Supporting device

The invention relates to a supporting device for a support (12) used to support a lower extremity, in particular a knee joint, a lower leg, a foot or an ankle, an upper leg support (14) and a lower leg support (16) being provided and interconnected via an articulation (17), the upper leg support (14) comprises at least a load-bearing surface (24, 28), the lower leg support (16) comprises at least a load-bearing surface (31), a support fixing (18) is provided, which engages with the support (12), the lower leg support (16) and the support fixing (18) being coupled to one another for the transfer of force.

This application claims priority of German Patent Application No. 10 2009 031 195.5 filed Jun. 29, 2010, which is hereby incorporated herein by reference in its entirety.

The invention relates to a supporting device for a support used to support a lower extremity.

Until now, when injuries were sustained to the knee, lower leg, foot or ankle a cast was provided in order to immobilise the lower extremity until a certain point of the healing process had been reached and the cast could therefore be removed. The injured person requires crutches in order to walk. Mobility is therefore restricted. For example daily household activities requiring use of the hands is also considerably restricted since the person has to hold onto the crutches so they can walk.

DE 600 17 944 T2 discloses an orthopaedic device that immobilises the lower extremity. A support of this type poses the advantage that it can be fitted and removed quickly and easily, in such a way that the drawbacks encountered with a cast, which is in place for a long time, are eradicated. With many types of injury to the lower extremity however, in particular in the case of breaks, it is necessary to avoid any loading at the point of break during the primary healing phase. Crutches must therefore also be used with these orthopaedic devices. These crutches are not necessary in the case of injuries to the soft tissue of the lower extremities since the supports also make it possible to walk without the use of crutches. In the case of a broken bone or the like the injured person therefore remains restricted with regard to use of their hands, at least during the primary healing phase, owing to the use of crutches. Controlled loading for controlled rehabilitation is also not provided by these supports.

DE 10 2006 011 465 A1 discloses a knee brace, in which an upper leg support and a lower leg support are connected to one another via an articulation. This supporting device is fixed to the upper leg and to the lower leg by fixing straps. Projections are provided at the lower end of the lower leg support, which are adapted to and also support the tibia condyle. It is thus possible to relieve any loading of the knee.

US 2003/0109817 A1 discloses a knee brace, in which the force is passed into the supporting device via the upper leg support and transferred directly to the ground via the knee articulation and the lower leg support so as to relieve any loading of the knee. The lower leg support comprises a cushioning means between an upper and lower support rod.

US 2006/0211967 A1 also discloses a knee brace that comprises an upper leg support and a lower leg support. A movement mechanism is controlled between a calf and foot shell and the lower leg support so as to control or lock the foot shell during a stepping movement. In order to use the knee braces according to DE 10 2006 011 465 A1, US 2003/0109817 and US 2006/0211967 there must be no injuries to the lower extremities so these knee braces can be applied and relieve the knee of any loading.

The object of the invention is to propose a supporting device that, in particular in the event of an injury to the lower extremities, makes it possible for the patient to walk without the use of crutches, even during the primary healing phase. In particular controlled rehabilitation is made possible, during which overloading is preferably prevented.

This object is achieved in accordance with the invention by the features of claim1. Further advantageous embodiments and developments are disclosed in other dependent claims.

The supporting device according to the invention comprises an upper leg support and a lower leg support that are interconnected via an articulation, the upper leg support comprising at least a load-bearing surface that abuts the pelvis and/or upper leg. The supporting device further comprises a lower leg support having a support fixing for a support, a cushioning means being provided between the lower leg support and the support fixing, which are coupled to one another for the transfer of any force and the cushioning force of which is adjustable.

Instead of the previous transfer of force via the crutches in order to relieve loading of the injured leg this supporting device now therefore makes it possible for force to be transferred via the supporting device and the support at the injured leg, the supporting device in conjunction with the support causing the force exerted when walking to pass into the supporting device owing to the weight of the human body and to be transferred from the supporting device to the ground via the support. It is thus possible to walk without crutches, i.e. the hands are kept free, for example so as to carry objects from one place to another. Owing to the use of the supporting device the injured person is therefore mobile right from the start, i.e. during the primary healing phase, once a support has been fitted to the lower extremity. The cushioning means also makes it possible to achieve controlled rehabilitation. Directly after the primary healing phase it is generally desirable for the lower extremity to initially be loaded, for example with 10% or 20% of the maximum loading capacity so as to counteract any muscle wastage and the risk of oedema. It is generally impossible for a person to carry out this task. By adjusting the cushioning force of the cushioning means it is possible to adjust the desired loading capacity in such a way that, during walking, a cushioning movement is produced between the support fixing and the lower leg support that allows, for example, 10% or 20% loading.

A further preferred configuration of the supporting device provides for the cushioning means or the boot arrangement to comprise a pressure or load detection means, in particular a pressure sensor. The desired load can be measured by a pressure or load detection means of this type and a cushioning effect of the cushioning means can therefore be adjusted. For example a pressure sensor may be integrated into the cushioning means or else be provided in such a way that the boot arrangement comprises a sole plate configured, for example, as a pressure-measuring sole, or one or more pressure sensors are distributed in the sole plate so the loading body weight can be measured. Loading can thus be increased selectively at predetermined or desired intervals.

Furthermore it is preferably provided for the pressure or load detection means to comprise a pressure-measuring sole, which detects the pressure or force acting thereon capacitively, inductively or by way of piezo effect. The data detected is preferably transferred wirelessly from the pressure sensors to an evaluation means that can be fixed to the supporting device or integrated into individual regions in the supporting device. Wireless or wired transfer can then be effected from there to an external evaluation means. Wired data transfer may also be made possible between the pressure sensor and the evaluation means that is provided at the supporting device.

The cushioning means can preferably be adjusted to a cushioning path of zero, in such a way that a rigid connection is provided between the lower leg support and the support fixing. This adjustment mode is selected, in particular during the primary healing phase, so no load is exerted on the lower extremity and, instead, any force exerted is transferred completely from the support fixing to the lower leg support when full loading is desired.

In accordance with a further preferred configuration of the invention the cushioning path can be adjusted as a function of the loading capacity that is optimal for the healing process. This cushioning means therefore makes it possible for a predetermined cushioning path to be released and, once this cushioning path has been passed through, for the support fixing to be held at a defined distance from the lower leg support, i.e. for any further loading to no longer be exerted on the lower extremity, but to be absorbed by the supporting device and the support. Overloading can therefore be avoided and controlled rehabilitation can be optimised for quicker mobilisation. At the same time, the load may be monitored or compared with the values detected by the load detection means.

In accordance with a further preferred configuration of the cushioning means the cushioning means comprises at least a mechanical cushioning member, in particular a tension or compression spring, a pneumatic, hydraulic, electromagnetic cushioning member or a resilient energy-storing member. The appropriate cushioning members may be provided as a function of the field of application and the space available for fitting. A simple embodiment is provided by the formation of a tension or compression spring. In this case coil springs may be used. Alternatively stacked, cupped spring washers may also be used. The spring constant and the spring characteristics of cushioning members of this type can be adapted precisely to different loading requirements. Furthermore, a pneumatic cushioning member, for example an air cushion, or a hydraulic cushioning member, for example as a hydraulic piston, may be provided. Electromagnetic cushioning members may also be arranged, in which a coil is movable relative to an iron core. Resilient energy-storing members, rubber-like or resiliently deformable cushioning members or else cushioning members made of foam or the like may also be provided.

Furthermore, one or more, preferably two mutually opposed guides are preferably arranged between the lower leg support and the support fixing. The relative movement between the support fixing and the lower leg fixing can therefore be guided. The guide/guides is/are preferably associated directly with the articulation in such a way that an optimal flow of force is made possible from the upper leg support to the lower leg support and the support fixing via the knee articulation.

In accordance with a further preferred configuration of the invention the support fixing is fixed to the upper end or upper edge region of the support and each guide is arranged beside the articulation. A very compact configuration of the supporting device can thus be made possible. In addition the support fixing may also be supported at the upper edge of the support. The support may preferably comprise one or more engagement points, for example projections or a shoulder, to provide support when the support fixing engages with the upper edge region of the support.

Furthermore the lower leg support preferably comprises a load-bearing surface, which abuts the lower knee or knee bone of the lower leg. This load-bearing surface is preferably configured so as to be saucer-shaped. Owing to the hump-like configuration at the lower leg a particularly good load-bearing capacity can be achieved and force can be passed effectively into the supporting device. This capacity is approximately 30% to 50% of the entire load-bearing capacity of the supporting device.

A cushioning member is preferably provided beneath the load-bearing surface of the lower leg support and is supported oppositely at the support fixing. A direct transfer of force can thus be made possible. At the same time a free space is thus created in the region of the hollow of the knee, in such a way that the supporting device does not restrict freedom of movement in any way.

In accordance with an alternative configuration of the supporting device it is provided for the support fixing to be fixed to the support in the region of the ankle joint and to comprise lateral guide portions, which are guided movably to and fro at guides, the guides each being associated with the articulation between the upper and lower leg supports and each being rigidly arranged at the lower leg support as well as extending along the support and comprising a sole plate at the lower end, which sole plate rolls over the ground. This alternative embodiment is advantageous, in particular if the outer shell of the support is configured so as to be not completely loadable. Force does not flow via the support through the lateral guides, which are provided between the sole plate and the load-bearing surface of the lower leg support, but instead may flow exclusively via the supporting device. The support is, however, guided movably relative to the supporting device via the guide portions of the support fixing.

Furthermore, in this alternative embodiment the cushioning means is preferably provided between the sole plate and the guide portion of the support fixing. Controlled rehabilitation can therefore be provided in turn.

Furthermore, in this alternative embodiment a fixing portion engaging with the upper region of the support is preferably arranged beneath the load-bearing surface of the lower leg. This fixing portion stabilises the support relative to the lower leg support so the support is only movable to and fro and movement in other directions is prevented.

A preferred configuration provides for the support to be arranged detachably relative to the support fixing. This detachable arrangement of the support is advantageous, in particular in the configuration of the supporting device with lateral guide portions at guides that extend from the articulation to the sole plate. The lower leg can thus be bent relative to the upper leg and, if the articulation is locked, force is transferred directly from the upper leg support to the lower leg support, via the articulation, and to the ground via the sole plate. With this arrangement or loading instance no force whatsoever is exerted on the foot. This arrangement also poses the advantage that with a supporting device of this type, if the articulation is locked in order to prevent any pivoting movement of the lower leg relative to the upper leg then there is no need to adapt the sole thickness to the healthy foot since the height of the supporting device, owing to the bent foot, only has to be geared to the height of the healthy foot. If compensation of this type were not provided, then the pelvis would be slanted, which would prevent a normal walking movement and could lead to discomfort. In this case the support fixing may, for example, be configured as a hook-and-loop fastening belt or other belt configured with an adjustable and detachable fastening so as to enable both a rigid arrangement relative to the lower leg support and a detachable arrangement.

A further preferred configuration of the invention provides for the support fixing to engage with the support via a fixing strap, a screwed connection, a clamped connection, a locking connection or an adhesive connection or lamination. A fixing strap comprising a hook-and-loop fastening or a belt fastening is preferably provided, whereby the supporting device can be fixed to the support and replaced quickly and easily.

In accordance with a further preferred configuration of the invention the upper leg support comprises a load-bearing surface that abuts the ischium, pubis or pelvis and preferably comprises a pressure-distributing or pressure-minimising pad. The upper leg support additionally comprises a fixing strap, which surrounds the upper leg. A fixing strap of this type makes it possible to fix the upper leg support to the upper leg over a large surface area, whereby loading can be sustained and force can be transferred.

In accordance with a further preferred configuration of the upper leg support a preferably hook-shaped curve is provided at the upper end of said support, a supporting pad being arranged on the upper face of this curve and abutting an ischium hump, ischium, pubis or the pelvis to provide support. A particularly large amount of force can therefore pass through. For example a seat cushion, similar to a saddle, is provided and is arranged so as to absorb force via the pelvis. This cushion is preferably made of plastics materials, such as thermosets, thermoplastics and/or elastomers. Bonded fabrics, composite foams, natural material, silicone, gels and/or a combination of these materials may also be used so pressure points can be selectively cushioned and the user's comfort during wear is therefore improved.

In accordance with a further preferred configuration of the invention the lower leg support comprises a fixing strap. The load-bearing surface can thus be fixed to the lower knee.

With reference toFIG. 1a schematic view from the front of a supporting device11is illustrated, which device is attached to a support12. A support12of this type may, for example, be available from Aircast Inc., Summit, N.J., US and, for example, is disclosed in greater detail in DE 600 17 944 T2. The support12is preferably configured as an orthopaedic ankle joint support. This comprises a boot arrangement that can sustain the load exerted by walking and is formed of one or more shell members, these shell members preferably being made of deflection-resistant or pressure-resistant plastics materials. The shell members may comprise air cushions and/or gel cushions at the inner face facing the foot. For example a boot may be provided that is configured as a shell member, only the tongue of the boot consisting of a flexible material so it can be put on and removed more easily. The boot may be fastened using hook-and-loop strips, straps or the like. Other boot arrangements may also be used.

The boot arrangement that can preferably sustain the load exerted by walking and is configured as the support12may preferably comprise a pressure or load detection means49, which comprises at least a pressure sensor50that is arranged, for example, on the insole of the support12or beneath a thin protective layer so as to form a type of pressure-measuring sole and so as to protect the pressure-measuring sole against damage. The load exerted on the leg can thus be detected. The detected data are supplied to an evaluation unit via a cable or wirelessly, said evaluation unit being fixed to the supporting device11or even integrated. This evaluation unit, which preferably comprises at least an IC module with a memory, can in turn transfer the detected and evaluated data to an external evaluation means, in particular a computer, wirelessly or else via a connection socket, for example a USB connection, fire wire or a similar connection or the like. A display may also be provided at the supporting device11, which displays the load, for example as a percentage or in kilograms, in such a way that the user knows the current load, the load that is required and whether this is too high or too low so as to therefore be able to preferably set the corresponding required or desired load himself. This setting may also be secured in such a way that only an authorised individual, in particular the doctor, can make changes of this type to the setting.

The supporting device11comprises an upper leg support14and a lower leg support16, which are interconnected via an articulation, in particular a double articulation17. The lower leg support16is motionally coupled to a support fixing18. In the embodiment according toFIG. 1the support fixing18is guided via a guide21relative to the lower leg support16in a non-rotational manner, movably to and fro. One or more guide rods22may therefore be arranged so as to guide the support portion18relative the lower leg support16. One or two mutually parallel guide rods22is/are associated with the articulation17in each case.

In a first embodiment it may be provided for a defined distance to be set between the lower leg support16and the support portion18via the guide rods22, which are preferably replaceable. The supporting device11can therefore be used as early as a primary healing phase since the lower extremity is not loaded. Crutches are not necessary.

The upper leg support14comprises a load-bearing surface24, which in this embodiment is formed by a hook-shaped curve of a supporting strut26. The load-bearing surface24preferably comprises a seat cushion and is configured similarly to a saddle in such a way that this load-bearing surface24abuts the pelvis or an ischium hump. The supporting strut26is connected to the right and left articulation17in such a way that it is possible to transfer force. This articulation may also be set so as to be completely rigid in order to ensure that the leg is completely relieved of loading. In order to make it possible to sit comfortably, if an angle setting defined by the doctor is approved during further progression of treatment, a corresponding angular deflection may be set and freedom of movement can therefore be determined and limited. The supporting strut26may also comprise a fixing strap27, for example having hook-and-loop fasteners, in such a way that an additional load-bearing surface28is created once the fixing strap27has been applied to the upper leg.

A load-bearing surface31is arranged at the lower leg support16and abuts the lower knee. This load-bearing surface31is provided in a semi-circular knee strap32, which is held in place by a guide rod22in each case and, in particular, is associated with the articulation17. The knee strap32may be configured as a resilient strap and may be individually adjustable in length so it is possible to achieve an optimal fit of the lower leg support16and to transfer force. Alternatively the knee strap32may also be saucer-shaped and preferably comprises gel cushions and/or air cushions at its inner face to hold and fit the knee closely. In particular it may be provided for the filling volume of the air cushions to be individually adjustable. Alternatively it may also be provided for the load-bearing surface31to directly engage with or be connected to the articulation17. A fixing strap27may also be configured at the lower leg support16in order to position the load-bearing surface31so it rests rigidly against the lower knee.

The support fixing18is preferably fixed to the support12by a fixing strap34. This fixing strap34may, for example, consist of two half shells, which are placed on an upper edge of the support12or surround an upper edge region and are held in place by a clamped connection. If a clamped connection is provided at the edge region then the at least one shell member of the support12may preferably comprise a peripheral shoulder or projection so as to make it possible for the fixing strap34to engage positively with the at least one shell member of the support12. Alternatively a plug-in and/or screwed connection may also be provided. In this alternative embodiment it is provided for the support12to comprise suitably configured members, which are attached to the at least one shell member of the support12or are integrated during production of the at least one shell member, or can be attached or fixed subsequently so as to form part of the screwed and/or plug-in connection. Furthermore the support12and the support fixing18may comprise fixing members that are coordinated with one another in such a way that a lock-snap connection or a releasable plug-in connection or the like is provided. Furthermore the support fixing18may alternatively be fixed to the support12by way of adhesion or lamination.

In accordance with this preferred embodiment the supporting device11therefore comprises the load-bearing surfaces24and28at the upper leg support14and the load-bearing surface31at the lower leg support16. A particular level of comfort during wear is therefore provided. Alternatively the supporting device11may only comprise the load-bearing surface24or only the load-bearing surface28at the upper leg support14. However, at least one of the two load-bearing surfaces24and28may preferably be provided at the upper leg support14or at least one load-bearing surface31may preferably be provided at the lower leg support16.

Alternatively to the rigid arrangement between the support fixing18and the lower leg support16, a cushioning means41may be positioned between the lower leg support16and the support fixing18. This cushioning means41is preferably adjustable, i.e. it is possible to set a fixed distance between the lower leg support and the support fixing18using this cushioning means41. The permanently adjustable distance can be adapted in length to the respective circumstance. The cushioning means also makes it possible to set a defined cushioning path. This setting is made by adaptation to the healing progress and the increasing loading capacity of the lower extremity. As soon as the defined cushioning path has been exceeded owing to excess load, the cushioning means41adopts a blocking action or a predetermined fixed distance between the support fixing18and the lower leg fixing16is occupied. Overloading is thus prevented. In order to adjust a predetermined cushioning path A, a stop that is movable to and fro may be set to a predetermined distance, for example via an adjustment dial, thus preventing any further movement of the support fixing18and the lower leg support16relative to one another.

This cushioning means41therefore enables use as early as the primary healing phase, the support fixing18being set at a fixed distance relative to the lower leg support16, in such a way that there is no loading of the lower extremity and instead the load is transferred from the supporting device11to the ground via the support12. It is then possible to achieve controlled rehabilitation, in which a cushioning path is released in accordance with the respective load that is optimal for the healing process and is reduced with regard to the maximum load.

The cushioning means41comprises at least a cushioning member42, preferably a compression spring, which is replaceable in particular and is preferably adapted to the body weight of the user so as to preferably provide smooth occupation of a defined cushioning path. Other energy-storing members may be used as an alternatively to the compression spring, in particular rubber-resilient energy-storing members or energy-storing members made of foam. Furthermore different compression springs having an appropriate spring constant may also be used as an alternative to the cushioning path that is adjustable by way of a stop.

The cushioning means41is, for example, configured as a pressure loadable cushioning means41. Alternatively the cushioning means41may, of course, also be tensioned. Force passing into the support fixing18and the lower leg support16is correspondingly deflected.

The cushioning means41may be arranged both in the region of the shin and oppositely or laterally directly beside the articulation17. A suitable arrangement may be provided as a function of the constructional configuration of the guide rod22or guide rods22and the configuration of the cushioning member42.

With reference toFIG. 2an alternative configuration of a supporting device11with regard to that ofFIG. 1is illustrated. The upper leg support14has the same function, but a supporting shell44is provided instead of a supporting strut26.

The structure of the lower leg support16and of the support fixing18differ from those inFIG. 1. In this case guide rods22arranged laterally in the direction of action of force relative to the articulation17are provided and comprise a sole plate46at the lower end. The support fixing18is fixed to the support12in the region of the ankle joint and comprises a guide portion48, which is guided between the two guide rods22in such a way that the support12is movable to and fro relative to the guide21. The cushioning means41is provided between the guide portion48and the sole plate46. A cushioning path B may be adjusted as a function of the set loading capacity. This determines the extent to which the guide rods22plunge into the sole plate46. The cushioning means41may also be set to a cushioning path of zero so no load is exerted on the lower extremity. The cushioning means41can also be used in this alternative configuration of the supporting device11and operates under tension.

In this embodiment a fixing portion47is also provided. This fixing portion47can only extend around the calf region. The direction of movement for cushioning may only be set along the guide21owing to the support provided by the fixing portion47. The fixing portion47may also comprise a strap, which is placed around the shin in such a way that an additional guiding of the support12relative to the guide21is provided.

With reference toFIG. 3an alternative use of the supporting device11compared toFIG. 2is illustrated. In this case it is provided for the support fixing18to be provided as a detachable support fixing in such a way that the support12can be pivoted out of the position shown inFIG. 2so as to transfer into a position according toFIG. 3. At the same time the articulation17is locked in such a way that the supporting strut26and the guide rods22make it possible to remove any loading of the sole plate46. The user's body is therefore supported on the load-bearing surface46. The user can bend his lower leg relative to the upper leg and relieve it of any loading as well as stand without crutches. Both the lower leg and the knee are therefore completely relieved of loading. In this embodiment the cushioning means41is set to a block setting, this means that no cushioning is set or else only such a low level of cushioning is set that this provides comfort during walking, yet the plunging path is very short so the toes don't contact the ground during walking.