The invention relates to a knee orthosis with an upper leg frame for arranging on an upper leg and a lower leg frame for arranging on a lower leg, wherein the lower leg frame is arranged on the upper leg frame such that it can be swivelled about a first swivel axis by means of at least one joint, and a calf pad for placing on a calf.
Such knee orthoses have been known from the prior art for many years and used particularly after operations on the posterior cruciate ligament so as to prevent the so-called “posterior drawer”. Particularly following a rupture to the posterior cruciate ligament and the subsequent operation, the lower leg may slip backwards relative to the upper leg, as the injury has caused an instability in the knee. This behavior has been known for many years and attempts made to resolve it using knee orthoses.
For example, EP 1 575 464 B1 discloses a knee orthosis according to the preamble whose calf pad is designed as a half-shell that is arranged around the calf. The half-shell has an end close to the knee and an end far from the knee, each of which is arranged on a splint, both splints being connected to the swivel joint between the upper leg frame and the lower leg frame. A spring is arranged between the two splints through which a force is exerted that is intended to reduce the angle between the two splints. A torque is thus applied to the calf pad, designed as a half-shell, which causes the part of the half-shell close to the knee to be pushed forward. However, the disadvantage is that this torque can create a situation that is perceived as unpleasant. The half-shall can also lose contact with the calf, especially when the knee is flexed, i.e. strongly bent, so that the desired effect does not occur or no longer occurs completely.
Knee orthoses are also known from the prior art that feature a Bowden cable, by way of which a bending or flexion of the knee is converted into an applied pressure that is applied to the calf by the calf shell. Such constructions are structurally complex and therefore expensive; they are also prone to error and require a lot of maintenance. In addition, all knee orthoses of the type described here that are known from the prior art have the disadvantage that the force applied by the calf pad cannot be adjusted, such that reproducibility cannot be achieved to the desired extent.
The invention therefore aims to propose a structurally simple knee orthosis by means of which the applied force can be applied in a manner that is comfortable for the wearer of the knee orthosis and reproducibility of the applied force is achieved.
The invention solves the problem by way of a knee orthosis according to the preamble of claim 1, which is characterized in that the knee orthosis comprises at least one elastic bearing element that is attached in such a way that the bearing element is tensioned when the knee orthosis is mounted and, in this state, presses the calf pad either directly or indirectly against a calf of the wearer of the knee orthosis.
The knee orthosis according to the invention thus features an upper leg frame for arranging on an upper leg. Preferably, at least one strap or belt is placed around the upper leg to fix the upper leg frame to the upper leg. The frame itself preferably features a medial splint and a lateral splint that are connected to each other by the specified strap, for example. The knee orthosis according to the invention also features a lower leg frame that can be arranged on a lower leg. Preferably, this can also be attached to the lower leg via at least one strap or belt. The lower leg frame preferably has a medial splint and a lateral splint that are connected to each other. The lower leg frame and upper leg frame are connected to each other by means of at least one joint. This is preferably a swivel joint that permits a swivelling of the upper leg frame relative to the lower leg frame about a first swivel axis. The lower leg frame and upper leg frame are preferably connected to each other by two joints whose swivel axes coincide. Here, one joint is preferably arranged medially and connects the medial splint of the upper leg frame to the medial splint of the lower leg frame. The second joint is preferably arranged laterally and connects the lateral splint of the upper leg frame to the lateral splint of the lower leg frame.
The at least one elastic bearing element acts as an elastic energy store, which is also referred to as a mechanical energy store. When mounting the knee orthosis, the at least one elastic bearing element is tensioned. During this process, mechanical energy, particularly deformation energy, is stored in the bearing element. The at least one elastic bearing element then exerts a force that directly or indirectly presses the calf pad against the calf of the wearer of the orthosis. Specifically, this means that the bearing element directly or indirectly exerts a force on the calf pad that acts in the direction of the calf of the wearer. This may also be a tensile force that is directly or indirectly exerted on the calf pad.
The knee orthosis preferably has a pad retainer, which is arranged on the lower leg frame. The pad retainer may be, for example, a plastic element, for example made of a rigid plastic, or a metal element. The pad retainer may also be in the form of a preferably inelastic yet flexible element, such as a textile strap. The pad retainer is preferably arranged on the medial splint and lateral splint of the lower leg frame. It is thus preferably connected to the lower leg frame at at least two points. This increases stability.
The at least one elastic bearing element is preferably arranged on the pad retainer. It is preferably located on a side of the pad retainer facing the calf and fixed to it. The at least one elastic bearing element can be detachably connected to the pad retainer or such that it cannot be detached. The calf pad is arranged on the at least one elastic bearing element, the calf pad being positioned towards the calf. It is preferably padding or a cushion, for example, to ensure the comfort of the wearer of the knee orthosis. If the knee orthosis is mounted, the upper leg frame is arranged on the upper leg and the lower leg frame on the lower leg of the wearer, so that the first swivel axis almost coincides, but preferably does so as precisely as possible, with the swivel axis of the knee of the wearer of the knee orthosis. The calf pad is arranged on the wearer's calf and comes into contact with it. The geometric design and/or length of the pad retainer ensures that the at least one elastic bearing element is tensioned when the knee orthosis is mounted. As it is an elastic bearing element, this generates a restoring force that counteracts the tension. As a result, a compression force is exerted on the calf of the wearer of the knee orthosis by the calf pad.
Preferably, the at least one elastic bearing element in the tensioned state exerts a frontal-acting force on the calf pad that is transferred to the wearer's calf by the calf pad. Unlike in some embodiments of a knee orthosis known from the prior art, there is no torque applied to the calf pad in this embodiment that is transferred to the lower leg of the wearer; rather, the at least one elastic bearing element generates a force that acts in a single direction, preferably frontally, and thus pushes the lower leg forwards.
The pad retainer can preferably be attached to the lower leg frame in multiple different positions and/or orientations relative to the lower leg frame. This may occur in various ways. For example, if the pad retainer is a plastic or metal element, it may feature a plurality of positive-locking elements, with correspondingly designed positive-locking elements being provided on the lower leg frame in this case. This can be achieved, for example, in the form of press studs so that the pad retainer can be arranged in different positions on the lower leg frame. In this way, it is particularly easy to adjust the effective length of the pad retainer, i.e. the distance between the two fastening elements on which the pad retainer is attached to the lower leg frame. This distance is measured along the pad retainer. The positive-locking elements may also be velcro elements, which enables the position and/orientation of the pad retainer relative to the lower leg frame to be infinitely changed.
If the pad retainer is a strap or belt, it may feature a plurality of holes, for example, which enable it to be fastened to clasps provided for such a purpose, which are arranged on the lower leg frame, for example. In this embodiment, the effective length of the pad retainer can be adjusted by selecting the respective hole by means of which it is to be fastened to the clasp.
In these embodiments, the effective length of the pad retainer determines how strongly the at least one elastic bearing element is tensioned, preferably compressed, when mounting the knee orthosis. The shorter the effective length, the more strongly the at least one elastic bearing element is tensioned when the knee orthosis is mounted. As a result, the force transferred by the at least one elastic bearing element to the calf pad and by said calf pad to the wearer's lower leg is changed. By changing the position and/or orientation of the pad retainer relative to the lower leg frame, the force exerted on the calf and the lower leg in the mounted state becomes adjustable.
In a preferred embodiment, the position and/or orientation of the pad retainer relative to the lower leg frame is infinitely adjustable and the pad retainer can be fixed in every one of these infinitely adjustable positions and/or orientations. This is partitularly easy to achieve if velcro elements are arranged on the pad retainer and velcro counter-elements are arranged on the lower leg frame, so that the pad retainer can be easily detached from the lower leg frame and reattached to it in the desired position and/or orientation.
Preferably, the calf pad is detachably arranged on the pad retainer. This can also preferably be achieved via positive-locking elements, such as press studs, velcro elements or other elements. It is therefore possible to remove the calf pad from the pad retainer and, for example, to clean it or replace it with another calf pad. This may be practical, for example, if the calf pad is not suited to the individual requirements of the wearer of the knee orthosis, as it is too large or small, for example, or a different degree of padding is desired. In this way, it is also possible to reuse the remaining components of the knee orthosis, so that not every patient requires their own knee orthosis of the type described here. This is an advantage because the knee orthosis is often not used for a long period of time, but for a limited time, for example following a surgical operation.
The at least one elastic bearing element preferably has a compression element, for example a compression spring and/or a component made of an elastic material. For example, it may be made of rubber or an elastomer, wherein the actual elasticity of the at least one elastic bearing element not only depends on the material of the compression element, but also its geometry. Preferably, more than one elastic bearing element is arranged on the pad retainer, which ensures that multiple elastic bearing elements are compressed when mounting the knee orthosis and a counterforce is thus exerted on the calf pad resting on the wearer's lower leg. This enables a more homogeneous distribution of force, which can increase the level of comfort felt when wearing the orthosis and the therapeutic effect. In addition, the already good auto-adaptation and auto-adaptive adaptation of the shape and contour of at least one calf pad to the wearer's calf and lower leg is further improved.
Preferably, the at least one elastic bearing element has at least one tension element, preferably a tension spring and/or at least one elastic strap. The calf pad is preferably arranged on another component of the knee orthosis, for example the lower leg frame, by at least one, preferably two such elastic straps. The bearing element is tensioned during mounting so that energy is stored. Here, a bearing element designed as an elastic strap is expanded. An expansion limiter is preferably provided, which is designed, for example, in the form of an inelastic strap or strap section, which is arranged parallel to the elastic strap. “Parallel” does not mean parallel in geometrical terms, but parallel with regard to the effectiveness of the two straps or strap sections, i.e. in particular not arranged one behind the other or in series.
In a preferred embodiment, the at least one calf pad is arranged on the pad retainer such that it can be swivelled about at least a second swivel axis, wherein the second swivel axis is preferably at least almost, but especially preferably completely, vertical to the first swivel axis. This renders it possible, for example, to optimally adjust the orientation of the calf pad to the individual conditions of the wearer's calf and lower leg by means of another swivel joint or ball joint. Ideally, this adaptability is achieved when several swivel joints coupled together, a cardan joint or a ball joint are used. As a result the calf pad is mounted on the pad retainer via the at least one elastic bearing element such that it can be swivelled in all directions.
The knee orthosis preferably features a measurement scale on which a strength of the compression of the at least one elastic bearing element and/or a force generated by this tension can be read. This ensures that the force generated by the tensioned, at least one elastic bearing element can be defined, so that it is possible to adjust it to a desired value and to subsequently check whether the generated force still has the desired strength. This is rendered particularly easy by the use of the measurement scale, so that it can be done by the patient without the help of an orthopedic technician. This further reduces the effort required when using the knee orthosis, which increases acceptance.
In the following, some examples of embodiments of the present invention will be explained in more detail by way of the attached figures: They show:
The lower leg frame 6 also features a medial splint 14 and a lateral splint not depicted in
A pad retainer 18 is also arranged on the lower leg frame, a calf pad 20 in the form of a half-shell being located on said pad retainer in the example of an embodiment shown. The pad retainer 18 is arranged on the lower leg frame 6 via two connecting elements 22, only one of which is depicted in
An elastic bearing element 28 is schematically depicted on the pad retainer 18, on which the calf pad 20 is located. This features a cushion 30 that can preferably be taken out for cleaning or for replacing with another cushion. When mounting the knee orthosis, the strap 24 is opened and the leg of the wearer of the orthosis introduced into the orthosis. The elastic bearing element 28 is compressed during this process. Specifically, this means that the calf pad 20 is displaced towards the pad retainer 18, so that a distance between the calf pad 20 and the pad retainer 18 is reduced. Since the elastic bearing element 28 is located in this gap, it is compressed when the knee orthosis is mounted.
In the example of an embodiment shown, the at least one elastic bearing element 28 is designed in the form of a leaf spring and may be made of a metal or a plastic, for example. Due to the elasticity of the elastic bearing element 28, the compression of the bearing element 28 results in a counter-force that presses the calf pad 20 against the wearer's calf. In the example of an embodiment shown, the calf pad 20 is arranged on the lower leg frame 6 via fastening straps 32 in order to ensure sufficient stability and mechanical strength.
The knee orthosis shown is also arranged on the wearer's lower leg via the strap 24 in this embodiment.
A positive-locking element 50 is located on the arm 42 to the left in
The two arms 42 are each fitted with a row of teeth 54 that engages in the positive-locking element, not depicted. Preferably, a snap connection is formed between one of the arms 42 and one of the positive-locking elements. In a preferred embodiment, the cap 56 can be rotated to release this snap connection. In this position, at least one arm 42, but preferably each arm 42, can be displaced relative to the calf pad 20, so that the effective length of the pad retainer 18 can be adjusted. It is therefore possible to adjust how strongly the elastic bearing element 28, not depicted, is compressed by the wearer's calf, so that the force acting on the calf is adjustable. The effective length of the pad retainer 18 is preferably the distance between the recess 48 and the positive-locking element 50.
2 upper leg frame
4 joint
6 lower leg frame
8 medial splint
10 frontal connecting element
12 strap
14 medial splint
16 dorsal connecting element
18 pad retainer
20 calf pad
22 connecting element
24 strap
26 frontal connecting element
28 elastic bearing element
30 cushion
32 fastening strap
34 spiral spring
36 guide pin
38 pin accommodation
40 expansion limiter
42 arm
44 fastening pin
46 hole
48 recess
50 positive-locking element
52 grip element
54 row of teeth
56 cap
58 gearwheel
Number | Date | Country | Kind |
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10 2019 120 181.0 | Jul 2019 | FR | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/070531 | 7/21/2020 | WO |