MODULAR PROSTHETIC SOCKETS AND METHODS FOR MAKING AND USING SAME

Abstract

Embodiments of a modular prosthetic socket for a residual limb of a lower extremity of a patient are provided. Modular components include a base, multiple strut connectors, and multiple longitudinal struts. The base is selected from a collection of bases. The multiple strut connectors are selected from a collection of strut connectors, each strut connector being adjustably connectable to the base along the periphery of the base. The multiple longitudinal struts are selected from a collection of struts, each strut including a thermoplastic-fiber composite material, each strut being connectable to the base along the base periphery via one of the strut connectors. At least one of the component collections includes at least one of multiple sizes or multiple shapes of bases, struts or strut connectors, respectively. The prosthetic socket circumscribes a proximally-open internal space configured to conform to the residual limb of the patient.

Claims

1. A method of assembling a modular prosthetic socket for a residual limb of a patient, the method comprising: selecting a base from a collection of bases, wherein the base has a circumference; selecting four longitudinal struts from a collection of struts, wherein each strut is made entirely of a thermoplastic-fiber composite material consisting of a polymethylmethacrylate matrix with continuous carbon fiber embedded therein, wherein each strut has an originally formed flat shape, a proximal end and a distal end, and wherein the distal end of each strut is adjustably connectable to the base along the circumference; reforming each of the struts to reshape each strut from the flat shape to a reformed shape comprising one or more curves, wherein the reformed shape of each strut is configured to conform to a corresponding contour of the residual limb, and wherein the reformed shape of at least one of the struts is different than the reformed shape of one or more of the other struts; attaching the four selected, longitudinal, reformed struts to the selected base to form an assembled prosthetic socket; attaching multiple brim elements to the proximal ends of the four longitudinal struts, wherein each of the multiple brim elements is fitted over and surrounds the proximal end of at least one of the four longitudinal struts, and wherein at least one of the brim elements comprises at least one tensioning element guide; and attaching a tensioning element around the multiple brim members, using the at least one tensioning element guide on the at least one brim member, wherein at least one of the collection of bases or the collection of struts comprises at least one of multiple sizes or multiple shapes of bases or struts, respectively, and wherein the assembled prosthetic socket circumscribes a proximally-open internal space configured to conform to the residual limb of the patient.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0202] Certain preferred embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description below having reference to the figures that follow.

[0203] FIG. 1 shows a side perspective view of an embodiment of a modular prosthetic socket in a fully assembled state.

[0204] FIG. 2A shows an exploded side perspective view of an embodiment of a modular prosthetic socket.

[0205] FIG. 2B shows schematic diagram of a system and method for assembling a modular prosthetic socket from inventories of modular component parts.

[0206] FIG. 3 shows a patient with an above-knee amputation wearing an embodiment of a modular prosthetic socket suitable for this level of leg amputation.

[0207] FIG. 4 shows a patient with an amputation at the knee, a knee-disarticulation, wearing an embodiment of a modular prosthetic socket suitable for this level of leg amputation.

[0208] FIGS. 5A and 5B shows a side view and a perspective view, respectively, of an embodiment of a thermoplastic-fiber composite strut attached to a strut connector.

[0209] FIGS. 6A-6E show views of a series of thermoplastic-fiber composite struts as may be found in an inventory of struts that vary in size and/or shape.

[0210] FIGS. 7A-7D show a strut attached to a strut connector, and cross sectional profiles of a various thermoplastic-fiber composite struts.

[0211] FIGS. 8A and 8B show a flow diagrams for forming (FIG. 8A) and reforming (FIG. 8B) a thermoplastic-fiber composite strut.

[0212] FIGS. 9A and 9B shows a schematic cross-sectional views of sections of a thermoplastic-fiber composite strut; FIG. 9A shows a 3-layered strut section and FIG. 9B shows the layers separated out as they would have been prior to molding them together.

[0213] FIGS. 10A-10D show a schematic views of aspects of forming and reforming a section of a thermoplastic fiber composite strut.

[0214] FIGS. 11A and 11B show aspects of an embodiment of a method of forming a multilayered thermoplastic-fiber composite strut; FIG. 11A shows a section of a multilayered strut and FIG. 11B shows the strut as a circumferentially wrapped layer of thermoplastic-fiber composite tape is being applied to the strut.

[0215] FIG. 12 shows an aspect of reforming a thermoplastic-fiber composite strut known as direct molding, wherein a strut has been heated sufficiently to make it pliable, and then is placed against the body and pressed against a portion of the residual limb of a patient by a prosthetist in order to impart a body-conforming shape to the strut.

[0216] FIGS. 13A and 13B show embodiments of a thermoplastic-fiber composite strut with a resistive heating element embedded therein, the element allowing the strut to be self-heating for thermal reforming. FIG. 13A shows a strut with a serpentine heating element; FIG. 13B shows a strut with a mesh heating element.

[0217] FIGS. 14A-14C show an embodiment of a thermoplastic-fiber composite strut in an initial state, as it was originally formed, and two examples of the strut after being thermally reformed to better fit against a portion of the residual limb. FIG. 14A shows the strut in its originally formed shape; FIG. 14B shows the strut after it has been reformed to include a site of curvature; FIG. 14C shows the strut after it has been reformed to include an axial twist of several degrees.

[0218] FIGS. 15A-15G show views of embodiments of a distal base for a modular prosthetic socket, each having four strut connecting sites. FIGS. 15A and 15B show an embodiment wherein strut connecting sites are distributed in an arrangement with intervening angles of about 120, 90, 60, and 90. FIGS. 15C-15F show distal bases wherein the strut connecting sites are equally distributed at about 90. FIGS. 15C-15E show distal bases that are identical in shape, but vary in size, as would components in an inventory. FIG. 15G shows an embodiment of a distal base for a modular prosthetic socket having a covering plate arranged over a base plate that includes strut connecting slots.

[0219] FIGS. 16A-16H show views of various embodiments of strut connectors for a modular prosthetic socket. FIGS. 16A-16C show an embodiment having a single attachment hole at the vertex of a triangular base. FIGS. 16A and 16B show an embodiment wherein a connector backside is at right angle to a horizontal base. FIG. 16C shows an embodiment wherein the backside resides at an obtuse angle with respect to the horizontal base. FIGS. 16E-16F show an embodiment similar to those of FIG. 16A-C, this particular embodiment further having buttress supports extending from the lateral edges of the backside to the horizontal base. FIGS. 16D and 16E show an embodiment wherein a connector backside is at right angle to a horizontal base. FIG. 16F shows an embodiment wherein the backside resides at an obtuse angle with respect to the horizontal base. FIGS. 16G-16H show an alternative embodiment of a strut connector, this embodiment having two attachment sites (to twin slots within a distal base) and a rotatable disc that cooperates in the attachment mechanism.

[0220] FIGS. 17A-17F show top views and a side view of an embodiment of a base for a modular prosthetic socket with the strut connectors positioned on a distal base into configurations that vary according to the radial position of the strut connectors and their degree of pivoting at their attachment site. This embodiment of a distal base accommodates four strut connectors, circumferentially spaced apart at 90 intervals. FIG. 17A shows four strut connectors, each of the four positioned at a minimal radial position. FIG. 17B shows four strut connectors, each of the four positioned at a maximal radial position. FIG. 17C shows four strut connectors, with one of the four (shown on the right) positioned at a maximal radial position, the other three being at a minimal radial position. FIG. 17D shows four strut connectors arranged as in FIG. 17C, but with the strut connector on the right pivoted clockwise at an angle of about 20. FIG. 17E shows four strut connectors arranged as in FIG. 17C, but with the strut connector on the left and on the right, each pivoted at an angle of about 20. FIG. 17F shows a side view of a distal base for a modular prosthetic socket with a strut connector positioned thereon, within a radial slot.

[0221] FIGS. 18A and 18B show, respectively, top and side views of an embodiment of a strut connector that includes a secondary pivot external to the primary pivot, the second pivot allowing a restoration of the angle of the strut toward the center of the distal base after that particular strut has been rotated at the primary pivot site.

[0222] FIG. 19A shows a top perspective view of an embodiment of a distal base similar to that of FIG. 14G with a with a single strut attached thereto by way of a strut connector; this view shows how a base plate and a top plate can cooperate to provide a strut connecting site that further stabilizes the strut, and provides a boundary to the pivoting latitude.

[0223] FIG. 19B shows an alternative embodiment of a strut that has an integrated strut connector portion on its distal end.

[0224] FIGS. 20A-20D show side views of thermoplastic struts that have a varying profile, ranging from substantially straight to having two or more sites of curvature.

[0225] FIGS. 21A-21G show face views of thermoplastic-fiber composite struts that have one or more tab-like features extending laterally.

[0226] FIGS. 22A-22K show views of various arrangements thermoplastic-fiber composite struts with pressure-distribution elements, such as strut caps, brim elements, and strut sleeves attached thereto.

[0227] FIGS. 23A-23C show views of modular prosthetic socket embodiments, each with a different arrangement of pressure distributing elements, including strut caps and strut brims, each arrangement including a circumferential tensioning member.

[0228] FIG. 24 shows an embodiment of a modular prosthetic socket that is particularly configured to accommodate a bulbous residual limb.

[0229] FIGS. 25A and 25B show views of an embodiment of a modular prosthetic socket arranged with a flexible inner liner and a tensioning mechanism; FIG. 25A shows the prosthetic socket and flexible inner liner without tension being applied and FIG. 25B shows the prosthetic socket and flexible inner liner in a tensioned state.

[0230] FIGS. 26A and 26B show views of an embodiment of a modular prosthetic socket in two configurations; FIG. 26A shows a socket with the struts and strut connectors positioned on a distal base within a relatively small radius, while FIG. 26B shows the same socket with the struts and strut connectors positioned on a distal base within a relatively large radius.

[0231] FIGS. 27A and 27B show views of an embodiment of a modular prosthetic socket in two configurations; FIG. 27A shows a socket with one the struts and its strut connector at a neutral non-pivoted position on a distal base, while FIG. 27B shows the same socket with the struts and strut connectors positioned at a pivoted position. The pivoted position allows the strut to move away from a site of irritation on the residual limb.

[0232] FIGS. 28A-28C and FIGS. 29A-29C show views of a modular prosthetic socket 100 being worn by a patient on residual limb 700, depicting two aspects of prosthetic socket strut flexing while walking. FIGS. 28A-28C show flexing in response to loading and unloading of weight on the struts during a stride. FIGS. 29A-29C show strut flexing in response to forward and rearward forces imparted to the residual limb during a stride.

DETAILED DESCRIPTION

[0233] Device, system, and methods of the disclosed technology relate to modular prosthetic sockets for residual limbs, and to the materials included within prosthetic socket components. Technology disclosed herein is related to the subject matter of U.S. patent application Ser. No. 13/675,761 of Hurley and Williams, entitled Modular prosthetic sockets and methods for making same, as filed on Nov. 13, 2012, and which is incorporated herein by this reference. Novel aspects of the technology relate to a modularity of the system, wherein primary structural elements are provided as interchangeable components, and to characteristics of component construction and materials. The use of particular materials, such as thermoplastics and thermoplastic-fiber composite materials, in prosthetic components is disclosed in U.S. Provisional Patent Application No. 61/783,662 of Williams and Hurley, entitled Modular prosthetic socket with components having thermoplastic-fiber composite materials, as filed on Mar. 14, 2012. Modularity of a prosthetic socket assembly and the material properties of modular components both contribute to practical attributes of the technology, such as optimizing the fit of a prosthetic limb socket, allowing a fast fitting and assembly session, and allowing a fast reconfiguration or adjustment of the system as may be needed.

[0234] Fitting of an assembled modular prosthetic socket to the residual limb of a patient may be understood as being of various types or levels, depending on factors taken into consideration for the fitting. Fitting may involve any of (1) a skilled prosthetist or professional technician who takes full advantage of the structural variation within the prosthetic component inventories when selecting components for assembly into a socket and (2) exploiting attributes of component materials of the provided technology, particularly to properties of thermoplastic-fiber composite materials, and (3) making mechanical adjustments of adjustable aspects of an assembled prosthetic, or exercising various mechanical options during the assembly of a socket. The skilled prosthetist or professional technician, in performing these various types of fitting options may also draw on the capabilities of a larger system of information flow and component logistics as disclosed in U.S. Provisional Patent Application No. 61/916,579 of Hurley and Pedtke, as filed on Dec. 16, 2013.

[0235] As disclosed in U.S. patent application Ser. No. 13/675,761, the provided technology includes a modular aspect in that a prosthetic socket can be assembled from an inventory of structural components. The components within an inventory, for example, an inventory of formed struts includes standardized strut forms that may vary in dimension and/or shape. Additionally, struts may be initially formed according to specifications specific to the patient. Accordingly, a conformal or complementary fitting can be accomplished by selecting a set of struts from the variety of strut forms, which, when assembled, provide the best possible fit as derived from standard strut forms.

[0236] This basic level of fitting is a conformal arrangement, wherein a prosthetic socket conformally complements a residual limb in terms of dimensions and shape. This type of fitting relates to the residual limb as a static form, in that the fitting is to a residual limb, which, when captured only in terms of static dimensions and a static shape, does not necessarily include movement or apply other biomechanical considerations.

[0237] For some individuals, this basic level of fit may be sufficient and fully satisfactory. For some individuals, however, it may be apparent to a prosthetist that the level of fit may be improved, as for example, by reforming or partially reforming any one or more of the struts included in a prosthetic socket, as described below.

[0238] Thermoplastic components of a modular prosthetic socket, such as the struts, can be reformed, per the properties of thermoplastics that allow for an indefinite number of cycles of warming a solid form into a pliable and reshapable form, and cooling to return to a solid form with a different shape. Thermoplastic reforming of an already initially formed component, according to methods described herein, may provide more advanced levels of fit. Reforming of a thermoplastic component, such as a strut, typically begins with a strut that has been selected for assembly in a prosthetic socket so as to produce a socket that has a good conformal fit. Reforming the strut to alter its shape in some way is typically done to improve the level of fit.

[0239] An improved level of fitting achieved by a reforming process can raise the level of fit according to dynamic considerations, such as a fitting that accommodates and is appropriate for a range of motion that the residual limb may be expected to exercise, and to changes in shape or dimension that may accompany such motion, or which may vary according to load and weight distribution incurred during daily activity. To some extent, these variable dynamic aspects of a residual limb may be directly observable by a prosthetist, and can be directly incorporated into a fitting process.

[0240] An improved level of fitting achieved by a reforming process may take biomechanical aspects into consideration, such as habits or practices of the individual being fitted, or of more general physical attributes, such as body weight or other particular strengths or weaknesses of the individual. To accomplish this biomechanically appropriate level of fitting, in addition to practicing at least a conformal level of fitting, a prosthetist needs to understand details of the subject being fitted that may not be immediately observable during a fitting session, but which can be understood by way of gathering aspects of the subjects personal and medical history, and forward-looking personal aspirations.

[0241] An improved level of fitting achieved by a reforming process may take into account temporary or transient situations. For example, an individual may have some days that include a lot of physical activity, or an unusual activity, or a day that may be relatively sedentary. By way of another example, an individual may incur muscular soreness, or an injury, or an ulcer. In a slightly longer term, a subject may gain or lose weight, with directly related accompanying changes in the residual limb. Change in weight by also have delayed or more subtle consequences, such as a change in gait. Any of these eventualities may indicate the desirability for a changed shape in a particular socket component or the configuration of the socket as a whole. By way of example, if an individual develops an ulcer or is showing signs of skin breakdown at a site that contacts the strut of a prosthetic socket, per embodiments of the technology, the curvature of the strut can be adjust such that pressure exerted by the strut at the point of body contact is minimized.

[0242] These various types of considerations that may enter into improving fit are described in order to facilitate an understanding of the technology, and an underlying rationale of fitting as provided by embodiments of the technology. Any of these types of fitting may be generally understood as a custom fitting, or an individualized fitting, in that every aspect of fitting described herein relates to optimizing fit for each individual being fitted, in accordance with the various and numerous attributes of the individual that are specific to the individual. These various types of fitting are not mutually exclusive. Further, as noted, while improving the fit of a prosthetic socket may occur by reforming particular components, it may also occur by way of selecting components to be included in the socket assembly, or by reconfiguring the prosthetic socket assembly into alternative configurations, or by making mechanical adjustments.

[0243] Reforming a modular prosthetic socket component, such as a strut, so as to provide an improved fit of the strut to a residual limb, is made possible by the material composition of particular strut components, per embodiments of the disclosed technology. In some embodiments, the material composition includes a thermoplastic polymer; in other embodiments, the material composition may include a thermoplastic-fiber composite material. Typical thermoplastic-fiber composite material included in struts, for example, may include a polymer, such as polymethylmethacrylate (PMMA), which is fortified with embedded fiber, such as glass fiber, carbon fiber, ballistic fiber, or any other suitable or particularly advantageous fiber. Accordingly, a reforming step typically includes heating the initially formed piece until it is pliable, and followed then, by appropriate bending or shaping toward a desired shape.

[0244] Remolding and reforming are substantially similar terms, just as are molding and forming. Molding and remolding generally refer more to the aspect of the process whereby an article, such as a strut, is shaped in accordance with a physical mold or cast, or against a portion of a residual limb. Forming and reforming relate more particularly to shaping or reshaping of an article or a portion thereof, such as a strut, without particular emphasis regarding the physical model being used to determine the shape arrived at.

[0245] Remolding (as may follow an initial molding or forming) can be accomplished with various methods that are directed to conforming the struts and/or other aspects of the socket to comfortably and effectively complement the contours of the residual limb. One such example of a method is to place a thermal barrier over the residual limb; padding or inner liners can be fit prior to the structural frame of the socket. The struts and/or other aspects of the socket are then heated to an appropriate molding or heat labile temperature, and the socket component is placed in the correct orientation on the residual limb. A two-part sealing bag is then placed over the limb portion and strut, and air is pulled out of the bag such that the sealing bag pushes or sucks down to the shape of the residual limb with the struts also being pushed into the shape of the residual limb. A prosthetist can then use his or her hands and/or a fitting jig to distribute pressure in select areas to maximize biomechanical control and/or comfort.

[0246] In one aspect, fitting may include a mechanical adjustment of an assembled prosthetic socket that is already has a level of conformal fit. U.S. patent application Ser. No. 13/675,761, as referenced above, discloses aspects of mechanical adjustments to attain better fit. Adjustment, by way of analogy, can be likened to lacing shoes that are already of the best available or initial fit. Although a prosthetist may perform such mechanical adjustments, per embodiments of the technology, some adjustment capabilities may be particularly in the realm of the patient, such as performing tensioning adjustments by way of tensioning and pulley arrangements. This type of adjustment is made primarily to suit the personal preference of the patient. Again, in a manner akin to the shoe lacing analogy, the major aspects of fit, in a conformal sense are not altered by this type of adjustment; what changes is the overall enclosed volume of the prosthetic socket assembly and the consequent change in tightness, as experienced by the patient. Mechanical adjustment of fit may well involve adjustment of prosthetic socket components that include thermoplastic-fiber composite materials, but such adjustments do not necessarily involve the thermoplastic properties of the materials.

[0247] A prosthesis wearer can improve or adjust fit during daily use by making mechanical adjustments of an assembled prosthetic socket. Mechanical adjustment may occur, by way of example, by adjusting a tensioning mechanism that is connected to socket components.

[0248] In another aspect, fitting may include mechanical adjustments made during the assembly of a prosthetic socket. These mechanical adjustments differ from those described immediately above in that these generally are options exercised by the prosthetist (not the patient) as he or she is assembling the prosthetic strut, making judgments based on clinical experience and knowledge of the patient. By way of example, embodiments of the technology described herein include strut connectors or base-strut connectors disposed on a distal socket base, to which the distal ends of struts are attached. Such strut connectors may be variably positioned. In one example, the strut connectors may be positioned at varying distances from the center of the socket base (this may be referred to as the radial position), or at varying distances from the central longitudinal axis of the prosthetic socket assembly as a whole. In another example, the strut connectors may include a freedom of pivotability, wherein the pivot represents a movement through an arc, a portion of a circumferential rotation. Both of these examples have proximal-ward and volume implications for the prosthetic socket as a whole with regard to fitting; the variations in distal attachment sites manifest as variation in volume circumscribed by an internal aspect of the assembled socket, as defined by the radial positioning of the struts collectively.

[0249] From another perspective, fitting may be understood as being applicable to individual socket components, but also to the configuration of the prosthetic socket as a whole. Accordingly, and by making use of inventories of component groups, a prosthetic socket can be reconfigured by removing an existing component and replacing it with a new component, as for example, a new component that differs in size or shape with respect to the existing component. In some instances, removing and replacing parts is undertaken to replace an old part that is worn or damaged. In this case, the overall socket configuration is not being reconfigured with regard to its shape. This non-reconfiguring part exchange may be understood more simply as a repair, restoration, or maintenance of the socket, conserving its original or intended configuration.

[0250] Configuring (and reconfiguring) a socket may further include exercising assembly options, such as varying the number of struts (e.g., three struts, four struts) and/or varying radial spacing of struts around the central longitudinal axis of the socket, or by varying the attachment angle of the proximal base of a strut with respect to the longitudinal axis of the prosthetic socket.

[0251] Although configuring and reconfiguring a prosthetic socket relates to the selection of modular components and replacement of such components, it may further relate to structural options provided by the technology even as provided with a given set of components. By way of contrast, even absent the adjustable capabilities provided by tensioning (as noted above), the configuration of a prosthetic socket is not wholly or fixedly determined by the selection of components. By way of example, as provided by some embodiments, the positioning of struts with respect to a distal base can be changed by adjusting the radial position of the struts from the center of the base, or by rotationally pivoting the strut from a given radial position.

[0252] FIGS. 1-28C illustrate various embodiments, examples, and aspects of the technology as described above. These figures depict aspects of the structure of a modular prosthetic socket, particularly embodiments that include multiple longitudinal struts formed from thermoplastic-fiber composite materials attached to a distal base. A particular focus includes structural and functional details of how the struts attach to the base by way of strut connectors and the aspects of the base that accommodate the strut connectors. By way of the strut connectors and their sites of attachment to the base, in various embodiments, several degrees of freedom and adjustability are provided. All of these forms of adjustability and variability of configurations are applied toward attaining and maintaining a clinically optimal fit of the prosthetic socket on the residual limb. Aspects of the adjustable arrangement of struts with regard to a distal socket base have implications with regard to adjustability of the struts as they project proximally from the base and, thus, how the prosthetic socket fits a residual limb. Aspects of methods are also illustrated, with particular attention to methods of forming and reforming thermoplastic-fiber composite struts. Such methods of forming and reforming are also related to adjustability and long-term maintenance of the fit of a modular prosthetic socket on a residual limb.

[0253] In the following description and in the attached drawing figures, a given numerical label may be used to refer to the same component part in different embodiments. For example, a strut of a prosthetic socket may be referred to as strut 300 in multiple different embodiments, rather than labeling different embodiments of struts with different numbers. Struts may have any of a number of different sizes, shapes and material properties in alternative embodiments, but some or all of these embodiments may be labeled with the same number below and in the attached drawing figures. This labeling consistency is used to facilitate understanding of the description and should not be interpreted as suggesting that there is only one embodiment of any given component.

[0254] Referring now to FIG. 1, in one embodiment, a modular prosthetic socket 100 may include four thermoplastic struts 300, each of which is attached to a strut connector 220, which in turn is connected to a distal base 200. A central longitudinal axis 101 is shown. The prosthetic socket 100 has a proximal portion 104 and a distal portion 105. These portions 104, 105 are identified for general orienting purposes; there is no bright line demarcation between the proximal and distal portions, although the distal base 200 is clearly included in the distal portion 105.

[0255] Struts 300 may also be divided into a proximal portion 314 and a distal portion 317. As with the socket 100 as a whole, these proximal 314 and distal 317 strut portions have no bright line demarcation, but are used for general orientation when describing the struts 300 or elements associated with them. Distal ends 318 of the struts 300 are connected or fastened to strut connectors 220. Details of the strut connectors 220 and their relationship to the distal base 200 and the struts 300 are detailed in FIGS. 16A-19 that follow. The proximal ends 315 of the struts 300 are not visible in FIG. 1, as they are covered by embodiments of strut caps 430. Strut caps 430 are included within a broader group of components referred to as pressure distributing elements. Other pressure distributing elements include brim elements 420 and a flexible inner liner 410, as depicted in FIGS. 22A-23C, and described below. An embodiment of a distal cup 290 is disposed above the distal base embodiment 200, nested within the distal ends of struts 300.

[0256] FIG. 1 further shows an embodiment of a tensioning mechanism 510 arranged around a generally central section of struts 300. Tensioning mechanism 510 is but one example of a number of different types of tensioning members. This particular arrangement includes a strap 510 with a tightening mechanism 512. Modular prosthetic socket embodiments may include one or more of such tensioning mechanisms 512, distributed along the length of the prosthetic socket. Other embodiments of tensioning mechanisms are depicted in FIGS. 22F-23C, and described below.

[0257] Struts 300, a distal cup or pad 290, and strut caps 430, collectively, form a proximally open space or cavity that is configured to accommodate a residual limb, such as a lower limb. In other embodiments of a modular prosthetic socket assembly, other components, particularly various embodiments of pressure distributing elements, may participate in defining this proximally open cavity. All embodiments, however, are configured to individually fit, at least in a conformal sense, the size and shape of the residual limb of the patient for whom the prosthetic socket is intended. An extensive description of the various types of fitting that may be ascribed to the relationship between (1) the space nominally defined by the inner boundary of the limb-hosting space of the socket and (2) the dimensions and contours of the residual limb itself is provided above.

[0258] Struts 300, despite being narrow, having minimal if any lateral curvature, and having only generally simple longitudinal curvature, nevertheless can very effectively define a complex shape with a fidelity that conformally fits a residual limb as well as larger, shell-like sections of prior art sockets, with broad surfaces, and having curves played out in two planes. As discussed below, the relatively simple structure of the struts 300 permits the use of thermoplastic-fiber composite materials, the fiber being of a continuous form. The use of such materials, in turn, advantageously provides high strength, a favorable strength/weight ratio, and a resilience to the socket as assembled.

[0259] Since the struts 300 provide the major structural boundary of the modular prosthetic socket 100 (setting aside liner embodiments that may be inserted within the socket), the socket 100 has a considerable amount of open spacee.g., spaces between the struts 300 as well as the proximal opening of the socket 100. The open aspect is advantageously associated with an ability to allow escape of heat and moisture from the residual limb. If the cross sectional profile of an embodiment of a socket is taken approximately at a socket midpoint (see FIGS. 26A and 26B, for example), each strut 300 may occupy an arc of no greater than about 25 angular degrees of that midpoint circumference, for example. Similarly, in a typical embodiment, the total enclosing coverage of struts 300 around a midpoint circumference is no greater than about 100 angular degrees.

[0260] FIG. 2A is an exploded view of the modular prosthetic socket 100. Distal base embodiments 200 may include one or more cooperating plates. A distal base assembly 200, per this embodiment, includes a lower plate 210 and an upper plate 215. An embodiment of a distal cup 290 is shown above the distal base 200. Distal cup embodiments may also be considered an assembly, optionally including one or more cooperating cups. This particular embodiment includes two cupsa lower pad 291 and an upper pad 293. In an arrangement such as this, the lower pad 291 would typically be of relatively high durometer, and the upper pad 292 would typically be of a relatively low durometer. A roll-on liner 110 is shown above the distal cup 290; the roll-on liner 110 is supported by a firm liner support cup 296, which may also be considered a part of distal cup 290, or in some embodiments represent the distal cup 290 in its entirety. Thus distal cup 290 may thus include multiple cooperating components such as lower pad 291, upper pad 293, and liner support cup 296. In some embodiments, distal cup 290 may be a single component, or particular components may be recognizable as having a form such as lower pad 291, upper pad 293, and liner support cup 296, but be integrated such that they are conjoined. In some embodiments, any one of these single components may comprise the entirety of a distal cup, and thus may be referred to as distal cup 290, as for example, in FIGS. 23A-23C. In some embodiments, the roll-on liner 110 may include moisture management features.

[0261] A set of four longitudinal struts 300 are arrayed about the distal base 200, the distal cup 290, and the roll-on liner 110. Struts 300 may be considered to be part of a strut assembly 301 that further includes a distally connected a strut connector 220 and a proximally connected pressure distribution element, such as a strut cap 430. Typical embodiments of a modular prosthetic socket assembly include four longitudinal struts 300, as shown here, although other embodiments may have fewer or more than four. Each strut 300 has a proximal portion 314, a proximal end 315, a distal portion 317 and a distal end 318. In this embodiment, the struts 300 are arrayed at 90 angular intervals, per the arrangement of strut connecting sites on the distal base assembly 200. Other angular intervals possible in alternative embodiments (see FIGS. 15A and 15B, for example).

[0262] An embodiment of a strut connector 220 is shown proximate the distal end 318 of each strut 300. Strut connectors 220, in an assembled socket 100, connect both to the distal end of a strut 300 and to the distal base 290, and by such arrangement, struts 300 are connected to the distal base.

[0263] A strut cap 430 is shown proximate the proximal end 315 of each strut 300. When assembled, the strut cap 430 is disposed over the proximal end of a strut 300. Strut caps 430 are an example of a pressure distributing element of the modular prosthetic socket assembly 100 Pressure distributing elements are configured to distribute pressure on a residual limb away from the site of contact between a structural element, such as a strut, and the area on the residual limb that the structural element contacts. Other pressure distributing elements include a proximal brim 420 and a flexible inner liner 410 (not shown in FIG. 2A).

[0264] FIG. 2A also provides a perspective with regard to various methods associated with the modular prosthetic socket, such as methods of assembling a modular prosthetic socket, replacing components of an existing modular prosthetic socket, mechanically adjusting the fit of a modular prosthetic socket, and making a modular prosthetic socket within 24 hours or less. In particular instances, a modular prosthetic socket can be assembled and delivered to patient within 12, 8, or even as few as 4 hours from the time first introduction to a prosthetist. These rapid turn-around times depend on the modular aspects of the assembly and having appropriately stocked inventories of components on hand.

[0265] To assemble the modular prosthetic socket 100, in one embodiment, upper distal plate 215 and lower distal plate b can be assembled together to form distal base 200. Distal bases may include one or more cooperating plates; any single plate embodiment, or any plate of a multiple-plate embodiment may be referred to as distal base 200. Struts 300 and strut connectors 220 can be assembled together. Strut connectors 220 can be assembled together with distal base 200, slidably fitting into radial slots 212 of lower base plate 210. Fastening elements 219, generally threaded bolts, are used to attach the various modular components together. Threaded fastening elements are generally advantageous in the assembly of a modular prosthetic socket because, in many aspects, the socket is configured for disassembly with an ease that is equal to that of assembly. Fastening elements, 219, typically threaded bolts, may be used variously to attach struts to strut connectors 220, strut connectors to a base 200, and to connect base plates together if there is more than one base plate.

[0266] Strut caps 430 are connected to the proximal ends of struts 300. The actual order of assembly steps can vary. The basic structural skeleton of a modular prosthetic socket embodiment is represented by the sum of correctly assembled component struts 300, strut connectors 220, and distal base 290. Further liner or residual limb support elements, such as the gel liner 110 and liner support cup 296, can be slipped into the assembled socket 100 from the proximally open end of the socket 100.

[0267] FIG. 2A also provides a perspective on the wide variety of sizes and shapes of prosthetic sockets 100 that can be assembled from modular components that vary in size or shape, using common connecting features. For example, as shown in various figures and described in further detail below, distal base embodiments 200 can vary both in size, and in the number of strut connecting sites. Strut connectors 220 can vary in shape, primarily with regard to the angle of the back portion 224 with respect to base portion 222. And the size and shape of struts 300 can vary in multiple ways. For example, any of length, width, and thickness can vary. Cross-sectional profile can vary. And curvilinear forms can vary widely, and be made to conform to the shape of an individual residual limb.

[0268] Aspects of replacing modular components can also be understood from FIG. 2A. Any particular existing component can be removed, leaving the remaining portion of the assembled socket intact, and the removed component can be replaced with a new component part. For example, if a strut 300 is damaged, it can be unbolted from its strut connector 220 and replaced with a new strut. Such a component replacement can also be made in order to improve the fit of the socket to a residual limb. For example, if a residual limb has atrophied, an original or existing strut may not fit a particular portion of the residual limb as it did originally, or as would be desired. In this instance, a new strut, one with a different shape, for example, could be selected and put into the same position as the old strut.

[0269] In some embodiments, it may be beneficial to remove an existing strut 300 and thermally reform it to a more desirable shape. This may be done, for example, to improve the fit of a given modular prosthetic socket.

[0270] FIG. 2B is a schematic diagram of a system for assembling a modular prosthetic socket 100 from modular component parts. Arrayed around an assembled modular prosthetic socket are inventories of modular component parts. These inventories include a strut inventory 131, a distal base inventory 132, a pressure distribution element inventory 133, a tensioning member inventory 134, and a strut connector inventory 135. Inventories may also be generally referred to as groups or collections of components. These are non-limiting examples of modular components that may be used in the assembly of a modular prosthetic socket. As described elsewhere, an inventory may be an actual physical inventory, or it may be a virtual or catalogue-based inventory. Inventories may also be used to package kits of components, or alternatively, a kit may also be considered a small inventory itself. Inventories of modular components typically include like components, with portions such as connecting sites in common, but otherwise including variations in size and/or variations in shape. In some instances, modular components may also differ from each other in material composition. FIG. 2B may also be interpreted as a diagram depicting a method of assembling a modular prosthetic socket in that components may be selected from such inventories (131-135) and assembled together to create a modular prosthetic socket of desired size and shape.

[0271] A strut inventory 131 may include struts 300 that can vary in size and shape. Size variations may include dimensions such as length, width, and thickness. Shape variations may include numerous contour profiles. Composition variations of struts 300 include variations in the thermoplastic composition of the thermoplastic fiber composite material as well as the fiber composition. Other strut embodiments of include struts 303, which include lateral tab elements 304. A distal base inventory 132 may include bases 200 of different dimensions and shapes, and as well as the number of struts that can connect to the base. FIGS. 15A-15E provide examples of bases that are alike in shape, but vary in size. FIGS. 15A and 15B shows bases 201, which vary from bases 200 in the angular distribution of strut connecting sites or radial slots 212 around the periphery of the base. A pressure distributing element inventory 133 may include one or more basic types of pressure distributing elements such as brims 420, strut caps 430, or a flexible inner liners 410. All of these pressure distributing elements can have variation in size and/or shape, and yet still have connection or attachment elements that allow them to assemble with other modular components. A tensioning member inventory 134 may include tensioners, such as strap or cord 510 or laceable corsets 520. Each of these types of tensioning members can vary in size and/or shape, and yet be able to be applied to an assembled prosthetic socket 100. A strut connector inventory 135 may include strut connectors 220, or variations thereof, such as strut connectors 220A, 220B and 220C, as seen in FIGS. 16A-16H. Strut connectors 220A and 220E differ in shape by virtue of the addition of buttress-like portions 223 of strut connector 22B. Each of these strut connector embodiments may vary in shape by virtue of variation in takeoff angle 226, which can be a right angle 226R (FIG. 16E) or an obtuse angle 226-O (FIG. 16F), which can range between about 90 up to about 150 or more.

[0272] FIGS. 3 and 4 each show a patient wearing an embodiment of a modular prosthetic socket assembly on a residual limb 700, as described herein. FIG. 3 depicts a patient with an above-knee (transfemoral) amputation wearing an embodiment of a modular prosthetic socket suitable for this level of leg amputation. FIG. 4 shows a patient with an at-the-knee (knee-disarticulation) amputation wearing an embodiment of a modular prosthetic socket suitable for this level of leg amputation. The modular prosthetic socket assemblies in the FIGS. 3 and 4 are similar for both levels of amputation, differing substantially only in the length of the struts 300 and in the number of tensioning mechanisms 510. These particular embodiments of a modular prosthetic socket include a brim element 400 rendered transparently and with a dotted outline, which is one of several pressure-distributing elements described herein. Pressure distributing elements are typically attached to one or more struts, but may include attachments to a distal base 200 as well. The modular prosthetic assembly for the patient with the transfemoral amputation (FIG. 3) has relatively short struts, and is making use of a single tensioning mechanism. The modular prosthetic assembly for the patient with an at-the-knee amputation (FIG. 3) has long struts, and is making use of two tensioning mechanisms. FIGS. 3 and 4 both also show prosthetic elements distal to the socket, including one or more prosthetic joints, a lower prosthetic limb, and a prosthetic foot.

[0273] In some embodiments, the modular prosthetic sockets of FIG. 3 and FIG. 4 could have been drawn from the same inventory. Such an inventory would include struts 300 of different length, or struts that could be cut to different lengths, and a selection of tensioning mechanisms. With reference to methods of practicing the disclosed technology, such methods include assembling a selected set of longitudinal struts together with a selected base, wherein such components are drawn from a group or inventory of components that vary in size and/or shape. By such a method, prosthetic sockets may be assembled that fit patients as varied as those depicted in FIGS. 3 and 4.

[0274] FIGS. 5A and 5b show views of an embodiment of a thermoplastic-fiber composite strut 300 attached to a strut connector 220. FIG. 5A is a side view; FIG. 5B is a perspective view. Strut 300 has a proximal portion 314 and a distal portion 317. When incorporated into a fully assembled socket, the proximal and distal portions of the strut 300 are associated with the proximal portion 104 and the distal portion 105 of the socket as a whole, as seen in FIG. 1. With continued reference to FIG. 1, it can be seen that a strut connector 220 connects to distal base 200, and that the distal portion of a strut may be associated with a pressure-distributing element such as a strut cap 430. Generally, struts 300 are typically long and rectangular, having a length, a width, and a thickness, all of which may vary, and examples of which may be included in an inventory of struts. Inasmuch as struts 300 may also have sites of curvature, it can be useful to identify a total length 321 and a projected length 322.

[0275] FIGS. 6A-6E show views of a series of thermoplastic-fiber composite struts 300 that are modular in character. Such a modular series may be found in an inventory or group of struts that vary in size and/or shape but nevertheless have attachment features 319 in common that are used for their assembly into a complete modular prosthetic socket 100, as seen in FIG. 1. The attachment sites 319 are mateable with attachment sites 319 that all strut connectors 220 have. (Strut connectors 220 are described in further detail below, particularly in the context of FIGS. 16A-16I.)

[0276] Struts can be dimensionally characterized by length, width, and thickness. Struts 300 of FIGS. 6A-6C have identical width and thickness, but vary in length. Strut 300 of FIG. 6A is relatively short, that of FIG. 6B is of medium length, and that of FIG. 6C is relatively long. Strut 300 of FIG. 6D has a length identical to that of FIG. 6C, but is wider. Strut 300 of FIG. 6E differs from the other struts depicted by having greater thickness. In spite of these dimensional variations, all struts 300 of FIGS. 6A-6E have identical attachment sites 319, by which the struts attach to a strut connector.

[0277] As alternative embodiments, struts 300 may include cut out portions or fork-like longitudinal cleavages (not shown). In still other embodiments, struts may include tabs that extend laterally (see FIGS. 21A-21G). Struts may further include embodiments wherein elements that can be separate modular components are integrated directly into a strut, such as pressure distributing elements, or a strut connector 220.

[0278] FIGS. 7A-7D show a thermoplastic-fiber composite strut embodiment 300 and cross sectional views of a various optional cross sectional profiles. FIG. 7A shows a perspective view of a strut 300; FIGS. 7B-7D show example profiles such as inward-facing concave surface (FIG. 7B), a flat or rectangular cross section (FIG. 7C), and an oval cross section (FIG. 7D). These are non-limiting examples of many suitable cross sectional profiles. Modular components can vary in shape in addition to varying in dimension, while still maintaining common attachment features that allow them to be assembled with other components. The examples of variation in shape provided in FIGS. 7A-7D relate to variation in cross sectional profile that may occur in embodiments of struts 300. FIG. 7A provides a perspective view of a strut 300 that is similar to that seen in FIG. 5B. In typical strut embodiments 300, the distal end 318 of a strut has a substantially flat or rectangular cross-sectional profile, as seen in FIG. 7C. The corners of the cross-sectional profile can be beveled or rounded to varying degree. A flat profile in the distal region of a strut is generally advantageous as in that it is compatible with the flat surface of a strut connector 220 to which it is attached. Accordingly, if a strut embodiment has a cross sectional profile that is different (such as those seen in FIG. 7B or 7D) from such a flat profile, the profile needs to change in a lofting point or region 325 to an oval cross sectional profile, shown here in a distal portion of strut 300. Strut embodiments may have more than one loft region, where cross-sectional profile changes, and a loft region may occur at any point along the length of a strut.

[0279] These various cross-sectional profiles are merely examples of numerous variations in a strut cross-sectional profile. FIG. 7B, for example, presents a concave inward-facing surface, but in a variation it could present a convex inward-facing surface. These various cross sectional profiles are typically provided to a strut during a forming process, whereby a forming mold has a cavity that imparts the cross-sectional profile. In other method embodiments, an alteration in an original cross-sectional profile, such as a rectangular profile, could be altered during a thermal reforming process, as described elsewhere herein.

[0280] FIGS. 8A and 8B are flow diagrams illustrating a method for forming 800A (FIG. 8A) and reforming 800B (FIG. 8B) a thermoplastic-fiber composite strut 300. As described in detail above, thermoplastics, when subjected to sufficient heat and with optional application of sufficient pressure, become fluidized or malleable or pliable to the extent that separate thermoplastic layers can anneal, bond, or comingle, and the overall form of bulk materials can take on a form complementary to a cavity of mold in which in which the bulk or starting materials are placed. A particular feature of thermoplastics, in contrast to thermoset plastics, is that the heat and pressure driven process can be repeated indefinitely without damaging or stressing an article. In this disclosure, a thermal forming process or method refers to an initial process, whereby bulk material or materials are first thermally rendered into an integrated article. Any secondary thermal forming process is referred to as a reforming process. In general, the conditions of heat and pressure that are suitable for an initial forming process are suitable for a reforming process. In some instances, a lower temperature or a lesser amount of heat input per unit material may be suitable in a reforming process as compared to an initial forming process.

[0281] In one embodiment, a method for forming a thermoplastic-fiber composite strut 800A may begin by placing one or more appropriately sized pieces of a thermoplastic-fiber composite material in a mold having a cavity complementary to the size and shape of a strut 801. The method continues by applying an amount of heat and pressure to the mold sufficient to render the thermoplastic-fiber composite material into a fluid or pliable state that the material assumes a form according to the cavity of the mold, such heat and pressure being maintained for a sufficient duration 802. The method typically concludes by cooling the mold (either by passive or active cooling) 803, and releasing the formed strut from the mold. In some instances, the formed strut may need to be cut or trimmed 804.

[0282] Referring now to FIG. 8B, in some embodiments, a formed strut 300 may be subjected to a thermal reforming process 800B (or secondary forming process). In alternative embodiments, reforming may occur immediately or soon after a forming process, thus being essentially an extension of the forming process itself, or it may occur at any subsequent time as a completely separate process. In one embodiment, a reforming method may begin by applying heat to the formed strut to render the thermoplastic-fiber material of the strut into a pliable state 805. In some instances, pressure may be advantageously applied as well, to accelerate or help evenly distribute heating. The method continues by applying sufficient and appropriately directed force to bend the thermoplastic-fiber composite material toward a desired reformed shape 806. This application of force may include bending the strut against a molding surface, or against a residual limb, as in a direct molding process. A final step includes cooling the now reformed thermoplastic-fiber composite strut 807. Cooling may be passive or active. In the event that a first attempt to move the shape of a formed strut to a desired shape is not satisfactory, the method may be repeated.

[0283] As described in the summary section, an initial forming process may be commonly referred to as molding, inasmuch forming typically occurs within or against a molding surface. If a mold has a fully contained cavity, physical pressure can be applied to the mold. In other examples, a mold need not be fully enclosed, in which case a vacuum may be applied to draw moldable materials against a mold surface. In some particular method embodiments that are applicable to making thermoplastic-fiber composite struts, as described herein, fully enclosed molds are used, and both heat and pressure are applied to the mold.

[0284] A mold may be used in a reforming process, but more typically, a heated strut may be manually bent against a molding surface or object. In some embodiments, a molding surface may be any suitable inanimate surface. Remolding is typically done in order to individualize a strut, accordingly there is typical no mold, and the bending is an ad hoc event, fully in the hands of the individual prosthetist, working with an individual patient. In some embodiments, accordingly, a portion of a residual limb of a patient may serve as a mold. In the prosthetic arts, this is referred to as direct molding and is described further below in the context of FIG. 12.

[0285] Thermal forming 800 and reforming 810 of the thermoplastic-fiber composite material of struts 300 is a process largely dependent on the physicochemical attributes of the thermoplastic portion of the composite material. However, the embedded fiber portion of the composite material is also a factor in the methods; to some extent the fiber plays a constraining role. In many embodiments the fiber included in the thermoplastic-fiber composite materials of the struts is in a continuous or substantially continuous form. Fibers, such as carbon or glass fibers, are substantially non-stretchable and non-compressible; accordingly, the freedom of reformability of an article containing them is constrained. Such constraints would manifest, for example, if a reforming of broad surfaces of thermoplastic-fiber composite material to create complex contours were to be attempted. Whereas the thermoplastic portion of a composite material is highly amenable to reshaping that involves sites of stretch or compression, the continuous fiber resists such reshaping if it creates sites of stretching or compression.

[0286] FIGS. 9A-11B show aspects of forming and reforming thermoplastic-fiber composite struts 300, as outlined in FIGS. 8A and 8B. FIGS. 9A and 9B illustrate a section of a thermoplastic-fiber composite material of a strut; FIG. 9A shows a 3-layered strut section 600, and FIG. 9B shows the layers separate, as they would have been prior to molding them together. The example depicted shows a material with three thermoplastic fiber composite layers (601, 602, 603) each layer having embedded continuous fiber. In each of these layers, the population of fibers embedded therein is wholly parallel. In other embodiments, fiber may be arranged in alternative patterns. In this particular embodiment, layers (601, 602, 603) are arranged such that they alternate with regard to the orientation of their embedded fibers, the fiber of each layer being orthogonal to the fiber of their neighboring layer. These figures generally draw attention to the presence of fiber within the thermoplastic matrix of materials included within the struts. In some embodiments, the struts may be substantially formed, in their entirety, from thermoplastic fiber composite material. In general, the processes associated with forming and molding thermoplastic-fiber articles are well known in the art. Aspects of the technology described herein that manifests as prosthetic socket structural component draws freely from any thermoplastic-fiber molding process that is known. Simple examples are provided in order to convey basic aspects of the technology, albeit directed specifically toward making thermoplastic-fiber (continuous fiber) composite components for a modular prosthetic socket.

[0287] FIGS. 10A-10D show a schematic views of aspects of forming and reforming thermoplastic fiber composite portions of struts. In FIG. 10A, several layers of a bulk form thermoplastic material 612 are shown disposed within walls of a mold 611. With application of heat H and pressure or force F, the original separate layers are integrated into a single article, such as a strut portion 613 for a modular prosthetic socket system, as in FIG. 10B.

[0288] In a reforming process, strut portion 613 is being subjected to heat H and force F. The heat is conveyed by a temperature that is sufficiently high, and of sufficient duration that the strut becomes pliable or malleable. In that state, amenable to reforming, a force of sufficient strength, and appropriately directed, is applied to the strut such that the shape moves toward a desired form 614, such as that depicted in FIG. 10D.

[0289] FIGS. 11A and 11B illustrate another embodiment of a method of forming a multilayered thermoplastic-fiber composite strut 300. FIG. 11A shows a section of a multilayered strut and FIG. 11B shows the strut as a circumferentially wrapped layer of thermoplastic-fiber composite tape is being applied to the strut. Some embodiments of thermoplastic fiber composite struts include layers of raw bulk material. These may be sections of bulk tape, or cut sections of larger sheets. Such laminated structures are known to have a vulnerability to delamination when stressed. Such a multi-layered thermoplastic fiber composite strut portion 620 is shown in FIG. 11A. One approach to stabilizing the integrity of annealed layers under stress includes wrapping the multilayered structure circumferentially with a bulk form thermoplastic-fiber composite tape 621. Wrapping could be included in an initial forming process. Alternatively, a strut 620 could be formed, subsequently wrapped circumferentially with one or more layers of bulk material tape, and then subjected to sufficient heat that the strut emerges, reformed, as an integrated thermoplastic fiber composite strut portion 622, as in FIG. 11B.

[0290] FIG. 12 shows an aspect of reforming a thermoplastic-fiber composite strut known as direct molding. In this embodiment, strut 300 has been heated sufficiently to make it pliable, and then is placed against the body (with an intervening thermal protective layer) and pressed against a portion of the residual limb of a patient to impart a body-conforming shape to the strut. Heating may be accomplished by any of several approaches. For example, a strut may be heated externally by a heater, such as a hairdryer, or a strut can be heated in an oven. In a particular embodiment, heating may occur through the use of a built-in resistive heating system, as described further below in the context of FIGS. 13A and 13B.

[0291] Strut 300 is shown as still being included within an assembled, or partially assembled, modular prosthetic socket 100. In alternative instances, strut 300 may be removed from socket 100 prior to this direct molding method. In other embodiments, it may be advantageous to reform the strut 300 when it is included within an assembled or partially assembled modular prosthetic socket 100.

[0292] It is often a part of the method to protect the residual limb with an intervening thermally protective layer. Another aspect of the method may involve selecting a position for the strut 300 in a desirable location on the residual limb for the reforming process. Toward this end, the method may further include a step of marking the residual limb or an overlying liner with an outline of where the strut contacts the body, and then making use of that marking when placing the strut against the residual limb.

[0293] Still another aspect of the method may include focusing the heating step on a particular area within the strut 300, in contrast to a method where the strut is heated with substantially equivalent heat throughout the structure of the strut. Focusing the heat on a particular region of the strut can be a helpful aspect of the method, wherein the prosthetist is intending to reform the strut.

[0294] FIGS. 13A and 13B show embodiments of a thermoplastic-fiber composite strut 300 with a resistive heating element 333, 334 embedded therein, thus allowing the strut 300 to be self-heating for thermal reforming. FIG. 13A shows a strut with a serpentine heating element 333; FIG. 13B shows a strut with a mesh heating element 334. Each strut 300 may further include a connection to a power supply 335. A typical use of a built-in resistive heating element 333, 334 is to warm the strut 300 to pliability prior to a reforming process, such process undertaken to effect a change in the shape of the strut. In some particular embodiments, the resistive heating elements 333, 334 are arranged such that heat can be directed to particular regions of the strut, while other portions remain unheated. Some embodiments of a modular prosthetic socket may include sensors and microprocessors in communication with strut elements, such sensors and microprocessors able to facilitate or automate aspects of controlling a thermal reforming process.

[0295] FIGS. 14A-14C show an embodiment of a thermoplastic-fiber composite strut 300 in an initial state, as it was originally formed, and two examples of the strut after being thermally reformed to better fit against a portion of the residual limb. FIG. 14A shows a strut 300 in its originally formed shape. The shape as shown here is substantially flat and advantageous for requiring a simple mold, and a good neutral starting shape that can be later reformed toward a desired shape for better fitting of a residual limb. FIG. 14B shows a strut 300 after it has been reformed to include a curve 320. Curves 320 may be imparted at any point along the length a strut, and more than one curve 320 may be included. Multiple curves 320 can be imparted in a reforming process at the same time, or they can be added serially. FIG. 14C shows a strut 300 after it has been reformed to include a twist 327 of several degrees. Twists 327, as imparted by a reforming process, may be advantageous for the fitting of modular prosthetic sockets to particular residual limbs.

[0296] Reforming of modular prosthetic components such as struts 300 may be performed to improve fitting of a prosthetic socket to a residual limb, in any aspect of fitting as described herein. Fitting may include biomechanical considerations that are not apparent in an approach that adheres strictly to fitting in a conformal sense. Another example where reforming to alter strut shape may be advantageous involves providing relief at a site of irritation or injury on a residual limb. In some instances, the struts and the socket may fit well overall, but one strut nevertheless creates irritation or is coincidentally positioned near such a site. In this case, a small reformation, moving a section of a strut a few millimeters outward for example, may be very helpful clinically. Another example of providing relief for a site of irritation is depicted in FIGS. 27A and 27B, which includes a mechanical adjustment of a modular prosthetic socket. Methods of forming and reforming are described elsewhere in detail, and depicted schematically in FIGS. 8A-12.

[0297] FIGS. 15A-15G show views of embodiments of a distal base 200 and 201 for a modular prosthetic socket 100, each having four strut connecting sites (or strut connector connecting sites), as represented by radial slots 212. Four is a typical number of strut connecting sites on a distal base. In other embodiments, not shown, distal bases may include either fewer or more than four strut connecting sites. FIGS. 15A and 15B show a distal base embodiment 201 wherein strut connecting sites are distributed in an arrangement with intervening angles of about 120, 90, 60, and 90. FIGS. 15C-15F show distal base embodiments 200 wherein the strut connecting sites are equally distributed at about 90. Distal base embodiments may include strut connecting sites circumferentially distributed in any clinically suitable arrangement; the examples provided here by distal bases 200 and 201 are merely non-limiting examples. The 120 angular spacing between neighboring struts (distal base embodiment 201) is an example of a relatively wide spacing between struts that may be positioned within a complete socket such that when being worn by a patient, the wide spacing occurs on a medial aspect of the residual leg, this being advantageous for minimizing interference with the opposite intact leg. Fastening elements 219 are shown; these are typically threaded bolts so as to facilitate both assembly and disassembly.

[0298] FIGS. 15C-15E show distal bases 200 that are identical in shape, but vary in size (the base in FIG. 15C is large, that in FIG. 15D is medium, and that in FIG. 15E is small). Any distal base, including embodiments 200 and 201 may include more than one component plate, the plates typically cooperating structurally and functionally.

[0299] Such variations in size and shape may be included in an inventory of distal base components, as are included in systems and kits of modular prosthetic sockets. Inventories of components from basic components groups (such as struts and distal bases, as well as other components) are included in embodiments of the technology such as modular prosthetic socket systems and kits. These inventories provide a supply of modular components that vary in size and/or shape, but nevertheless maintain commonality at attachment sites for connecting to other components. Modular component inventories are described elsewhere herein; briefly, they are simply an available selection of groups of components. An inventory of distal bases would have a supply of distal bases of different sizes and shapes that could be drawn from in order to assembly a complete modular prosthetic socket 100. FIG. 15G shows an embodiment of a distal base for a modular prosthetic socket having a proximal plate 215 arranged over a base plate 200 that includes strut connecting slots 212.

[0300] Proximal plate 215 has four surface features 217 within the distal base near each of the slots for limiting pivoting movement of the strut connectors in the slots. In the example shown in FIG. 15G and elsewhere, such surface features include one or more indented portions 217 in upper or proximal plate 215. Other arrangements on distal base 200, such as surface features on the base 200 that similarly provide the same type of containment of swivel or pivot are included within the scope of the technology. These indented portions 217 that expose the portions of the lower base plate that include radial slots 212. The exposed area defined by indented portions 217 and the radial slots 212 cooperate to form a strut-connector connecting or attachment site. Radial slots 212 host strut connectors in such a manner that the connectors can radially slide in and out, and pivot or swivel at any point along the line. Sliding and pivoting are allowed when bolts 219 are loose; sliding and pivoting are disallowed when bolts are tight, thereby creating a friction lock between the base of a strut connector and an upper surface of the base plate to which the strut connector is connected. The indented portions 217 of the proximal plate 215 provide a boundary of the arc in which strut connectors can pivot or swivel. Indented portions 217 may be considered an example of any feature on a distal plate that limits the pivot or swivel of a strut connector 220. Strut connectors are described in detail below.

[0301] FIGS. 16A-16I show views of various embodiments of strut connectors 220A, 220B, 220C for a modular prosthetic socket. Strut connectors will be generically referred to as strut connector 220, embracing all of the variations, such as 220A (FIGS. 16A-16C), 220B (FIGS. 16D-16E), and 220C (FIGS. 16G-16H). All strut connectors 220 have a base portion 222 and a back or takeoff portion 224. Strut connectors 220 connect struts to a distal base 200 (FIGS. 15A-15G), having an attachment hole 231 for the distal base on base portion 222 and attachment holes 232 for a strut on the back portion 224.

[0302] Strut connectors 220 are also modular, in that they can have different shapes, but maintain common connecting features for the struts and the distal base. An inventory of components from which to assemble a modular prosthetic socket may include strut connectors of varying shape, such variable aspects manifesting in the assembled socket primarily in the shape of the proximal portion of the socket. Any of the dimensions of a strut connector can vary, including the width, the length of the base portion 222, and the length or height of the back portion 224. As discussed below, the angle 226 (226-R, 226-O) disposed between the base and back portions (the takeoff angle) may also vary.

[0303] In various embodiments of a modular prosthetic socket assembly, strut connectors 220 are a significant determinant of the shape of the socket 100, particularly in its distal portion 105 (see FIG. 1), proximate the distal base. In addition to effecting shape or distal cross-sectional profile of an assembled socket, the strut connectors 220 provide a significant level of adjustability in the overall cross-sectional profile and volume of the socket. Aspects of these functionalities are described further below, and shown in FIGS. 17A-18B, and FIGS. 26A-26B.

[0304] FIGS. 16A-16C show a strut connector embodiment 220A having a single attachment hole 228 at the vertex of a triangular base. FIGS. 16A and 16B show an embodiment wherein a connector backside 224 is at right angle to a horizontal base 222. The angle between the base portion 222 and the back side 224 of a strut connector 220 is referred to as a takeoff angle 226). Takeoff angle, in addition to referencing the base portion of the socket, also relates directly to the angle of a distal portion 317 of the strut 300 with respect to the central longitudinal axis 101 of a modular prosthetic socket as a whole (FIG. 1). The smallest takeoff angle 226 is approximately 90 with respect to the base portion of a socket connector and the distal base as a whole; this minimal angle configures a strut connected to the connector such that it is parallel to the central longitudinal axis 101 of socket 100. Takeoff angles 226 may also be obtuse, for example, the takeoff angle 226-O shown in FIGS. 16C and 16F are approximately 110 with respect to the base portion of a socket connector. Accordingly, takeoff angles 226 may vary from about 90 to about 160. Such a variations in takeoff angle represents a modular aspect of strut connectors, as discussed above, and would manifest in strut connector inventories.

[0305] FIG. 16C shows an embodiment wherein the backside 224 resides at an obtuse takeoff angle 226-O with respect to the horizontal base. FIGS. 16E-16F show an embodiment similar to those of FIG. 16A-C, this particular embodiment further having buttress supports 223 extending from the lateral edges of the backside 224 to the horizontal base 222. FIGS. 16D and 16E show an embodiment wherein a strut connector backside 224 is at right angle 226-R to a horizontal base. FIG. 16F shows an embodiment wherein connector backside 224 resides at an obtuse angle 226-O with respect to the horizontal base. FIGS. 16G-16H show an alternative embodiment of a strut connector, this embodiment having two attachment sites 235 (twin slots within a distal base) and a rotatable disc 236 that inserts into circular receptacle 237. Fasteners 239 connect to twin tracks in the base (not shown).

[0306] The takeoff angle 226 of strut connectors 220, i.e., the angle of back portion 224 with respect to base portion 222, may be formed in alternative ways. In some embodiments, for example, a strut connector may have a 90 takeoff angle but further include an insertable triangular wedge (not shown) that fits into the front facing aspect of the strut connector, and which has a sloping face. In this manner, a variable takeoff angle for the strut connector, as a whole, is provided by wedges having a front facing slope of varying angle. This arrangement essentially transforms the profile of an embodiment such as seen in FIG. 16B into a profile such as that seen in FIG. 16C. In this type of modular prosthetic socket system embodiment, accordingly, an inventory of modular components may include wedges that have varying front facing slopes but all nevertheless fit into a front facing aspect of a common strut connector.

[0307] FIGS. 17A-17E show top views of an embodiment of a distal base 200 for a modular prosthetic socket with the strut connectors 220 positioned on the distal base into configurations that vary according to the radial position (ranging between close to the center of the base and close to the periphery of the base) of the strut connectors and their degree of pivoting at their attachment site. The attachment site of the strut connectors on the base is largely obscured by the strut connectors 220, themselves, in these views, but includes radial slots 212, some of which are partially visible in FIGS. 17B-17E. Struts 300 are connected to the strut connectors, but only visible in a narrow cross sectional profile as they are projecting forward from the base that is seen in a top facing view.

[0308] The embodiment of a distal base seen in FIGS. 17A-17E accommodates four strut connectors 220, circumferentially spaced apart at 90 intervals. FIG. 17A shows four strut connectors 220, each of the four positioned at a minimal radial position on base 200 within radial slots (not visible). FIG. 17B shows four strut connectors 220, each of the four positioned at a maximal radial position; with the strut connectors moved to their maximal radial position, the inner portion of radial slots 212 become visible. FIG. 17C shows four strut connectors 220, with one of the four (shown on the right) positioned at a maximal radial position (and a portion of radial slot 212 thus visible), the other three strut connectors being at a minimal radial position. FIG. 17D shows four strut connectors 220 arranged as in FIG. 17C, but with the strut connector on the right pivoted clockwise at an angle A of about 20. FIG. 17E shows four strut connectors arranged as in FIG. 17C, except that strut connector 220 on the left, still in its minimal radial position, is pivoted counterclockwise at an angle A of about 20.

[0309] FIG. 17F shows detail of how a friction locking mechanism controls movement of the strut connectors 220 with respect to the distal base. FIG. 17F is a cross sectional side view of a distal base 200 for a modular prosthetic socket with a strut connector 220 positioned thereon, within a radial slot 212. Strut 300 is attached to strut connector 220. A fastener or fastening element 219 such as a threaded bolt extends through aligned holes in the distal base and the strut connector. This arrangement represents a friction locking mechanism. When bolt 219 is tightened against nut 279, drawing the base of the strut connector against the upper surface of the distal base, the strut connector cannot slide or rotate. When the bolt is loosened, typically by a prosthetist or shop technician, the strut connector is free to slide and rotate within the slot.

[0310] FIGS. 18A and 18B show, respectively, top and side views of an embodiment of a strut connector 220 that includes an intermediate linking pivotable element 241 disposed between base 200 and the main connector body 220. Intermediate connector element 241 attaches to base 200 by way of threaded bolt (not shown) through a first hole 231a. As seen in cross sectional side view (FIG. 18B), intermediate connector element 241 has a lateral slot that accommodates an internally projecting piece of strut connector 220. A second hole 231b through both the intermediate connector element and the internally projecting piece of connector 220 can host a bolt connecting the two pieces together. When the bolt is loose, strut connector 220 can pivot with respect to the intermediate connector element 241. FIG. 18A shows the function of this second pivoting mechanism. A cross sectional profile of a distal aspect of residual limb 700 is shown. Were it not for the second pivoting mechanism, as a consequence of the pivoting around connecting hole 213a, the internal face of strut 300 would not remain tangent to the surface of the residual limb 700. By virtue of the pivotability around hole 231B, the internal face of strut 300 can be maintained or restored such that it aligns tangentially with the surface of residual limb 700.

[0311] It may be appreciated that the arrangement of strut connectors 220 with respect to distal base 200 provides at least two levels of structural adjustment that project proximally by way of struts 300, and which have implications for the size and shape of the internal proximally open space defined collectively by the struts, distal base, and any pressure distributing elements that may be present. Further, the pivotability of the strut connectors 220 within radial slots 212 of the distal base 200 provide an adjustability with regard to the circumferential distribution of struts around the distal base, or around the central longitudinal axis 101 of a socket 100 as a whole. These aspects of the technology are described further below, in the context of FIGS. 26A-27B.

[0312] FIGS. 19A and 19B show an embodiment of a strut 300 and an alternative embodiment 305 for inclusion in a modular prosthetic socket as described herein, each embodiment attached to a distal base 200. FIG. 19A shows a top perspective view of an embodiment of a distal base 200 similar to that of FIG. 14G with a with a single strut 300 attached thereto by way of a strut connector 220; this view shows how a base plate 210 and a top plate 215 of base 200 can cooperate to provide a strut connecting site that further stabilizes the strut, and provides a boundary to the pivoting latitude. FIG. 19B shows an embodiment of a strut 305 with an integrated connector portion on its distal end.

[0313] FIGS. 20A-20D show side views of thermoplastic-fiber composite struts 300 that have a varying side profile, ranging from substantially straight to having two or more sites of curvature. Each strut has a proximal end 315 and a distal end 318. The strut 300 of FIG. 20A is straight, having no significant curvature. The strut 300 of FIG. 20B has a two sites of curvature 326 in its distal portion. The strut 300 of FIG. 20C also has a two sites of curvature 326 in its distal portion, but the sites of curvature are spaced more closely together than those seen in FIG. 20B. The strut 300 of FIG. 20D has three sites of curvature 326 distributed through its length.

[0314] These various configurational variations of thermoplastic-fiber composite struts 300 (FIGS. 20A-20D) may be the result of at least two method processes. In one example, these variations could represent initial forms of struts, directly from a mold, each being the product of a thermal forming process. In such an instance, struts as seen in FIGS. 20A-20D could all be stocked in an inventory or collection of modular strut forms. In another example, the straight strut (FIG. 20A) could be strut delivered directly from a mold, a product of a thermal forming process, and each of the struts in FIGS. 20B-20D could be the products of a secondary thermal process, a reforming of a stock item in an inventory such as the strut seen in FIG. 20A.

[0315] Further with regard to curvature in struts 300, as noted, struts emerging from a mold could be considered modular variants that could be included in a collection, a grouping, or an inventory. Sites of curvature can be characterized in several ways. For example, curves may be concave or convex with regard to their internal aspect, facing internally toward the central longitudinal axis of the strut. The directionality or bias of curves may commonly alternate along a length of a strut, for example, a convex curve following a concave curve, to form an S-shaped curve. An example of such S-shaped curvature is seen in FIG. 24. Curves may further be characterized with regard to their relative acuity or obtuseness, the degree of angulation per unit length. Other examples of curved struts are provided in FIGS. 15B, 14C, 21G, 22A and 22B.

[0316] FIGS. 21A-21G show face views of thermoplastic-fiber composite struts 303 that differ from strut 300 by having a proximal end 315 and a distal end 318, and further having one or more tab-like features 304 extending laterally. Tabs 304 may be disposed either in the proximal portion of the strut and/or in the distal portion. They may serve one or more purposes. In one example, the tabs are, themselves, pressure-distributing elements, engaging in distributing pressure laterally away from the main linear body of a strut. In a second example, tabs 304 may serve as anchoring sites either for tensioning features, or larger pressure distribution elements. In a third example, strut tabs may serve as pressure deflecting elements that specifically distribute pressure away from a tensioning element that otherwise would press too hard against a site on the residual limb.

[0317] FIG. 21A shows a baseline example of a strut 300 unadorned with any tabs. FIG. 21B shows a baseline example of a strut 303, with rounded tabs 304 on either side of a proximal portion of a strut, disposed at a point distal to the proximal end of the strut. FIG. 21C shows a baseline example of a strut 303, with rounded tabs 304 positioned both at the proximal end of the strut, and in the distal portion, but short of the distal end. FIG. 21D shows a baseline example of a strut 303, with rectangular tabs 304 disposed asymmetrically on either side a strut, and in both the proximal and distal portions of the strut. FIG. 21E shows a baseline example of a strut 303, with modified rectangular tabs 304 disposed on either side of a strut, the modification of the rectangle including a rectangular corner assuming an arc of repose profile. FIG. 21F shows a baseline example of a strut 303, with tabs 304 arranged in a manner similar to that seen in FIG. 21F, with all centrally facing rectangular corners modified into an arc of repose profile.

[0318] There are several embodiments of methods of fabricating struts 303 that include tabs 304. In some embodiments, the tabs are derived from the same or closely related thermoplastic-fiber composite material with which the main body of the strut is made. In some embodiments, the tab forms are included in a mold in which struts are initially formed. In some embodiments, the tabs are added to the main body of the strut after the strut has been made. Some of these methods include a thermal joining of the tab forms and a strut body such that the strut and associated tabs become an integrated article. In some embodiments of a prosthetic socket 100, tabs 304 of neighboring struts may be joined by a tensioning element.

[0319] FIGS. 22A-22K show numerous of various arrangements of thermoplastic struts 300 with strut caps 430 or brim elements 420 attached thereto, and typically configured such that the strut cap or brim element supports a circumferentially arranged tensionable element or member 510. Tensioning elements may take any suitable form, such as a strap, or a cord, or lacing, and may be elastic or substantially non-elastic. Tensioning elements typically are arranged circumferentially around the socket, or they are more generally included in a system that ultimately applies inwardly directed force on the struts from a circumferential vantage. From such vantage, the struts are forced centrally, toward each other, generally narrowing a nominal circle that represents the cross sectional profile of the space included within the struts, collectively. A given tensioning element may be supported by any one or more of the multiple longitudinal struts of a given modular prosthetic socket embodiment. Tensioning element embodiments are described further below in the context of FIGS. 23A-23C.

[0320] Embodiments of strut caps, brim elements, and a flexible inner liner are may all be understood as pressure distributing elements. Each element is configured to distribute pressure impinging on a residual limb away from sites where struts would otherwise focus concentrated pressure on the surface of a residual limb. Strut caps and brim elements differ primarily in their width, strut caps being generally narrow, brim elements being more expansive and more highly contoured. Strut caps and brim elements are typically fixed to one or more struts, and are positioned at or near the proximal ends of struts. A flexible inner liner 410 (as in FIGS. 25A and 25B) is even more expansive, fully embracing the residual limb. All pressure-distributing elements have an internal aspect that faces toward the residual limb, and an external aspect facing outward.

[0321] FIGS. 22A and 22B show a strut 300 and strut cap 430, the strut cap configured slip over a proximal end of the strut, and then being secured thereto. A belt-loop element 435, typically on an exterior aspect of the strut cap, is configured to accommodate a tensioning element or member (not shown). FIGS. 22C and 22D show an alternative configuration of a strut cap 430, in which the strut cap has a wider lateral aspect, similar in shape and pressure distributing ability to the strut tabs 304, as shown in FIGS. 21A-21G. Strut cap 430 in FIG. 22C has tensioning element holder or guide 435, through which a tensioning element may be threaded. Strut cap 430 in FIG. 22D has tensioning element holder or guide 435, that can be slipped over a circumferential tensioning element.

[0322] FIG. 22C shows an external aspect of a strut cap 430 with a tensioning element guide 435 that is configured to support a tension element such as a strap or a cord by having the element threaded therethrough like a belt through a belt loop. FIG. 22D shows an external aspect of a strut cap that is configured to support a tensionable element with a tensioning element holder 435 configured as clasping mechanism.

[0323] FIG. 22E shows a strut cap 430 with a hook and loop attachment arrangement that stabilizes a tensionable element across an external aspect of a strut cap. In this embodiment, a first mateable portion 437 of a hook and loop attachment on the strut cap 430 is configured to match up against a second mateable portion of a hook and loop attachment on tensioning guide 435. This arrangement permits a stable coupling a strut cap and a tensioning element that can be easily repositioned.

[0324] FIG. 22F shows an arrangement in which a tensionable element 510 in the form of a wide strap is threaded through a tension-lockable belt looping mechanism 439 positioned bilaterally on either side of a tensioning element guide 435 that can slip over the end of a strut 300.

[0325] FIG. 22G shows a pressure-distributing element in the form of a brim element 420 that has two tensioning element guides 435 positioned on its external surface. This brim embodiment 420, with raised upper lateral surfaces, is fitted over the end of strut 300. FIG. 22H shows a strut with a belt-loop mechanism 435 integrated into an external aspect of the strut.

[0326] FIGS. 22I and 22J each show brim elements 420 arranged at the proximal ends of struts 300. The embodiment of FIG. 22I shows an arrangement in which the proximal end of a strut is inserted into a pocket on the back aspect of a brim element 420. FIG. 22J shows an arrangement in which strut 300 and brim element 420 are seamlessly integrated. The brim elements 420 of FIGS. 22I and 22J both have a high profile all the way across the top or proximal edge of the brim; this configuration contrasts with the scooped central portion of the proximal edge of the brim 420 shown in FIG. 22G.

[0327] FIG. 22K shows a fabric sleeve 360 fitted over a single strut 300 with bilateral attachments 435 suitable for attaching either to a tensioning member or an adjacent strut sleeve. A fabric sleeve may be placed over a strut and any associated pressure-distributing element. Sleeves may be advantageous for their soft-good character that provides an interface friendly to the residual limb, and which further may include attachment features that can support tensioning elements and/or fixed-length connections to other struts or other pressure-distributing elements. The corset-lace arrangement of tensioning element as seen in FIG. 23C is another example of a soft-good feature.

[0328] FIGS. 23A-23C show views of modular prosthetic socket embodiments, each with a different arrangement of pressure distributing elements, including strut caps and strut brims. Each embodiment may include a roll-on gel liner 110 (as in FIG. 2) but which is omitted in these views. FIGS. 23A-23C each show a prosthetic socket 100 having struts 300, distal base 200, and an embodiment of a distal cup 290. They differ with regard to their respective arrangements of tensioning elements and pressure distribution elements. FIG. 23A shows prosthetic socket 100 fitted with strut caps 430 as a pressure distributing element, and a tensioning band 510 and an adjustment mechanism 512 arranged circumferentially around the struts 300. FIG. 23B shows prosthetic socket 100 fitted an integrated brim 420 as a pressure distributing element, and a tensioning band 510 and an adjustment mechanism 512 arranged circumferentially around the struts 300.

[0329] FIG. 23C shows prosthetic socket 100 fitted with laceable corset 520 as a combined pressure distributing element and tensioning mechanism that is arranged circumferentially around the struts 300 or more generally within or proximate the circumference nominally defined by the struts. Tension adjustment mechanism 513 is shown at the proximal end of the lacing mechanism. In related embodiments, there may be more than one tensioning mechanism, allowing tensioning to independently adjustable in different longitudinal sections of the corset. This arrangement, as noted above, has a soft-goods character that is friendly to the residual limb. A corset 520 such as this is typically fabricated from fabric or leather, and may also be considered as a type of sleeve, or include specific aspects that act as sleeves, enclosing or wrapping the strut, or wrapping one of more pressure-distributing elements associated with a strut, such as a strut cap or brim element.

[0330] In the context of discussing tensioning elements, it may be understood that the struts 300, longitudinally disposed, have a neutral radial position with respect to the central longitudinal axis of the socket 100 as a whole. Tensioning elements 510, when applying tension, pull the struts inward. Resistance to such an inward pull is provided by the integrity of the distal attachment of the struts to the distal base 200, and by the strength and resilience of the strut throughout its length. The thermoplastic-fiber composition of struts, as described herein, is a major structural factor underlying strut strength and resilience, as distributed with substantial uniformity throughout the length of the strut. The presence of a residual limb within the socket also will provide resistance to an inwardly directed tension on the struts. The socket, itself, has no integral structure that connects the struts in any portion proximal to the distal base 200 that resists circumferential compression of the struts. With regard to an outwardly directed tension or constraint on the radial position of the struts, outwardly directed tension is typically provided only by presence of the residual limb. Outwardly directed force is resisted by the same strength and resilience of the struts that resists radial compression, and by a tensioning element, if present on the modular prosthetic socket assembly.

[0331] Inwardly directed tensioning around a socket 100 tends to drive the struts 300 radially inward. Soft prosthetic socket elements such as a liner, and the contained residual limb will be compressed inward at regions of contact with the struts, but bulge or buckle outward at regions between strut contact regions. A residual limb has a cross sectional area at each point along its length. The struts in a neutral position (untensioned, and the socket not hosting a residual limb) that nominally defines a circle or near-circle with a cross sectional area. The degree of radial compression exerted by a prosthetic socket on a residual limb can be expressed by comparing the cross sectional area of the socket (struts in a neutral position) to the cross sectional area of the residual limb when it is not in the socket. Inventors have estimated that in typical embodiments of the modular prosthetic socket 100, when fitted appropriately to a residual limb, the area of a circle described by the struts in a neutral position is not less than 75% of the corresponding cross sectional area of the residual limb. Ranging upward from there, in some embodiments, the cross sectional area of the socket with the struts in a neutral position is substantially equal to the corresponding cross sectional area of the residual limb. Accordingly, in some embodiments, the prosthetic socket itself exerts some degree of compression on the residual limb, and in other embodiments, compression, in substantial entirety, may be provided only by tensioning arrangements.

[0332] FIG. 24 shows an embodiment of a modular prosthetic socket 100 that is particularly configured to accommodate a bulbous residual limb (not shown). Bulbous residual limbs are relatively common; these residual limbs have a distal portion that flares out from a narrower more proximal portion. These types of limbs are often difficult to fit with prior art prosthetic sockets. Embodiments of a modular prosthetic socket 100, as described herein, can easily accommodate such a residual limb. The strut connectors 220 all have an obtuse takeoff angle 226, shown here as being about 150. In their distal portion, struts 300 have a site of curvature 326 with a concave inward facing aspect. In their proximal portion, struts 300 have a site of curvature 326 with an outwardly flaring aspect. In donning such a socket, a patient with a bulbous limb would encounter no difficulty spreading the struts to accommodate the bulbosity, and tensioning elements (not shown) could appropriately tighten the socket along the full length of the socket.

[0333] FIGS. 25A and 25B show views of a patient wearing an embodiment of a modular prosthetic socket 100 arranged with a flexible inner liner 410 nested within the socket, and two tensioning elements 510, one proximal and one distal. FIG. 25A shows the inner liner without tension being applied and FIG. 25B shows the liner in a tensioned state. Embodiments of flexible inner liner 410 are sufficiently flexible that they bend under sites of pressure. As the patient adjusts the tensioning elements 510 by way of tensioning adjuster 512, the struts 300 are drawn closer to each other and more tightly around the residual limb. In response to inward pressure from the strut, the flexible inner liner buckles in slightly as the sites of contact with the struts, and bulges outward slightly in the inter-strut regions.

[0334] Adjusting tensioning elements around a socket 100 may also be understood as exercising a method of adjusting or improving the fit of a socket on a residual limb. Practice of this method of fitting or improving the fit of a socket is typically in the hands of the patient, unlike other mechanical adjustments that can be made on the socket, which are typically in the hands of a prosthetist or trained technician. Improving the fit by adjusting tension can be understood as creating greater comfort for the patient, but in a more critical interpretation, improving the fit can be understood as making the fit more biomechanically appropriate, and as improving the functionality of the socket.

[0335] FIGS. 26A and 26B show views of an embodiment of a modular prosthetic socket 100 in two configurations; FIG. 26A shows a socket 100 with the struts 300 and strut connectors 220 positioned on a distal base 200 within a relatively small radius, while FIG. 26B shows the same socket 100 with the struts and strut connectors 220 positioned on a distal base within a relatively large radius. Four struts 300 are shown; the two struts in the foreground are truncated to expose a view into an internal space within the socket. Prior art devices typically are of fixed non-adjustable dimensions, particularly at their distal end. These figures show how, in contrast, embodiments of a modular prosthetic socket, as described herein, are eminently adjustable at their distal end. Further, such distal-based adjustability projects forward or proximally by way of the struts, thereby supporting an adjustable quality to the shape and volume of the socket as a whole.

[0336] The configurations of distal base 200 in FIGS. 26A and 26B correspond to the configurations see in FIGS. 17A and 17B, respectively. In FIG. 26A all of strut connectors 220 are locked into their respective minimal radial position. They are as close to the center of the distal base 200 (or the socket in general) as they can be within the confines of radial slots 212. In FIG. 26B all of strut connectors 220 are locked into their respective maximal radial position. They are as far from the center of the distal base as they can be within the confines of radial slots 212.

[0337] A circle 331 is drawn at approximately a midpoint of the struts 300; this circle 331 represents a cross sectional profile of the internal volume defined collectively by the struts 300 and the distal base 200. It can be seen, according to the laws of geometry, that what may appear to be minor radial expansion of the strut connectors 220 (FIG. 26A vs. FIG. 26B) manifests as a significant expansion in cross sectional area, which would, in turn, translate into an even larger relative increase in volume.

[0338] In addition to the structural aspects of the provided technology just described, these features support particular method embodiments. For example, a method of adjusting the fit of a modular prosthetic socket 100 may include mechanically adjusting the arrangement between the struts 300 and the distal base 200 so as to improve the conformal fit of the prosthetic socket on the residual limb. This type of adjusting may typically occur over an extended period of time during which the residual limb of a patient may expand or atrophy; in such a circumstance, a prosthetist could mechanically adjust the patient's prosthetic socket so as to improve the fit. In another instance, this type of adjustment may occur during the initial assembly of a prosthetic socket, or during an initial fitting of a prosthetic socket to a patient. The various sizes of a distal base 200, as seen in FIGS. 15A-15C represent a way for a modular prosthetic socket system to be readily adaptable to be able to fit residual limbs of different width and volume by exploiting modular aspects of the technology; the adjustable features described here (FIGS. 26A and 26B) expand that same general type of adjustability or adaptability such that it is available as an option within an individual modular prosthetic socket.

[0339] FIGS. 27A and 27B show views of an embodiment of a modular prosthetic socket 100 in two configurations; FIG. 27A shows a socket 100 with one the struts 300 and its strut connector 220 at a neutral non-pivoted position on a distal base 200, while FIG. 27B shows the same socket 100 with the struts and strut connectors 220 positioned at a pivoted position. These figures relate to the pivotability or swivelability of strut connectors 220 on a distal base 200, as seen particularly well in FIGS. 17D and 17E. As can be seen, depending on the particulars of the dimensions of the distal base, the radial position of the strut connector 220, and the confines of the strut connector site as determined by the configuration of base 200, a strut connector can swivel up to about 45 from a central or neutral position within radial slot 212. This angular degree of pivoting is reduced considerably as it translates into a pivoting of an attached strut, in the context of the full 360 circumference embodied by the struts collectively. However, being able to adjust the circumferential position of a strut only a few degrees, for example 5, can be clinically significant.

[0340] FIGS. 27A and 27B provide an example where a small degree of circumferential adjustability of a strut position can be important. It is not uncommon for patients to develop a so-called hot-spot, a site of irritation on the limb that will only grow worse if its aggravated. Skin breakdown and/or infection can ensue. Such a site of irritation 701 is seen on residual limb 700 on the depicted patient. In FIG. 27A, that site of irritation 701 is located directly below indicated strut 300. The patient visits his prosthetist, and the prosthetist then pivots the strut connector 220 at the base of strut 300 such that the strut rotates laterally a few degrees (see arrow), exposing the site of irritation 701 and thereby providing it relief, and allowing it to heal.

[0341] FIGS. 28A-28C and FIGS. 29A-29C show views of a modular prosthetic socket 100 being worn by a patient on residual limb 700 while walking. These two sets of figures depict separate aspects of a complex flexing of struts 300 during a stride. FIGS. 28A-28C show flexing in response to loading and unloading of weight on the struts during a stride. FIGS. 29A-29C show flexing in response to forward and rearward forces imparted to the residual limb during a stride.

[0342] In FIG. 28A, the patient's right leg is under a load, the right foot is starting to push off the ground and forward, as the left foot is swinging forward. In FIG. 28B, the right leg (residual limb 700) has swung forward and is momentarily free of load, now being absorbed by the left leg. In FIG. 28C, the heel of the right foot has made contact with the ground and the right leg, once again, absorbing load. Thus, in FIGS. 28A and 28C, the right leg (residual limb 700) is absorbing load, and in FIG. 28B it is unloaded. As the leg absorbs load, the struts 300 generally flex outward. As load is released, struts 300 generally flex inward. There may be differences in flexure according to the circumferential position of the struts. For example, as load is released from a leg, a strut in a posterior position may tend to flex inward more than an anterior strut.

[0343] FIGS. 29A-29C show views of a modular prosthetic socket being worn by a patient while walking that are similar to those of FIGS. 28A-28C, except that these views show an aspect of the struts flexing in response to back and forth movement of the residual limb during strides. In FIG. 29A force originating at the point of contact of the right foot with the ground imparts forward directed force to residual limb 700, driving an anterior strut 300 forward. A posterior strut 300 is consequently pulled forward by tensioning member 510. In FIG. 29B, the struts 300 assume a nominal neutral position. In FIG. 29C, a net rearward force is imparted to the residual limb 700, consequently causing a rearward flexion of struts 300.

[0344] Patients evaluating an embodiment of the modular prosthetic socket 100 have commented on the flexing aspect of the socket during an evaluation; they speak of this flexing as an advantage, something that feels right, and helps their gait. It is understandable that kinetic energy derived from a heel strike that could be absorbed and released as body weight (as in FIGS. 28A-28C) is being shifted away from the leg that struck the ground would benefit that following step, and generally enhance the gait. The forward and rearward flexing of the socket struts detailed in FIGS. 29A-29C further enhance the totality of strut flexion that supports the stride.

[0345] Inventors theorize that the flexing of modular prosthetic socket may relate to several aspects of the socket. First, the struts, by virtue of their thermoplastic-fiber composite material, in the dimensions and configuration embodied by struts 300, may be appropriately balanced between stiffness and compliance, such that the struts are generally non-flexing when the patient is standing still, or making small movements. However, body weight loading of a leg, as for example, by the force delivered by a heel strike during a purposeful walk, coupled to fore and aft forces associated with forward stride movement, may be sufficient to create the flexing. Second, the flexing may further be dependent on or enabled by an appropriate level of circumferential tensioning of the socket, as provided by adjusting tensioning elements. Third, the structure of the modular prosthetic socket may be particularly amenable to flexing from their fixed position on the distal base because of the lack of any circumferential integral structure in the socket that would preclude or constrain an inward flexing of the struts.

[0346] Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.