Orthopedic equipment and shock absorbers

Description

[0001] The invention relates to an orthopaedic device with a piston for arrangement in a damper with a cylinder, in which the piston is mounted so as to be displaceable relative to the cylinder, wherein the piston has a base body on the outside of which at least one contact element is arranged, which is displaceable towards the cylinder and coupled to an elastic element. The invention also relates to a damper with a cylinder and such a piston.

[0002] Damping devices, particularly in prosthetic and orthotic systems or devices, can be designed as hydraulic or pneumatic dampers, in which a piston within a cylinder is subjected to a force via a piston rod. The hydraulic or pneumatic medium is displaced from a piston chamber by the piston, deflected, for example, by a valve or throttle, and diverted into a reservoir or into a volume located behind the piston. The passage of the medium through a throttle dissipates kinetic energy and removes kinetic energy from the system.

[0003] Pneumatic and hydraulic systems require a relatively high level of effort to be protected against leaks. Motion seals are present, and it is also necessary to design, install, and fit throttles, valves, check valves, and the like, making these damping devices relatively complex.

[0004] However, in both prosthetics and orthotics there is also a need for simple dampers and associated components that make it possible to implement simple damping, for example swing phase damping in a knee joint, in an inexpensive and robust manner.

[0005] From CN 201768054 U, a prosthetic knee joint with a solid damper is known, in which an expanding sleeve is guided in a cylinder. The distance between two cones can be changed and the expanding sleeve widened via a threaded rod.

[0006] GB 2 499 859 A relates to a lower extremity prosthesis comprising an attachment section, a lower leg section, a foot section, a knee joint that pivotally connects the attachment section and the lower leg section, and an ankle joint section that pivotally connects the lower leg section and the foot section. A damping device is assigned to each joint to dampen the pivoting movement. The damping device is sensor-controlled and may have a hydraulic and a pneumatic section. Valves are opened or closed to change the damping characteristics.

[0007] US Patent 2013 / 0264157 A1 concerns a pneumatic damper that operates without adjustment. A piston is located inside a cylinder and incorporates a check valve. A corresponding check valve is located in the cylinder housing. If the volume within the chamber associated with the cylinder-side check valve increases, the cylinder-side check valve opens; if the volume decreases, the check valve in the piston opens.

[0008] US Patent 2010 / 0049332 A1 relates to a prosthetic leg with a cylinder in which a piston is longitudinally mounted on a piston rod. The piston rod is mounted on an outer tube, and the lower part of the cylinder is attached to an inner tube. The inner tube is inserted into the outer tube. A pneumatic or hydraulic fluid is located within the cylinder, and the inner and outer tubes form a receptacle for a torsion element. The outer tube can be rotated around the inner tube. The torsion element has an elastomer attached to the outer tube.

[0009] From DE 10 2014 006 688 A1, a piston for arrangement in a damper and a damper for an orthopaedic device are known, comprising a cylinder in which the piston is displaceably mounted relative to the cylinder and has a base body. At least one deformation element made of a preferably elastic, incompressible material is arranged on or in the base body, to which at least one displaceable pressure device is assigned, which acts at least partially on the at least one deformation element, wherein the deformation element bulges at least partially outwards when a pressure force is applied at a location different from the point of force application.

[0010] DE 10 2013 016 800 A1 relates to a damper device with a piston in which a movable closure element is mounted to allow or prevent pneumatic flow, thus enabling position-independent and direction-controlled venting. A closure element rests against a cylinder wall to open or close a flow channel. An actuating element can press a clamping element against the cylinder wall. In one embodiment, it is shown that the clamping element presses against the contact element via the actuating element, thereby adjusting the preload of the piston ring.

[0011] The object of the present invention is to provide an orthopaedic device comprising a piston for a damper device and a damper as such, with which the resistances can be easily adjusted and the set resistance maintained over a long period of time.

[0012] According to the invention, this problem is achieved by a damper having the features of the main claim and an orthopaedic device having the features of the dependent claim. Advantageous embodiments and further developments of the invention are disclosed in the dependent claims, the description, and the figures.

[0013] The damper according to the invention, comprising a piston and a cylinder in which the piston is displaceably mounted relative to the cylinder, wherein the piston has a base body on the outside of which at least one contact element is arranged which is displaceable in the direction of the cylinder and coupled to an elastic element, provides that the elastic element can be pre-tensioned in the displacement direction of the contact element via an adjustment device.

[0014] The preload of the elastic element allows a constant or nearly constant force to be exerted on the contact element, so that the contact element is pressed against the inner cylinder wall with a constant force, thereby compensating for tolerances and material loss due to abrasion. Furthermore, despite abrasion, constant friction is exerted both between the contact element and the cylinder, and between the opposing surface of the base body and the inner cylinder wall. The surface opposite the contact element provides the abutment or counterforce.

[0015] An additional friction element can be attached to the surface opposite the contact surface on the base body. This friction element is connected to the base body, and in particular, is fixed to it in a replaceable manner. The friction element can be slightly flattened compared to the radius of the base body to create a larger contact area on the inner wall of the cylinder.

[0016] The contact element, or contact surface, is preferably mounted to be movable exclusively transversely to the direction of movement of the piston and moves out of the base body towards the cylinder wall or away from the cylinder wall into the base body. The contact element can also move obliquely out of the piston, provided that the contact surface remains parallel to the cylinder wall. Thus, the adjusting device can be arranged not only transversely to the axis of movement but also obliquely to it. The adjusting device can be designed as an eccentric.

[0017] The invention provides that the adjusting device is designed as an adjusting screw that can be moved in and against the displacement direction of the contact element, so that the elastic element can be pre-tensioned in the displacement direction of the contact element. The elastic element can be variably pre-tensioned in and against the displacement direction of the contact element, particularly via the adjusting screw, but also via other adjusting devices, since the adjusting device performs or effects a displacement in or against the displacement direction of the contacted element, thereby tensioning or releasing the elastic element. The adjusting device thus sets the elastic element so that it presses directly or indirectly against the contact element with the desired force and also pre-tensions the contact element towards the cylinder wall.The adjusting device or screw allows the elastic element to be tensioned as desired, so that the adjustable force applied via the elastic element is transferred to the contact element. The resulting frictional force between the contact element and the cylinder wall allows for varying degrees of damping. To exert a force on the cylinder via the contact element, the base body is pressed against the cylinder on the side opposite the contact element, i.e., with a counter-surface. The damper, consisting of a piston and cylinder, serves, for example, to control a movement phase, particularly the swing phase, in an artificial knee joint, such as in an orthosis or prosthesis.Depending on the preload of the elastic element, which is determined by the position of the adjusting device or screw in or against the direction of movement of the contact element, different frictional forces are generated. The interposition of the elastic element allows any wear that may occur during operation of the piston in the damper to be compensated for, thus enabling the generation of a constant or nearly constant frictional force over a comparatively long period. The design, featuring an adjusting screw arranged in a thread, provides a very simple and cost-effective solution for fine-tuning the preload force via the elastic element and, consequently, the frictional force applied between the contact element and the cylinder wall, and thus between the mating surface and the cylinder wall.

[0018] In a further development of the invention, the elastic element can be configured as a disc spring assembly, a helical disc spring, a helical spring, and / or an elastomer. It is also possible to provide a combination of disc spring assembly, helical spring assembly, helical spring, and / or elastomer spring in any variation, so that the inherent design advantages of each elastic element configuration can be utilized. Disc spring assemblies and helical disc springs have the advantage of providing high spring stiffness over a comparatively short spring travel. Furthermore, in the event of spring breakage, the basic functionality of the spring is generally not affected or only minimally impaired. A helical spring or a coil spring has the advantage of being inexpensive and readily available as a standard component.Designing the element as an elastomer, for example a cylinder made of an elastic material, has the advantage of relatively inexpensive manufacturing, but the disadvantage of a comparatively short spring travel. As a further embodiment of the elastic element, it can be designed as a pneumatic element, for example as a pressure pad or elastic foam, which can be open-cell or closed-cell.

[0019] In a further development of the invention, a receiving device for the elastic element is arranged, attached, or formed on the contact element. The receiving device makes it possible to securely position the elastic element within the piston and the base body and, optionally, to pre-assemble the elastic element within the receiving device to facilitate coupling with the contact element. The receiving device can be integrally molded onto the contact element, for example, using a primary forming process such as injection molding. To accommodate different material pairings and utilize different material properties, a two-component injection molding process can be used to design the contact element with a material-adapted receiving device.Alternatively, the receiving device can be attached to the contact element, resulting in a two-part or multi-part design of the contact element together with the receiving device. Besides a permanent attachment, or optionally a detachable attachment, of the contact element to the receiving device, it is possible to arrange the contact element on the receiving device so that it rests against the receiving device and transmits the compressive force. The receiving device allows the compressive forces exerted by the elastic element towards the contact element to be distributed over a larger area, thus ensuring even contact of the contact element against the inside of the cylinder.

[0020] The receiving device is relocatable, in particular slidably arranged within the base body, and may have a recess into which the elastic element is inserted. The recess allows the elastic element to be guided laterally. In particular, the recess can accommodate a stack of disc springs and ensure the alignment of the individual disc spring elements with one another. If the elastic element is designed as a helical disc spring, a coil spring, or a plastic element, the recess serves in particular as a safeguard against buckling when an axially acting force is applied to preload the elastic element towards the cylinder wall.

[0021] The contact element can surround the base body by more than half its circumference, so that when a compressive force is applied outwards towards the cylinder wall, the respective ends of the contact element slide along the surface of the cylindrical base body, thereby causing an outward movement or expansion of the ends or end regions of the contact element. This provides an increased frictional area between the contact element and the cylinder wall. For this purpose, the piston base body is designed to be substantially circular, at least in the area where the contact element rests, or has a circular cross-section, and the contact element has a corresponding shape. In principle, the expansion function also exists with square or polygonal cross-sections of the piston and a corresponding shape of the contact element.Provided that the contact element, in the case of a circular cross-section of the piston, does not extend over half the circumference of the base body, i.e., is smaller than a semicircle, no widening occurs at the outer edges or the opposite ends of the contact element, and the contact element is pressed against the cylinder without further deformation.

[0022] The contact element can extend over more than half the height of the piston's base body to provide a large friction surface. For this purpose, the receiving device can be designed as a dimensionally stable component on which the contact element is arranged on the outside.

[0023] The adjusting device is preferably mounted in the base body, for example in a metallic threaded insert, in order to be able to adjust the preload by adjusting the adjusting device in the form of a screw, without the function of the damper being impaired by protruding components or the like.

[0024] A further development of the invention provides that a frictional force is generated to dampen movement between the piston and the cylinder. In particular, the frictional force is generated via the surface of the contact element, its mating surface on the base body, and the inner wall of the cylinder.

[0025] The invention also relates to an orthopaedic device with a damper comprising a cylinder and a piston movably mounted therein, as described above. In particular, such a damper can be used and is used in an orthosis or prosthesis, especially in an orthotic knee joint or prosthetic knee joint, to control the swing phase.

[0026] The adjusting screw can also act on an expanding element coupled to the contact element, in order to exert pressure on the contact element in the desired direction. Multiple adjusting screws and contact elements, as well as elastic elements, can be arranged in and on the piston to achieve fine-tuning, adjustment, calibration, and adaptation to the needs of, for example, the prosthesis or orthosis wearer, as well as to ensure even support of the piston within the cylinder.

[0027] The base body is advantageously made of a dimensionally stable material, for example a high-strength plastic or a light metal, and at least partially surrounds the elastic element to provide guidance. The piston can be rotationally symmetrical, with the contact element also essentially following the contour of the piston.

[0028] The elastic element can be made at least partially from a polymer material, in particular TPU, so that almost any shape can be used to absorb and transmit the preload force through the adjusting screw.

[0029] The contact element can be designed as an expandable cover for the base body, thus initially preventing direct frictional contact between the elastic element and the cylinder wall. This allows the contact element to be designed as a wear part and replaced as needed. The contact element can also be pivotally attached to the base body via a hinge mechanism, which could, for example, be a film hinge. If the piston is designed as a plastic part, it can be manufactured as a whole in a single operation. This also makes it possible to easily produce relatively complex shapes, requiring only the adjusting screw and the elastic element as separate components. This saves on components and assembly steps.

[0030] The piston and / or the contact element can have at least one flat surface, preferably positioned in the direction of action of the elastic element. Two or more flat surfaces can be formed, preferably opposite each other, to ensure uniform contact between the components and a uniform distribution of the contact forces and thus the frictional forces. The flat surface(s), for example on the contact element and the mating surface, can create active friction surfaces between the piston, the contact element, and the cylinder in the circumferential direction, adjacent to the flat surface. The radii of curvature of the contact surfaces of the contact element and the mating surface of the piston can be optimized to better match the inner diameter of the cylinder.If the piston has a slightly smaller radius than the cylinder, without flattening, increased contact pressure would occur in the area of ​​the elastic element's direction of action against the contact element and the mating surface. Furthermore, nearly linear contact surfaces would form. The flattening distributes the frictional forces more evenly around the circumference. Areas of increased frictional forces are preferably found laterally, i.e., circumferentially adjacent to the flattening, which is preferably located in the area of ​​the elastic element's direction of action. The piston's friction surfaces can also be adapted to the cylinder through elastic deformation of the contact element and, if necessary, the mating surface.

[0031] The damper according to the invention, comprising a cylinder and a piston movably mounted therein as described above, allows for easy adjustment of the damping by changing the position of the adjusting screw and is of particularly simple construction. Due to the solid-state damping via mechanical friction, it is not necessary to provide seals for fluids.

[0032] Exemplary embodiments of the invention are explained in more detail below with reference to the accompanying figures. These show: Figure 1 – a perspective external view of a piston; Figure 2 – a sectional view of a piston; Figure 3 – a sectional view of a detail; Figure 4 – a sectional view of a piston in a prosthetic knee joint; Figure 5 – an overall view of a prosthetic leg; and Figure 6 – a horizontal section view of a piston.

[0033] In the Figure 1Figure 10 is shown in a perspective view of the exterior of a piston 10 with a base body 3, which has at least one outer surface 31. Receptacles 32 for a piston pin 8 are formed on the upper end face of the piston 10, via which a piston rod 7 can be coupled to another orthopaedic component. Both the pin 8 and the piston rod 7 are shown in the Figure 4 shown. Compressive and tensile forces are transmitted from the component to the piston 10 via the piston rod 7, so that the piston is longitudinally movable in a cylinder 2, which is located in the Figure 4As shown, the cylinder 2 can be displaced. The cylinder 2 is attached to another component of the orthotic device, for example, a prosthesis or orthosis, so that relative movement of the two different components of the orthotic device results in a relative displacement of the piston 10 within the cylinder 2. For example, in an arrangement on a prosthesis or orthosis of the lower extremity in the area of ​​a knee joint, the piston rod 7 is attached to the upper part or component associated with the thigh, and the cylinder 2 is attached to the lower part or component associated with the lower leg, so that during extension or flexion of the artificial knee joint, the piston 10 extends or retracts into the cylinder 2.

[0034] A contact element 6 is arranged on the outer surface 31 of the piston 10, extending in height over more than half the height of the base body 3. The contact element 6 is positioned on the outer surface 31 and is shaped to correspond substantially to the circumference of the piston 10, thus having a form that corresponds to a portion of the lateral surface of a circular cylinder. A recess is machined into the outer surface 31 of the base body 3, the thickness of which corresponds substantially to that of the contact element 6, so that the contact element 6 is essentially flush with the outer surface 31 of the piston 10 during assembly. This facilitates or enables the insertion of the piston 10, together with the contact element 6, into the cylinder 2.

[0035] Within the piston 10, a bore 35 is machined or formed in the base body 3. The bore 35 extends radially inwards and provides access to an adjusting screw 5, which is shown in the cross-sectional view according to Figure 2 or Figure 3 The bore 35 is formed in the solid base body 3 of the piston 10 and widens radially to accommodate a threaded insert 51, into which the adjusting screw 5, in the form of a setscrew, is screwed. The adjusting screw 5 has an internal hexagon socket at one end, allowing it to be moved towards or away from the cylinder wall, i.e., in both radial directions, by rotating the adjusting screw 5 with a suitable tool.

[0036] In the area of ​​the bore 35, the base body 3 is flattened to distribute the frictional forces onto the counter surface 6' of the piston 10. A washer 52 or a retaining device can be arranged at the end of the adjusting screw 5 to prevent the screw 5 from unscrewing from the base body 3.

[0037] Furthermore, an elastic element 4, in the illustrated embodiment in the form of a disc spring assembly, is arranged within the base body 3, upon which the adjusting screw 5 acts. By turning the adjusting screw 5 towards the elastic element 4, this element is compressed. The resulting spring force is transmitted radially outwards via a receiving device 64. The contact element 6 or 6 are arranged on the outside of the receiving device 64, through which the compressive force of the elastic element 4 or the spring assembly is then exerted on the inner wall of the cylinder. Depending on the spring preload, the contact pressure of the contact element 6 on the inner wall of the cylinder changes, and thus the frictional resistance generated when the piston 10 moves within the cylinder 2 changes.

[0038] Figure 3 shows a detailed view of the Figure 2without the bore 35, which provides access to the adjusting screw 5. The adjusting screw 5 is screwed into the threaded insert 51 and acts on the disc spring assembly as an elastic element 4 via a pressure plate 41. As an alternative to a disc spring assembly, a helical spring, a helical disc spring, or an elastomer element, for example made of TPU, can be used. It is also possible to arrange a combination of different spring elements or spring types in series to generate different spring characteristics or to achieve the desired elastic behavior. The elastic element 4, in turn, exerts pressure on the receiving device 64, which is mounted to be longitudinally displaceable in the radial direction outwards in the base body 3. A recess 644 is formed in the receiving device 4, in which the elastic element 4 is inserted.The recess 644 is designed, for example, as a bore or circular cylindrical recess into which correspondingly round pressure discs 41 and round disc spring elements can be inserted. The recess or bore 644 serves to guide the spring elements. Alternatively, instead of a bore, a pin or similar feature can also be arranged or formed on the receiving device 64 to receive the elastic element 4.

[0039] When the adjusting screw 5 is screwed in towards the elastic element 4, the spring preload increases, and thus the pressure with which the contact element 6 and correspondingly the counter surface 6' are pressed against the cylinder wall.

[0040] The adjusting screw 5 allows for very simple and precise adjustment of the applied frictional force. The elastic element 4 compensates for wear of the contact element 6 during prolonged use, thus achieving automatic readjustment of the preload force. This makes it possible to apply a permanent, virtually constant frictional force to the cylinder via the contact element, thereby ensuring a defined resistance to piston movement within the cylinder 2.

[0041] In case of further wear, contact element 6 can be replaced. By inserting additional disc spring assemblies or by replacing the elastic elements, four different force levels can be set. The replacement is very simple.

[0042] Since no liquids need to be moved in cylinder 2, the cylinder wall can be interrupted, as in the Figure 4 As shown, an access opening 25 in the cylinder wall allows the spring preload to be changed or adjusted during operation or when the cylinder 2 is assembled. This opening 25 also facilitates assembly, as the piston 3 can initially be inserted into the cylinder 2 without preloading the contact element 6. Thus, without preload, the receiving device 4, together with the contact element 6, can be brought fully into contact with the base body 3, so that the contact element 6 is flush with the outer surface 31 of the piston 10. After insertion into the cylinder 2, the spring preload can then be adjusted by screwing the adjusting screw 3 in towards the elastic element.

[0043] The invention utilizes the deformation of the elastic element 4 to generate a continuously adjustable braking force. The elastic element 4 itself is wear-free; wear of the contact element 6 is compensated for by the elastic element. A decrease in spring force can be compensated for by adjusting the adjusting screw 5.

[0044] In the Figure 5A prosthetic leg with a prosthetic knee joint 1 is shown in an overall view. The upper part 12 comprises a prosthetic component 12 and a lower part 13 articulated to it. A receiving device 14, in the form of a prosthetic socket or liner for receiving a femoral stump, is attached to the upper part 12. A lower leg tube 15 is attached to the lower part 13, at the distal end of which a prosthetic foot 16 is arranged. The prosthetic joint 11, as the prosthetic knee joint, is a multi-link joint with an anterior link 17 and a posterior link 18, which are connected to the upper part 12 and the lower part 13 via two joint axes.

[0045] In the Figure 4In the figure, which shows the prosthetic knee joint 11 in a sectional view, the upper part 12 and the lower part 13 can be seen. Inside the lower part 13 is the cylinder 2, in which the piston 10 is moved distally, i.e., towards the prosthetic foot, via the piston rod 7 against a spring force exerted on the piston base by the spring 19 when the prosthetic knee joint 11 is flexed. During flexion or flexion, both the anterior linkage 17 and the posterior linkage 18 pivot about their respective axes and rotate counterclockwise in the view shown. Figure 4This causes a pin located on the rear linkage 18 to also be displaced counterclockwise, resulting not only in a pivoting of the piston rod 7 about the piston pin 8, but also in a force component opposite to the force direction of the spring 19. The piston 10 is then pushed downwards. When the prosthetic knee joint 11 is extended again, the spring 19 pushes the piston 10 upwards towards the upper part 12.

[0046] To adjust the resistance of the piston 10 to displacement within the cylinder 2, the adjusting screw 5 can be moved through the opening 25 and the bore 35 towards the contact element 6, so that an increased contact force and thus an increased friction effect of the piston can be set via the contact element 6 and the counter surface 6' on the piston 10.

[0047] In Figure 6Figure 1 shows a sectional view through a piston 10, with the section perpendicular to the piston stroke direction. The cylinder 2 is only partially shown, namely in the form of active friction surfaces that form the contact surfaces between the piston 10 and the cylinder 2. The contact element 6 is movably mounted on the piston 10. The elastic element 4, in the form of a spring, is elastically pre-tensioned by two pressure plates 41 in the direction of the active friction surfaces of the cylinder 2. The direction of the contact force on the contact element 6 is indicated by an arrow. The oppositely directed arrow indicates the direction of the contact force of the counter surface 6' against the associated active friction surfaces of the cylinder 2. The adjusting device 5, in the form of an adjusting screw, is arranged inside the base body 3.The adjusting screw 5 is accessible radially from the outside through the bore 35, allowing the preload of the elastic element 4 relative to the contact element 6 to be changed. In the illustrated embodiment, the pressure plate 41, which is located at the end of the elastic element 4 opposite the adjusting screw 5, acts directly on the contact element 6 and presses it against the active friction surfaces of the cylinder 2. The resulting frictional force is generated between the contact element 6, the counter surface 6', and the active friction surfaces of the cylinder 2. The highest frictional forces are achieved in the direction of action of the preload through the elastic element 4 and decrease laterally in the circumferential direction.Ideally, the radii of the piston 10 with the counter surface 6' and the contact element 6 as well as the cylinder 2 have the same dimensions, whereby any tolerances that may occur can be compensated by elastic deformation of the components.

[0048] In the illustrated embodiment of the Figure 6In the direction of action, a flattening 61 is arranged on opposite sides of the piston 10, resulting in a flattening 61 in the base body 3, the counter surface 6', and the contact element 6 in the area of ​​the bore 35 and on the side of the piston 10 opposite the bore 35. The flattening 61, which extends partially around the circumference of the piston 10 and the counter surface 6' in these areas, prevents high surface pressure in these regions and distributes the effective contact forces more effectively and evenly around the circumference of the piston 10 and the contact element 6. Without the flattening 61, increased contact pressure would primarily act along the line of force of the elastic element 4 if the radius of the piston 10 is slightly smaller than the radius of the cylinder 2.

Claims

1. Orthopedic device with a piston (10) for arrangement in a damper (1) and a cylinder (2), in which the piston (10) is mounted displaceably relative to the cylinder (2), wherein the piston (10) has a base body (3) on the outer side (31) of which at least one contact element (6) is arranged, which is displaceable in a direction toward the cylinder (2) and is coupled to an elastic element (4), wherein the elastic element (4) can be preloaded via an adjusting screw (5) along the direction of displacement of the contact element (6) along force action line, characterized in that a bore (35) is formed or provided in the base body (3), the bore (35) extending radially inward, such that the adjusting screw (5) can be displaced in a radial direction along the force action line toward the elastic element (4), the resulting spring force being transmitted further radially outwards to the contact element (6).

2. Orthopedic device according to claim 1, characterized in that the elastic element (4) comprises a disc spring arrangement, a screw disc spring, a coil spring, and / or an elastomer.

3. Orthopedic device according to one of the preceding claims, characterized in that a receiving device (64) for the elastic element (4) is arranged, fastened, or formed on the contact element (6).

4. Orthopedic device according to claim 3, characterized in that the receiving device (64) is arranged displaceably in the base body (3).

5. Orthopedic device according to claim 3 or 4, characterized in that the receiving device (64) has a recess (644) into which the elastic element (4) is inserted.

6. Orthopedic device according to one of the preceding claims, characterized in that the contact element (6) extends over more than half the heigh of the base body (3).

7. Orthopedic device according to one of the preceding claims, characterized in that the adjusting screw (5) is mounted in the base body.

8. Orthopedic device according to one of the preceding claims, characterized in that a frictional force is generated for damping a movement between the piston (10) and the cylinder (2).

9. Orthopedic device according to claim 8, characterized in that the frictional force is generated via the surface of the contact element (6), its counter surface (6') on the base body (3), and the inner wall of the cylinder.

10. Orthopedic device according to one of the preceding claims, characterized in that at least one flattened portion (61) is formed on the piston (3) and / or the contact element (6).

11. Orthopedic device according to claim 10, characterized in that at least one active friction surface is formed between the piston (3), the contact element (6), and the cylinder (2) in the circumferential direction next to the flattened portion (61).

12. Damper (1) for an orthopedic device, with a cylinder (2) and a piston (10) moveably mounted therein, according to one of the preceding claims.