BACKGROUND OF THE INVENTION

[0001] This invention relates to a synovial joint protector.

[0002] In this specification a“joint” refers to a connection made between bones in the body which link the skeletal system into a functional whole. Different joints allow for different degrees and types of movement. Connective tissues such as ligaments, tendons and cartilages each play an important role in the functioning and stability of a joint and any damage or injury to such tissue could result in temporary or permanent frailty of the joint. [0003] Hyperflexion and hyperextension are typical causes of joint injuries that may cause the connective tissue to rupture.

[0004] Depending on the extent of damage caused by an injury, the tissue may be repaired by surgery process or by immobilising the joint for an extended period of time. The injury can take a considerable time to heal and, even after healing, the joint may perhaps not function as effectively as it did before the injury. In the case of a professional athlete, the down-time required to allow an injury of this type to heal could end the athlete’s career.

[0005] A sleeve can be worn over a joint to provide additional stability, especially during sport activities. If sufficient force (e.g. during a fall or the like) is applied to a limb or appendage, the sleeve will not always be able to prevent hyperextension or hyperflexion of the joint and the tissue may thus sustain damage despite the additional support. [0006] Other types of joint guards restrict mobility of the joint and are typically employed to expedite healing of injured connective tissue. This form of guard is generally not suited for providing support during sporting activities, as the supported joint will be substantially restricted in respect of its normal range of movement. [0007] A need exists to be able to prevent hyperextension or hyperflexion of a joint during vigorous body movement without unduly interfering with a normal range of movement of the joint.

SUMMARY OF THE INVENTION

[0008] The invention provides a synovial joint protector which includes at least one support configured to be attached to a body of a user at or adjacent the joint while allowing the joint to move freely within a normal range, the support including a mechanism which restricts movement of the joint outside of the normal range.

[0009] ’’Normal range” in the context of this specification, means a range of movement that does not cause injury to the joint. It falls within the scope of the invention for the normal range to be adjustable, to take account of factors such as the health, age, fitness or other factors of the person wearing the protector. For example an older person who may be of good health may find, nonetheless, that movement of a joint is restricted to be within a range which is substantially smaller than what was a normal range when that person was younger. To prevent the joint from moving outside of that restricted range the protector may be adjusted to allow movement of the relevant joint only within the restricted range.

[0010] “Abnormal range” in the context of this specification means a range of movement, not within the normal range, which may cause injury to the joint. [0011] In particular, the protector is capable of preventing or restricting hyperflexion of the joint without interfering with mobility of the joint in the normal range.

[0012] The support may be a flexible sleeve which may fit snugly around the joint.

[0013] The sleeve may be provided in a configuration which is tailored to fit a particular joint, which may be prone to hyperflexion or hyperextension, including an ankle, a knee, a wrist or an elbow. The flexibility of the sleeve allows the sleeve to bend or flex thereby to allow unhampered movement of the joint in the normal range.

[0014] The sleeve may comprise any suitable support or substrate on, in or to which, the mechanism is mounted or attached. [0015] In one form of the invention, the mechanism includes at least two spaced anchor points and at least one element with opposed ends respectively fixed to the anchor points, and wherein the element allows movement of the joint up to a limiting position at which the movement of one anchor point relative to the other anchor point is restricted. Thus the element allows relative movement of the two anchor points only up to a predetermined stage which corresponds to a limiting point or boundary of the normal range of movement of the joint.

[0016] The element may have a degree of“slack” which is attributable to a weave or zigzag path followed by the element between the anchor points. As the path is straightened movement of one anchor point relative to the other anchor point is restricted possibly to an increasing degree.

[0017] The elements may be flexible fibres or filaments of carbon or Kevlar™ or an equivalent material, which has only a limited degree of stretch or, preferably, which effectively is non-stretchable. [0018] Use may be made of any suitable material which has limited elasticity i.e. the material can stretch to a limited extent only and, therefore, is essentially non-extensible.

[0019] The length of the element may be dependent on a normal flexion or extension range of the particular joint and the limiting position may be at the end of the range. [0020] The element may be in or on a suitable carrier i.e. the element or constituents of each element may be in or on the sheath or on a pad of a suitable material.

[0021] In a first embodiment the element is in a non-linear configuration, in which movement of the joint is allowed at least in one direction and, when the element is extended to a linear configuration, the element prevents further movement of the joint in that direction.

[0022] In a second embodiment of the invention, the element includes a slip knot and movement of the slip knot creates an amount of slack in the element. With movement of the joint, in the normal range, the slip knot tightens e.g. around one of the anchor points until a limiting stage is reached at which relative movement of the anchor points is restricted.

[0023] A“limiting stage” refers to a joint configuration at which further movement of the joint would be outside of the normal range.

[0024] In a variation the“slack”, which is the factor which controls the extent of permitted movement of the relevant joint, is determined by movement of one or both anchors. Each anchor may be located on a band which extends around a limb and the size of the band, i.e. its loop length, may be adjustable to allow for movement of the anchor. In this form of the invention the anchor may be formed by two points on the band which can be moved towards each other or apart from each other. The permitted degree of movement towards each other determines the slack i.e. the extent to which the flexible element can be moved.

[0025] In another embodiment of the invention, the element includes a plurality of rigid members which are pivotally interconnected to mimic the movement of the joint in the normal range. One or more hinges may be used for each pivotal interconnection. The support then comprises a fastener at one end of the rigid members, which fastener also serves as an anchor, and a similar arrangement at an opposing end of the rigid members. ^'

[0026] Each hinge may allow relative, to-and-fro pivotal movement of two interconnected rigid members, so as to permit mono-directional or bi-directional movement of the joint.

[0027] Each interconnection may be in the form of a knuckle joint to limit movement of the rigid members to within a plane, and to restrict movement of each rigid member relative to an adjacent connected member transversely to the plane.

[0028] The members may be made from a material such as titanium or polycarbonate or an equivalent material.

[0029] The element and the anchor points may respectively correspond to the connective tissue of the particular joint and to attachment locations of the respective ligament at the joint or the connective tissue.

[0030] Preferably, a plurality of the elements are included in the sleeve for each connective tissue or alternatively, each element may correspond to a respective connective tissue of the relevant joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention is further described by way of examples with reference to the accompanying drawings wherein:

Figure 1 shows a portion of a ligament protector according to the invention;

Figures 2 to 4 are different views of a sleeve in a protector configured to guard an ankle; Figures 5 and 6 are different views of a sleeve in a protector configured to guard a wrist; Figure 7 shows a protector which is used to support a knee joint;

Figure 8 depicts a different embodiment of the invention; and

Figure 9 depicts a version of the Figure 8 embodiment. DESCRIPTION OF PREFERRED EMBODIMENTS

[0032] Figure 1 shows a synovial joint protector 10 according to one form of the invention which includes a sleeve 12 with two anchor points 14 and 16 respectively, and a plurality of elements 18 fixed or embodied in the sleeve 12, each element following a sinuous, zig-zag or non-linear path, (referred to herein as being“slack”) between the points 14 and 16.

[0033] The sleeve 12 is made from an elastic, light-weight material and is shaped to be worn on a particular joint such as an ankle, knee, wrist or elbow. The sleeve fits over the joint like a second skin.

[0034] The elements 18 are made from a flexible and durable material such Kevlar™ or carbon fibres or filaments which optionally may be in a braided form. The elements are not stretchable to any significant degree.

[0035] The anchor points 14 and 16 are situated at locations, in bands 19, which correspond to attachment positions of a ligament or a tendon of the joint over which the sleeve is worn. The bands 19 are broad and are positioned so that in use they closely encircle a body portion thereby to form a generally movable location together with an underlying body part or basis for the anchor points 14 and 16. The anchor points are not movable though relative to the encircled body portion.

[0036] A space 20 between the anchor points 14 and 16 corresponds to a length of the ligament or tendon in a relaxed state. The elements 18, in an extended form (i.e. when the elements are substantially fully extended or linear and all slack is taken up), have a length which corresponds to a length of the ligament or tendon in a tensioned state, i.e. when the joint in question is extended or flexed to a maximum.

[0037] In use, during normal flexion or extension of the joint, the sleeve 12 bends or flexes with the joint, with the anchor points 14 and 16 respectively remaining at the indicated locations on the bands 19 relative to the joint. Each element initially lies on or follows a non-linear path which straightens to an increasing degree as the joint is extended or flexed. The effective length of each element 18 corresponds to the maximum length between the anchor points 14 and 15 which, in turn, occurs at a limiting position of the tendon or ligament as the tendon or ligament reaches an end of a normal range of movement.

[0038] The elements 18 are capable of resisting a relatively high tensile force and, as the elements straighten, movement of the joint is stopped short of a position at which it would enter a hyperflexion or hyperextension stage i.e. enter an abnormal range. [0039] The lengths of the elements may be adjusted in any appropriate way to determine the extent of normal range movement. It is also possible to adjust the spacing between the anchor points to achieve a similar objective.

[0040] Each anchor point 14, 16 may be formed in any suitable way e.g. by means of a fixing point on a respective band or strap, of appropriate proportions, which in use is wrapped around a part of the limb in such a way that a comfortable, relatively immovable location is provided to act as a point of restraint, i.e. as an anchor for the element.

[0041] Figures 2 to 4 show an example of a synovial joint protector 10A which has a sleeve 12A configured to fit an ankle 30 and which has elements 18Ai, I 8A2, I 8A3, I 8A4 and18A5 which correspond to respective connective tissues of the ankle. The elements are secured to an interior of the sleeve 12A and are anchored at opposed ends to respective anchor points 14 and 16 which are located at positions which correspond to attachment locations of the respective connective tissue at the joint. The respective anchor point 14, for each element, is located in or on a sole 32 of the sleeve 12A. The sole 32 could be slightly rubberized so that the sleeve is in the form of a boot or sock.

[0042] The number of elements 18, used in a protector 10, can be varied to meet requirements. Figure 2 shows 5 elements but this is exemplary only, and is non-limiting.

[0043] Figure 2 shows the ankle 30 in a relaxed state, while Figure 3 shows the ankle 30“rolled”. In the latter state the elements I 8A1, I8A3 and 18A ₄ , are straightened to a maximum extent and all slack is eliminated. Thus the elements prevent the ankle from rolling further. The ligament is constrained to move only in the normal range and thus does not enter an abnormal range of movement. This action prevents the anterior talofibular, posterior talo-fibular and the calcaneo-fibular ligaments, which stabilise the ankle, from tearing or straining. [0044] Figure 4 depicts the ankle 30 from the rear and shows a posterior part of the foot and potential ligaments or tendons which may be affected by hyper-dorsiflexion etc.

[0045] Figures 5 and 6 show a joint protector 10B which includes a sleeve 12B configured to be used as a wrist guard. The sleeve 12B takes the form of a glove that is worn on a hand 34 to protect a wrist 36. For each element 18B fingers 38 of the hand 34 are used to form respective second anchor points 16. The corresponding first anchor points 14 are positioned at respective locations on the sleeve 12B which, in use, would fit around the wrist 36 or a lower part of the arm. The elements 18B extend from the first anchor points 14, around the fingers 38 and return to the anchor points 14. Thus each element 18B is fixed at its ends to an anchor point 14 and, between the ends, to an anchor point 16.

[0046] During flexion of the wrist 36, the elements 18B extending around the fingers 38 and across the palm 40, are straightened to a limiting point and thus prevent hyperflexion. During extension, the elements 18B are straightened across a face 42 of the hand 34 until a limit is reached thereby preventing hyperextension of the wrist 36.

[0047] The description of this embodiment is by way of example only arid the invention is not limited to this description.

[0048] The concept of the invention can be adapted for an elbow or a knee.

[0049] As the sleeve (12; 12A; 12B) encloses a joint like a second skin, and due to the light weight and small size of the elements (18; 18A; 18B), the joint protector (10A, 10B, 10C) is unobtrusive and can be worn without discomfort. The joint protector 10 is designed to allow a normal range of motion of a joint and does not interfere with mobility. The joint protector can be worn by an athlete while participating in sport activities and will at least reduce the likelihood of joint injuries occurring during these activities. The joint protector can also be used to protect a joint which has been injured by over-extension. In this case the protector acts as a shield and support, and functions to limit movement of the injured joint so that the injury is not aggravated by unwanted movement.

[0050] The elements 18, 18A, 18B are flexible and follow a non-linear path thereby to provide a degree of slack which allows full movement of the associated limb up to a limiting degree of movement. A similar effect can be achieved by using elements which have a limited amount of elasticity or extension and which then become non-extendible i.e. by adopting a configuration which is similar to that used for a rope or cord used in climbing and mountaineering - described hereinafter with reference to Figure 8. [0051] In some of the attached drawings the non-linear paths of the elements, in the non-extended or slack positions have been over-emphasised purely for the purpose of illustrating the principles of the invention. Such depictions are not limiting.

[0052] Figure 7 shows a joint protector 10C, according to another embodiment, which is worn on a knee 70. An element 18C comprises a plurality of rigid members 72. Adjacent pairs of the members 72 are interconnected by means of respective knuckle joints 74 which allow mono-directional movement of the knee. The knuckle joints can flex to and fro in one plane only, and are not relatively movable to any significant extent transverse to this plane. The element 18C is connected to and extends between anchor points 14C and 16C which are respectively located on reinforced bands 19Ci and 19C ₂ of a sleeve 12C which is worn like a second skin over the knee 70 and which carries the element 18C.

[0053] The rigid members 72 are shown in an enlarged scale but in practice are small, lightweight, and relatively non-obstructive. The members 72 can be made from a suitable material such as a high strength plastic e.g. polycarbonate or a metal such as aluminium or titanium. The degree of the angular movement of one member 72 relative to an adjacent interconnected member 72 is readily controlled during manufacture (as is known in the art) by forming one member with a shoulder which abuts the adjacent member when it reaches a particular degree of angular movement and which then prevents further angular movement of the one member relative to the other. [0054] Figure 8 schematically depicts a different embodiment of the invention. Use is made of a flexible band 88 which is designed to enclose a limb 90. The band is shown in an expanded form with opposed ends 92 and 94 of the band spaced apart by a distance L. A flexible but inextensible element 98 passes though an eyelet 100 at the end 92 and is anchored to the end 94. A remote end of the element 98 is attached in a similar way to another band, not shown. The element 98, which is one of a plurality of similar elements, spans a joint which is to be protected. Another band, similar to the band 88, is positioned on an opposing side of the joint and a remote end of the element 98 is fixed to anchor points on that band. [0055] With movement of the joint tension in the band 98 increases or decreases and the band 88 can thus close or open in a corresponding manner i.e. the size of a loop, formed by the band, is increased or reduced. When the joint reaches an end of a normal range of movement the ends 92 and 94 abut and effectively restrict further movement of the element which, in turn, restricts further movement of the joint. The band thus acts as an anchor point which has a degree of flexibility in that it can be“closed” with movement of the element 98 but, thereafter, acts as a“fixed” anchor point when the ends 92 and 94 abut each other.

[0056] The band 88 has been shown notionally. As depicted in Figure 8 the band 88 may be in the form of a sleeve 88A of a flexible material which is comfortable to wear and which extends around a limb 90, on one side of a joint, in the form of a loop. The sleeve has a plurality of eyelets 104 at spaced intervals and opposing edges 106 and 108 of the sleeve can be drawn together by means of a flexible tie 110 which is passed through the eyelets in zig-zag fashion. An element 98 (flexible and inextensible) is fixed to the tie 110 and, as before, spans a joint which is to be protected. A remote end 114 of the element 98 is fixed to a sleeve 88B (similar to the sleeve 88A). [0057] With movement of the joint in one way the edges 106 and 108 are drawn towards each other i.e. the size of the loop is reduced, and with opposing movement of the joint the edges 106 and 108 can move apart. This mechanism allows the degree of free movement of the joint to be controlled. [0058] The size of the normal range of movement can be adjusted simply by varying the length of the tie 104. This is exemplary only and non-limiting.