Abstract:
A modular prosthesis system that can be inexpensively manufactured using modern technology and advanced polymer materials. The modular prosthesis system will be immediately fit on the residual limb and aligned for optimal gait without specialized tools or labs, alleviating the many steps involved with conventional labor-intensive and costly prosthesis construction. The modular prosthesis system also accommodates the changing in size and shape of the limb, eliminating the need for multiple prostheses and adjustments to an existing prosthesis during the lifetime of an amputee.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates to the field of prostheses, and more particularly to a modular prosthesis system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0002]      FIG. 1  illustrates an exploded view of an exemplary embodiment of a modular prosthesis system. 
           [0003]      FIG. 2  illustrates an exploded view of an exemplary embodiment of a connector component for a modular prosthesis system. 
           [0004]      FIG. 3  illustrates a front view of an exemplary embodiment of a connector for a modular prosthesis system. 
           [0005]      FIG. 4  illustrates a side view of an exemplary embodiment of a connector for a modular prosthesis system. 
           [0006]      FIG. 5  illustrates a top view of an exemplary embodiment of a connector for a modular prosthesis system. 
           [0007]      FIG. 6  illustrates a sectional view of an exemplary embodiment of a connector for a modular prosthesis system. 
           [0008]      FIG. 7   a  illustrates a top view of an exemplary embodiment of a central plate of a connector. 
           [0009]      FIG. 7   b  illustrates a side view of an exemplary embodiment of a central plate of a connector. 
           [0010]      FIGS. 8   a ,  8   b , and  8   c  illustrate front-back, side-to-side, and angular adjustment of an exemplary embodiment of a connector. 
           [0011]      FIGS. 9   a  and  9   b  illustrate perspective views of exemplary embodiments of a socket for a modular prosthesis system. 
           [0012]      FIG. 10  illustrates a perspective view of an exemplary embodiment of a liner for a modular prosthesis system. 
           [0013]      FIG. 11  illustrates a perspective view of an exemplary embodiment of an assembled modular prosthesis system. 
           [0014]      FIG. 12  illustrates an exploded view of a second embodiment of a modular prosthesis system. 
       
    
    
     GLOSSARY 
       [0015]    As used herein, the term “dynamic stress point profile” refers to the unique anatomic and physiologic characteristics of an amputee&#39;s residual limb which govern the distribution of forces and stresses on the residual limb during activity. 
         [0016]    As used herein, the term “grid pattern” refers to a configuration of uniformly repeating shapes arranged in a network of uniformly spaced horizontal and perpendicular lines. 
         [0017]    As used herein, the term “modular prosthesis system” refers to a prosthesis system comprised of components that are interchangeable and designed to function together as a unit. Components of a modular prosthesis system may be off-the-shelf or custom-made. 
         [0018]    As used herein, the term “pivotal side joints” refers to components of a suspension system that allow an amputee to bend his or her knee while wearing the prosthesis. Pivotal side joints may be comprised of one or more straight, curved, or irregular-shaped components. The components of a multi-component pivotal side joint are connected at a pivot point, the location of which may vary. 
         [0019]    As used herein, the term “shank” refers to a tubular component attached to a connector at one end and a prosthetic foot at the other end. 
         [0020]    As used herein, the term “supporting component” refers to a component which provides additional foundation for bearing the weight of the central plate and upper assembly of a connector as well as the weight of the amputee. 
         [0021]    As used herein, the term “washer” refers to a component which distributes pressure from another component and provides a firm attachment through friction to prevent movement of the component. For example, a washer placed under a threaded fastener will distribute the pressure from the head of the fastener and prevent movement of the fastener. 
       Background 
       [0022]    Over 150,000 amputations occur in the United States annually. Amputations are rising in frequency due to diabetes and peripheral vascular disease. The transtibial level of amputation is the most frequently performed. 
         [0023]    A transtibial amputation is an amputation of the lower limb below the knee. A transtibial prosthesis is an artificial limb that replaces the portion of the leg below the knee that is missing. The shape of the residual limb varies for each individual and generally requires a custom-fitted prosthesis. A custom-fitted prosthesis that is comfortable is difficult to fabricate and is costly. 
         [0024]    The initial cost of a conventional prosthesis for a transtibial amputee typically ranges from $6000 to $10,000. In addition, there are additional costs to ensure the comfort and functionality of the device. The present state of prosthesis fabrication often requires three or more visits to the prosthetist and there are multiple steps in the fabrication process. First, a cast mold of the residual limb is made and a positive cast that resembles the residual limb is generated. Then, a prosthetic socket is built to custom-fit over the positive cast. Sometimes a check or temporary socket is made to insure a better fit. Typical fabrication techniques require specialized facilities. Generally, the final prosthesis requires post-fabrication adjustments as the residual limb tissue changes over time. 
         [0025]    Recent advancements have been made in the field of prosthetic devices. However, devices such as computerized knee mechanisms and energy storing feet are costly and beyond the economic means of the majority of prosthetic users, particularly those in nations outside the United States. 
         [0026]    Attempts have been made in the prior art to develop prosthesis systems that can be globally manufactured and distributed. These prosthesis systems, however, have several limitations. They are difficult to fabricate and require specialized facilities for initial manufacturing (e.g., casting) and subsequent adjustments. These systems all require expertise and consulting support that is not widely available. In particular, the socket (i.e., the portion of the prosthesis into which the residual limb fits), socket attachment, and alignment aspects of the device seem to be a common problematic area of development. 
         [0027]    It is desirable to create a prosthetic device which eliminates the need for complex fabrication and specialized tools or labs, and which can be economically manufactured and distributed on a global basis. 
       Summary of the Invention 
       [0028]    The present invention is a modular prosthesis system comprised of a connector, socket, and liner. The connector is made up of two main components: an upper assembly which is secured to the socket and a lower assembly which is secured around a shank. The design of the connector allows for angular adjustment which ensures proper positioning and alignment of the foot. In addition, the socket and liner include tightening components, resulting in a prosthesis that may be fit to any residual limb and which can accommodate long-term and daily changes in the amputee and residual limb as well as other aspects of an amputee&#39;s dynamic stress distribution profile. 
       DETAILED DESCRIPTION OF INVENTION 
       [0029]    For the purpose of promoting an understanding of the present invention, references are made in the text to exemplary embodiments of a modular prosthesis system, only some of which are described herein. It should be understood that no limitations on the scope of the invention are intended by describing these exemplary embodiments. One of ordinary skill in the art will readily appreciate that alternate but functionally equivalent materials, component, and designs may be used. The inclusion of additional elements may be deemed readily apparent and obvious to one of ordinary skill in the art. Specific elements disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to employ the present invention. 
         [0030]    It should be understood that the drawings are not necessarily to scale; instead, emphasis has been placed upon illustrating the principles of the invention. In addition, in the embodiments depicted herein, like reference numerals in the various drawings refer to identical or near identical structural elements. 
         [0031]    Moreover, the terms “substantially” or “approximately” as used herein may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. 
         [0032]      FIG. 1  illustrates an exploded view of an exemplary embodiment of modular prosthesis system  100  comprised of connector  10 , socket  80  with suspension system  85  (see  FIG. 9 ), liner  90  (see  FIG. 10 ), and shank  110  (see  FIG. 11 ). In the embodiment shown, socket  80  and liner  90  include tightening components  84   a,    84   b  and  95 , respectively. Also visible in the embodiment shown is optional padding insert  88  which is placed at the bottom of socket  80  to support liner  90 . 
         [0033]      FIG. 2  illustrates an exploded view of an exemplary embodiment of connector  10  for modular prosthesis system  100 . In the embodiment shown, connector  10  is comprised of upper assembly  20 , central plate  30 , and lower assembly  40 . 
         [0034]    Upper assembly  20  is a tubular component with socket flange  25 . In the embodiment shown, socket flange  25  is cup-shaped with a flat top surface. At the interface of socket flange  25  and the lower tubular portion of upper assembly  20  is ridge  18  for receiving and supporting cover  15 . Socket flange  25  further includes apertures  27   a,    27   b,    27   c,    27   d  ( 27   a,    27   d  not visible) for inserting securing components  29   a,    29   b,    29   c,    29   d  (not visible) used to secure connector  10  to socket  80 . In the embodiment shown, apertures  27   a,    27   b,    27   c,    27   d  are oval-shaped and are located near the edge of socket flange  25 . In various other embodiments, apertures  27   a,    27   b,    27   c,    27   d  are eliminated and socket  80  is secured to connector  10  in an alternate way. For example, one or more bolts or other fasteners may be threaded through apertures positioned on a substantially horizontally surface of upper assembly  20  and corresponding apertures on socket  80  (see  FIG. 12 ). 
         [0035]    Centered in the bottom of upper assembly  20  is aperture  22  for tapered shoulder screw  70 . In the embodiment shown, aperture  22  is round and has a diameter that is substantially larger than the diameter of tapered shoulder screw  70 . 
         [0036]    Central plate  30  is located between upper assembly  20  and lower assembly  40 . The top surface of central plate  30  has raised grid pattern  32 . In the embodiment shown, raised grid pattern  32  is uniform and has a plurality of raised protuberances in the shape of isosceles trapezoids. The bottom surface of upper assembly  20  has recessed grid pattern  28  (see  FIGS. 3 and 4 ) that corresponds to raised grid pattern  32  on the top surface of central plate  30 . Corresponding grid patterns  28 ,  32  on the bottom surface of upper assembly  20  and the top surface of central plate  30 , respectively, allow for forward and backward adjustment and side-to-side adjustment. 
         [0037]    In the embodiment shown, the bottom surface of central plate  30  has a rounded protuberance  37  (see  FIG. 6 ) which corresponds to the shape of the upper surface of lower assembly  40 . Central plate  30  further includes aperture  35  for tapered shoulder screw  70 . In the embodiment shown, aperture  35  is round and has a diameter that is substantially larger than the diameter of the shank of tapered shoulder screw  70 , but smaller than the diameter of aperture  22  in upper assembly  20 . 
         [0038]    Lower assembly  40  is a tubular component with central plate flange  45 . In the embodiment shown, the outer edge of the top surface of central plate flange  45  is flat, while the center portion of the top surface of central plate flange  45  is concave to accommodate rounded protuberance  37  of central plate  30 . 
         [0039]    The flattened portion of the top surface of central plate flange  45  includes a plurality of apertures  47   a,    47   b,    47   c,    47   d  for central plate supporting components  75   a,    75   b,    75   c,    75   d  ( 75   d  not visible). In the center of central plate flange  45  is aperture  43  for tapered shoulder screw  70 . In the embodiment shown, aperture  43  is oval-shaped to accommodate and secure tapered shoulder screw  70 . 
         [0040]    In the embodiment shown, the outer edge of concave portion on the top surface of central plate flange  45  further includes a plurality of apertures  49   a,    49   b,    49   c,    49   d  ( 49   d  not visible) for insertion of set screws  66   a,    66   b,    66   c,    66   d  ( 66   b  not visible). Apertures  49   a,    49   b,    49   c,    49   d  pass completely through central plate flange  45  and set screws  66   a,    66   b,    66   c,    66   d  help to firmly anchor connector  10  once the final position has been attained. In the embodiment shown, set screws  66   a,    66   b,    66   c,    66   d  are coin point set screws; however, in other embodiments may be another type of set screw known in the art (e.g., domed point, cup point, dog point). 
         [0041]    In the embodiment shown, upper assembly  20  further includes depressions  51   a,    51   b,    51   c,    51   d  (see  FIGS. 3 and 4 ) located on the top of the tubular portion of lower assembly  40  just under apertures  49   a,    49   b,    49   c,    49   d.  Depressions  51   a,    51   b,    51   c,    51   d  provide a space which allows a tool (e.g., a Hex driver) to be used to insert set screws  66   a,    66   b,    66   c,    66   d.    
         [0042]    In addition, one side of tubular portion of lower assembly  40  further includes raised surface  50  which has aperture  52  for insertion of set screw  68 . Aperture  52  passes completely through the side of lower assembly  40  and when set screw  68  is inserted, the end of set screw  68  crosses the plane of the inner surface of lower assembly  40  and bumps against shank  110  (not shown). In the embodiment shown, the top of raised surface  50  is flat; however, in other embodiments, the top of raised surface  50  may have slight curvature, mimicking the contours of lower assembly  40 . In the embodiment shown, set screw  68  is a cone point set screw. 
         [0043]    In the embodiment shown, lower assembly  40  further includes protuberance  55  having apertures  57  for insertion of shank securing component  59 . Protuberance  55  is rounded and extends perpendicularly outward from lower assembly  40 . In the embodiment shown, lower assembly  40  further includes groove  60  which starts at the bottom of lower assembly  40  and extends to approximately the center of lower assembly  40 , cutting protuberance  50  in half. In the embodiment shown, lower assembly  40  further includes depressions  64   a,    64   b  ( 64   b  not visible) in lower assembly  40  on each side of protuberance  55 . Depressions  64   a,    64   b  provide a space which allows a tool (e.g., wrench, socket wrench) to be used to tighten shank securing component  59 . 
         [0044]    In the embodiment shown, shank securing component  59  is comprised of a bolt and nut; the bolt is inserted through aperture  57  and the nut is threaded onto the end of the screw and tightened, securing lower assembly  40  to shank  110  and preventing lower assembly  40  from rotating around shank  110 . 
         [0045]    In the embodiment shown, shank  110  has a diameter of 30 mm; however, in other embodiments, lower assembly  40  may be designed to accommodate shanks of varying diameters. In an exemplary embodiment, shank  110  will include a connector at the bottom which allows various types of feet known in the art, such as an SACH foot or the NIAGRA foot, to be connected to shank  110 . In an exemplary embodiment, the length of shank  110  is adjustable, eliminating the need to cut shank  110  to a length sized for each amputee. 
         [0046]    Tapered shoulder screw  70  is inserted through aperture  22  in upper assembly  20 , aperture  35  in central plate  30 , and aperture  43  in lower assembly  40 . When tapered shoulder screw  70  is positioned, the threaded end of tapered shoulder screw  70  extends into lower assembly  40 . Nut  72  is threaded onto the treaded end of tapered shoulder screw  70  and tightened, securing upper assembly  20 , central plate  30 , and lower assembly  40  together. 
         [0047]    In the embodiment shown, nut  72  is a K-nut, that is, a nut with an attached, free-spinning washer. In the embodiment shown, the washer is an external star washer. The use of a K-nut provides maximum torsional resistance and prevents loosening caused by vibration. 
         [0048]    In the embodiment shown, tapered shoulder screw  70  is inserted through washer  65  before tapered shoulder screw  70  is inserted through aperture  22  in upper assembly. Washer  65  has a larger diameter than aperture  22  covering aperture  22  and preventing tapered shoulder screw  70  from directly touching upper assembly  20 . Washer  65  distributes the load of tapered shoulder screw  70 . 
         [0049]    In the embodiment shown, tapered shoulder screw  70  is a shoulder screw with a flat, tapered head and machined grooves  74   a,    74   b  cut on opposite sides of tapered shoulder screw  70 . Machined grooves  74   a,    74   b  lock tapered shoulder screw  70  automatically into place inside oval-shaped aperture  43  in lower assembly  40 , allowing tapered shoulder screw  70  to be tightened from one end. 
         [0050]    In the embodiment shown, the bottom of washer  65  is flat while the top of washer  65  has a beveled outer edge. The edges of the aperture in the center of washer are also beveled. The bevel angle is greater on the top of washer  65  to accommodate the tapered head of tapered shoulder screw  70 . When washer  65  is used, only a small portion of the head of tapered shoulder screw  70  is visible above washer  65 . 
         [0051]    The large diameters (i.e., diameters substantially larger than the diameter of the shoulder of tapered shoulder screw  70 ) of aperture  22  in upper assembly  20  and aperture  35  in central plate  30 , the oval shape of aperture  43  in lower assembly  40 , rounded protuberance  37  of central plate  30  and corresponding concave center portion of top surface of lower assembly  40 , and tapered shoulder screw  70  allow for angular adjustment of upper assembly  20  and central plate  30  in relationship to lower assembly  40 . The ability to angularly adjust connector  10  allows connector  10  to accommodate various stump configurations, providing additional comfort to the amputee. 
         [0052]    Once upper assembly  20 , central plate  30 , and lower assembly  40  are correctly positioned, nut  72  is tightened on tapered shoulder screw  70  and central plate supporting components  75   a,    75   b,    75   c,    75   d  are inserted into apertures  47   a,    47   b,    47   c,    47   d  from the bottom and are tightened until the ends of central plate supporting components  75   a,    75   b,    75   c,    75   d  press against the bottom of central plate  30 , supporting central plate  30  and upper assembly  20  and further securing upper assembly  20 , central plate  30 , and lower assembly  40  together. 
         [0053]    Cover  15  is placed on upper assembly  20  so that it rests on ridge  18  of upper assembly  20 , covering tapered shoulder screw  70  and washer  65 . When cover  15  is positioned, the surface of cover  15  is flush with the inside surface of socket flange  25 . 
         [0054]    In the embodiment shown, cover  15  and ridge  18  are shown for ease of illustration. In various other embodiments, ridge  18  and cover  15  are omitted and the inner surface of socket flange  25  is a single piece. 
         [0055]    In the embodiment shown, upper assembly  20 , central plate  30 , lower assembly  40 , and cover  15  are comprised of polyphthalamide (i.e., PPA or high performance polyamide); however, in various other embodiments may be comprised of other thermoplastics/synthetic resins, such as nylon, acrylonitrile butadiene styrene (ABS), polypropylene, polyamide-imide, polybenzimidazole (PBI), polybutylene (PB-1) or combinations thereof, or any other suitable non-metal material. 
         [0056]      FIG. 3  illustrates a front view of an exemplary embodiment of connector  10  for modular prosthesis system  100 . Visible in  FIG. 3  are upper assembly  20 , including socket flange  25  and recessed grid pattern  28 ; central plate  30 , including raised grid pattern  32  and rounded protuberance  37 ; lower assembly  40 , including central plate flange  45 , aperture  49   b,  depression  51   b,  raised surface  50 , and aperture  52 ; set screw  66   b;  central plate supporting components  75   a,    75   d;  and shank  110 . 
         [0057]      FIG. 4  illustrates a side view of an exemplary embodiment of connector  10  for modular prosthesis system  100 . Visible in  FIG. 4  are upper assembly  20 , including socket flange  25  and recessed grid pattern  28 ; central plate  30 , including raised grid pattern  32  and rounded protuberance  37 ; lower assembly  40 , including central plate flange  45 , aperture  49   a,  depression  51   a,  raised surface  50 , aperture  52 , protuberance  55 , aperture  57 , and depression  64   a;  set screw  66   a;  central plate supporting components  75   a,    75   d;  and shank  110 . 
         [0058]      FIG. 5  illustrates a top view of an exemplary embodiment of connector  10  for modular prosthesis system  100 . Visible in  FIG. 5  are socket flange  25  of upper assembly  20 , cover  15 , and apertures  27   a,    27   b,    27   c,    27   d  for securing components  29   a,    29   b,    29   c,    29   d  (not visible), which are used to secure connector  10  to socket  80  (not visible). 
         [0059]      FIG. 6  illustrates a sectional view of an exemplary embodiment of connector  10  for modular prosthesis system  100  taken along line VI of  FIG. 5 . Visible in  FIG. 6  are cover  15 ; upper assembly  20 , including aperture  22 , socket flange  25 , recessed grid pattern  28 , aperture  27   d,  and ridge  18 ; central plate  30 , including aperture  35 , raised grid pattern  32 , and rounded protuberance  37 ; lower assembly  40 , including aperture  43 , central plate flange  45 , aperture  49   a,    49   d,  depression  51   a,    51   d,  and protuberance  55 ; set screws  66   a,    66   d;  central plate supporting components  75   b,    75   c;  tapered shoulder screw  70 , and shank  110 . 
         [0060]      FIG. 7   a  illustrates a top view of an exemplary embodiment of central plate  30  showing raised grid pattern  32  and aperture  35 . 
         [0061]      FIG. 7   b  illustrates a side view of an exemplary embodiment of central plate  30  showing raised grid pattern  32 , aperture  35 , and rounded protuberance  37 . 
         [0062]      FIGS. 8   a ,  8   b , and  8   c  illustrate front-back, side-to-side, and angular adjustment of an exemplary embodiment of connector  10 , which allow the angle and position of prosthetic foot  120  ( FIG. 11 ) to be changed (e.g., to compensate for foot inset-outset). In  FIG. 8   a , upper assembly  20  has been shifted backward (i.e., along x-axis) in relation to central plate  30  and lower assembly  40 . In  FIG. 8   b , upper assembly  20  has been shifted sideways (i.e., along y-axis) in relation to central plate  30  and lower assembly  40 . 
         [0063]    When upper assembly  20  is shifted forward-backward or sideways (i.e., along x- or y-axis) in relation to central plate  30  and lower assembly  40 , a portion of recessed grid pattern  28  (not visible) on the lower surface of upper assembly  20  and portion of raised grid pattern  32  on the upper surface of central plate  30  are exposed. The size of aperture  22  in upper assembly  20  and aperture  35  in central plate  30  permit tapered shoulder screw  70  (not visible) to be angled when upper assembly  20  is shifted forward-backward and/or sideways in relation to central plate  30  and lower assembly  40 , ensuring that upper assembly  20 , central plate  30 , and lower assembly  40  are secure. 
         [0064]    In  FIG. 8   c , upper assembly  20  and central plate  30  are in tilted in relation to lower assembly  40  so that central plate  30  and central plate flange  45  on lower assembly  40  are no longer parallel. The concave center portion of the top surface of lower assembly  40  allows rounded protuberance  37  on the bottom of central plate  30  to tilt, allowing for angular adjustment of upper assembly  20  and central plate  30 . When upper assembly  20  and central plate  30  are positioned at the desired angle, central plate supporting components  75   a,    75   b,    75   c,    75   d  are tightened, securing lower assembly  40  to upper assembly  20  and central plate  30 . 
         [0065]    In the embodiment shown, connector  10  is capable of being adjusted in one or more directions concurrently, allowing for maximum adjustment of connector  10  to specifically accommodate each amputee&#39;s residual limb and gait. For example, connector  10  may be adjusted front-back, side-to-side, and angled. In other embodiments, connector  10  may be capable of only one type of adjustment (e.g., angular). 
         [0066]      FIGS. 9   a  and  9   b  illustrate perspective views of exemplary embodiments of socket  80  for modular prosthesis system  100 . Socket  80  includes tightening components  84   a,    84   b,  which allow the tension in socket  80  to be adjusted by each amputee. In the embodiment shown, socket tightening components  84   a,    84   b  are buckle assemblies. 
         [0067]    In the embodiment shown, socket  80  further includes suspension system  85  with optional pivotal side joints  87   a,    87   b.  Suspension system  85  secures the prosthesis on the amputee&#39;s residual limb. The inclusion of pivotal side joints  87   a,    87   b  allows the amputee to move his or her knee more freely with less hindrance from the prosthesis. In various other embodiments, suspension system  85  may vary. For example, suspension system  85  may be comprised of a roll-on neoprene sleeve with an adjustable strap that goes around the amputee&#39;s thigh and one or more length-adjustable straps that connect the sleeve to socket  80 . 
         [0068]    In  FIG. 9   a , optional pivotal side joints  87   a,    87   b  are comprised of two pieces connected at a joint. In various embodiments, the joint may be located further from or closer to suspension system  85 . In  FIG. 9   b , optional pivotal side joints  87   a,    87   b  are comprised of a single straight piece. In various embodiments, there may be fewer or more joints, the pieces may be of varying length, and/or curved or irregularly-shaped. 
         [0069]    In various other embodiments, there may be more or socket tightening components  84   a,    84   b  and/or the type of tightening components may vary. For example, socket  80  may include laces or one or more straps secured by hook-and-loop fastener or another means. 
         [0070]    Also visible are apertures  82   a,    82   b,    82   c,    82   d  for inserting securing components  29   a,    29   b,    29   c,    29   d  for securing connector  10  to socket  80 . 
         [0071]      FIG. 10  illustrates a perspective view of an exemplary embodiment of liner  90  for modular prosthesis system  100 . Liner  90  is shaped to fit inside socket  80 . In the embodiment shown, liner  90  further includes liner extension component  96  which allows the height of the liner to be adjusted to the length of each amputee&#39;s residual limb. In the embodiment shown, liner extension component  96  is a plurality of accordion fabric folds at the bottom portion of liner  90 . In various other embodiments, liner extension component  96  may be comprised of adjustable or removable panels or another component that allows the length of liner  90  to be adjusted. 
         [0072]    In the embodiment shown, liner  90  has tightening component  95  which allow the tension of liner  90  to be adjusted as the residual limb changes, accommodating long-term or daily changes of the residual limb, as well as allowing the individual amputee to adjust liner  90  to his or her comfort. For example, liner tightening component  95  allows liner  90  to be loosened as a result of swelling of the residual limb. In the embodiment shown, liner tightening component  95  is laces. In various other embodiments, liner tightening component  95  may include one or more adjustable straps. 
         [0073]    In the embodiment shown, liner  90  includes stress distribution panels  92   a,    92   b  secured to the outer surface of the sides of liner  90  and stress distribution panels  92   c,    92   d  ( 92   d  not visible) secured to the outer surface of the front and back of liner  90 . Stress distribution panels  92   a,    92   b,    92   c,    92   d  help to distribute pressure and shear stresses. In the embodiment shown, stress distribution panels  92   a,    92   b  are comprised of plastic. In various embodiments, the shape of the stress distribution panels varies depending on the placement of the panel (i.e., the side panels have a shape different than that of front and back panels). 
         [0074]    In an exemplary embodiment, liner  90  further includes one or more optional removable padding inserts  98 , which can be inserted into liner  90  for further adjustability, allowing liner  90  to accommodate the shape of each individual amputee&#39;s residual limb. For example, padding inserts may be inserted into the bottom of liner  90  to accommodate a bony prominence at the end of a residual limb or into the sides of liner  90  to add additional padding in areas that are less pressure tolerant. 
         [0075]    Liner  90  is comprised of a soft, comfortable material, such as Pelite or silicone, that doesn&#39;t break down the skin of the amputee&#39;s residual limb. In various other embodiments, liner  90  may be comprised of a plastic mesh material or other material that allows for breathability for use in warmer climates or during physical activities. In various embodiments, liner  90  may be manufactured by gluing together layers of foam having different durometers. 
         [0076]      FIG. 11  illustrates a perspective view of an exemplary embodiment of assembled modular prosthesis system  100 . In an exemplary embodiment, modular prosthesis system  100  will include all items and components required for immediate fitting. Connector  10 , shank  110 , and foot  120  will be one fully adjustable system that readily connects to socket  80  and suspension system  85 . Liner  90  is inserted into socket  80 . In an exemplary embodiment, modular prosthesis system  100  will include a telescoping shank. 
         [0077]      FIG. 12  illustrates an exploded view of a second embodiment of modular prosthesis system  100  comprised of socket  80 , liner  90 , and connector  10 . In the embodiment shown, socket  80  and liner  90  include tightening components  84   a,    84   b,  and  95 , respectively, and socket  80  further includes suspension system  85 . 
         [0078]    In the embodiment shown, connector  10  is comprised of upper assembly  20  and lower assembly  40 . Upper assembly  20  is cup-shaped with a rounded bottom and a single elongated side. Lower assembly  40  is tubular-shaped having a flange with a concave center portion and a bottom portion for accepting shank  100 . In the embodiment shown, upper assembly  20  is secured to lower assembly  40  by inserting a connecting screw (e.g., a tapered shoulder screw) or another type of fastener into each of the apertures in the rounded bottom of upper assembly  20  and into the apertures in the concave center portion of lower assembly  40 . The position of the connecting screws can be adjusted to adjust the tilt between upper assembly  20  and lower assembly  40 , allowing the position of the prosthetic foot to be adjusted (e.g., to compensate for foot inset-outset). 
         [0079]    In the embodiment shown, the apertures in the bottom of upper assembly  20  are recessed to allow for placement of a washer. 
         [0080]    In the embodiment shown, the single elongated side of upper assembly  20  includes a plurality of apertures which correspond to the apertures on socket  80 . Socket  80  is secured to upper assembly  20  of connector  10  by threading a screw through two apertures (single row) in socket  80  and upper assembly  20 . The plurality of rows of apertures accommodates for height adjustment. For example, for a shorter socket, the amputee would thread screws through the top four apertures of socket  80  and the top four apertures of upper assembly  20  (or any four corresponding apertures). For a longer socket, the amputee would thread screws through the bottom four apertures of socket  80  and the top four apertures of upper assembly  20 . For shorter lengths, additional screws could be threaded through corresponding apertures to secure socket  80  and upper assembly more tightly together. 
         [0081]    Modular prosthesis system  100  is easily fit to an individual and can be fully constructed and aligned in a reasonable amount of time. No casting or fabrication is required, eliminating the need for specialized tools and centers. 
         [0082]    Modular prosthesis system  100  is highly adjustable, making it ideal for growing children, eliminating the need for many prosthetic revisions to insure a comfortable and functional device. In addition, modular prosthesis system  100  can be fit without a prosthetist making it desirable for a developing countries, war-torn countries, and for individuals who are without insurance and/or don&#39;t have access to a prosthesis. The use of advanced technology and materials allows modular prosthesis system  100  to be economically manufactured and distributed.