Orthotic joint

Description

[0001] The invention relates to an orthotic joint, in particular for a leg joint, e.g. a hip, knee or ankle joint, or an arm joint, such as a shoulder, elbow or wrist, with a first joint arm and a second joint arm which are pivotably connected to each other, in particular with deflection on both sides, and with at least one functional means acting as a return element between the joint arms.

[0002] Such an orthotic joint is particularly advantageous for use in lower extremity orthoses, such as ankle-foot orthoses (AFOs) or knee-ankle-foot orthoses (KAFOs). However, it is not limited to this area or application and can theoretically also be used as a prosthetic joint.

[0003] In principle, it is also possible to use such a joint, for example in positioning therapy, especially in the area of ​​the upper extremities.

[0004] Movement in a joint can be supported or restricted with orthotic joints to protect the joint, provided this is therapeutically appropriate. In the case of restricted movement, the orthotic joint acts as a stop for the joint, with the aim of building up a gently increasing resistance within the orthotic joint up to this point. This resistance then acts on the natural joint and limits its range of motion.

[0005] An orthotic joint can generate a restoring force to counteract the resistance, returning the body joint to its initial position. In the initial position, there is no restoring force. When the body joint is moved from this initial position, the restoring force in the orthotic joint preferably increases. The initial position is also referred to as the home position.

[0006] In an orthotic joint that works with a restoring force, the joint arms are usually set to a basic position that corresponds to that of the body joint, forming an angle between the first and second joint arms.

[0007] Such an orthotic joint with a basic position and a restoring force during bilateral deflections is disclosed in DE 20 2011 004 130 U1. This design uses as its functional means two stacks of disc springs attached laterally to an upper joint arm, which are housed in two casings and which generate a strong restoring force when the joint arms are deflected.

[0008] To set a maximum functional angle by which the two joint arms can be pivoted relative to each other from the basic position when using the orthosis, an adjusting element with a stop surface is provided on each plate spring stack, so that the lower joint arm, which is equipped with a foot bracket shell, can only be pivoted relative to the upper joint arm in a limited angular range.

[0009] Different spring characteristics are provided by interchangeable, pre-configured spring modules. Fine-tuning of the maximum spring force is possible to a limited extent by pre-tensioning the disc spring stacks. However, this results in a loss of spring travel and may also increase the minimum force.

[0010] Similar designs can be found in DE 10 2016 107 779 A1 or DE 10 2013 011 382 A1, featuring two spring-loaded functional elements on either side of an upper articulated arm, for example, of an ankle joint. A lower articulated arm is, for example, a foot stirrup shell that can be attached to a foot. Depending on the direction of the possible deflection (in both directions), one of the two functional elements is activated to generate a restoring force. The functional elements and, if applicable, their housings are removable and replaceable for adjusting the restoring forces. A wide range of different functional elements is available to meet various requirements.

[0011] The problem with all previously known designs remains that when a joint pivots from one direction beyond its neutral position into the other, during the transition or changeover phase of the deflections in opposite directions, the restoring forces generated by the functional components drop and rise abruptly. However, it is precisely during this phase of movement that a natural joint not only tilts back and forth without resistance, i.e., without a restoring force, but also exhibits smooth, i.e., jerk-free, decreasing and increasing restoring forces from the muscles and ligaments.

[0012] In contrast, according to the state of the art, orthotic joints create a jerky transition between the functional elements acting in opposite directions precisely during this critical phase of movement.

[0013] To avoid such a sudden transition, a free movement phase can be provided for this tilting phase of the orthosis joint, during which none of the functional elements exert any force. However, this abruptly interrupts the force transmission, which results in noise when the force is applied to the functional elements, and this noise is also associated with wear.

[0014] Even cosmetic requirements are only partially met by such well-known orthotic joints, e.g., ankle joints, due to the two protruding functional elements.

[0015] US 2006 / 116616 discloses an orthotic joint according to the preamble of claim 1.

[0016] The object of the present invention is therefore to provide an orthotic joint that is more compact and lighter than the prior art, which enables a natural-looking movement with extensive adjustment options for a functional angle and with a physiologically introduced restoring force.

[0017] According to the invention, this problem is solved by a joint having the features of the main claim. Advantageous embodiments and further developments of the invention are disclosed in the dependent claims, the description, and the figures.

[0018] The orthotic joint according to the invention provides for generating the restoring force with only one functional element, which consists of at least one bending spring that is essentially longitudinally oriented. By using only one bending spring, the orthotic joint can be made significantly smaller than previously known embodiments.

[0019] In a preferred embodiment of the invention, the bending spring is designed as a leaf spring, and in a particularly preferred embodiment, this leaf spring has a stacked arrangement. Within the scope of this invention, such a stacked arrangement is understood to mean arranging a plurality of individual leaf springs, which, for example, have different lengths, next to each other, i.e., stacking them, so that the individual leaf springs are used successively depending on the deflection.

[0020] This type of stacking arrangement allows the leaf spring within the orthotic joint to be restacked as needed, thereby enabling the orthotic joint to be adapted or configured as required. No additional range of special parts is necessary. For this purpose, the orthotic joint according to the invention is equipped with a variable suspension or bearing for the individual leaf springs.

[0021] The use of bending springs in orthotic joints is generally known, but so far they have only been used for other purposes. For example, EP 1 768 620 B1 discloses a polycentric orthotic joint designed to create a unilateral extension stop for knee extension. For this purpose, various spacers are inserted between the stop surfaces, and these spacers are held in position by leaf springs. A spring-like restoring force acting on the two joint arms or on the limbs is not disclosed.

[0022] For the generation of restoring forces in the orthotic joint according to the invention, the control points are arranged laterally to the functional element, i.e., the bending spring or leaf spring or leaf spring assembly, in a triangular arrangement. When the joint arms are deflected in a first direction, at least three control points, which are located on the joint arms in the form of transmission elements, are displaced transversely to the longitudinal axis of the bending spring or leaf spring or leaf spring assembly, thereby bending the functional element and thus generating a restoring force.

[0023] This well-known principle of a triangular arrangement is essentially applied in reverse in the joint according to the invention. By varying the distances between the actuation points on both sides of the functional element, the restoring forces can have different rates of increase.

[0024] A functional element can be positioned either parallel to a longitudinal axis of the orthosis joint, which is essentially defined by the extended extremity to be fitted with the orthosis, or perpendicular to this longitudinal axis. The transmission elements can be located on one side of the leaf spring assembly and can be spaced closer together. In each configuration, the restoring forces generated by the flexor spring transition smoothly into one another during alternating deflection.

[0025] The joint arms of the orthosis joint are in constant force-lock contact with the functional element, so that no jerky transition occurs due to the restoring force. The movement sequence possible with a joint according to the invention is thus comparable to that of a natural joint with the smooth and continuous force exertion of the muscles.

[0026] In its resting position, the functional element, i.e., the bending spring or leaf spring or leaf spring assembly, is in a rest position without internal tension. In this rest position, it is easy to continuously move the adjustable transmission elements, which are mounted on the articulated arms, along their longitudinal axis and then fix them in place. This allows the distance between the actuation points on the functional element to be changed, thereby altering the bending length and, consequently, the stiffness of the functional element, and thus the restoring force of the bending spring, leaf spring, or leaf spring assembly.

[0027] In a particularly preferred embodiment of the invention, one of the articulated arms, in particular the second lower articulated arm, has a pivot arm to which it can be continuously rotated and locked at any desired angular position. The force is then transmitted from the functional element to the second articulated arm via this pivot arm. It is particularly proposed to mount the pivot arm and the second articulated arm on a common pivot point to create a robust counter-support for clamping.

[0028] Another variant provides for an additional locking mechanism between the linkage arm and the lower articulated boom, which engages in at least one groove on the linkage arm to set one or more predetermined functional angles between the first and second articulated booms.

[0029] Further advantageous features of the invention will become apparent from the dependent claims and the following description of the drawing. Particularly preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawing. This drawing shows: Fig. 1 shows an exemplary bending spring and a leaf spring. Fig. 2 shows a front view of an arrangement with leaf springs. Fig. 3 shows a front view of a one-sided triangular arrangement of the actuation points with bilateral action. Fig. 4 shows a front view of an alternative one-sided triangular arrangement of the actuation points with bilateral action. Fig. 5 shows a front view of a two-sided triangular arrangement of the actuation points with bilateral action. Fig. 6 shows a front view of an orthotic joint in its rest position. Fig. 7 shows a front view of an orthotic joint according to... Fig. 6in left-sided deflection, Fig. 8 the front view of an alternative embodiment of an orthotic joint e.g. as an ankle joint in left-sided deflection.

[0030] In the drawings, the same parts are essentially provided with the same reference numerals.

[0031] The Fig. 1Figure 1 shows two embodiments of functional means 29 according to the invention in the form of a bending spring 16 or a leaf spring 17, which are shown here in a straight orientation, wherein the leaf spring 17 is provided at one end with an end-face bend 21. With this end-face bend 21, a single spring can be suspended in a device to prevent the leaf spring 17 from slipping. Also visible are transmission elements 4, 4a, 4b, 9, 9a, 9b and the direction of a force application line 20, through which control points 32, 33 are formed on a transmission surface 12 located, in particular, laterally on the outside of the functional means 29.

[0032] Fig. 2 shows a schematic front view of a functional device 29 for an orthosis joint 5 in the form of a leaf spring arrangement, consisting of several stacked leaf springs 17 arranged next to each other.

[0033] The functional element 29 is shown schematically here in the form of a preferred arrangement of leaf springs 17 and is mounted between the transmission elements 4, 4a, 4b, 9, 9a, 9b. When the articulated booms 1, 2, on which the transmission elements 4, 4a, 4b, 9, 9a, 9b are mounted, are deflected 24, forces are transmitted to the functional element 29. These forces are shown by the force application lines 20, which are perpendicular to a longitudinal axis 8 of the leaf springs 17. The transmission elements 4, 4a, 4b and 9, 9a, 9b are each shown in a triangular arrangement with connecting lines. This also defines the control points 32, 33, which are effective alternatively in opposite directions when deflections 24 occur. With corresponding deflections 24 of the articulated booms 1, 2, restoring forces 27 are generated at the articulated booms 1, 2, as shown below. Fig. 7, 8 will be explained.

[0034] Fig. 3Figure 1 schematically shows a leaf spring 17 with only a triangular arrangement of the control points 32 for generating a restoring force 27. In this variant, only three control points 32 are mirrored about the axis of symmetry 31 on the force application line 20. The ends of the leaf spring 17 are actuated alternately. The advantage of this is the very compact design. The restoring force 27 of the leaf spring 17 can be changed in either direction by moving the central control point 32 parallel to the longitudinal axis of the leaf spring 17.

[0035] Fig. 4Figure 1 shows a particularly preferred embodiment with a functional means 29 having two triangular arrangements formed with at least five control points 32, 33 for generating a restoring force 27. In this embodiment, the control points 32, 33 are mirrored on the axis of symmetry 31 of the force application line 20. The ends of the leaf spring 17 are deflected alternately, so that two control points 32, 33 in the triangular arrangement are alternately active.

[0036] Fig. 5Figure 1 schematically shows two triangular arrangements of the control points 32, 33 on a leaf spring 17, mirrored on the longitudinal axis 8. The force on the force application line 20 for generating a bending and a restoring force 27 can be seen. A key feature is the mirroring of six control points 32, 33 in two triangular arrangements on the longitudinal axis 8. The restoring force 27, which can be generated in either direction, can be changed by moving any control point.

[0037] The Fig. 6 Figure 5 shows a schematic front view of an orthotic joint. Two triangular arrangements of the control points 32, 33, mirrored on the longitudinal axis 8, can be seen on a leaf spring 17 according to the Fig. 5 .

[0038] The functional element 29 for generating a restoring force 27 is arranged here in the area of ​​a pivot point 10 of the orthosis joint 5. The joint arms 1, 2, which are connected to each other at the pivot point 10, are clearly visible. Both joint arms 1, 2 can be pivoted to the right and left relative to each other. In this illustration, the functional element is in the rest position 19, i.e., without any deflection of the joint arms.

[0039] The lower articulated boom 2 is mounted on the pivot point 10 together with a linkage arm 3 for setting a functional angle 14 shown between articulated boom 1 and articulated boom 2. As can be seen, the angle between articulated boom 1 and linkage arm 3 always remains unchanged, even when articulated booms 1 and 2 are pivoted relative to each other.

[0040] The articulated arm 3 can be continuously pivoted to either side of the centerline relative to the articulated boom 2 and locked against the articulated arm 2 by a clamping device 22. The second articulated boom 2 thus remains connected to the functional device 29 and to the first articulated boom 1 via the articulated arm 3 at any set operating angle 14.

[0041] For each of the aforementioned triangular arrangements, transmission elements 4, 4a, 4b, 9, 9a, 9b are adjustable and lockable on the first articulated boom 1 with displacement means 25 along the longitudinal axis 8 of the bending spring 16 or leaf spring 17. This allows the restoring force 27 of the functional element 29 to be changed.

[0042] A transmission element 9 / 23 positioned outside the reach of the functional means 29 also allows free deflection of the articulated arms 1, 2 and disables the functional position and the restoring force 27.

[0043] A shaft configured as an eccentric 13 is visible on the transmission element 9a. By rotating the transmission element 9a about the eccentric 13, a limited freewheel 23 of the transmission element can be set relative to the functional element 29, whereby the articulated arm 1 is decoupled from the restoring force 27.

[0044] Fig. 7 Figure 1 shows a front view of an embodiment of the orthosis joint 5, depicted with a leftward deflection 24 of the joint arms 1, 2, while at the same time the pivot arm 3 is deflected to the right to form a restoring force 27 on the leaf spring 17.

[0045] The principle with a double triangular arrangement of the control points 32, 33 is applied here mirrored around the longitudinal axis 8 of the functional means 29.

[0046] The illustrated arrangement of several leaf springs 17, which are combined to form a leaf spring stack, is clamped for a bilateral deflection between six transmission elements 4, 4a, 4b and 9, 9a, 9b according to Fig. 2, 5 . In the depicted left-side deflection 24 of the linkage arm 3, the individual leaf springs 17 are bent over the linkage arm 3, for example.

[0047] When the articulated boom 2 and the linkage arm 3 are deflected together, a rotatably mounted transmission element 4, 9 adjusts itself to the course of the leaf spring 17 or the leaf spring stack formed by it in the embodiment shown here.

[0048] By changing the distance between the transmission elements 4a, 9a and the transmission elements 4, 9, the active bending length of the arrangement of leaf springs 17 shown here is changed, thus creating a different bending profile between the transmission elements 4, 9 and 4a, 9a with a resulting different restoring force 27.

[0049] To set a functional angle 14, the clamping devices 22 are loosened so that the second articulated boom 2 can be rotated relative to the linkage arm 3. The second articulated boom 2 can be continuously locked in the selected position via the clamping surfaces 11 between the shaft 7 and the linkage arm 3.

[0050] A predetermined setting of a functional angle 14 is possible with a latch 26 and at least one groove 28 on the pivot arm 3. In a simple embodiment of the joint 5 with limited adjustability of the functional angle 14, the transmission elements 4b, 9b and the transmission elements 4, 9 are arranged directly on the second pivot arm 2. Thus, the pivot arm 3 is not rotatable relative to the second pivot arm 2, and a functional angle 14 is only adjustable to a limited extent. The bilateral restoring force 27 is maintained.

[0051] Fig. 8 Figure 1 shows an alternative embodiment of an orthotic joint 5 as an ankle joint with left-sided active deflection 24 of the joint extensions 1, 2 and the articulating arm 3 to generate a restoring force 27 on the leaf spring 17. The principle here is represented by a triangular arrangement of the control points 32, 33 according to the Fig. 4applied. The transmission elements 4, 4b and 9, 9b are arranged on the first articulated boom 1. During the illustrated left-sided deflection 24 of the linkage arm 3, the individual leaf springs 17 are bent at one end over the linkage arm 3.

[0052] In this embodiment of the joint 5, the individual leaf springs 17 within the joint 5 can be repositioned to the outer edge of the transmission elements 4, 9, as indicated by arrow 30, with the transmission elements 4, 9 being held in position between the leaf springs 17. These thus form configurable leaf springs 15. This makes it possible to configure the restoring force 27 of these leaf springs 15 for any body weight. Fine adjustments to the restoring force 27 are made by sliding the transmission elements 4, 9 along the leaf spring 15.

[0053] The invention offers versatile possibilities and is not limited to the embodiments illustrated for orthotic joints 5. Reference symbol list

[0054] 1. First, upper articulated arm 2. Second, lower articulated arm 3. Linkage arm 4, 4a, 4b Transmission element 5 Orthotic joint 6 Joint centerline 7 Shaft 8 Longitudinal axis of the functional element 9, 9a, 9b Transmission element 10. Pivot point 11. Clamping surfaces 12. Transmission surface on the functional element 13. Eccentric 14. Functional angle 15. Configurable leaf spring 16. Bending spring 17. Leaf spring 20. Force application line 21. Angle of a leaf spring 22. Tensioning device 23. Freewheel 24. Deflection with restoring force 25. Displacement device 26. Latch 27. Restoring force 28. Groove 29. Functional element 30. Arrow 31. Mirror axis 32. Control point Triangular arrangement 33. Control point triangular arrangement

Claims

1. An orthosis joint with a first joint arm (1) and a second joint arm (2), which are mounted such that they can pivot with respect to one another, and at least one functional element (29) acting between the joint arms (1, 2) as a restoring element, characterized in that the functional element (29) has at least one bending spring (16, 17) which generates a restoring force (27) on one side or the other when the joint arms (1, 2) are deflected.

2. The orthosis joint according to claim 1, characterized in that the functional element (29) has a leaf spring (17) with a stacking arrangement.

3. The orthosis joint according to one or more of the preceding claims, characterized in that at least three actuation points (32) are arranged in a triangular arrangement on the functional element (16, 17, 29) for generating different restoring forces (27) in opposite directions.

4. The orthosis joint according to one or more of the preceding claims, characterized in that at least one actuation point (32, 33) is adjustably arranged via a transmission element (4, 4a, 4b, 9, 9a, 9b) on one of the joint arms (1, 2) for changing the restoring force (27) of the functional element (16, 17, 29).

5. The orthosis joint according to one or more of the preceding claims, characterized in that the joint arms (1, 2) can be decoupled for a freewheel (23).

6. The orthosis joint according to one or more of the preceding claims, characterized in that an articulated arm (3) is connected to the second joint arm (2) in an adjustable and lockable manner for setting a functional angle (14) between the joint arms (1, 2).

7. The orthosis joint according to claim 6, characterized in that the second joint arm (2) can be continuously locked with the articulated arm (3) via common clamping surfaces (11).

8. The orthosis joint according to claim 6, characterized in that the articulation arm (3) is provided with at least one groove (28) for locking at a functional angle (14) relative to the second joint arm (2).

9. The orthosis joint according to one or more of claims 6 and 7 or 8, characterized in that the force transmission from the functional element (29) to the second joint arm (2) takes place only via the articulated arm (3).

10. The orthosis joint according to one or more of claims 6 to 9, characterized in that the articulated arm (3) has a common pivot point (10) with the first joint arm (1) and the second joint arm (2).