Prosthetic foot comprising support element and damping element

Abstract

The invention relates to a prosthetic foot comprising a heel (2) and a toe (3) configured to be supported on the ground, an ankle support (4) and a damping element (5) comprising two ends, a first end (51) being connected to the toe and a second end (52) being connected to the ankle support, characterized in that the heel (2) and the toe (3) are supported on the ground. The foot further comprises at least one plate (6) hinged at one end to the toe and connected at the other end to the ankle support, by means of which plate the damping element is connected to the ankle support and by means of a second end to the heel, the damping element is disposed parallel to the plate.

Description

Technical Field

[0001] The present invention generally relates to a prosthetic foot.

[0002] More specifically, the present invention relates to a prosthetic foot by means of which a user can perform metatarsophalangeal movements in an easy and natural manner. Background Art

[0003] Patent FR3063889 discloses a prosthetic foot including an ankle-foot support for attaching the foot to a patient's tibia. The ankle-foot support is connected to the dorsum of the foot by means of a mechanism at the lower part.

[0004] The prosthetic foot further includes a heel and a toe configured to bear on the ground, and a damping element connecting the toe to the ankle-foot support.

[0005] The dorsum of the foot is connected to the heel by means of a connecting rod that is hinged to the dorsum of the foot and to the heel. The connecting rod allows the force to be transmitted from the heel to the dorsum of the foot.

[0006] The dorsum of the foot is connected to the toe by means of a universal joint. The universal joint includes a first hinge portion forming a first pin and a second hinge portion forming a second pin, and the second pin is connected to, for example, a spring-type shock absorber.

[0007] Such a prosthetic foot improves the comfort of walking and allows adaptation to the type of walking desired by the patient.

[0008] During the phase when the foot bears on the ground, walking mobilizes some muscle groups so that the impact from the foot is attenuated, and during the propulsion phase, other muscle groups are mobilized so that energy is recovered.

[0009] However, due to the number of components and the connections between the components, the system as described above is complex and causes friction between the individual components.

[0010] Therefore, the object of the present invention is to provide a prosthetic foot that is simpler and more practical to use, such that the impact from the foot is attenuated during the ground-bearing phase and energy is recovered during the propulsion phase, while also being economical to manufacture. Summary of the Invention

[0011] To achieve this result, the present invention relates to a prosthetic foot comprising a heel and a toe, as well as an ankle support and a damping element, the heel and the toe being configured to rest on the ground, the damping element having two ends, a first end connected to the toe and a second end connected to the ankle support, the foot further comprising at least one plate which is hinged at one end to the toe and connected at the other end to the ankle support, the damping element being connected to the ankle support by virtue of the plate, and the damping element also being connected to the heel by the second end, the damping element being arranged parallel to the plate.

[0012] The present invention allows a user having such a foot to perform metatarsophalangeal movements and thus to take at least one step in an easy and natural manner.

[0013] Specifically, the combined action of the heel and the plate and the damping element attenuates the impact at the start and allows the energy to be naturally restored during the propulsion phase, thus ensuring a natural gait for the user (similar to that of a human foot). In addition, the arrangement of the damping element relative to the plate allows the force to be distributed between the rear and the front of the foot when the foot is in the flat position, thus achieving better stability of the prosthetic foot.

[0014] Advantageously, the damping element comprises at least one tension spring which is connected at one end to the toe by means of a pivoting connection and at the other end to the heel by means of another pivoting connection, both of said connections forming an axis orthogonal to the plane of symmetry of the toe.

[0015] In the dorsiflexion position, the spring is in the rest position and the plate is straight. Subsequently, in the flat position, the plate is straight and extends parallel to the spring. Subsequently, in the plantar flexion position, the spring pivots both about the axis of the pivoting connection which attaches it to the toe and about the axis of the pivoting connection which attaches it to the heel. The spring is then in the extended position and the plate bends, and together they store energy. Next, the spring and the plate restore the stored energy to help the user lift the toe off the ground and thus enter the propulsion phase.

[0016] Advantageously, the damping element comprises one or two or three tension springs.

[0017] Preferably, the plate is hinged to the toe by means of a pivoting connection which forms an axis orthogonal to the plane of symmetry of the toe.

[0018] Advantageously, the plate is made of fibreglass.

[0019] Equally advantageously, the plate is made of fibreglass and comprises a carbon fibre layer.

[0020] Equally advantageously, the plate is obtained by plastic injection or polymer injection.

[0021] During the metatarsophalangeal movement of the prosthetic foot, the plate bends to support the movement of the foot and allows the user to take a step in an easy and natural manner.

[0022] Preferably, the heel has a U-shaped cross-section and includes a damper disposed in the U-shaped cross-section of the heel.

[0023] Advantageously, the damper is a foamed polyurethane foam.

[0024] Due to its U-shaped cross-section, the heel deforms to compress the damper, thereby attenuating the impact caused by the contact of the prosthetic foot with the ground, thus stabilizing the foot. The foot then stores energy. The energy stored by the heel is then restored to cause the prosthetic foot to rotate from the dorsiflexed position to the flat position.

[0025] Also preferably, the heel includes at least one male connector, the plate includes at least one female connector, and the ankle support includes at least one female connector, and the male connector of the heel is configured to interact with the female connector of the plate and with the female connector of the ankle support.

[0026] Advantageously, the prosthetic foot further includes an adjustment element configured to allow adjustment of the angle between the prosthetic foot and the ground supporting the foot.

[0027] Advantageously, the adjustment element is fixed to the plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Other features and advantages of the present invention will become apparent by reading the following description, which is purely illustrative and should be read with reference to the accompanying drawings, in which:

[0029] Figure 1 : Figure 1 is a schematic perspective view of a prosthetic foot according to the present invention in a flat position, seen from the left side, the prosthetic foot including a damping element, a plate, an adjustment element, and an ankle support;

[0030] Figure 2 : Figure 2 is a schematic view of the prosthetic foot according to the present invention seen from above Figure 1 ;

[0031] Figure 3 : Figure 3 is a schematic view of the prosthetic foot according to the present invention seen from below Figure 1 , but in this case having two springs instead of three;

[0032] Figure 4 : Figure 4 in a similar manner to Figure 1shows a prosthetic foot according to the present invention but without a plate, without an adjustment element and without an ankle-foot support;

[0033] Figure 5 : Figure 5 shows in a manner similar to Figure 1 a prosthetic foot according to the present invention but without an adjustment element and without an ankle-foot support;

[0034] Figure 6 : Figure 6 is a schematic perspective view seen from the left side of a prosthetic foot according to the present invention in a plantarflexed position, the prosthetic foot including a damping element, a plate, an adjustment element and an ankle-foot support; and

[0035] Figure 7 : Figure 7 shows in a manner similar to Figure 6 a prosthetic foot according to the present invention but without a plate, without an adjustment element and without an ankle-foot support.

[0036] It should be noted that the drawings show the present invention in detail for implementing the present invention, and of course the drawings can be used to better define the present invention when necessary. Detailed Description

[0037] The prosthetic foot 1 according to the present invention is configured to allow the user having such a prosthetic foot 1 to perform metatarsophalangeal movements.

[0038] Specifically, the prosthetic foot 1 is configured to allow the user to take at least one step in an easy and natural manner.

[0039] To take this step, the prosthetic foot 1 is first in its stage of being supported on the ground, then it enters the propulsion stage, and subsequently returns to the support stage again to take the next step.

[0040] During the ground support stage, the prosthetic foot is first in the dorsiflexed position, then it assumes a flat position (as shown in Figures 1 to 5 ), and finally assumes a plantarflexed position (as shown in Figure 6 and Figure 7 ) before the propulsion stage.

[0041] The prosthetic foot 1 includes a heel 2 and a toe 3. The heel 2 and the toe 3 are configured to be supported on the ground in the flat position.

[0042] The prosthetic foot 1 extends along a longitudinal axis 11 between the heel 2 and the toe 3. In addition, the prosthetic foot 1 extends along a transverse axis 12 orthogonal to the longitudinal axis 11 and a vertical axis 13 orthogonal to both the longitudinal axis 11 and the transverse axis 12.

[0043] As shown in Figure 1As shown, the toe tip 3 is a one-piece unit and includes a first region 31 and a second region 32. The first region 31 corresponds to the end of the foot including the toes, and the second region 32 corresponds to the fleshy part at the base of the metatarsals.

[0044] Advantageously, the toe tip 3 (especially the first region 31) is adjustable. Thus, the size of the first region 31 can be reduced to adjust the toe tip 3 and thus the prosthetic foot 1 to a smaller size than the initial size, and / or to adapt the size of the prosthetic foot to the size of the user's shoe.

[0045] The prosthetic foot 1 further includes a damping element 5 and at least one plate 6.

[0046] The prosthetic foot 1 further includes an ankle support 4 for connecting the heel 2, the at least one plate 6 and the adjustment element 7. The adjustment element 7 is thus fixed to the ankle support 4 and is, for example, pyramidal. It allows the prosthetic foot to be connected to the tibia.

[0047] The damping element 5 has two ends: a first end 51 connected to the toe tip 3 and a second end 52 connected to the heel 2.

[0048] Specifically, the first end 51 of the damping element 5 is connected to the toe tip 3, as specifically visible in Figure 3 and Figure 4 . The first end 51 is connected to the toe tip 3 by means of a pivotal connection 54, and the second end 52 is connected to the heel 2 by means of another pivotal connection 54. Each pivotal connection 54 forms an axis orthogonal to the plane of symmetry of the toe tip 3.

[0049] The damping element 5 includes at least one tension spring 53.

[0050] According to one embodiment, the damping element 5 includes a tension spring 53. The tension spring 53 is connected at one end to the second region 32 of the toe tip 3 by means of a pivotal connection 54 and at the other end to the heel 2 by means of another pivotal connection 54.

[0051] According to another embodiment and as Figure 3 shown, the damping element 5 may include a plurality of tension springs 53, especially two tension springs 53. Each tension spring 53 is connected at one end to the second region 32 of the toe tip 3 by means of a pivotal connection 54 and at the other end to the heel 2 by means of another pivotal connection 54.

[0052] According to yet another embodiment and as Figure 4 shown, the damping element 5 may include three tension springs 53. Each tension spring 53 is connected at one end to the second region 32 of the toe tip 3 by means of a pivotal connection 54 and at the other end to the heel 2 by means of another pivotal connection 54.

[0053] The plate 6 is hinged at one end to the toe 3 and connected at the other end to the ankle support 4. The plate 6 is hinged to the toe 3 by means of a pivot connection 61 which forms an axis orthogonal to the plane of symmetry of the toe 3.

[0054] Specifically, the plate 6 is hinged to a first region 31 of the toe 3, as can be specifically seen in Figure 1 and Figure 2 as specifically visible.

[0055] Advantageously, the plate 6 is flexible so that it bends during metatarsophalangeal movement.

[0056] According to one embodiment of the invention, the plate 6 can be made of fiberglass.

[0057] According to another embodiment of the invention, the plate 6 can be made of fiberglass and include a carbon fiber layer.

[0058] According to a further embodiment of the invention, the plate 6 can be obtained by plastic injection or polymer injection.

[0059] According to a further embodiment of the invention, the plate 6 can be made of carbon fiber.

[0060] Both the damping element 5 and the plate 6 are connected to the toe 3 by respective pivot connections 54 and 61 (connected to the second region 32 and the first region 31 respectively). The pivot connection 61 is arranged along the longitudinal axis 11 between the free end of the toe 3 and the pivot connection 54 of the second region 32.

[0061] As can be seen in Figure 1 in the "flat" position, the damping element 5 and the plate 6 are arranged parallel to each other.

[0062] Furthermore, the damping element 5 is connected to the ankle support 4 by means of the heel 2 and the plate 6. Specifically, the damping element 5 is connected to the heel 2 by means of a pivot connection 54, the heel 2 is in turn fixed to the plate 6, and the plate 6 is in turn fixed to the ankle support 4. In this flat position, the spring 53 of the damping element 5 is in the rest position.

[0063] The heel 2 of the prosthetic foot 1 has a U-shaped cross-section. The heel 2 is arranged between the plate 6 and the ground.

[0064] Furthermore, the heel 2 includes a damper 22 arranged in the U-shaped cross-section of the heel 2.

[0065] Advantageously, the damper 22 is a foamed polyurethane foam.

[0066] The geometry of the heel connected to such a damper 22 allows for better attenuation of shocks during the support phase when the heel 2 contacts the ground.

[0067] The heel 2 includes at least one male connecting portion 21. The plate 6 includes at least one female connecting member 62. The ankle support 4 includes at least one female connecting member 41.

[0068] Specifically, as can be seen in Figure 4 here, the heel 2 includes three male connecting portions 21. Further, as can be seen in Figure 2 and Figure 5 here, the plate 6 includes three female connecting members 62, and the ankle support 4 here includes three female connecting members 41.

[0069] Each male connecting member 21 of the heel 2 is configured to interact with the female connecting member 62 of the plate 6 and the female connecting member 41 of the ankle support 4.

[0070] Thus, the heel 2, the plate 6 and the ankle support 4 are rigidly connected to each other.

[0071] The adjustment element 7 of the prosthetic foot 1 is configured to allow adjustment of the angle between the prosthetic foot 1 and the ground supporting the foot 1.

[0072] The adjustment element 7 is fixed to the ankle support 4, which in turn is fixed to the plate 6.

[0073] The adjustment element 7 is a standard connecting device that includes a mechanical lock and allows adjustment of the plantar flexion and dorsiflexion angles of the prosthetic foot 1.

[0074] Figure 6 and Figure 7 show the prosthetic foot 1 in the plantar flexion position.

[0075] In this position, only the toe 3 is supported on the ground. The plate 6 has pivoted about the axis of the pivot connection 61, and the ankle support 4 fixed to the plate 6 has also pivoted about the axis of the pivot connection 61.

[0076] Further, since the heel 2 is rigidly connected to the plate 6, the heel 2 has also pivoted about the axis of the connection 61.

[0077] The damping element 5 pivots about the axis of the pivot connection 54 that connects the damping element 5 to the toe 3 through its first end 51, and pivots about the axis of the pivot connection 54 that connects the damping element 5 to the heel 2 through its second end 52.

[0078] In this position, the spring 53 of the damping element 5 is extended and the plate 6 is biased (i.e., bent).

[0079] Now the function of the prosthetic foot 1 during the user's step will be described starting from the dorsiflexion position when the heel 2 contacts the ground.

[0080] In the dorsiflexion position, the heel 2 contacts the ground and the toe 3 points upward.

[0081] At this position, the springs 53 are in their rest positions and the plate 6 is straight.

[0082] Due to its U-shaped cross-section, the heel 2 deforms so as to depress the damper 22, thereby attenuating the impact caused by the contact of the prosthetic foot 1 with the ground, thus stabilizing the foot. The heel 2 then stores energy.

[0083] The energy stored by the heel 2 is then restored to rotate the prosthetic foot from the dorsiflexion position to the flat position.

[0084] In this regard, the U-shaped cross-section of the heel 2 and the damper 22 return to their initial positions.

[0085] Once in the flat position, the heel 2 and the toe 3 rest on the ground; the plate 6 is straight and extends parallel to the damping element 5. When flat, the prosthetic foot 1 distributes the force between the rear part of the foot and the front part of the foot (i.e., between the heel 2 and the toe 3).

[0086] During the transition to the plantarflexion position, the center of gravity of the prosthetic foot 1 moves towards the front of the foot (i.e., towards the toe 3).

[0087] In this plantarflexion position, only the toe 3 rests on the ground.

[0088] The damping element 5 has pivoted respectively about the axis of the pivot connection 54 that connects it to the toe 3 and about the axis of the pivot connection 54 that connects it to the heel 2 through its first end 51 and second end 52. The heel 2 has also pivoted about the axis of the pivot connection 54 that connects it to the damping element 5. Therefore, it is no longer in contact with the ground. The plate 6 bends between its two ends and pivots about the pivot connection 33, thus supporting the movement of the prosthetic foot 1.

[0089] Therefore, the springs 53 of the damping element 5 are in the extended position, the plate 6 is bent, and the springs 53 and the plate 6 store energy together.

[0090] Next, the springs 53 and the plate 6 restore the stored energy to help the user lift the toe 3 off the ground and thus enter the propulsion phase.

[0091] After this propulsion phase, the user returns to the dorsiflexion position.

[0092] The user can then start the next step.

[0093] The coordinated action of the heel 2 and the plate 6 with the springs 53 attenuates the impact at the beginning and enables the energy to be restored naturally during the propulsion phase, thus ensuring a natural gait for the user (similar to that of a human foot).

[0094] In a variant not shown:

[0095] - The prosthetic foot includes multiple plates instead of a single plate, the multiple plates being hinged at one end to the toe and connected at the other end to the ankle support, so as to be able to adjust the stiffness of the prosthetic foot;

[0096] - The spring can be replaced by a hydraulic or pneumatic damper or any other device that allows adaptation to the desired walking type of the user, while also allowing energy to be stored and restored as described above (similar to the human body);

[0097] - The ankle support can include a movable member that allows the prosthesis to be movable along the front - rear axis or along multiple axes, and the movable member can be coupled to a damper and / or a carbon plate.

[0098] The present invention is not limited to the above - described embodiments and also encompasses any equivalent embodiments.

Claims

1. A prosthetic foot, which includes a heel (2) and a toe (3), as well as an ankle support (4) and a damping element (5). The heel (2) and the toe (3) are configured to be supported on the ground. The damping element (5) has two ends, with a first end (51) connected to the toe (3) and a second end (52) connected to the ankle support (4). Characterized in that the foot (1) further includes at least one plate (6). The at least one plate (6) is hinged to the toe (3) at one end and connected to the ankle support (4) at the other end. The damping element (5) is connected to the ankle support (4) by virtue of the plate (6), and the damping element (5) is also connected to the heel (2) through its second end (52). The damping element (5) is arranged parallel to the plate (6).

2. The prosthetic foot according to claim 1, Characterized in that the damping element (5) includes at least one tension spring (53). The tension spring (53) is connected to the toe (3) at one end by means of a pivoting connector (54) and connected to the heel (2) at the other end by means of another pivoting connector (54). The connectors (54) both form axes orthogonal to the symmetry plane of the toe (3).

3. The prosthetic foot according to claim 2, Characterized in that the damping element (5) includes one or two or three tension springs (53).

4. The prosthetic foot according to any one of the preceding claims, Characterized in that the plate (6) is hinged to the toe (3) by means of a pivoting connector (61), and the pivoting connector (61) forms an axis orthogonal to the symmetry plane of the toe (3).

5. The prosthetic foot according to any one of the preceding claims, Characterized in that the plate (6) is made of glass fiber.

6. The prosthetic foot according to any one of claims 1 to 4, Characterized in that the plate (6) is made of glass fiber and includes a carbon fiber layer.

7. The prosthetic foot according to any one of claims 1 to 4, Characterized in that the plate (6) is obtained by plastic injection or polymer injection.

8. The prosthetic foot according to any one of the preceding claims, Characterized in that the heel (2) has a U-shaped cross-section and includes a damper (22), and the damper (22) is arranged in the U-shaped cross-section of the heel (2).

9. The prosthetic foot according to any one of the preceding claims, Characterized in that the heel (2) includes at least one male connector (21), the plate (6) includes at least one female connector (62), and the ankle support (4) includes at least one female connector (41). The male connector (21) of the heel (2) is configured to interact with the female connector (62) of the plate (6) and with the female connector (41) of the ankle support (4).

10. The prosthetic foot according to any one of the preceding claims, Characterized in that The prosthetic foot further includes an adjustment element (7), which is configured to allow adjustment of the angle between the prosthetic foot (1) and the ground supporting the foot (1).

11. The prosthetic foot according to claim 10, characterized in that the adjustment element (7) is fixed to the plate (6).

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