undulating member, a first prosthesis body coupled to the longitudinal shaft and contacting the first surface of the undulating member, and a second prosthesis body comprising a longitudinal lumen and contacting the second surface of the undulating member, wherein the longitudinal shaft is movably located in the longitudinal lumen. The undulating body may comprise a first plurality of recesses on the first surface of the undulating body. The first prosthesis body may comprise a first plurality of projections configured to form a mechanical interfit with the first plurality of recesses of the undulating body. The undulating body may comprise a second plurality of recesses on the second surface of the undulating body. The second prosthesis body may comprise a second plurality of projections configured to form a mechanical interfit with the second plurality of recesses of the undulating body. The first plurality of recesses may be rotationally offset from the second plurality of recesses when no net rotational forces are acting on the undulating body. The first plurality of recesses may comprise an equal angular spacing relative to a central axis of the undulating body, and the second plurality of recesses may comprise an equal angular spacing relative to the central axis of the undulating body. The undulating body may further comprise an internal seal extending from the second surface of the undulating body that is radially offset from the outer perimeter of the undulating member and surrounding the interior opening of the undulating body. The angular spacing of the first plurality of recesses and the angular spacing of the second plurality of recesses may be <NUM> degrees. The first and second pluralities of recesses may be offset by <NUM> to <NUM> degrees. The first and/or second plurality of recesses may each comprise four recesses. Each recess of the first plurality of recesses and the second plurality of recesses may comprise an outer perimeter opening region, a radially inward wall opposite the outer perimeter opening, and opposing first and second side walls flanking the radially inward wall. The radially inward wall and the opposing first and second walls may comprise a U-shape on a transverse cross section through the undulating member. The recesses of the first plurality of recesses may further comprise a first surface opening region on the first surface of the undulating body, wherein the first surface opening region is contiguous with the outer perimeter opening region of the same recess, and a middle wall opposite the first surface opening region, wherein the middle wall is flanked by the first and second walls of the same recess. Each of the recesses of the second plurality of recesses may further comprise a second surface opening region on the second surface of the undulating body, wherein the second surface opening region is contiguous with the outer perimeter opening region of the same recess, and a middle wall opposite the second surface opening region, wherein the middle wall is flanked by the first and second walls of the same recess. Each recess of the first and second pluralities of recesses comprises a non-planar surface opening. The first prosthesis body may be integrally formed with the longitudinal shaft. The second prosthesis body may be configured to permit axial and rotational movement of the longitudinal shaft in the longitudinal lumen of the second prosthesis body. The prosthetic assembly may further comprise a shaft retainer removably attached to the shaft, and may be configured to resist separation of the longitudinal shaft and the second prosthesis body. The shaft retainer may comprise a removable fastener configured to removably attach to the longitudinal shaft, an annular seal configured to slidably seal the shaft retainer to the second prosthesis body, and a retaining washer with a circumferential recess in which the annular seal partially resides. The shaft retainer may further comprise a spring. The spring may be configured to maintain compression of the resilient body when the prosthetic assembly is in an unloaded state. The prosthetic assembly may further comprise an attachment pyramid. The attachment pyramid may be integrally formed with the longitudinal shaft. The second prosthesis body may further comprise a mounting interface configured to attach to a foot prosthesis. The mounting interface may comprise a plurality of lumens, each lumen configured to removably receive a fastener. The plurality of lumens may be a plurality of transverse lumens. The second prosthesis body may further comprise an annular cavity to at least partially receive the undulating body. The diameter of the interior opening of the undulating body may be greater than a diameter of the longitudinal shaft located in the interior opening of the undulating body. The longitudinal shaft may comprise a transverse stop surface located between a first end and a second end of the longitudinal shaft, and configured to displaceably abut against a corresponding stop surface of the second prosthesis body. The prosthetic assembly may further comprise a compression collar located between the first and second prosthesis bodies and configured to limit displacement of the longitudinal shaft relative to the longitudinal lumen of the second prosthesis body.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appending claims, and accompanying drawings where:.

For example, steps that may be performed concurrently or in a different order are illustrated in the figures to help to improve understanding of embodiments of the present technology.

The present technology may be described in terms of functional block components and various processing steps. Such functional blocks may be realized by any number of components configured to perform the specified functions and achieve the various results. For example, the present technology may be used with a prosthetic foot for various amputation types (above knee, below knee, etc.). In addition, the present technology may be practiced in conjunction with any number of materials and methods of manufacture and the system described is merely one exemplary application for the technology. In the present disclosure <NUM> inch is <NUM> long, <NUM> pound force is <NUM>,<NUM> N and <NUM> in-lb is <NUM>.

While exemplary embodiments are described herein in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that logical structural, material, and mechanical changes may be made without departing from the scope of the claims. Thus, the following descriptions are not intended as a limitation on the use or applicability of the invention, but instead, are provided merely to enable a full and complete description of exemplary embodiments.

The function and features of a lower limb prosthetic may be selected based on the user's ability to ambulate and to transfer from various positions from a chair or bed. For patients that are able to ambulate at a single speed on level surface, a solid ankle-cushion heel foot prosthesis, or a single-axis prosthesis may be selected, for users who are able to traverse curbs, stair and uneven surfaces, a flexible-keel foot or a multi-axial ankle/foot prosthesis may provide improved ambulation efficiency and safety. For users with greater rehabilitation potential and are able to ambulate at different speeds and traverse most environmental obstacles, a multi-axial ankle foot with vertical-loading pylon may be beneficial.

In some examples, a prosthetic assembly may be provided that permits limited axial rotation and vertical loading between two housings in which a resilient body is located. The resilient body provides limited resilient vertical loading and axial rotation as it undergoes deformation by the relative displacement and motion between the two housings. A movable shaft is attached to one of the housings, and is longitudinally and rotationally movable relative to a lumen located in the other housing in which the shaft resides. A retention member or retention assembly may be provided at the end of the shaft to releasably and movably retain the shaft in the other housing. The shaft is typically a rigid shaft that does not flex under typical loads, but in other embodiments, the shaft may comprise a resiliently flexible shaft with one or more bend regions, e.g., helical spring region that can bend away from its central longitudinal axis.

To resist substantial separation of the resilient body from the housings, the resilient body may comprise a closed shape with an interior opening in which a portion of the shaft is located. To provide increasing resistance to greater degrees of axial rotation, the housings and the resilient body may comprise complementary projections and recesses configured to resist greater amounts of rotational slippage. The complementary interface may be sized and located to also distribute rotational forces acting on the resilient body in order to reduce the concentration of forces that may increase the fracture or breakage of the resilient body. In some further embodiments, the configuration of the assembly may include projections from the first and second housings into recesses located in the resilient body. The recesses may be located around the periphery of the resilient body such that each recess is open and confluent on both a side surface and a horizontal surface of the resilient body. The angular arrangement of the recesses may be configured such that recesses are located on alternating horizontal surfaces to receive alternating projections from the two housings. This results in an undulating configuration to the side or periphery surface of the resilient body. The resilient body may further comprise one or more flanges or sealing structures to help resist water or liquid intrusion into the interior regions of assembly.

The first and second housings of the assembly may also comprise recesses or cavities to partially contain a portion of the resilient body, and an interface to fixedly or movably couple to the shaft of the assembly. In some variations, a first or upper end of the shaft is configured to fixedly attach to the first or upper housing, so that the first housing and shaft move in a fixed relationship relative to the resilient body and second housing. In other variations, the first housing and shaft may be integrally formed. Typically, the shaft is inserted through the resilient body and into a longitudinal lumen of the second or lower housing in which the shaft movably resides.

The first or upper housing, or the first or upper end of the shaft, may comprise an attachment interface to attach to a pylon or residual limb socket. The second or lower housing may comprise an attachment interface to attach the assembly to a foot prosthesis.

The second or lower end of the shaft may be accessible at the second or lower end of the second housing, and a retention member or assembly may be attached to the shaft in order to retain the shaft in the lumen of the second housing. The retention member or assembly may be detached in order to perform maintenance on the assembly or to change out the resilient body.

In one exemplary embodiment as described generally above, a prosthetic assembly <NUM> that provides vertical shock absorption and rotational movement is depicted in <FIG>. The assembly <NUM> comprises a resilient bumper or body <NUM>, located between a first or upper housing <NUM> and a second or lower housing <NUM>. A longitudinal or vertical shaft <NUM> is coupled to the first housing <NUM>, passing through the resilient body <NUM> and coupled to the second housing <NUM>. A retention member or retention assembly <NUM> is attached to the shaft <NUM> to resist separation of the shaft from the second housing <NUM>. The assembly <NUM> is configured to permit limited longitudinal and rotational displacement of the shaft <NUM> relative to the second housing <NUM>, with the resilient body <NUM> providing increasing resilient resistance to increasing vertical compression and increasing rotational displacement. A pyramid attachment structure <NUM> is provided on the shaft <NUM> for attachment of the assembly <NUM> to a pylon or residual limb socket (not shown), while the second housing <NUM> is configured for attachment to a foot prosthesis. A cover piece <NUM> may also be provided on the assembly <NUM>. In some variations, the cover piece <NUM> may provide a cosmetic/trademark function and/or a protective function to protect one or more areas of the assembly <NUM> from intrusion of unwanted materials (e.g., dirt, liquid) and/or inadvertent snagging of the assembly <NUM> with environmental objects and hazards. Although the assembly <NUM> described in this particular embodiment may be provided separate from a foot prosthesis, in other examples, the assembly <NUM> may be integrated with foot prosthesis at the point-of-manufacture.

The shaft <NUM> is sized to pass through a lumen <NUM> of the lower housing <NUM> such that a retention member or retention assembly <NUM> may be used to releasably retain the shaft <NUM> in the lumen <NUM>.

The resilient body <NUM> of the assembly <NUM> may comprise a resilient material such as silicone, rubber, polyurethane, urethane, thermoplastic elastomers, thermoplastic vulcanizates (e.g., SANTOPRENE™ and ELASTRON™), and the like. In some further embodiments, the resilient material may comprise a durometer in the range of 40A to 100A, or 50A to 90A or 60A to 90A, and may be selected based on the user's weight and/or activity level. In some examples, the resilient body <NUM> is selected to provide up to <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> or more vertical deflection or compression, and selected to provide up to <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, <NUM> degrees, or <NUM> degrees of rotational deflection, or more.

In one exemplary analysis, resilient bodies of various durometers were evaluated using various loads to achieve a minimum of <NUM> of vertical deflection and a minimum of <NUM> degrees of angular deflection. The results of the analysis are depicted below as Table <NUM>:.

In some examples, the density of the material of the resilient body may be different or lower inside the resilient body versus the exposed surfaces of the resilient body, or the exposed surfaces may comprise a different material. The resilient body may also comprise a coating, e.g. a hydrophobic or water-resistant coating to reduce water absorption into the resilient body.

As shown in <FIG>, the upper housing <NUM> comprises a plurality of inferior projections <NUM> extending from its peripheral surface <NUM> and lower surface <NUM>. The inferior projections <NUM> are located in and form a complementary interfit with the upper recesses <NUM> of the resilient body <NUM>. Likewise, the lower housing <NUM> comprise a plurality of superior projections <NUM> extending from its peripheral surface <NUM> and upper surface <NUM>, and are located in and form a complementary interfit with the lower recesses <NUM> of the resilient body <NUM>. The lower housing <NUM> further comprises an attachment interface <NUM> which is used to attach the assembly to a foot prosthesis (not shown).

Referring to <FIG>, the resilient body <NUM> may comprise a first or upper surface <NUM>, a second or lower surface <NUM>, a central lumen <NUM> therebetween defining an inner surface <NUM>, and an outer lateral surface <NUM>. Each of the upper and lower surfaces <NUM>, <NUM> may comprise a generally planar configuration, but in other examples, may comprise a concave or convex configuration, or other non-planar configuration, such as a frustoconical configuration, or combination thereof. The central lumen <NUM> has a generally circular cross-sectional shape across its central longitudinal axis <NUM>, but in other variations may comprise a triangular, square, rectangle, or oval shape, for example. The diameter, transverse dimension or surface area of the central lumen <NUM> may be constant, or may vary along the longitudinal axis <NUM>. As depicted in exemplary resilient body <NUM> in <FIG>, the central lumen <NUM> may comprise a larger diameter about its upper and lower regions <NUM>, <NUM>, but a smaller diameter about the middle region <NUM>. In this example, the transitions along the regions <NUM>, <NUM>, <NUM> are gradual, such that the inner surface <NUM> comprise a convex configuration on the cross-sectional view in <FIG>, but in other examples, the transitions may be abrupt, with a stepped surface configuration, for example. Similarly, the outer surface <NUM> of the resilient body <NUM> also comprises a convex shape on cross-section, but in other examples, may comprise a concave, linear, frustoconical or other shape. The larger diameter may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The smaller diameter may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches, and the average diameter may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The central lumen <NUM> may be sized such that its inner surface <NUM> is spaced apart and not in contact with the shaft <NUM> during typical usage. In some variations, some radially inward bulging of the inner surface <NUM> may be expected during vertical compression of the resilient body <NUM>, and thus the dimension of the central lumen <NUM> may be size sufficiently to reduce the likelihood that the inner surface <NUM> will contact the shaft <NUM> during compression. The annular gap between the inner surface <NUM> and the shaft <NUM> may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The average diameter or maximum transverse dimension of the resilient body <NUM> across opposite sides of the outer surface <NUM> may be in the range of. <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches.

Referring still to <FIG>, the exemplary resilient body <NUM> comprise a set of upper recesses <NUM> and a set of lower recesses <NUM>. The recesses in each set of recesses may comprise the same recess shape or configuration, and may be equally spaced apart, though between the upper recesses <NUM> and the lower recesses <NUM>, the angular orientations are offset such that the angular position of each upper recess <NUM> is spaced equally apart from the adjacent lower recesses <NUM>, as is each lower recess <NUM> is spaced equally apart from the adjacent upper recesses <NUM>. In this example, each set of recesses <NUM>, <NUM> comprises four recesses that are spaced <NUM> degrees apart around the resilient body, and are offset by <NUM> degrees between the two sets of recesses <NUM>, <NUM>. This permits the resilient body <NUM> to be assembled or serviced without requiring a particular angular alignment or top/bottom orientation, which may simplify assembly and replacement, and may reduce premature wear. In other examples, however, the resilient body <NUM> may not have such symmetry and therefore may be limited to a single or smaller number of positions/orientations. In other variations, for example, one or more recesses may comprise a different size, shape or spacing than the other recesses of the same set, and/or the number of recesses between the two sets of recesses may be different. In other examples, the number of recesses in each set of recess may be in the range of <NUM> to <NUM> recesses, <NUM> to <NUM> recesses, or <NUM> to <NUM> recesses.

Referring still to the recesses <NUM>, <NUM> depicted in <FIG>, the recesses comprise openings <NUM>, <NUM> that are angled or non-planar, with portions 222a, 224a of the openings <NUM>, <NUM> on the upper and lower surfaces <NUM>, <NUM> of the resilient body <NUM>, respectively, that are contiguous with portions 222b, 224b of the openings <NUM>, <NUM> that are located on the outer surface <NUM>. Thus, each opening <NUM>, <NUM> has a non-planar configuration with a boundary located on the outer surface <NUM> and either upper or lower surfaces, and where the different portions 222a, 222b, 224a, 224b are generally orthogonal to each other. In this particular embodiment, the recesses <NUM>, <NUM> comprise an inner wall <NUM>, <NUM> such that the recesses <NUM>, <NUM> do not open to the central lumen <NUM> of the resilient body <NUM>. This configuration may reduce the intrusion of debris or foreign matter into the device during use, which may interfere with smooth movement of the shaft <NUM> with the lumen <NUM> of the lower housing <NUM>. This configuration may also shift, distribute or transfer torque exerted by the upper and lower housings <NUM>, <NUM> from the inner regions to the outer regions of the resilient body <NUM>, which will reduce torque forces acting on the resilient body <NUM> and may prolong its usable life being requiring replacement.

Each of the recesses <NUM>, <NUM> also comprise side walls <NUM>, <NUM> and end walls <NUM>, <NUM>. As shown in <FIG>, the transitions between the walls <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and with the upper and lower surfaces <NUM>, <NUM> of the resilient body <NUM> may be rounded rather than sharply angled. This may reduce the concentration of forces transferred from the lower and upper extensions of the upper and lower housings <NUM>, <NUM>, or otherwise distribute the transferred forces or stresses throughout the resilient body <NUM>, which may reduce the risk of fracture or tearing, thereby extending the life of the resilient body <NUM>. The height <NUM> of each recess <NUM>, <NUM> may be characterized by as the distance between either upper or lower surfaces <NUM>, <NUM> of the resilient body <NUM> to the corresponding end wall <NUM>, <NUM>, as best seen in <FIG>. The height <NUM> may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The height <NUM> of each recess <NUM>, <NUM> may also be characterized as a percentage of the height of the resilient body <NUM>, e.g., the distance between the upper and lower surfaces <NUM>, <NUM>. In the particular embodiment depicted in <FIG>, each of the recesses <NUM>, <NUM> have a relative height <NUM> of <NUM>% of the resilient body <NUM>, each with an end wall <NUM>, <NUM> at the midplane <NUM> of the resilient body <NUM>. In other variations, the recesses may have a relative height <NUM> in the range of <NUM>% to <NUM>%, <NUM>% to <NUM>%, <NUM>% to <NUM>%, or <NUM>% to <NUM>%, for example. The width <NUM> of each recess <NUM>, <NUM> may be the average width or the maximum width based on the distance between the sidewalls, and may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The radial depth <NUM> of the recesses <NUM>, <NUM> may be characterized by the distance between the outer surface <NUM> and the inner walls <NUM>, <NUM> of the recesses <NUM>, <NUM>, as depicted in <FIG>, and may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. In some variations, the width of each recess <NUM>, <NUM> between the side walls <NUM>, <NUM> may be tapered in a radially inward direction, e.g., each side wall <NUM>, <NUM> is located in a plane intersecting the center longitudinal axis <NUM> of the resilient body <NUM>. In other variations, the angles of the side walls <NUM>, <NUM> relative to the plane may vary from about ±<NUM> to ±<NUM> degrees, ±<NUM> to ±<NUM> degrees, or ±<NUM> to ±<NUM> degrees, relative to the plane intersecting the center longitudinal axis <NUM>, for example. In some further variations, the angles of the side walls <NUM>, <NUM> may be altered such that the side walls <NUM>, <NUM> are parallel, or where the width of each recess <NUM>, <NUM> is constant or increases toward the center axis, so that during rotation, the resilient member has a radial displacement force component that drives the resilient member towards the center line. This is in contrast to side wall angles that generate a radial outward displacement force from portions of the resilient body <NUM> being squeezed between, which may reduce the working life of the resilient member. The radial depth <NUM> of the recesses <NUM>, <NUM> may also be characterized as a relative percentage of the radial or annular distance <NUM> between the inner and outer surfaces <NUM>, <NUM> of the resilient body <NUM>, also depicted in <FIG>. The relative radial depth <NUM> may be in the range of <NUM>% to <NUM>%, <NUM>% to <NUM>% or <NUM>% to <NUM>%, for example. The radial thickness <NUM> of the inner walls <NUM>, <NUM> may also be characterized as the radial distance between the inner walls <NUM>, <NUM> and the inner surface <NUM> of the central lumen <NUM>. The radial thickness <NUM> may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches, and may also be characterized as a relative thickness <NUM> as a percentage of the annular distance <NUM>. The relative thickness <NUM> may be in the range of <NUM>% to <NUM>%, <NUM>% to <NUM>%, or <NUM>% to <NUM>%, for example. These dimensions may be measured based on the average dimension and exclude the curved regions of the recesses <NUM>, <NUM> at the transitions between different walls and surfaces.

<FIG> depicts additional details of the upper housing <NUM> of the assembly <NUM> depicted in <FIG>. As noted previously, the upper housing <NUM> comprises a plurality of inferior projections <NUM> extending from its peripheral surface <NUM> and lower surface <NUM>. When assembled, the inferior projections <NUM> are located in and form a complementary interfit with the upper recesses <NUM> of the resilient body <NUM>. In this exemplary embodiment, the peripheral surface <NUM> comprises a convex, tapered shape with a larger diameter or transverse dimension in the lower region <NUM> closer to the inferior projections <NUM> and lower surface <NUM>, and a reduced diameter or transverse dimension in the upper region <NUM> of the upper housing <NUM>. Because of the taper, the upper surface <NUM> has a minimal or substantially reduced surface area as compared to the lower surface <NUM>. In other variations of the upper housing <NUM>, however, the peripheral surface <NUM> may not be as tapered or may comprise a generally cylindrical in shape, or comprise a non-circular or polygonal shape with linear or vertically oriented surface.

The average length <NUM>, average width <NUM> and average radial depth <NUM> of each inferior projection <NUM> may be complementary to the sizes of the corresponding recesses <NUM>. In some variations, the dimensions <NUM>, <NUM>, <NUM> of each inferior projection <NUM> may be slightly smaller or larger than the dimensions <NUM>, <NUM>, <NUM> of the recesses <NUM>. In some examples, the inner surface <NUM> of each inferior projection <NUM> may have a generally vertical orientation or parallel orientation relative to the center longitudinal axis <NUM> of the upper housing <NUM>. The outer surface <NUM> of each inferior projection <NUM> may comprise a taper that is in continuity with the taper and/or curvature of the peripheral surface <NUM>, and may be flush, recessed, or protrude from the portion of the recess <NUM> on the outer surface <NUM> of the resilient body <NUM>. Like the recesses <NUM>, the inferior projections <NUM> may comprise rounded edges between the transitions of the lower surface <NUM>, inner surface <NUM>, outer surface <NUM>, and side walls <NUM> and end wall <NUM>.

The upper housing <NUM> further comprises a central lumen <NUM> between the lower and upper surfaces <NUM>, <NUM>. The central lumen <NUM> is configured to receive the longitudinal shaft <NUM> of the assembly <NUM>. As illustrated in <FIG>, the central lumen <NUM> comprises a reduced dimension upper region 504a, and enlarged dimension lower region 504b, with a stepped surface 504c therebetween. The upper region 504a may comprise a threaded interface for attaching the shaft <NUM> to the upper housing <NUM>, though in the variations the lower region 504b or both regions 504a, 504b may comprise threads, or other type of mount (e.g. bayonet mount) may be provided between the upper housing and shaft. A glue, such as an acrylate or cyanoacrylate may also be added to the threaded interface, to resist decoupling from torsional forces acting through the shaft.

As illustrated in <FIG> and <FIG>, the pyramid attachment structure <NUM> is provided on the shaft <NUM> for attachment of the assembly <NUM> to a pylon or residual limb socket. The pyramid <NUM> typically comprises an industry standard four-sided configuration, but in other examples, may comprise an alternative or proprietary design. The pyramid configuration may be changed by using a different shaft with a different pyramid configuration. Referring to <FIG>, the pyramid <NUM> is located at a first end <NUM> of the shaft <NUM> and may include a threaded lumen <NUM> to facilitate attachment of the pyramid <NUM>. Next to the pyramid <NUM> is an attachment region or interface <NUM> of the shaft <NUM> that forms a complementary interfit with the central lumen <NUM> of the upper housing <NUM>. This may be a threaded interface as depicted, or a bayonet mount or other type of mechanical interfit or friction fit as noted above. As depicted in <FIG>, the shaft <NUM> may be configured such that when assembled with the upper housing <NUM>, the pyramid <NUM> protrudes from the upper surface <NUM> of the upper housing <NUM>. Adjacent to the attachment interface <NUM> of the shaft <NUM> may be a tool interface <NUM>, which may be used to grip the shaft <NUM> with a wrench or pliers or other tool when coupling or decoupling the shaft <NUM> and the upper housing <NUM>. Although the tool interface <NUM> depicted in <FIG> is a hexagonal interface, in other variations, the tool interface <NUM> may be square or rectangular or other polygonal shape, or may comprise a lumen in which a torque bar may be inserted to facilitate rotational coupling and decoupling of the shaft <NUM> and upper housing <NUM>.

In still other variations of the assembly <NUM>, the upper housing <NUM> and the shaft <NUM> and pyramid <NUM> may be integrally formed as a monolithic component, as shown in <FIG>. In still other examples, as illustrated in <FIG>, the assembly <NUM> may comprise a pyramid structure <NUM> that is integrally formed with the upper housing <NUM> of the assembly <NUM>, but with a recess or lumen <NUM> in the upper housing <NUM> to couple to a shaft <NUM>. In this particular embodiment, the lumen <NUM> of the upper housing <NUM> is open at both ends and is located through the pyramid <NUM> and the main body <NUM> of the upper housing <NUM>, but in other variations, the lumen <NUM> may be close-ended and with only a lower opening <NUM> of the lumen, with the upper opening <NUM> in the pyramid <NUM>.

Referring back to <FIG>, adjacent or inferior to the tool interface <NUM> of the shaft <NUM> is the body <NUM> of the shaft <NUM>, which is configured to reside and move in the lumen <NUM> of the lower housing <NUM> when assembled. The length of the body <NUM> of the shaft <NUM> may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The diameter or cross-sectional dimension of the shaft <NUM> may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. Different lengths of the shaft <NUM> may also be provided in order to accommodate different patient preferences, height, and functional levels, with corresponding different heights of the resilient body <NUM>.

The second or lower end <NUM> of the shaft <NUM> is sized and configured to extend out from the lumen <NUM> of the lower housing <NUM>. A retention member or assembly <NUM> may be attached to the second end <NUM> to resist pullout of the shaft <NUM> from the lower housing <NUM>, but may be configured to permit some vertical displacement of the shaft <NUM> within the lumen <NUM>. This acts as a shock absorber as the upper housing <NUM> and lower housing <NUM> resiliently compress the resilient body <NUM>. In this particular example, the retention assembly <NUM> is attachable to the second end <NUM> of the shaft <NUM> by a closed threaded lumen <NUM>, but in other variations, may be attached via a clevis pin or other coupling interface. The retention assembly <NUM> is also configured to permit the shaft <NUM> to rotate within the lumen <NUM> and thereby to permit axial rotation. In the particular examples depicted in <FIG>, the axial rotation is limited by the increasing resistance to rotation provided by rotational compression of the resilient body <NUM> between the inferior and superior projections <NUM>, <NUM>. In other variations, however, the retention member or assembly <NUM>, the shaft <NUM> and/or the lower housing <NUM> may be configured with one or more complementary flanges and recesses to provide a hard limit angle limit to the rotation range.

Referring now to the lower housing <NUM>, which is detailed in <FIG>, as noted previously, the lower housing <NUM> comprise a plurality of superior projections <NUM> extending from its peripheral surface <NUM> and upper surface <NUM>. The superior projections <NUM> are positioned and configured to form a complementary interfit with the lower recesses <NUM> of the resilient body <NUM>. The lower housing <NUM> further comprises a longitudinal lumen <NUM> to receive the shaft <NUM>. The lower housing <NUM> comprises a main body <NUM> in which the lumen <NUM> resides, and also includes the prosthesis attachment interface <NUM> described earlier. The lumen <NUM> may include a lubricant or lubricious coating to facilitate longitudinal and rotational movement of the shaft <NUM> therein, but in some examples, a tubular bearing may be provided to facilitate such movement, such as a SPRINGGLIDE™ bearing (St. Gobain; Courbevoie, France).

Like the inferior projections <NUM> of the upper housing <NUM>, the average length <NUM>, average width <NUM> and average radial depth <NUM> of each superior projection <NUM> may be complementary to the sizes of the corresponding recesses <NUM> of the resilient body <NUM>. In some variations, the dimensions <NUM>, <NUM>, <NUM> of each superior projection <NUM> may be slightly smaller or larger than the dimensions <NUM>, <NUM>, <NUM> of the recesses <NUM>. In some examples, as depicted in <FIG>, the inner surface <NUM> of each superior projection <NUM> may have a generally vertical orientation or parallel orientation relative to the longitudinal axis of the upper housing <NUM>. The outer surface <NUM> of each superior projection <NUM> may comprise a taper that is in continuity with the taper and/or curvature of the peripheral surface <NUM>, and may be flush, recessed, or protrude from the portion of the recess <NUM> on the outer surface <NUM> of the resilient body <NUM>. Like the recesses <NUM>, the superior projections <NUM> may comprise rounded edges between the transitions of the superior surface <NUM> of the lower housing <NUM>, and the inner surface <NUM>, outer surface <NUM>, side walls <NUM> and end wall <NUM> of the superior projections <NUM>.

The superior surface <NUM> of the lower housing <NUM> may comprise a similar configuration as the lower surface <NUM> of the upper housing <NUM> but with an angular offset to the projections <NUM>. In the embodiment depicted in <FIG>, however, the superior surface <NUM> further comprises an annular projection or flange <NUM>. The annular flange <NUM> is spaced radially inward from the peripheral surface <NUM> and the superior projections <NUM>, surrounding the longitudinal lumen <NUM> of the lower housing <NUM>. This flange <NUM> may be configured to insert or reside inside the central lumen <NUM> of the resilient body <NUM>. In some variations, the annular flange <NUM> may reduce the risk of eccentric displacement of the resilient body <NUM> during various compression and rotational movements, and may also limit the radially inward bulging of the inner surface <NUM> during vertical compression, and/or may act as barrier reduce the intrusion of debris and liquid into the lumen <NUM> of the lower housing <NUM>. The flange <NUM> also provides additional support for longer tubular bearings that might be used in the lumen <NUM>. The use of a longer bearing may augment or reduce resistance that may be generated by off-axis forces or forces transverse to the longitudinal shaft and lumen. This may also improve bearing life and tactile prosthesis response. In embodiments comprising a tubular bearing, the ratio of the bearing length to the bearing inner diameter may in the range of <NUM>:<NUM> and <NUM>:<NUM>, or <NUM>:<NUM> to <NUM>:<NUM> or <NUM>:<NUM> to <NUM>:<NUM>. The flange <NUM> also allows the resilient member to be placed lower in the overall prosthesis, relative to the lumen <NUM>, which can shorten the build height of the prosthesis, which allows the use of the prosthesis across a greater range of residual limb lengths. Depending on the height of the annular flange <NUM>, the flange <NUM> may also provide a hard compression stop if the amount of vertical compression results in the annular flange <NUM> abutting against the inferior surface <NUM> of the upper housing <NUM>. In some variations, the height of the annular flange <NUM> is the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The wall thickness of the flange <NUM> may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The inner diameter may be <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches, and the outer diameter may be <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches.

The peripheral surface <NUM> of the lower housing <NUM> may also comprise a convex, tapered shape with a larger diameter or transverse dimension in the upper anterior region <NUM>. The attachment interface <NUM> of the lower housing <NUM> may comprise a flat, vertically planar surface to facilitate attachment of the lower housing <NUM> to a foot prosthesis, but in other variations, the lower housing <NUM> may comprise an angled or horizontal region to facilitate attachment to foot prostheses with a corresponding angled or horizontal attachment site.

The attachment interface <NUM> of the lower housing <NUM> comprise one or more threaded lumens <NUM> to facilitate attachment of the lower housing <NUM> to a foot prosthesis using screws, bolts or other fasteners. In <FIG>, the assembly <NUM> is attached to a foot prosthesis <NUM> with a vertically mounted attachment interface, using bolts <NUM>, <NUM>.

As depicted in <FIG>, the attachment interface <NUM> of the lower housing <NUM> may also comprise cover attachment sites <NUM> which facilitate the attachment of cosmetic covers <NUM> to the body <NUM> of the lower housing <NUM>. The lumen <NUM> of the lower housing <NUM> may comprise a retention cavity <NUM> in which the retention assembly <NUM> resides. In other variations, however, a retention cavity is not provided such that the retention assembly <NUM> may protrude from the lumen <NUM> and the lower housing <NUM>.

As noted previously, the retention member or assembly <NUM> may be attached to the shaft <NUM> using the threaded lumen <NUM> at the lower end of the shaft <NUM>, as depicted in <FIG>. The retention assembly <NUM> may comprise a bolt <NUM> or other type of fastener, and a retention washer <NUM> which is movable in the retention cavity <NUM>. The retention washer <NUM> resists further upward displacement of the shaft <NUM> once it abuts the superior surface of the retention cavity <NUM>. The retention washer <NUM> comprises a washer cavity <NUM> to receive the bolt <NUM>, and may include a reduced diameter shaft cavity 804a and an enlarged head cavity 804b which allows the bolt <NUM> to have a recessed position partially in the retention washer <NUM> when attached to the shaft <NUM>. To reduce the risk of debris and liquid interfering with the movement of the shaft <NUM> in the lumen <NUM> of the lower housing <NUM>, an O-ring or annular sliding seal <NUM> may be provided on the retention washer <NUM>. The seal <NUM> is maintained in a slidable arrangement with the retention cavity <NUM> by a seal recess <NUM> on the retention washer <NUM>, bound by recess walls 808a and 808b, as shown in <FIG>. The retention washer <NUM> may also comprise a spring recess <NUM> that is superior or proximal to the recess wall 808a. Referring back to <FIG>, the spring recess <NUM> permits the positioning of a spring <NUM> which can be used to provide some limited inferior bias to the shaft <NUM> and may keep the resilient body <NUM> in a minimum amount of compression to the assembly <NUM>. This minimum compression may be useful if or as the resilient body <NUM> undergoes any permanent compression or compression set during use. The spring <NUM> may be a helical spring or a wave washer, for example. The seal <NUM> may comprise silicone, Buna-N rubber, and Fluorinated elastomer such as VITON™ (Chemours; Wilmington, DE).

<FIG> illustrate the assembled configuration of the upper housing <NUM>, lower housing <NUM> and shaft <NUM>, without the resilient body <NUM>. The shaft <NUM> may be configured such that the tool interface <NUM> is located generally at the level of the longitudinal location of the resilient body <NUM>. The gap or distance between the lower surface <NUM> of the upper housing <NUM> and the superior surface <NUM> of the lower housing <NUM> may be equal to the unstrained height of the resilient body <NUM>. In other examples, the gap or distance may be smaller than the unstrained height of the resilient body <NUM>, such that when assembled, the upper and lower housings <NUM>, <NUM> place the resilient body <NUM> in vertical compression at baseline. This baseline compressed configuration may make the haptic feel of the assembly to be more linear or predictable compared to a baseline configuration that is not compressed or where the housing gap is greater than the unstrained height of the resilient body <NUM>.

The upper housing <NUM>, lower housing <NUM>, shaft <NUM> and/or cover piece <NUM> may comprise stainless steel (e.g. <NUM>-<NUM> stainless steel), titanium or cobalt chromium, aluminum or other metal, and anodized variants thereof, but in other examples may comprise a rigid polymer, ceramic or a composite thereof.

In another exemplary embodiment, shown in <FIG>, a prosthetic assembly <NUM> that provides vertical shock absorption and rotational movement is depicted in <FIG>. The assembly <NUM> comprises many components similar to the prosthetic assembly <NUM> described above and the similar components will not be discussed in detail below. The assembly <NUM> comprises a resilient bumper or body <NUM>, located between a first or upper housing <NUM> and a second or lower housing <NUM>. A longitudinal or vertical shaft <NUM> is coupled to the first housing <NUM>, passing through the resilient body <NUM> and coupled to the lower housing <NUM>. A retention member or retention assembly <NUM> is attached to the shaft <NUM> to resist separation of the shaft <NUM> from the lower housing <NUM>. The assembly <NUM> is configured to permit limited longitudinal and rotational displacement of the shaft <NUM> relative to the lower housing <NUM>, with the resilient body <NUM> providing increasing resilient resistance to increasing vertical compression and increasing rotational displacement.

As illustrated in <FIG> and <FIG>, the pyramid attachment structure <NUM> is provided on the shaft <NUM> for attachment of the assembly <NUM> to a pylon or residual limb socket. The pyramid <NUM> typically comprises an industry standard four-sided configuration, but in other examples, may comprise an alternative or proprietary design. The pyramid configuration may be changed by using a different shaft with a different pyramid configuration. Referring to <FIG>, the pyramid <NUM> is located at a first end <NUM> of the shaft <NUM> and may include a threaded lumen <NUM> to facilitate attachment of the pyramid <NUM>. Next to the pyramid <NUM> is an attachment region or interface <NUM> of the shaft <NUM> that forms a complementary interfit with the central lumen <NUM> of the upper housing <NUM>. This may be a collar interface as depicted, or a thread interface, as discussed above, a bayonet mount or other type of mechanical interfit or friction fit as noted above. As depicted in <FIG>, the shaft <NUM> may be configured such that when assembled with the upper housing <NUM>, the pyramid <NUM> protrudes form the upper surface <NUM> of the upper housing <NUM>. Adjacent to the attachment interface <NUM> of the shaft <NUM> may be a bore interface <NUM>, which may be used to grip the shaft <NUM> with a wrench or pliers or other tool when coupling or decoupling the shaft <NUM> and the upper housing <NUM>.

The bore interface <NUM> may comprise at least one contact surface <NUM> configured to contact the rounded lobes on the flange of the lower housing to restrict torsional rotation between the upper housing <NUM> and the lower housing <NUM>, as will be further discussed below. Although the contact surfaces <NUM> depicted in <FIG> are a rectangular interface, in other variations, the contact surfaces <NUM> of the bore interface <NUM> may be square or hexagonal or other polygonal shape, or may comprise a lumen in which a torque bar may be inserted to facilitate rotational coupling and decoupling of the shaft <NUM> and upper housing <NUM>. The contact surfaces <NUM> of bore interface <NUM> on the shaft <NUM> be configured to provide a hard limit angle limit to the rotation range with respect to the lower housing <NUM> as shown in <FIG> and <FIG>. The contact surfaces <NUM> may be configured in any suitable shaft to cooperate with the internal configuration of the flange of the lower housing <NUM>.

Referring back to <FIG>, adjacent or inferior to the bore interface <NUM> of the shaft <NUM> is the body <NUM> of the shaft <NUM>, which is configured to reside and move in the lumen <NUM> of the lower housing <NUM> when assembled. The length of the body <NUM> of the shaft <NUM> may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The diameter or cross-sectional dimension of the shaft <NUM> may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. In one embodiment, the diameter of the shaft may be approximately <NUM> inches and the length of the body of the shaft may be approximately <NUM> inches. Different lengths of the shaft <NUM> may also be provided in order to accommodate different patient preferences, height, and functional levels, with corresponding different heights of the resilient body <NUM>.

The second or lower end <NUM> of the shaft <NUM> is sized and configured to extend out from the lumen <NUM> of the lower housing <NUM>. A retention member or assembly <NUM> may be attached to the second end <NUM> to resist pullout of the shaft <NUM> from the lower housing <NUM>, but may be configured to permit some vertical displacement of the shaft <NUM> within the lumen <NUM>. This acts as a shock absorber as the upper housing <NUM> and lower housing <NUM> resiliently compress the resilient body <NUM>. In this particular example, the retention assembly <NUM> is attachable to the second end <NUM> of the shaft <NUM> by a closed threaded lumen <NUM>, but in other variations, may be attached via a clevis pin or other coupling interface. The retention assembly <NUM> is also configured to permit the shaft <NUM> to rotate within the lumen <NUM> and thereby to permit axial rotation.

In the particular examples depicted in <FIG>, the axial rotation is limited by the increasing resistance to rotation provided by rotational compression of the resilient body <NUM> between the inferior and superior projections <NUM>, <NUM>. In other variations, however, the retention member or assembly <NUM>, the contact surfaces of bore interface on the shaft <NUM> and the rounded lobes on the flange of the lower housing <NUM> may be configured to provide a hard limit angle limit to the rotation range.

In the embodiment depicted in <FIG>, and <FIG>, the lower housing <NUM> may comprise an annular projection or flange <NUM>. The remainder of the components for the lower housing <NUM> are similar to those described above regarding lower housing <NUM>.

The annular flange <NUM> is spaced radially inward from the peripheral surface <NUM> and the projections <NUM>, surrounding the longitudinal lumen <NUM> of the lower housing <NUM>. This flange <NUM> may be configured to insert or reside inside the central lumen <NUM> of the resilient body <NUM>. In some variations, the annular flange <NUM> may reduce the risk of eccentric displacement of the resilient body <NUM> during various compression and rotational movements, and may also limit the radially inward bulging of the inner surface <NUM> during vertical compression, and/or may act as barrier reduce the intrusion of debris and liquid into the lumen <NUM> of the lower housing <NUM>.

The flange <NUM> also provides additional support for longer tubular bearings that might be used in the lumen <NUM>. The use of a longer bearing may augment or reduce resistance that may be generated by off-axis forces or forces transverse to the longitudinal shaft <NUM> and lumen <NUM>. This may also improve bearing life and tactile prosthesis response. In embodiments comprising a tubular bearing, the ratio of the bearing length to the bearing inner diameter may in the range of <NUM>:<NUM> and <NUM>:<NUM>, or <NUM>:<NUM> to <NUM>:<NUM> or <NUM>:<NUM> to <NUM>:<NUM>. The flange <NUM> also allows the resilient member to be placed lower in the overall prosthesis, relative to the lumen <NUM>, which can shorten the build height of the prosthesis, which allows the use of the prosthesis across a greater range of residual limb lengths. Depending on the height of the annular flange <NUM>, the flange <NUM> may also provide a hard compression stop if the amount of vertical compression results in the annular flange <NUM> abutting against the inferior surface <NUM> of the upper housing <NUM>. In some variations, the height of the annular flange <NUM> is the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The wall thickness of the flange <NUM> may be in the range of <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. The inner diameter may be <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches, and the outer diameter may be <NUM> inches to <NUM> inches, <NUM> inches to <NUM> inches or <NUM> inches to <NUM> inches. In one embodiment, the height of the flange may be approximately <NUM> inches and the outside diameter may be approximately <NUM> inches. In one embodiment, the lobed design the flange <NUM> wall thickness may be irregular within the range of <NUM> to <NUM> inches and the inside of the lobed feature has an inscribed circle diameter of approximately <NUM> inches at minimum to approximately <NUM> inches at maximum.

<FIG> illustrate the assembled configuration of the upper housing <NUM>, lower housing <NUM> and shaft <NUM>, without the resilient body <NUM>. The shaft <NUM> may be configured such that the bore interface <NUM> is located generally at the level of the longitudinal location of the resilient body <NUM>. The gap or distance between the lower surface <NUM> of the upper housing <NUM> and the superior surface of the lower housing <NUM> may be equal to the unstrained height of the resilient body <NUM>. In other examples, the gap or distance may be smaller than the unstrained height of the resilient body <NUM>, such that when assembled, the upper and lower housings <NUM>, <NUM> place the resilient body <NUM> in vertical compression at baseline. This baseline compressed configuration may make the haptic feel of the assembly to be more linear or predictable compared to a baseline configuration that is not compressed or where the housing gap is greater than the unstrained height of the resilient body <NUM>.

Referring now to <FIG> and <FIG> the flange <NUM> may comprise an internal bore <NUM> having a plurality of rounded lobes <NUM>. The rounded lobes <NUM> and the contact surfaces <NUM> of the bore interface <NUM> on the shaft <NUM> are configured to limit the rotation of the upper housing <NUM> with respect to the lower housing <NUM>. The rounded lobes <NUM> are spaced apart and located opposite of one another on the internal bore <NUM>. In one embodiment the internal bore <NUM> may comprise four rounded lobes, that are configured to contact the four contact surfaces <NUM> of bore interface <NUM> on the shaft <NUM>.

In various embodiments, the contact surfaces <NUM> of bore interface <NUM> on the shaft <NUM> and the rounded lobes <NUM> on the flange <NUM> of the lower housing <NUM> may be configured to provide a hard limit angle limit to the rotation range as shown in <FIG> and <FIG>. In one embodiment, the angle limit of rotation is approximately <NUM>° in the clockwise and counterclockwise directions for a total range of rotation of approximately <NUM>°. In various embodiments, the number of contact surfaces <NUM> of bore interface <NUM> on the shaft <NUM> are the same as the rounded lobes <NUM> on the flange <NUM>.

<FIG> shows the lower housing <NUM> with a portion of the shaft <NUM> placed within the lumen <NUM> and the shaft <NUM> in the neutral position. The contact surfaces <NUM> of the bore interface <NUM> are not in contact with the rounded lobes <NUM> on the flange <NUM> of the lower housing <NUM>.

<FIG> is a side perspective view of the lower housing <NUM> with a portion of the shaft <NUM> placed within the lumen <NUM> and the shaft <NUM> rotated clockwise from the neutral position. The contact surfaces <NUM> of the bore interface <NUM> are in contact with the rounded lobes <NUM> on the flange <NUM> of the lower housing <NUM> to resist torsional rotation of the upper housing <NUM> attached to the shaft <NUM> with regard to the lower housing.

<FIG> is a side perspective view of the lower housing <NUM> with a portion of the shaft <NUM> placed within the lumen <NUM> rotated counterclockwise from the neutral position. The contact surfaces <NUM> of the bore interface <NUM> are in contact with the rounded lobes <NUM> on the flange <NUM> of the lower housing <NUM> to resist torsional rotation of the upper housing <NUM> attached to the shaft <NUM> with regard to the lower housing.

The specific examples and descriptions herein are exemplary in nature and variations may be developed by those skilled in the art based on the material taught herein without departing from the scope of the present subject matter.

The technology has been described with reference to specific exemplary embodiments. Various modifications and changes, however, may be made without departing from the scope of the present technology. The description and figures are to be regarded in an illustrative manner, rather than a restrictive one and all such modifications are intended to be included within the scope of the present technology. Accordingly, the scope of the technology should be determined by the generic embodiments described and their legal equivalents rather than by merely the specific examples described above. For example, the steps recited in any method or process embodiment may be executed in any order, unless otherwise expressly specified, and are not limited to the explicit order presented in the specific examples. Additionally, the components and/or elements recited in any apparatus embodiment may be assembled or otherwise operationally configured in a variety of permutations to produce substantially the same result as the present technology and are accordingly not limited to the specific configuration recited in the specific examples.

Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments; however, any benefit, advantage, solution to problems or any element that may cause any particular benefit, advantage or solution to occur or to become more pronounced are not to be construed as critical, required or essential features or components.

As used herein, the terms "comprises," "comprising," or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus. Other combinations and/or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present technology, in addition to those not specifically recited, may be varied or otherwise particularly adapted to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same.

Furthermore, in understanding the scope of the present invention, the term "comprising" and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, and/or steps. The foregoing also applies to words having similar meanings such as the terms, "including," "having" and their derivatives. Any terms of degree such as "substantially," "about" and "approximate" as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±<NUM>% of the modified term if this deviation would not negate the meaning of the word it modifies.

Claim 1:
A prosthetic assembly, comprising:
a resilient undulating body (<NUM>) comprising an outer perimeter, a first surface (<NUM>), a second surface (<NUM>) opposite the first surface (<NUM>), and an interior opening (<NUM>) therebetween;
a longitudinal shaft (<NUM>) located in the interior opening (<NUM>) of the undulating member (<NUM>), the shaft (<NUM>) comprising a bore interface (<NUM>) with at least one contact surface (<NUM>);
a first prosthesis body (<NUM>) coupled to the longitudinal shaft (<NUM>) and contacting the first surface (<NUM>) of the undulating member (<NUM>); and
a second prosthesis body (<NUM>) contacting the second surface (<NUM>) of the undulating member (<NUM>) and comprising:
a longitudinal lumen (<NUM>); and
a flange (<NUM>) located on an upper surface of the second prosthesis body comprising an internal bore (<NUM>) with at least one lobe (<NUM>),
wherein the longitudinal shaft (<NUM>) is movably located in the longitudinal lumen (<NUM>) and wherein the at least one contact surface (<NUM>) contacts the at least one lobe (<NUM>) to limit the rotation of the first prosthesis body (<NUM>) with respect to the second prosthesis body (<NUM>).