Prosthetic foot insert

Abstract

The invention relates to a prosthetic foot insert (10) having a. A proximal fastening device (20) for fastening the prosthetic foot insert (10) to a proximal part (2) or a patient, b. A holder (30) which is arranged distally with respect to the fastening device (20) and which is connected to the fastening device (20), and c. A main spring (40) which extends into a forefoot region (11) and is coupled to the holder (30), the retaining part (30) is mounted on the main spring (40) in a pivotable manner in a sagittal plane, a rear limiting element (92) is arranged between the main spring (40) and the retaining part (30), said rear limiting element limiting a displacement of the retaining part (30) away from the main spring (40), and the fastening device (20) is mounted on the retaining part (30) in an articulated and longitudinally displaceable manner.

Description

[0001] This case is a divisional application of the patent application filed on January 24, 2020, with application number 202080010156.1 and invention title "Prosthetic Foot Insert". Technical Field

[0002] The present invention relates to a prosthetic foot insert having a proximal fixation device for securing the prosthetic foot insert to a proximal component or a patient, a retainer disposed distally relative to and connected to the fixation device, and a main spring extending in the forefoot region and coupled to the retainer. Background Technology

[0003] A prosthetic foot insert is a component of a prosthetic service device, for example, in the case of a lower leg amputee. The prosthetic foot insert may have a cover or prosthetic trim to achieve the most natural appearance possible and to provide additional functionality; the prosthetic trim may be made of plastic. The prosthetic foot insert may be fixed to the ankle joint or non-jointedly to the calf tube or calf socket. The fixation device is typically constructed as a so-called pyramid adapter, through which multiple settings and orientations of the prosthetic foot insert relative to the proximal component, i.e., the calf tube, prosthetic socket, or ankle joint, can be adjusted and fixed. The fixation device is fixed to a retainer, on which a spring extending in the forefoot direction, such as a forefoot spring or top spring, may be arranged. An elastic heel element is provided to dampen vibrations when the heel strikes the ground; this heel element is, if necessary, fixed to the retainer via an insert. Examples of prosthetic inserts are described in EP 2 420 212 A1, EP 1 976 463 A1, US 2005 / 0038525 A1 or EP 2 688 522 B1.

[0004] Problems with existing prosthetic foot inserts include the potential for structural space, unsatisfactory sinking, uneven rolling characteristics, and difficulty in compensating for unevenness. Furthermore, they require complex molding processes, which increase manufacturing costs and create difficulties in achieving optimal material utilization. Summary of the Invention

[0005] Therefore, the objective of this invention is to provide a prosthetic foot insert that achieves optimized characteristics when standing and walking, particularly providing sufficient stability when walking without sacrificing comfort.

[0006] According to the present invention, this task is solved by a prosthetic foot insert having the features of the present invention, the prosthetic foot insert having: a. A proximal fixation device for securing the prosthetic foot insert to a proximal component or a patient. b. A retaining member disposed at the distal end relative to and connected to the fixing device, and c. A main spring that extends into the forefoot region and is coupled to the retainer. d. The retainer is pivotally supported on the main spring in the sagittal plane, wherein a rear limiting element is arranged between the main spring and the retainer, the rear limiting element restricting displacement of the retainer away from the main spring. The fixing device is hinged to the ground and is movably supported on the retaining member in the longitudinal direction.

[0007] Advantageous configurations and further embodiments of the invention are disclosed in the specification and drawings.

[0008] The prosthetic foot insert has a proximal fixation device for securing the prosthetic foot insert to a proximal component of the prosthesis or to the patient, a retainer disposed distally relative to and connected to the fixation device, and a main spring extending into the forefoot region and coupled to the retainer. The prosthetic foot insert is configured such that the retainer is rotatably supported on the main spring in the sagittal plane. A posterior limiting element is disposed between the main spring and the retainer, limiting displacement of the retainer away from the main spring. The prosthetic foot insert can be constructed as a separate component capable of being secured to a distal prosthetic component, such as a calf tube or calf socket; or as a prosthetic foot insert integrally manufactured with a corresponding fixation device for securing the prosthetic foot insert to a patient or user, such as a device for osseointegral fixation to a patient; or, alternatively, as an integrated component of a calf socket.

[0009] Prosthetic foot inserts can be used as a base for other structures, such as mechatronic joints, ML adapters, adapters for adjusting heel height, hydraulic joint units, or the like.

[0010] The rear limiting element prevents the retainer from shifting away from the main spring beyond a predetermined limit. The rear limiting element defines the maximum distance between the rear end of the retainer and the main spring, particularly the rear end of the main spring, while allowing the retainer to continue moving in the opposite direction. Thus, on the one hand, the compression of the prosthetic foot insert is not negatively affected, or is only negligibly affected, under heel load or during heel strike, and on the other hand, it provides sufficient stability under forefoot load during rolling motion or during forward flexion while standing, thereby limiting, except for the elastic deformation that is theoretically possible during standing, the rotation in the sagittal plane in the forward direction about the tilt axis.

[0011] The main spring can be constructed as a combination of at least one distal spring and / or at least one proximal spring. In the case of, for example, two distal springs, the distal spring at the proximal end constitutes the medial spring, and the distal spring at the distal end constitutes the base spring or bottom spring, which preferably extends into the heel region of the prosthetic foot insert. The proximal spring is configured for a retainer or a guide element for the retainer. All springs are constructed, in particular, as leaf springs. Leaf springs can have a substantially rectangular cross-section and a uniform thickness in the longitudinal direction or a varying thickness, particularly gradually decreasing in the forward direction. The spring can be slotted in the forefoot region to allow for medial-lateral flipping of the prosthetic foot or to form openings or cutouts, for example, for receiving a toe strap of a sandal or similar shoe.

[0012] The distal and proximal springs of the main spring are preferably fixed to each other at a distance while creating free space, so as to achieve compression of the pseudo-foot under load and to make full use of the individual spring characteristics of each spring. The spring is particularly constructed of composite materials, especially fiber-reinforced plastics. The spring can be made of glass fiber, carbon fiber, aramid fiber, Kevlar fiber, Dyneema fiber, or other particularly high-strength fibers or combinations thereof embedded in the matrix.

[0013] In a further embodiment of the invention, the distal and proximal springs are biconvexly oriented relative to each other to form an increased free space in the intermediate region between the two springs. This free space is approximately elliptical in shape and allows for compression over a relatively long spring stroke in the middle or forefoot region. The proximal springs can also be biconvexly oriented relative to each other. In the biconvex formation between the distal and inner springs, an increased gap in the rearward direction can be formed between the distal or base spring and the inner spring in the rear region to achieve deep compression of the retainer toward the base or bottom spring.

[0014] In a further embodiment of the invention, the guide element is fixed to the main spring in either the front or rear region and extends in opposite directions, and the retainer is preferably pivotally supported on the main spring via the guide element about a pivot axis perpendicular to the sagittal plane. By supporting the retainer on the main spring via the guide element, different support and motion variables can be adjusted and changed, thereby achieving individual matching or increasing the number of variables. The retainer is not directly connected to and fixed to the main spring, for example, by directly screwing a leaf spring to the underside of the retainer base, but is pivotally supported, for example, via the guide element, hinge, or other intermediate element about an axis transverse to the direction of travel, which allows relative movement between the main spring and the retainer. The guide element can be fixed in either the front or rear region of the main spring, wherein the rear region of the fixing device is located after the fixing device or pyramid adapter, particularly after the force transmission point when standing. The front region is located before the fixing device, such as the pyramid adapter, or before the position of the bottom reaction force vector generated when standing. The guide element extends from its corresponding fixed region in opposite directions; that is, it extends in the forward direction when fixed in the rear region and in the rear direction when fixed in the front region. The retainer is rotatably supported on the main spring in the sagittal plane about the guide element, so that the oscillating motion is also achieved by the guide element as if the retainer were moving vertically relative to the main spring.

[0015] In a further embodiment, a front limiting element is positioned between the guide element and the retainer or main spring. This front limiting element restricts the displacement of the front end of the retainer away from the guide element or the displacement of the main spring away from the guide element under heel load. Similar to the case of the rear limiting element, the front limiting element prevents relative displacement of the retainer relative to the main spring during defined load phases, thereby influencing the compression and rebound characteristics of the prosthetic foot insert. Adjusting the length of the front and / or rear limiting elements can change the spring tension and achieve a match with the energy transfer characteristics of the foot in different gait phases. Similarly, changing the preload and / or length used to limit the displacement of the front and / or rear end of the retainer can achieve a match with different user habits, intended uses, or different or altered body characteristics of different users, and so on.

[0016] The corresponding limiting element can be constructed to be both rigid and flexible to ensure accurate adjustment of possible displacement and the distance between the retaining element and the spring, or between the spring and the limiting element or guide element. The limiting element can be constructed, for example, as a belt, cable, or rope, or as a tube guide with a stop element for correspondingly limiting the maximum distance.

[0017] The preload of this or these limiting elements is adjustable, particularly to allow for a clear distinction between walking with pulsating loads and standing with, in fact, static loads. Damping should occur during walking, especially during heel strike, but also during rolling movements, in case of corresponding displacement of the components. When standing, the user should have a sense of stability, achieved through preload on the retainer relative to the elastic element. This preload is preferably between 5% and 60% of the user's body weight, particularly between 5% and 40%, and especially preferably between 10% and 25%. In the latter case, the preload on the retainer by this or these limiting elements against the spring action of the main spring or other elastic element or component is between 10 kg and 25 kg in the case of a user with a body weight of 100 kg, corresponding to a force between approximately 98.1 N and 245.25 N.

[0018] The main spring and guide element are preferably constructed as leaf springs, particularly straight leaf springs, which has the advantage that the manufacture of the spring components is particularly easy. Especially when the main spring or its individual spring components are made of fiber-reinforced plastic, the main spring can be constructed with relative rigidity overall, thereby improving retention. The rigid spring configuration of the individual spring components achieves high retention of the spring components; however, the rigid spring configuration does not result in a particularly rigid false foot insert when the heel strikes the ground, as this is compensated for by a relatively large spring travel and long force transmission. The guide element can also be constructed as a leaf spring, particularly a metal leaf spring in the form of a spring tongue. Alternatively, the retainer can be supported on the main spring by a hinge or at least one spacer element, thus the guide element is constructed as a spring tongue, hinge, or spacer element.

[0019] To further adjust walking behavior and improve the adaptability of rolling characteristics, as well as to protect the distal section of the distal spring or main spring, the forefoot pad and / or heel pad can be fixed, for example, glued, screwed, or inserted onto the main spring, or, particularly in the case of the heel pad, held onto the main spring by appropriate limiting elements. The pad is preferably arranged on the base spring or bottom spring.

[0020] In a further embodiment of the invention, the force is transmitted from the retainer to the main spring via a front force transmission region and a rear force transmission region, wherein the force transmission regions extend before or after the fixing device, respectively. This allows the retainer to be supported on the main spring at two points or regions spaced apart along the longitudinal extension of the main spring, if necessary, by an intermediate element, an intermediate plate, or a damping device, or if necessary, by an intermediate spring. Support in the force transmission regions reduces point loads and controls force transmission under different load conditions. Preferably, the force transmission region is located between two end supports, with the main spring supported in the distal region on the end supports, for example, between the heel pad and the forefoot pad. This allows at least one four-point flexion when the patient is standing and the foot is on the ground, thereby significantly reducing the maximum flexural moment of the main spring due to a wider force distribution.

[0021] At least one of the force transmission regions can be displaceably or interchangeably supported on the retainer or main spring, thereby altering the spring characteristics and energy transfer characteristics of the prosthetic foot insert during use by adjusting the position of the respective force transmission region. The adjustment of the corresponding position of the force transmission region is preferably performed in one step to match the characteristics of the prosthetic foot insert to the corresponding user and can be adjusted and matched before the corresponding use. In principle, the position of the force transmission region can also be changed by a motor. The corresponding motor or drive unit can be adjusted during walking via control devices and sensor assemblies to match different speeds, loads, or walking conditions.

[0022] At least one damping device can be arranged between the retainer and the main spring to gently re-establish contact between the retainer and the main spring after the retainer has separated from the main spring in the front or rear region, or to dampen oscillating motion. This avoids disruptive force spikes and pulsations caused by contact between the retainer and the main spring during walking, which would result in uneven and unsuitable rolling characteristics for the patient. The oscillation characteristics of the retainer relative to the main spring can also be adjusted.

[0023] The retainer can be supported on the main spring with an adjustable proximal-to-distal distance, so as to achieve angular adjustment in the same way as changing the action characteristics and the timing of action, and thereby change the energy conduction.

[0024] In a further embodiment of the invention, in the unloaded state of the prosthetic foot insert, the main spring is elastically preloaded relative to the guide element by means of this limiting element and / or these limiting elements, so that the various components of the prosthetic foot insert are held together in the unloaded state solely by the preload of the main spring relative to the guide element. These limiting elements, or the limiting element itself, act between the retainer and the main spring. The guide element is arranged between the main spring and the retainer, and if only a vertical force is generated, i.e., no horizontal movement force is generated, the prosthetic foot insert stably holds the components together without additional stops. Additional stops or fixing elements are only used for stopping against generated lateral or shear forces. The fixing device may be movably and / or hingedly supported on the retainer so that it can be fitted to different requirements or patients.

[0025] If the fixing device is fixed to the retainer as a separate element, a damper can be arranged between the fixing device and the retainer. The damper allows for easy relative movement between the fixing device and the retainer, reduces load peaks, and achieves pulse-free, uniform rolling motion.

[0026] Advantageously, the fixing device is capable of swinging about the swing axis relative to the retainer.

[0027] Advantageously, the damper is configured as a hydraulic damper.

[0028] Advantageously, in addition to the damper, an actuator is provided to motor-adjust the tilt angle.

[0029] In a further embodiment of the invention, replaceable and / or movable contact elements are arranged between and / or between the proximal and distal springs, respectively. These contact elements allow for fixing, setting, or adjusting the corresponding force transmission points, coupling times, and coupling positions between the distal and proximal springs, or between the distal springs. The replaceable and / or movable contact elements enable the modification and matching of the compression and force transmission characteristics of the prosthetic foot insert in a simple manner.

[0030] The retainer can be rotatably supported on the main spring in the sagittal plane on a surface that allows for positional change, so that the retainer can roll on the main spring during loading and is allowed to displace relative to the main spring. The retainer thus does not have a fixed point of rotation relative to the main spring; rather, the point of rotation of the retainer moves during the rolling process.

[0031] The prosthetic foot insert is particularly suitable for and designed to match different heel heights or desired tilt angles, allowing for easy individual matching by the user. This can be achieved, in particular, by changing the length of one or more limiting elements. The corresponding limiting elements can be replaced, lengthened, or shortened and then fixed at the desired length, for example, by clamping. The retainer can be adjusted and fixed at a desired angular position relative to the bottom or main spring, for example, by replacing the pad, damping device, intermediate piece, internal piece, or spacer element between the retainer and the main spring, thereby achieving optimal orientation of the retainer and the fixing device. Matching to the corresponding heel height can be achieved by orienting and fixing at the desired position, based on the ability of the fixing device to swing before or after the vertical line. The position of the shaft support or shaft can be adjusted to achieve orientation and heel height matching. If a hydraulic damper, pneumatic damper, or adjusting cylinder is present, the desired position and orientation of the retainer can be adjusted by opening and closing the valve. The retainer is supported on the main spring with an adjustable proximal-to-distal spacing, allowing for matching to different sole thicknesses in the shoe while uniformly changing the spacing. If the spacing before and after the fixing device is changed differently, the tilt of the retaining member is adjusted as desired. For this purpose, the front and rear spacing can be adjusted individually as previously described by adjusting the adjusting cylinder or damping device, or by using an internal component or similar means. Attached Figure Description

[0032] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings: Figure 1 A schematic cross-sectional view illustrates a first embodiment of the prosthetic foot insert; Figure 2 Show Figure 1 A variant with a hinge; Figure 3 Show Figure 1 A variant with a bent guide element, Figure 4 A variant of the invention is shown with a retainer protruding at the rear; Figure 5a - 5c shows the load conditions under different load conditions. Figure 1 A variant with a pad; Figure 6 A variation of the invention is shown with a pad between the guide element and the main spring; Figure 7 Show Figure 6 Variations; Figure 8 A variant with a hinge and two springs is shown; Figure 9 Show Figure 8 Variations; Figure 10 A variant is shown with a height adjustment device in the retainer; Figure 11 A variant is shown with two springs that are guided in substantially parallel directions and a base spring that is bent in the opposite direction; Figure 12 A variant of the contact that can be displaced between the retainer and the main spring is shown; Figure 13 A variant with a sheath is shown; Figure 14 A variant of the invention with a delay element is shown; Figure 15 The basis shown under load Figure 14 The false foot insert; and Figure 16 The basis shown in the flipped position Figure 14 The false foot insert. Detailed Implementation

[0033] Figure 1 A schematic cross-sectional view shows a prosthetic foot insert 10 having a proximal fixation device 20 in the form of a pyramid adapter, which is reversibly fixed to a proximal component 2 in the form of a lower tube. Alternatively, the fixation device 20 may have a receiving portion for the lower leg stump or a connection device for osseointegration into the limb. The fixation device 20 may be integrally constructed, for example, within the framework of an additive manufacturing method and simultaneously form the stump receiving portion. Similarly, the proximal component 2 may also be integrally constructed onto the fixation device 20, for example, using an additive manufacturing method.

[0034] A retainer 30 is disposed at the distal end of the fixing device 20. The retainer may be integrally constructed with the fixing device 20 or may be constructed to be connected to a separately manufactured fixing device 20. The retainer 30 has an adjustable receiving portion 31 that protrudes rearward from the retainer 30 and is used to receive a rear restraining element 92. The length of the retainer 31 may be adjusted and fixed by a nut 32, which may be pre-tightened relative to the retainer 30.

[0035] The retainer 30 is fixed to the main spring 40 in the front region 41 and the rear region 42, which in the illustrated embodiment consists of three leaf springs 44, 45, and 46. In the illustrated embodiment, the retainer 30 is supported on the proximal spring 44 via the front force transmission region 410 and the rear force transmission region 420. A front damping element 50 is arranged between the front force transmission region 410 and the retainer 30, and is positioned on the receiving portion 910 for the front restraining element 91. A swing axis 110 is constructed between the force transmission region 410 and the proximal spring 44 below the damper 51, which can be constructed, for example, as an elastomeric damper, and extends substantially perpendicular to the leaf plane or orthogonal to the sagittal plane and substantially horizontally. The retainer 30 can rotate about the rotation axis 110 relative to the main spring 40, and particularly relative to the proximal spring 44. Not only the front limiting element 91 but also the rear limiting element 92 is guided around the distal spring 46 or the base spring 46 and has a preload in the unloaded state of the illustrated prosthetic foot insert 10, which is caused by the deformation of the leaf springs 44, 45, and 46. This preload holds all components of the prosthetic foot insert 10 together. In the region of the front limiting element 91, a contact element 48 is arranged between the rear leaf spring 45 or the inner spring 45 and the distal spring 46, the position of which is movable in the front-rear direction. The contact element 48 can be replaced, for example, to determine the position of force transmission between the inner spring 45 and the distal spring 46. Depending on the position in the front or rear direction, the compression characteristics are changed based on different force transmission points. A contact element 47 is also arranged between the front end of the inner spring 45 and the front end of the distal spring 46, which is movably or replaceably supported thereon. The spring characteristics of the prosthetic foot insert 10 can be adjusted by the material selection, size, and position of the contact elements 47 and 48.

[0036] Furthermore, a guide element 80 is arranged between the proximal spring 44 and the retainer 30. This guide element is fixed in the rear region 42, i.e., in the region where the force is transmitted rearward to the fixing device 20, for example by screwing, bonding, welding, form-fitting, or clamping to the retainer 30. The guide element 80 extends through the front force transmission region 410 to the front end region of the proximal spring 44 and is configured as a spring plate to allow the retainer 30 to flip relative to the main spring and to allow the retainer 30 to roll on its upper side of the proximal spring 44 within the region of the front force transmission region 410.

[0037] The limiting elements 91 and 92 can be specifically constructed as straps, ropes, or cables, and can be constructed as loops and guided around the upper or lower side of the retainer or base spring 47. It is also possible that the limiting elements 91 and 92 are held tensioned between the retainer 30 and the receiving portion on the base spring 47 as telescopic tubes or flexible yet tensile-rigid ropes. The prosthetic foot insert 10 is embedded in the foot ornament 3 and can be replaceably fixed to the foot ornament.

[0038] The limiting elements 91 and 92 can be individually or both adjustable, particularly shortenable or extendable. Alternatively, the preload between this or these limiting elements 91 and 92 and the retainer 30 and / or the base spring 46 can be changed by built-in elements or spacers. Alternatively, the preload can be changed by replacing the limiting elements 91 and 92 with elements of different lengths. To prevent slippage when the limiting elements 91 and 92 are unloaded or the preload is removed, the limiting elements 91 and 92 can be form-fitted into corresponding receiving portions. The receiving portion 93, having a through portion or a device for securing the limiting element 92, is provided, for example, on the rear end of the base spring 46. The receiving portion 93 can also function as a pad.

[0039] If, for example, a heel load exceeding that of a standing foot is applied upon heel strike, the three springs 44, 45, 46 of the base spring 40 are compressed such that the retainer 30 is subjected to an axial force toward the bottom via the rear force transmission region 42 and the main spring 44 is compressed in the rear region, thereby unloading the rear restraining element 92 while the front restraining element 91 remains taut. During continued foot load, uniform compression, particularly of the proximal spring 44 and the inner spring 45, occurs in the substantially vertical force transmission from the proximal member 2 to the fixing device 20, thereby unloading these two restraining elements 91, 92. If the proximal member flips forward in the forward direction during a forward step, the rear end of the retainer 30 is lifted from the proximal spring 44, resulting in separation or a gap between the rear force transmission region 420 and the proximal spring 44. The retainer 30 is then stopped by the guide element 80 in the inner-outer direction and against rotation relative to the main spring 40. The rolling can be achieved relatively easily without very high resistance, based on the retainer 30 being tumbled or oscillatingly supported on the main spring 40. Once the oscillation angle becomes so large that the gap between the rear end of the retainer 30 and the rear end of the base spring 46 becomes so large that the rear limiting element 92 is tensioned, the base spring 46 is additionally activated and provides additional reaction force against further forward oscillation. This allows for activation of switching between the individual springs 44, 45, 46 during the walking cycle, as the maximum oscillation stroke of the retainer 30 relative to the proximal spring 44 is limited. This limitation is achieved by the limiting element 92.

[0040] Figure 2 A variant of the prosthetic foot insert 10, also featuring three springs 44, 45, and 46, is shown, wherein the proximal spring 44 and the medial spring 45 are arranged biconvexly opposite each other, thereby forming an elliptical or nearly elliptical free space 400. A free space 401 is also formed in the rear region between the underside of the medial spring 46 and the upper side of the distal spring 45 to allow for compression upon heel strike.

[0041] according to Figure 2 The variant has receiving portions 910 and 940 in the front and rear regions of the retainer 30, configured as slots for receiving corresponding limiting elements 91, 92. Receiving portions 920, 930 are also configured on the base spring 46, serving as protection for the base spring 46 and simultaneously preventing undesirable displacement of the corresponding limiting elements 91, 92. The receiving portion 930 on the rear end of the base spring 46 has a through-hole preventing the limiting element 92 from disengaging during unloading. The receiving portion 930 is configured in the heel pad 100, with the forefoot pad 120 arranged on the front end of the base spring 46. Replaceable or movable contact elements can be arranged between the springs, shown by reference numeral 49 only between the rear end of the proximal spring 44 and the inner spring 45 in the illustrated embodiment. A damping element 52, acting as an elastomeric damper, can be arranged between the retainer 30 and the proximal spring 44. The front end of the retainer 30 is connected to the spring 44 via a hinge, allowing the retainer 30 to swing relative to the proximal spring 44, but preventing it from separating from the proximal spring in the vertical direction. The hinge support is form-fitted to the proximal spring 44 to withstand torque, thus preventing rotation about the vertical axis. However, rotation about a substantially horizontal swing axis 110 extending longitudinally perpendicular to the direction of travel or the prosthetic foot insert is possible. The hinge can be secured, for example, in the rear region 42 of the main spring 40 by a spring plate or spring element, but can also be secured in the front region 41 by clamping or other form-fitting fasteners.

[0042] exist Figure 3 The diagram illustrates another variation of the invention, with the spring structure substantially corresponding to... Figure 1 Alternatively, a spring structure of type 2, wherein the difference is that the retainer 30 is fixed to the main spring 40 by a guide element 80. Figure 1The guide element 80 extends from the front end region of the proximal spring 44 to the rear end region of the retainer 30. The illustrated embodiment features a bent guide element 80 or a multi-piece guide element 80, which is first secured to the proximal spring 44 in the front region 41, for example, by an elastomeric damper 51 or a fixing element. The guide element 80 extends from the front region 41 to the rear region 42 of the proximal spring 44 and from there forward until it extends below the front limiting element 91 near the front damper, where it is held under the retainer 30 by a fixing element 61. The bent configuration of the guide element 80, which may be configured, for example, as a spring plate, allows for forward rotation about the front swing axis 110 in the region of the front force transmission region 410 and, furthermore, backward rotation about the rear swing axis 111 above the rear damper 52 in the rear region 42. The rear swing shaft 111 functions, for example, to shift rearward under axial load, until the front limiting element 91 is switched on due to the corresponding shift and spring unloading. Alternatively, in an integrated, bent embodiment of the guide element, the guide element can also be constructed in two pieces and connected in the rear region.

[0043] exist Figure 4 The diagram illustrates another variation of the invention in which a guide element 80 extends from a rear region 42 on the main spring 40 to a front region 41 on the retainer 30 and is clamped therein or secured by a front fixing element 61, the guide element being held on the main spring, for example by a fixing element 62 in the form of a clip or clamp. Dampers 51, 52 may be arranged between the fixing elements 61, 62 and the proximal spring 44 or the retainer 30 to achieve soft contact between the retainer 30 and the spring 44 during walking. Restricting elements 91, 92 are configured as loops, the front loop being guided from the inside out around the prosthetic foot insert 10, and the rear restricting element 92 being guided on the inside and / or outside. Multiple restricting elements 92 may also be arranged on the inside and / or outside of the retainer 30 and the base spring 47.

[0044] In the appendix Figures 5a to 5c The image shows different load phases of the pseudofoot insert 10 in another embodiment. Figure 5aThe illustration shows a pseudofoot insert 10 within a foot ornament 3, having a substantially horizontally oriented retainer 30, which is supported at its anterior end on a distal spring 46 by a double-spring assembly having a proximal spring 44 and an inner spring 45. A bottom spring 43 is arranged below the distal spring 46, and a heel pad 100 and a forefoot pad 120 are arranged on the bottom spring. The distal spring 46 and the bottom spring 43 are fixed to each other at the anterior end of the distal spring 46, generally in the region of the forefoot pad 120. The distal spring 46 may extend to the forefoot tip or the anterior end of the bottom spring 43. A contact element 47 is arranged between the upwardly curved distal spring 46 and the base spring 43, which can adjust the force transmission point, particularly under heel load.

[0045] The stiffness of the prosthetic foot insert 10 against overturning in the front-to-back direction can be adjusted by preloading the two restraining elements 91 and 92, which are constructed as bands. The greater the preload of the restraining elements 91 and 92, the more rigid or stable the prosthetic foot insert is.

[0046] exist Figure 5b The arrangement and characteristics of the prosthetic foot insert 10 under strong heel load are schematically shown. The rear portion of the retainer 30 is loaded and pressed against the rear end of the distal spring 46, which is compressed toward the rear end of the base spring 43. Because the front end of the distal spring 46 is fixed to the forefoot region of the base spring 43, the distal spring bends in the middle foot region via the contact element 47, thus achieving three-point bending. Furthermore, a vertically downward force is applied to the double springs 44 and 45 based on the preload of the restraining element 91 before the contact element 47. Figure 5b As shown, the limiting element 92 is completely unloaded, and a guide device is arranged after the retainer 30 not only for the distal spring 46 but also for the retainer 30, the guide device preventing the rear limiting element 92 from slipping off the retainer 30.

[0047] During rolling, for example, under forefoot load generated after a so-called roll over, the front region of the retainer 30 is loaded and supported by two springs 44, 45 on the distal spring 46 and by the distal spring 46 on the base spring 43. The force transmission point is defined by the contact element 47 and altered by movement along the longitudinal extension of the spring. The proximal spring 44 and the inner spring 45 move toward each other, thereby reducing or minimizing the free space 400 between the two springs. The rear end of the retainer 30 is displaced upward by its pivotal support on the proximal spring 44 until it contacts the rear restraint element 92. In this state, the rear end of the retainer 30 is lifted from the distal spring 46.

[0048] Figure 6A further variation of the prosthetic foot insert 10 is shown, featuring a retaining element 80 in the form of a spring tongue, which is secured to the underside of the retainer 30 by a bolt 62 or other retaining element. The retainer 30 is supported not only on the proximal spring 44 but also on the upper side of the guide element 80 by a pad 53. Under forefoot load, the retainer rotates about an indeterminate axis of oscillation in the support region of the pad 53 until the rear restraining element 92 prevents further oscillation relative to the proximal spring 44. The guide element 80 extends to the front end of the proximal spring 44 and is held there by a retaining element 61, such as a hook, clip, or strap. The distal spring 46 terminates at approximately the same height as the proximal spring 44. The medial spring 45 continues to extend forward beyond the forefoot pad 120. In the rear region, dampers 51 and 52 are arranged between the retainer 30 and the proximal spring 44, and between the proximal spring 44 and the inner spring 45, to induce a damping pulse when the spring is lifted from the retainer 51 or when the spring contacts the retainer. The dampers 51 and 52 are preferably fixed on one side to the retainer 30 or one of the springs 44 and 45 to allow the components to move away from each other. In the case of highly elastic materials, the dampers 51 and 52 may also be bonded to the components on both sides.

[0049] Figure 7 Show Figure 6 A variant of this design, which has a similar structure in principle, however, instead of a latch or clip, has a bolt as a fixing element 61 passing through all the springs 44, 45, 46, which prevents the springs 44, 45, 46 from moving relative to each other under load. Pads or dampers 54, 55 are arranged between the springs 44, 45, 46 respectively, and similarly, pad elements can be arranged between the head of the bolt 61 and the proximal spring 44, and between the nut and the distal spring 46. By clamping in the forefoot region, the springs 44, 45, 46 are subjected to superimposed moments upon deformation, thereby shortening the free spring length. The clamping of the bolt 61 prevents shear slippage and generally makes the pseudo-foot insert 10 more rigid than in solutions where the springs move relative to each other.

[0050] Figure 8A further variation of the invention is shown, featuring a guide element 80 configured as a hinged retraction of a retainer 30, the retainer being oscillating about a swing axis 110 at its front end. The rear end of the retainer 30 is limited by a rear limiting element 92 and by the maximum oscillation of the rear end about the distal spring 46. The guide element 80 extends into the forefoot region and is arranged on the base spring 46 together with the distal spring by a fixing element 61. A damper 51 is arranged between the retainer 30 and the guide element 80, the guide element extending to the rear end of the retainer 30, and similarly, for example, an additional damper 52 is arranged between the guide element 80 and the rear end of the proximal spring 44.

[0051] Figure 9 Show Figure 8 A variant in which a bottom guide element 88 is arranged to receive and guide the main spring 40 instead of a base spring. The guide element 80 and the bottom guide element 88 are connected to each other in the region of the forefoot pad 120 by a fixing element 61, and the guide element 80 has an extension tongue at its front end, by which it is elastically and springily supported on the bottom guide element 88.

[0052] Figure 10 Showing according to Figure 8 A variant configuration in which a damper 50 is arranged between the retainer 30 and the fixing device 20, such that not only is the retainer 30 oscillatingly supported relative to the proximal spring 44 about the swing axis 110, but the fixing device 20 is also oscillating relative to the retainer 30 about the swing axis 110. The fixing device 20 is shown in three positions: solid lines indicate the basic setting, dotted lines indicate the forward-flipped position of the fixing device 20, and dashed lines indicate the downward-flipped position of the fixing device 20.

[0053] In addition to the configuration of damper 50, an actuator can also be provided, through which the tilt adjustment can be achieved by a motor, thereby matching, for example, different heel heights. If the device is configured as damper 50, a constant force or constant torque can cause the adjustment to descend or tilt forward. Slow descent or rise achieves precise adjustment, for example, by closing the corresponding regulating valve in the desired position and locking the damper 50 of the hydraulic damper in its configured position.

[0054] Figure 11 Show Figure 6A variant with a retainer has a shape on its underside that approximates the shape of the upper side parallel to the proximal spring 44. A contact element 47 between the distal spring 46 and the inner spring 45 is arranged in the region of the front limiting element 91. Pads 51 and 52 are secured in the rear region of the pseudo-foot insert by the rear limiting element 92 to prevent lateral displacement. A guide device on the rear end of the distal spring 46 prevents the pads 51 and 52 from shifting rearward. A guide element 80 extends from the rear end in the rear region 42 to the front end of the springs 44, 45, and 46 and is secured to the front end by bolts 62. Not only the springs 44, 45, and 46, but also the guide element 80 are clamped and form-fitted by bolts 62, thereby superimposing a thrust torque on the springs during deformation, thus shortening the overall free spring length.

[0055] According to Figure 11 As in all other embodiments, stabilization is possible by fixing the limiting element 91, 92 or at least one of the limiting elements 91, 92 to the retainer 30 and the distal spring 46 or the heel pad 100 to prevent inversion and / or supination, since this prevents the corresponding limiting element 91, 92 from moving relative to the retainer 30 and / or the distal spring 46, allowing only compression under the corresponding axial load.

[0056] According to Figure 11 In this embodiment, the proximal spring 44 and the inner spring 45 are shaped to be substantially parallel, thereby reducing the compression space while achieving a gentler overall rolling motion. The distal spring 46 is bent away from the inner spring 45, thereby creating a rearwardly increasing gap between the distal spring and the inner spring and creating a free space between the distal spring and the inner spring that extends substantially to the front limiting element 91 or the contact element 47.

[0057] Figure 12 Showing something similar to Figure 6Another variation of the implementation, however, lacks the guide element and instead has a pad 51 in the front region of the retainer 30. In the region below the retainer 20, a contact element 48 is arranged between the lower side of the retainer 30 and the upper side of the proximal spring 44, springs 44, 45, 46 being secured to each other by bolts 42 and coupled to the forefoot pad 120. The location of the pressure point or force transmission point is defined by the positioning of the contact element 48. As long as there is heel load and the forefoot is not on the ground, the rolling point of the heel determines the force transmission point. The rear restraint element 92 is unloaded, and springs 44, 45, 46 are compressed in the heel region and displaced toward each other. The front restraint element 91 is tensioned and prevents the retainer 30 from displaced from the proximal spring 44. As long as the forefoot is on the ground, the front restraint element 91, for example, is unloaded, the distal spring 46 and the rear end of the retainer 30 move away from each other, and the rear restraint element 92 is tensioned up to a set maximum distance. The further forward the contact point between the retainer 30 and the proximal spring 44 is positioned in the forward direction, the softer the axial deflection must be.

[0058] exist Figure 13 The diagram illustrates another variation of the invention, the spring structure of which substantially corresponds to... Figure 12 In addition to the limiting elements 91 and 92, a functional sleeve 200 is arranged around the spring member and the retainer. The functional sleeve 200 is constructed in a sock-like manner and is used in addition to the foot ornament 3. In the illustrated embodiment, the functional sleeve 200 does not surround the heel pad 100 and the forefoot pad 120; however, the sleeve may also include the heel pad and the forefoot pad. The functional sleeve 200 may be made of a material with matching elasticity, non-stretchable or high strength and is particularly used to reduce friction and thus noise within the prosthetic foot. Additional straps or tensioning elements 93 and 94 may be used with the functional sleeve 200 to adjust the elastic and rolling characteristics and energy transmission characteristics of the prosthetic foot insert 10; the tensioning elements 93 and 94 may also be integrated into the functional sleeve 200.

[0059] Figure 14 A variant is shown with a retainer 30, on the front end of which a cylinder chamber 71 is constructed or arranged to receive a movable piston 70. The piston 70 is supported on a proximal spring 44 by a piston rod 72. Additionally, the retainer 30 is connected at its rear end to the front end of the proximal spring 44 by a guide element 80. The guide element 80 is coupled to the spring 44 in the front region by a fixing element 61. The inner spring 45 and the distal spring 46 are individually connected to each other by bolts 62.

[0060] The retainer 30 is pivotally supported on the proximal spring 44 about the pivot axis 110 via the contact element 49. During heel load, such as in Heel Strike, up to the early standing phase with the prosthetic foot insert flat on the ground, the piston 70 is inactive within the cylinder chamber 71, thus no axial force is applied to the proximal spring 44 via the piston rod 72. Once rolling motion begins and increasing forefoot load is applied, the piston 70 contacts the upper cylinder chamber boundary and pressure is applied to the spring via the piston rod 72. This transmits axial force to the master spring 40 from a predetermined point in time and prevents or makes further forward displacement or forward roll difficult, thus preparing the user with improved stability from the intermediate standing phase. Rolling and slight roll around zero are achieved by the clearance of the piston 70 within the cylinder chamber 71. A restoring force can be provided via the guide element 80.

[0061] Figure 15 The following position is shown, in which the piston 70 abuts against the upper side of the cylinder 71 under high axial load and applies pressure to the spring. The rear restraint element 92 is relieved of force, and the rear end of the guide element 80 is lifted from the upper side of the proximal spring 44.

[0062] Figure 16 Showing according to Figure 14 and 15 The pseudofoot insert is in the following state, in which the retainer 30 flips in the opposite direction of travel, the piston 70 contacts the lower side of the cylinder chamber 71 and prevents it from continuing to swing in the opposite direction in a clockwise direction, and thereby prevents the retainer 30 or the front end of the retainer 30 from continuing to move away from the proximal spring 44.

[0063] In all embodiments of the invention, the prosthetic foot insert 10 is constructed relatively flat, thus making it theoretically possible for the prosthetic foot insert 10 to be used with an additional prosthetic foot joint or to be fitted to patients with long lower leg stumps, such as amputation stumps. The few components that are easy to manufacture and do not require complex molding methods facilitate both manufacturing and robust and reliable design, which can be easily matched by orthopedic technicians to the different needs and usage variations of the respective users. The mechanical configuration of the prosthetic foot insert 10, with its limited range of motion, requires little or no maintenance, thus allowing for individual fitability and, if necessary, modifiability during the duration of use with minimal service costs.

[0064] In most embodiments of the invention, three leaf springs are arranged, which can be divided into two functional pairs. The proximal and medial springs typically function as forefoot springs, while the medial and distal springs primarily function as heel springs. The distal spring is also connected at the end of forefoot movement. Similarly, during normal standing load, the heel is preloaded in the unloaded state by a restraining element, just like the forefoot. The retainer is fixed to the spring assembly, typically to the proximal spring, by a guide element. The force transmission point is adjusted by at least one contact element arranged between the retainer and the proximal spring, thereby regulating the transition from heel load to the standing phase and forefoot load. A second contact point in the region of the physical stability point in front of the fixation device functions to define the force transmission point during forefoot load. The spring stiffness of the entire system is changed by shifting the contact points or contact elements between the respective springs without altering the configuration of the individual springs and thus without changing the overall structure of the prosthetic foot insert. During standing, under normal load in the prosthetic foot, the axial force is evenly distributed across the patient's two feet.

[0065] Typically, the spring is preloaded so much that the two restraining elements or the rear restraining element are not yet unloaded. In other words, the preload is selected through the restraining elements or preload elements to provide sufficient stability through the prosthetic foot insert during standing, thus giving the user a sense of security. Under forefoot load, i.e., during slight forward flexion, a gentle rolling process occurs based on the receptivity of the retainer around the swing axis, and energy is also stored in the spring, achieving energy transfer from the heel spring to the forefoot load.

[0066] Furthermore, it is possible to achieve a uniform descent and movement that matches the natural walking motion by adjusting the spring to provide descent during the intermediate standing phase. The energy stored in the spring during the intermediate standing phase is released during continued walking, making forward movement easier.

[0067] Especially after the swing phase, when the foot lands, i.e., when the heel strikes, the prosthetic foot insert provides multiple spring strokes in the heel. Furthermore, the spring preload can be preloaded by a limiting element in the heel area. At the end of the standing phase, when the forefoot is loaded, all three springs or all springs work together. The user moves in the walking direction due to the energy transfer from heel strike during rolling to the forefoot at the end of the standing phase, as there is no upward vertical movement due to descent during rolling. Therefore, a technically short prosthetic foot insert is possible without giving the user the feeling of sinking into a pit at the end of the standing phase, because an unnatural early rolling and a drop in the center of gravity occur in a mechanically short foot. Descent is achieved through uniform spring preload in the middle of the standing phase via the prosthetic foot insert, and this spring preload causes a lift at the end of the standing phase when the springs in the forefoot are unloaded.

[0068] In addition to the location of the contact elements, the shape and size of the contact elements also determine the walking characteristics and energy transmission. The narrower the contact elements and the narrower the force transmission area, the more accurate and appropriate the characteristics will be; the wider the contact elements or the force transmission area, the softer the walking feel.

[0069] Preferably, the spring is perpendicular or nearly perpendicular to the load orientation. In the case of a leaf spring, the longitudinal extension is thus substantially perpendicular to the load direction, thereby making optimal use of the material properties of the leaf spring. The preload of the spring is advantageously chosen so that no deformation or only minimal deformation occurs during normal standing, thereby keeping the force transmission point stable and achieving smooth standing without excessive stiffness.

[0070] List of reference numerals 2 - Proximal components 3 - Foot ornaments 10 - Prosthetic Foot Insert 20 - Fixture 30 - Retaining parts 40 - Main Spring 41- Front Area 42 - Back Area 43 - Base Spring 44 - Proximal Spring 45 - Inner Spring 46 - Distal spring 47 - Contact Elements 48 - Contact elements 49 - Contact Elements 50 - Dampers 51 - Dampers 52 - Dampers 53 - Pad 54 - Pad 55 - Pad 60 - Sliding support 61 - Fixed Components 62 - Bolt 70 - Piston 71 - Cylinder 72 - Piston Rod 80 - Guide element 88 - Bottom guide element 91 - Limiting Components 92 - Limiting Components 100 - Heel Pads 110 - Swing axis 111 - Swing Axis 120 - Forefoot pad 200 - Package 400 - Free Space 401 - Free Space 410 - Force Transmission Region 420 - Force Transmission Area 910 - Receiving Department 920 - Receiving Department 930 - Receiving Department 940 - Receiving Department.

Claims

1. A prosthetic foot insert (10) having: a. proximal fixation means (20) for fixing the prosthetic foot insert (10) on a proximal component (2) or on a patient, b. a holder (30) arranged distally relative to the fixation means (20) and connected with the fixation means (20), and c. a main spring (40) which extends into a forefoot region (11) and is coupled with the holder (30), a rear limiting element (92) is arranged between the main spring (40) and the holder (30), which limits the displacement of the holder (30) away from the main spring (40), characterized in that the fixation means (20) is supported on the holder (30) in a hinged and longitudinally movable manner. The main spring (40) is configured as a combined spring having at least one proximal spring (44) and at least one distal spring (45, 46). The proximal spring (44) and the distal spring (45, 46) are fixed on one another at a distance from one another with a free space (400, 401) being formed. The proximal spring (44) and this or these distal spring(s) (45, 46) are oriented relative to one another in a biconvex manner. d. the retaining element (30) is pivotably supported on the main spring (40) in the sagittal plane, wherein A guide element (80) is fixed on the main spring (40) in a front region (41) or a rear region (42) and extends in opposite directions, respectively, and the holder (30) is supported pivotably by the guide element (80). A front limiting element (91) is arranged between the guide element (80) and the holder (30) or the main spring (40), which limits the displacement of the front end of the holder (30) away from the guide element or the displacement of the main spring (40) away from the guide element (80) upon heel loading.

2. The prosthetic foot insert according to claim 1, characterized in that The main spring (40) and the guide element (80) are configured as leaf springs.

3. The prosthetic foot insert according to claim 2, characterized in that The limiting elements (91, 92) are configured rigidly and flexibly in a pulling manner.

4. The prosthetic foot insert according to claim 2 or 3, characterized in that A forefoot pad (120) and / or a heel pad (100) is fixed on the main spring (40).

5. The prosthetic foot insert of any one of claims 1 to 3, characterized in that The holder (30) is supported on the main spring (40) by a spring tongue, a hinge or at least one spacer element.

6. The prosthetic foot insert according to claim 5, characterized in that The holder (30) conducts forces into the main spring (40) via a front force transmission region (410) before the fixation means (20) and a rear force transmission region (420) after the fixation means (20).

7. The prosthetic foot insert according to claim 5, characterized in that At least one of the force transmission regions (410, 420) is displaceably or exchangeably supported on the holder (30) or the main spring (40).

8. The prosthetic foot insert according to claim 6, characterized in that At least one damping means (51, 52) is arranged between the holder (30) and the main spring (40).

9. The prosthetic foot insert of any one of claims 1 to 3, characterized in that The holder (30) is supported on the main spring (40) with an adjustable proximal-distal spacing.

10. The prosthetic foot insert of any one of claims 1 to 3, characterized in that ​ 11. The prosthetic foot insert of any one of claims 1 to 3, characterized in that ​ 12. The prosthetic foot insert according to claim 11, characterized in that ​ 13. The prosthetic foot insert of any one of claims 1 to 3, characterized in that ​ 14. The prosthetic foot insert of any one of claims 1 to 3, characterized in that ​ 15. The prosthetic foot insert of any one of claims 1 to 3, wherein In the unloaded state, the main spring (40) is elastically preloaded relative to the guide element (80) by the limiting element (91, 92).

16. The prosthetic foot insert of claim 1, wherein Between the fixing device (20) and the holder (30) a damper (50) is arranged.

17. The prosthetic foot insert of claims 1 or 16, wherein, The fixing device (20) can be pivoted relative to the holder (30) about a pivot axis (110).

18. The prosthetic foot insert of claim 16, wherein, The damper (50) is configured as a hydraulic damper.

19. The prosthetic foot insert of claim 16, wherein, In addition to the damper (50) an actuator is provided, by means of which the inclination is motorically adjustable.

20. The prosthetic foot insert of any one of claims 2 to 3, wherein, Between the proximal spring (44) and the distal spring (45) and / or between the distal springs (45, 46) a replaceable and / or movably supported contact element (47, 48, 49) is arranged.

21. The prosthetic foot insert of any one of claims 1 to 3, wherein, The holder (30) is pivotably supported on the main spring (40) on a positionally variable surface in the sagittal plane.

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