JOINT

Abstract: The invention relates to a hinge intended to be used preferably in an orthosis and having the function of supporting, protecting and/or controlling a body joint, said hinge including at least two flexible, essentially strip shaped elements (1, 2) arranged mutually slidable in a plane-to-plane relationship, which elements (1, 2) are carried by supporting members (3, 4) having a controlling and guiding function, at least one of these strip shaped elements (1, 2) being a resilient strip element (1) of a high degree of springiness and of a high stiffness, which element is resiliently flexible in the longitudinal direction of the strip, about an axis located in the main plane of the strip essentially perpendicular to the longitudinal direction of the strip, but which is essentially rigid against bending about an axis essentially perpendicular to the main plane and longitudinal direction of the strip, the remaining strip elements (2) having a lower degree of springiness and a less stiffness than the resilient strip elements (1), to serve as spacer elements having the function of guiding and supporting the resilient strip elements (1) and having essentially the same longitudinal extension as the resilient elements (1) so that in flexing the hinge the spacing of the strip shaped elements (1, 2) is maintained constant along substantially the whole extension of the strip shaped elements (1, 2), and at least one of the strip shaped elements (1, 2), preferably at least one of the resilient strip elements (1), being directly or indirectly fixed at both ends, means being provided in order to allow the supporting members (3, 4) to move, when the hinge is flexed or extended, along curves which are defined mutually and relatively in dependence of the flexion and extension, which curves are determined by the hinge movement.

Description: JOINT The invention relates to a hinge intended to be used pre¬ ferably in an orthosis and having the function of supporting, protecting and/or guiding a body joint, said hinge including at least two flexible, essentially strip shaped elements ar¬ ranged mutually slidable in a plane-to-plane relationship, which elements are carried by supporting members having a con¬ trolling and guiding function. The present invention has for its object to provide a hinge which is to form part of some kind of joint supporting or pro¬ tecting bandage, orthosis, or to form part of a device intended to support or stiffen one or more bodily joints. The hinge can also be applied for prophylactic purposes in order to prevent injury in sports practice or in other physical activity, or to consolidate a joint which has been injured or operated upon, or to limit the range of movement of the joint, or to facilitate control or guidance of one or more joints of the body. Usually orthoses, i.e. joint supporting bandages, include pivot means of the hinge type provided on either side of the joint of the body, e.g. the knee joint. These orthosis hinges have essential disadvantages. Firstly, they are usually provid¬ ed with hinge pivots which impart to the articulation of the orthosis a stationary pivot axis, as distinguished from an ana¬ tomic joint whose axis of articulation is displaced, for examp¬ le, in movement of the joint. This displacement between the or¬ thosis and the part of the body must be assumed by the adjacent soft tissues. Furthermore, such a hinge based articulation in the orthosis does not offer any possibility of performing the rotation which takes place in e.g. the final phase of knee ex¬ tension, and also this movability in relation to the orthosis must be assumed by the soft tissues. Prophylactic use of hinge pivots is hardly possible as, in order to offer adquate strength, they must be made so large that there will be a risk of injury not only to the wearer but also to other persons participating in the activity. A knee orthosis, for example, must allow extension and fie- xion, and it is also to protect against violence sideways and frontways, and possibly also it has to prevent hyperextension. The problem of the locked and immovable pivot axis has been solved, at least in part, by means of another type of hinge dis¬ closed in the German Patent Specification No. 838479, where the hinge includes a plurality of thin steel leaf springs placed one upon the other in a similar way as in a laminated type spring. However, in order to afford sufficient lateral and rotational stability, particularly if only one spring assembly is to be used on the outside of the knee, the hinge will become too stiff in flexing to be usable in practice. Another type of hinge, which also offers at least some adap¬ tion to the anatomic joint, is disclosed in the U.S. Patent No. 4 130 115. The hinge disclosed therein comprises two opposite holders or housings, each provided with a plurality of elongated flexible rib elements spaced to form interspaces, so that the ribs of one housing are slideably received between the ribs of the other housing. These ribs are secured in the housing elements in such a way that they will define grooves wherein the ribs of the oppo¬ site housing element are slideably received. This brings with it i.a. that the two housing elements have different widths. The hinge is made of plastics so that it can be washed and cleaned together with the orthosis or bandage. In order to be able to alter the strength of this hinge one applies the method of adjusting the distance between the two housing elements. It is thus quite clear that this is a type of ready-made hinge which cannot readily be adjusted to a particular application. In the type of design presented in this U.S. patent application the two housing elements must definitely have the same longitudinal extension (cf. Fig. 1 of the U.S. patent specification), which clearly illustrates the inconvenience involved by this inflexi¬ bility. Obviously the hinge cannot in a smooth and simple way be adapted to the configuration of the leg. As to the strength of the hinge there is no great variability, as one is limited to alter this strength merely by means of the distance between the housing elements. In addition, due to its structure this hinge develops a friction which is double that developed by the hinge according to the invention. A hinge of this type could hardly be provided with the de¬ sired flexibility and at the same time offer sufficient lateral strength to permit it to be used on the outside only of the knee. Consequently the hinge would hardly allow rotation and thus not make room for the above mentioned rotation in the final phase of the knee movement. Instead, adaption is carried out by the rotational movement being compensated by the soft tissues of the leg assuming the same. Also, in all probability this hinge cannot assume vertical loads. This type of hinge can scarcely be limited as to its range of motion, a capacity which is an important property of the hinge according to our invention. The hinge according to our invention, with its present design, can also be limited as to its range of motion in order to prevent violation caused by superextension. A further type of hinge is disclosed in the Swedish Patent No. 8503612-7, which hinge is in the form of a single hinge, that is, it is intended to be placed on one side of a joint of the body. Of course it can also be used in combination with a further hinge placed on the opposite side of the bodily joint to be supported. The hinge described in the above Swedish patent comprises two opposite holders or housings each receiving the opposite ends of a number of strip shaped elements. These elements are maintained at a mutual predetermined and constant distance from each other, partly by using said housing elements, partly by using rigid spacer members provided in the central portion of the strip elements. These spacer members have a limited exten¬ sion lengthwise of the strip elements, which causes the distance between the strip elements to vary in accordance with the degree of flexion of the hinge. It has now turned out that this hinge has certain deficien¬ cies. Due to its structure it is clumsy to use. The central por¬ tion accommodates a large space which means that besides the end pieces the hinge includes a further part which represents a risk of injury to the practicer and opponents. Owing to its design the hinge will show certain specific properties which are determined already at manufacture. The present invention has for its object to eliminate most deficiencies of the hinges previously known. The hinges already known are cut and dried products. That means that although the assortment is large, in all probalitiy, problem will still arise when the orthosis hinge is to be adapted to the anatomic joint. Neither must problems of a cosmetic nature be neglected. The known hinges are difficult to apply to various joints of the body in a manner which is satisfactory from an esthetic view¬ point. A further drawback of the known hinges is the fact that the distribution of forces within the hinge is established al¬ ready at the manufacture and cannot be changed in an easy and smooth way. Although we feel that the hinge known from the Swe¬ dish Patent No. 8503612-7 has meant a definite improvement in comparison with prior art, this hinge exhibits a somewhat too great instability in certain applications. In order to solve these problems we have now designed a new hinge. The hinge is characterized by the feature that at least one of these strip shaped elements is a resilient strip element of a high degree of springiness and of a high stiffness, which element is resiliently flexible in the longitudinal direction of the strip, about an axis located in the main plane of the strip, essentially perpendicular to the longitudinal direction of the strip, but which is essentially rigid against bending about an axis essentially perpendicular to the main plane and longitudinal direction of the strip, the remaining strip ele¬ ments having a lower degree of springiness and a less stiffness than the resilient strip elements, to serve as spacer elements having a function of guiding and supporting the resilient strip elements and having essentially the same longitudinal extension as the resilient elements so that in flexing the hinge the spac¬ ing of the strip shaped elements is maintained constant along substantially thewhole extension of the strip shaped elements, and in that at least one of the strip shape elements, preferably at least one of the resilient strip elements, is directly or indirectly fixed at both ends, means being provided in order to allow the supporting members to move, when the hinge is flex¬ ed or extended, along curves which are defined mutually and relatively in dependence of the flexion and extension, which curves are determined by the hinge movement. The invention will now be described with reference to the accompanying figures which show diagrammatically examples of embodiments: Fig. 1, the hinge in its basic design. Fig. 2, the hinge according to fig. 1 in a flexed posi¬ tion. Fig. 3, embodiment of the hinge according to Fig. 1. Fig. 4, the hinge according to Fig. 3 where the longer hous¬ ing has been parted. Fig. 5, embodiment of the hinge according to Fig. 4. Fig. 6, embodiment of the hinge according to Fig. 1. Fig. 7, embodiment of the hinge according to Fig. 1. Fig. 8, embodiment of the hinge according to Fig. 1, view¬ ed in elevation and wherein one support element (the one having a controlling function) exhibits in plane a curved surface. Fig. 9, a diagrammatical view of a number of possible em¬ bodiments of the abutment, that is, the bottoms of the support elements, and empty spaces possibly arranged in the support ele¬ ments in order to make room for the strip elements and the re¬ silient elements in joint articulation, possibly locking means. Fig. 10, examples of the design of strip element and spacer element. Fig. 11, embodiments of the hinge according to Fig. 1, and in Figs, lla-e examples of cross-sections through the hinge along line A-A in Fig. 11 (lie corresponds to a parted support element). Fig. 12, the hinge provided in an ankle-joint support. Fig. 13, the hinge provided in a wrist orthosis. The hinge shown in Fig. 1 includes strip or rib elements 1 made of spring steel or a material of corresponding qualities. Spacer elements 2 are interleaved between the strip shaped ele¬ ments 1, which spacer elements, for example, are made of teflon or a similar material, have a coefficient of friction adapted to the specific use and which have essentially the same area as the strip elements 1. The ends of the strip and spacer ele¬ ments are inserted into pocket like support elements 3, 4 (car¬ rying members having a guiding function). In the figure also a locking device (5) is indicated at one end of the two support elements. Locking members to maintain the elements spaced at a predetermined distance from each other are to be provided in both support elements, which members lock one or more of the strip elements, whereof at least one is locked at both ends. The design of this locking member is not critical as long as it fulfils its intended function to prevent the hinge from fall¬ ing apart and also to define the range of motion and the strength of the hinge. When it comes to locking one or more elements to the support element said locking member is preferably arranged in the form of a pin or the like passing completely or partly through the support elements. If all strip shaped elements in a support element is to be locked this can of course be carried out in some other suitable way, for example, by glueing or the like. It can also be conceived that the strip element or ele¬ ments used for locking are longer than the remaining strips in order to make room for locking this very strip element or ele¬ ments. In all figures locations contemplated for locking are mark¬ ed P. In Fig. 2 the same hinge as in Fig. 1 is shown but in a bent or flexed condition. It can be seen that the hinge is lock¬ ed on its right side and that a free space will arise on the left side of the support elements where strip and spacer ele¬ ments no longer reach down to the bottom of the respective sup¬ port element at the bending. In the figure arrows illustrate conceivable directions of movement of the hinge. In Fig. 3 there is shown an embodiment of the hinge accord¬ ing to Fig. 1 where one of the support elements has been shorten¬ ed for e.g. space reasons or cosmetic reasons. In comparison with Fig. 1 of the above American patent spe¬ cification it is easy to see why a support element has been shor¬ tened. In addition, this is an essential difference between the hinge according to our invention and the American hinge, where it is not possible, because of its structure, to shorten one- -sidedly one of the support elements. In Fig. 1-5 the support elements 3, 4 have been drawn as square, hollow pockets wherein the strip elements 1 and spacer elements 2 are introduced, but within the scope of the invention the support element design can be widened to include in general an abutment (a bottom) in the pocket whose curve line describes the same curve line as the motion of the hinge. The bottom can also be formed as an inverted V-like curve or assume other forms conditioned by the specific application and the specific body joint for which the hinge is intended. In addition, the support elements can be bestowed a curved form corresponding longitu¬ dinally to the body joint concerned in order that the hinge be adjusted to the body joint. Fig. 4 and 5 illustrate how the longer support element here has been divided lenghtwise in two parts. This structure can be useful for application on certain body joints in order to pro¬ vide a smooth and flexible orthosis. The hinge shown in Fig. 5 is provided with preformed bent strip elements which can ren¬ der a further gain of space possible. It should also be pointed out that in certain specific ca¬ ses of loss of function, when the extending muscles work but the flexing muscles do not, there is a possibility to provide a hinge which is preflexed, that is, the strip elements are preformed so that a bent orthosis is obtained. Here the wearer can use his tensioning muscles to straighten the body joint af¬ ter which, when the tensioning muscles are relaxed, a return movement of the body joint to a flexed position is brought about. In Fig. 6 it is shown how it is possible e.g. to arrange a stable locking of the hinge in one direction of movement there¬ of. In the opposite direction the range of movement is control¬ led, on the one hand, by the shape of the support element exte¬ rior at A and, on the other hand, by the free space existing at top right and top left in the support elements and which is created by adjusting, in accord with the application, the length of the strip and spacer elements. Preferably one of the central strip elements is locked here, see the figure. The embodiment shown in Fig. 7 is particularly intended to make room for anatomical prominences. The shape of the short support element can of course be modified as desired, but the figure illustrates the basic principle. In Fig. 8 a support element of a specific design is examp- lified. This support element is associated with a particular form of the strip and spacer elements (see Fig. lOg). The surface of the support element, curved longitudinally, creates a rotation when flexing the hinge. This rotation is determined by the radius of curvature. In Fig. 9 it is examplified how the bottom (abutment) of the support element can be formed, locking of an element at the point designated P being proposed. The non-hatched part of the respective support element shows that part which can be left more or less empty, by those strip and/or spacer elements lo¬ cated on the corresponding place being adapted to make room for the movement of the elements when the hinge is flexed. In Fig. 10 some examples are shown of various embodiments of strip and spacer elements, respectively. The apertures marked in Figs. 10b and 10c are intended for locking the hinge, and the slits marked in lOd and lOe are provided in order to make it possible to lock one or two strips only, in which case the remaining strips will not hamper, thanks to the slits, the mov- ability of the hinge. As a matter of course slits of this type can also be used for limiting the range of movement, possibly in combination with the design of the strip and spacer elements. In Fig. lOf there is shown, instead of slits, an alternative design. At the bottom of Fig. 10 an element is shown which is designed for use in a hinge according to Fig. 8. As can be seen the present invention is based . on the fea¬ ture that the hinge aimed at has been considerably simplified, thereby gaining a great flexibility, which previously has not been possible to attain with these hinges. The new hinge is based on the feature, as we have seen, that one or more stiff but resilient strip elements are provided between two end pie¬ ces. Between these strip elements an optional number of spacer elements are interleaved as desired, for example, when adjusting the hinge to the individual concerned or the purpose concerned, which spacer elements exhibit essentially the same surface area as the stiff but resilient strip elements. Within the scope of the invention and in accordance with the function desired the spacer elements can be flat, tape formed, circular, oval, or trapezoidal. Strips of the type here shown are of course also useable for limiting the range of movement. Also, the spacer elements can be provided as desired with a wedge-shaped cross section (e.g. for use in a support element of a design similar to that of Fig. lib), and, moreover, they can vary as to their width, one edge of the elements then possibly being even and the other uneven. The apertures and the slits can be provided when manufac¬ turing the strip, or they can be suitably placed when the hinge is assembled. Fig. 11 illustrates how the shape of the support elements can appear in cross section. Figs, lla-d all show a section through the support element along line A-A in Fig. 11. The sup¬ port element shown in Fig. 11a has a configuration narrower at the dashed line A and wider at the dashed line B. The line A and B, respectively, show the limit positions of the hinge axis in relation to an imagined joint, in particular the knee joint. That is to say that one line corresponds to the position of the axis when the le " g " is straight and the other line to the axis position when the leg is bent. This arrangement has the feature that here it is possible to design the hinge such that it will be stronger in one position than in another, this in order to make it possible to adjust protection so that it will fit the need of strength in various situations. Fig. lib shows a cosme¬ tic hinge design having the purpose to follow the shape of the leg. Fig. lie shows a further embodiment. Fig. lid represents a further design for adjusting purpose, possibly also for offer¬ ing a possibility to change the strength of the hinge. Finally, as shown in Fig. lie, these embodiments can be parted (cf. Fig. 4, 5, for example). Fig. 12 shows the hinge mounted in an ankle support. This ankle support, or this joint orthosis, comprises two parts. One U-shaped part which grasps around the ankle from behind and one bottom part comprising an "insertion" placed under the heel and possibly the instep and having end pieces placed on either side of the heel, this bottom part being made in one piece. The bottom part and the U-shaped part are united, by way of the end pieces, on either side of the foot joint by means of a hinge according to the invention. This foot support (joint orthosis) can of cour¬ se be designed in a plurality of ways whereof the present one only represents an embodiment. is joint orthosis can either be placed loosely in a shoe, possibly lined and cushioned where appropriate, or it can be mounted in a shoe already when this is manufactured. Fig. 13 shows a wrist support, which is primarily intended to support the wrist when exercising movements which can stress the joint and bring with it a risk of injury thereto. It can of course also be used for controlling or limiting the range of movement of the wrist, or for other purposes such as, for example, to train a particular movement of joint. The wrist or¬ thosis shown in Fig. 13 comprises substantially three parts. One part intended to rest against the topside of the hand, one part intended to grasp the arm at the wrist, and one connecting hinge according to the invention. This wrist orthosis can suit- bly be provided with a hook and loop type fastening means on the two parts which secure the orthosis about the wrist. It can also be provided-with a glove of the type used within various branches of sports, the glove being secured in a suitable man¬ ner. As a matter of course, the embodiments shown in the figu¬ res and described in the aforegoing only represent examples of design within the scope of the invention. To summarize the pos¬ sibilities offered when it comes to vary the properties of the joint when assembling and mounting the same it could be said that 1) the number of strip elements in relation to spacer ele¬ ments can be varied as desired in order to attain de¬ sired effects, 2) the distribution of the strip elements in relation to the spacer elements affects the strength of the hinge, 3) by designing the support elements differently in relation to the strip and spacer elements ranges of motion of varying size can be allowed in the hinge, 4) by designing the cross sectional shape of the support elements the strength of the hinge at different posi¬ tions of the anatomical joint axis can be varied, 5) by locking an optional element or elements specific properties can be imparted to the hinge and, of course, the properties of the hinge with respect to strength and flexibility can be affected by the material of the strip elements as also by the material of the spacer elements, where the spacer elements need not necessarily be flat but can have a slightly oval shape in order to change e.g. the lateral stability of the hinge, or said elements can show some other of the designs mentioned in the description. This hinge can thus be assembled and prepared for that very situation and for that very individual concerned, and we have obtained a smooth and readily adaptable joint which, beyond the technical improvement it represents, also means that it will provide, thanks to its smoothness, an attractive alternative in the prophylactic use of joint supporting and joint stabiliz¬ ing orthoses. In the above manner an individual adaption of the hinge can always be brought about.

Claims: Claims 1. A hinge intended to be used preferably in an orthosis and having the function of supporting, protecting and/or controll¬ ing a body joint, said hinge including at least two flexible, essentially strip shaped elements (1, 2) arranged mutually slidable in a plane-to-plane relationship, which elements (1, 2) are carried by supporting members (3, 4) having a controll¬ ing and guiding function, characterized in that at least one of these strip shaped elements (1, 2) is a resilient strip ele¬ ment (1) of a high degree of springiness and of a high stiff es, which element is.resiliently flexible in the longitudinal di¬ rection of the strip, about an axis located in the main plane of the strip essentially perpendicular to the longitudinal di¬ rection of the strip, but which is essentially rigid against bending about an axis essentially perpendicular to the main plane and longitudinal direction of the strip, the remaining strip elements (2) having a lower degree of springiness and a less stiffness than the resilient strip elements (1), to serve as spacer elements having the function of guiding and supporting the resilient strip elements (1) and having essentially the same longitudinal extension as the resilient elements (1) so that in flexing the hinge the spacing of the strip shaped elements (1, 2) is maintained constant along substantially the whole extension of the strip shaped elements (1, 2), and in that at least one of the strip shaped elements (1, 2), preferably at least one of the resilient strip elements (1), is directly or indirectly fixed at both ends, means being provided in order to allow the supporting members (3, 4) to move, when the hinge is flexed or extended, along curves which are defined mutually and relatively in dependence of the flexion and extension, which curves are determined by the hinge movement. 2. A hinge according to claim 1, characterized in that the strip shaped elements (1, 2) carried by the supporting members (3, 4) determine the desired properties of the finished hinge by means of the ratio of dimensions, position and number of resi¬ lient strip elements (1) in relation to the position, dimensions and number of spacer elements (2). 3. A hinge accorjling to any of the preceding claims, characte¬ rized in that the spacer elements are made of a material having a suitable coefficient of friction, which then is subject to variation. 4. A hinge according to any of the preceding claims, characte¬ rized in that the resilient strip elements (1) are formed of a material having properties with respect to resilience which are suitable to the application contemplated, which strip ele¬ ments (1) can then have different properties. 5. A hinge according to any of the preceding claims, characte¬ rized in that the spacer members (2) have a cross-sectional area rounded at one or more of its corners in order to affect the torsional properties of the hinge. 6. A hinge according to any of the preceding claims, characte¬ rized in that those means, which cause the supporting members (3, 4) in flexing the hinge to move along curves mutually and relatively defined in dependence of the flexion or extension and determined by the hinge movement, comprise a locking mem¬ ber (5) provided in one or both of the supporting members (3, 4), by means of which locking member one or more of the resi¬ lient strip elements (1) can be locked in the respective supporting and guiding member (3, 4) by the locking member (5) engaging an aperture existing in one or more strip elements or being provided therein when manufacturing the hinge. 7. A hinge according to any of the preceding claims, characte¬ rized in that tϋe locking member (5) is arranged in the support¬ ing member (3, 4) in such a way that is passes through all the strip elements (1, 2), apertures for the purpose being provided in the strip elements to be locked, and slits or recesses pre¬ ferably being provided in the elements not to be locked. 8. A hinge according to any of the preceding claims, characte¬ rized in that one or more of the strip shaped elements are longer than the remaining elements, locking then being possible to carry out by using the excess part of the strip element. 9. A hinge according to any of the preceding claims, characte¬ rized in that in order to limit the range of motion of the hinge it is possible, beyond locking one or more strip elements whereof at least one has been locked at either end, to combine locking with a particular design, selected in view of the range of motion intended, of one or both of the guiding and supporting members (3, 4), an abutment being provided in said members to affect in conjunction with the length of the strip elements tne range of motion. 10. A hinge according to any of the preceding claims, characte¬ rized in that the guiding and supporting members are defined so as to show a curved shape corresponding lenghtwise to the body joint concerned, in order to adapt the orthosis hinge to the body joint. 11. A hinge according to any of the preceding claims, characte¬ rized in that for limiting the range of motion of the hinge, the guiding and-supporting members can be designed such that they have transversely to the hinge parallell edges engaging one another, preferably up to the locked strip element, said parallell edges merging into a curve shaped such that the ed¬ ges diverge, thereby determining, alone or in combination with bottom designing or strip element curtailing, the range of mo¬ tion of the hinge. 12. Use of the hinge according to any of the preceding claims as one or more components of joint orthoses or supporting or guiding devices, in doing which one or more hinges can be ar¬ ranged on one or both sides in relation to the body joint con¬ cerned, also one hinge after the other lengthwise.

Inventors: KOEHLER PETER, LINDH LEIF, KOEHLER, PETER, LINDH, LEIF
Applicants: KOEHLER PETER, LINDH LEIF, KOEHLER, PETER, LINDH, LEIF
Application year: 1990
Main classification: A61F5
IPC codes: A61F5