GB2436799A

GB2436799A - Leg brace having elastic elements

Info

Publication number: GB2436799A
Application number: GB0606933A
Authority: GB
Inventors: David Allen Seaby
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-04-06
Filing date: 2006-04-06
Publication date: 2007-10-10
Anticipated expiration: 2026-04-06
Also published as: GB2436799B; GB0606933D0

Abstract

A leg brace, being hinged at the knee has elasticated elements 15. The elastic elements 15 may be variably tensioned by means of a cleat 12. The aim of the leg brace is to resist flexing at the knee and to help support the body weight. The brace may also have a hinge close to the ankle which may be attached to footwear 27 such as a ski boot. The hinge close to the ankle may comprise a pair of male elements at the lower end which may slip into upward facing slots 11 attached at the sides of or built into the footwear 27. The leg brace may have a pair of outer elements, each having a chamfered peg 10 that snaps into a hole in a side below the top of one of the slots 11. The cleat 12 may be released by pushing down an external lever 30. The cleat 12 may comprise a slot, cut into a hoop, to allow the stops on the elasticated element to be hooked into and be released by pressing the stop out of the hoop.

Description

2436799

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LEG BRACE / SKI ARMOUR

This invention relates to a device to protect legs both against injury and fatigue while skiing. It aims to reduce the load on the thigh muscles and to provide impact protection for the whole leg. It may also be of medical assistance where a weakened leg is being exercised to help strengthen it.

When skiing, legs are flexed and thigh muscles not only support torso weight, they also act as shock absorbers. After skiing down an irregular slope, possibly several kilometres long, thigh muscles tend to 'burn'. Due to the strain placed on them, there may also be discomfort where tendons attach to kneecaps. There is a relatively high risk of twisting a knee in a fall, or possibly suffering a broken leg in a collision. In most ski resorts very many serious leg injuries occur every season, often these are to the cruciate ligaments - repair of which requires surgery and months on crutches. Accidents are more likely when muscles are fatigued. This is due to the skier being slower in taking avoiding action. Leg braces aim to reduce such hazards for the wearer.

To help protect legs, in particular knee joints, there are numerous types of leg brace made. The simplest and most common is a reinforced elastic sleeve. This is slipped over, or is strapped around the knee joint; its shape is designed to hold the kneecap in position. It may provide some resistance to leg flexing. But this is minimal and any weight that it does support is transferred to the top of the calf muscles where continuing pressure on them can prove painful.

The next step in complexity is the addition of long-armed metal hinges to one, or both sides of such sleeves. These give some resistance against leg twisting at the knee and knee joint protection against side impact. However, in such an impact the hinge arms, being slim, may cause bruising. It is beneficial that these hinges usually have a 'stop' to help resist forward bending of the leg (as might occur in a head-on collision at speed).

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Yet more complex leg braces are made up of a pair of long, semi rigid tapering sleeves. These are made to measure and in use are wrapped around both thigh and calf and are held closed using 'Velcro' straps (multiple hook and loop strip).

One, (or two) metal arms connect these two sleeves. Such an arm has a complex bearing situated at the side of the knee joint. This can be 'locked', to give support. This lock can also be released to allow sitting or walking. Elasticity at the hinge/s and in the material of the sleeves gives flex at the knee, even when the hinge is locked.

Sleeves may also help keep the kneecap in position. Because thigh, shin and calf are sheathed, there is some protection from impact. Furthermore, sideways or forward twisting of the leg is largely prevented. However, any downward force is transferred to the calf muscles, possibly making them sore. Also the severity of a fall, with the leg 'locked' in a semi flexed position, may be greater.

Among medical leg braces and splints are thick padded semi rigid sleeves done up with 'Velcro' straps. These stretch from top of thigh to ankle. They are aimed to almost entirely prevent leg flexing but would not be useful in skiing as it is essential to bend legs to get up after a fall, or to sit in a chair lift.

There are also many specialised devices that replace the function of all or part of a leg or foot.

According to the present invention there is provided a leg brace as claimed in the claims. It is designed to aid skiers, but it is not exclusively for that purpose. The brace described does not lock and unlock at the knee. It is almost the full length of the leg. Means of 'hinged' attachment to the ski boot or other footwear are provided. Most of the front of the brace is rigid, thus providing very good impact protection from front or side. The brace flexes at the knee (backwards only) and has elastic 'shock-cords' and or elasticated webbing running over its front surface. These aim to support a good proportion of torso weight if the leg is slightly flexed (as in typical skiing pose). But full leg bend is possible in an accident.

Furthermore, the weight supported is not transferred to the back of the calf, it is instead taken by a semi rigid part of the ski boot or shoe. Although the shock-cords are 'captive', they are attached at the top via a small rectangle of metal to a reinforced cord. The shock cords may be relaxed by allowing this cord to slide back

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through a quick release cleat. The wearer is then unimpeded walking or sitting.

A specific embodiment of the device will now be described by reference to the drawings in which: -

In figure 1, the leg brace is shown in side view, fitted over a 'leg' and attached to a ski boot.

In figure 2, a plan view of the quick release cleat is shown with the securing bolts and upper cover plate absent There is also shown the details of means of shock-cord attachment.

In figure 3, a longitudinal section of part of one side of the leg brace is shown (not to scale). It has at its centre the knee bearing'.

Dimensions of the brace, shown in figure 1, vary depending upon the wearer's leg length and build. In this embodiment, the brace is fitted over a 'long slim leg'. Dimensions may be judged from the plastic, chevron shaped side element (6). This is 4.5 cm in width and a minimum of 4mm thick. Also in this embodiment the aluminium alloy used for making parts (2), (3), (4), (5), (7), (12) and (17) in fig. 1 and (28), (29), (30), (31), (33), (45) in figs. 2 and 3 is 1.8mm thick.

In figure 1, the side-pieces (5), (6), (7), (8) and (11) are in pairs (one for each side of the leg). In the case of the lower end pieces (9) there is a pair of them on each side of the boot. They may be made from metal or tough shatter proof plastic, for example 2.2mm thick and are joined to (6) by three 4mm diameter bolts, (25), (3 small circles).

The thigh guard (1) is made from moulded plastic, being in this embodiment, 3.5mm thick.

The shin guard (2) also holds the pair of side elements (6) the correct distance apart, in this embodiment 13.6cm.

The U shaped boot attachment (3) is held in place by 'Velcro', stuck to the inside of it and to the rear and sides of the boot. (3) has a tough plastic panel (11) on each side. (11) is for example 2.2mm thick and is attached to (3) by 4mm diameter bolts (shown as five circles). These have nuts centrally placed (between elements (3) and (11), separating them. There is thus provided a narrow slot, into which in use the inner of the pair of plastic end pieces (9) is slipped. The outer end piece (9) is positioned to the outside of (11). It has a

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5mm peg (10) chamfered on its lower side and made so that it can slide down to snap into a slot-shaped hole in (11). This, plus its 'twin' (on the other side of the boot) retain the brace firmly attached to (3) and so to the boot. To release the brace, the outer end piece (9) on both sides of the boot are bent away from (11) and pushed up. The hoop shaped knee guard (4) is joined to (1) by outer strip (5). One of the two chevron-shaped side-pieces (6) is shown in fig. 1. It could be made of metal, but is this embodiment is shatter-proof-plastic. Together element (6) on both sides of the leg transfer torso weight down to the boot or shoe. The size of this force depends on the tension, number and size of the shock-cords employed (15). The outer metal strip (7) joins (6) and (4). There is also an inner strip (45), see fig.3. The two small central circles on (7) represent two 4mm diameter bolts holding this 'sandwich' together.

The upper end of (6) is hidden below (7) and is cut in such a manner (as shown by the dotted line) that it may only hinge backwards. One of a pair of load bearing joints (8) are positioned each side of the leg at the knee, (see figure 3).

Thigh guard (1) is held close to the front upper thigh by a thin, wide strip (24), made for example from strong, plastic-coated cloth. (24). It is adjustably attached at each end to (1) using self adhesive 'Velcro' (23). Inside (24) there is a pad of soft material, for example as made from two thin rectangles of carpet (22) these may be 24cm x 24cm, stuck back-to-back using rubber glue, also stuck to (24).

In this example, there is also soft, light carpet stuck to the inside of pieces (1), (2) and (4), as shown at (20) and (21).

As stated, a significant fraction of upper body weight may be supported. This is achieved by creating great resistance to flexing at the knee, due to stretching six (for example) rubber shock-cords (15), for example 8.5mm in diameter.

At the knee, shock-cords (15) pass over a smooth curved bearing plate (16) and are attached (by 'sewing' loops) through three holes at point (19) in a hidden slightly curved rectangle of aluminium bolted to the inside, lower end of (2), using two 4mm diameter bolts.

At the upper end, shock-cords (15) are also attached using multiple loops (35), fig.2, 'sewn' through holes in a small metal strip (17). In turn, a cord (14) is also attached to (17) by 'sewing' then 'Super gluing'. Cord (14) passes up through a quick release cleat (12) and ends in a toggle (13) plus knot.

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The construction of the quick release cleat is shown in figure 2. The 'anvil' (28) is 5.4mm deep and against it a reinforced cord (14) is crimped by release-arm (30). Through the bearing (34) for arm (30) goes a 6mm diameter bolt, threaded through the front pate (not shown) and through the back plate (29). A compression spring (32) helps to keep (30) in the position shown and is itself prevented from flexing by (31) and loop (33).

Four 4mm diameter bolts (not shown) go through clearance holes in (28) and (29) and also though the top end of thigh guard (1) to secure cleat (12).

The multiple loops of thread (35), (36), and (37) that hold shock-cords (15) and cord (14) in position are shown in fig. 2. All loops of thread are 'reinforced', by soaking with 'Superglue'.

Shock-cord (15) is covered by a strip 7.7cm wide made of elasticated webbing (28), and also underneath (not shown). These strips are loosely sewn together at their edges to make a flat tube. This 'power unit' is held in its central position at the knee by a cross strip of webbing (18) and by two 4mm diameter bolts (not shown) that also help to secure (16) to (4). They are placed centrally, longitudinally and project up 8mm between the shock cords. There is also a slit in the lower webbing strip (not shown) to accommodate movement past them. To reduce any possible wear to shock cords (15) these short projections are sheathed with plastic tube.

The top end of webbing (28) is 'bolted' to the top surface of cleat (12). At its lower end there is a pocket. This holds, and is thus secured to the protruding ends of the shock cords (15) just below their point of attachment at (19).

As a safety feature, to avoid the danger of pinching at the groin, the top inner edge of thigh guard (1) is cut away and replaced by a strip of softer, more flexible plastic (26). This is attached to (1) by four multiple loops of thread that pass through 4mm diameter holes (indicated along the dotted line, representing the inner edge of (23).

The bearing (8) at the knee is shown in figure 3. Its central element is a brass tube 11mm long and 6mm in diameter. This is held in place by a 5mm diameter bolt (39). To reduce wear, there is a plated steel washer (40), with a chamfer cut in it. There are also three 1mm thick plastic washers (41), (42) and (43) and a 2mm thick plastic spacer (44) below (7) to aid alignment.

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It is envisaged that, to simplifying construction, pieces (26), (1), (4), (5) and (16) may be combined as a single plastic moulding, also that many of the 4mm diameter bolts described could be replaced by rivets. The cleat (12) may be simplified by having one or more stops on cord (14). This cord is then looped into a suitable slot in (12). A disadvantage is that the tension in (15) is not infinitely variable. In use, pulling on the toggle, tensions the shock-cords. The slightly flexed leg is then supported by the front of the boot (27), also by an upward force at (24) and possibly by the top of the shin pressing against the carpet at point (21). To release shock-cord tension, arm (30) (fig.2) is pushed downwards. This allows the section of woven cord (14) (that had been previously been 'hardened' along part of its length by soaking with 'Superglue') to slip back through the cleat.

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Claims

1. A leg brace, in form, like armour, hinged at the knee, bearing elasticated elements that may be variably tensioned via a cleat, in order to resist flexing at the knee, the aim being to help support torso weight.

2. A leg brace, as claimed in claim 1, wherein the elasticated elements are shock cords.

3. A leg brace, as claimed in claim 1, wherein the elasticated elements are strips of rubber.

4. A leg brace, as claimed in claim 1, wherein the elasticated elements are rubber threads comprising the warp, in one or more woven strips.

5. A leg brace, as claimed in claim 1, wherein the elasticated elements are long narrow tension springs

6. A leg brace, as claimed in claim 1, wherein the elasticated elements are in any combination of those in claims 2 and/or 3 and/or 4 and/or 5.

7. A leg brace, as claimed in any of the claims 1-6, wherein there is also a hinge close to the ankle and attached to footwear, such as a ski boot.

8. A leg brace, as claimed in any of the claims 1-7, wherein the hinge close to the ankle is comprised of a pair of 'male' elements at the lower end and these may slip into upward facing slots attached at the sides of footwear such as a ski boot.

9. A leg brace, as claimed in any of the claims 1-8, wherein the upward facing slots are built into the footwear.

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10. A leg brace, as claimed in any of the claims 1 -6, wherein the hinge close to the ankle is comprised of a pair of 'male' elements at the lower end that may be slipped into upward facing slots and that the means of forming these slots is attached to the sides of a U shaped piece that is stuck by 'Velcro' to the back and sides of footwear, such as a ski boot

11. A leg brace, as claimed in any of the claims 1-6, wherein the hinge close to the ankle is comprised of a pair of 'male' elements at its lower end that may slip into upward facing slots and that the means of making these slots is attached to the sides of a U shaped piece that is attached by screws to the back and sides of footwear, such as a ski boot

12. A leg brace, as claimed in any of the claims 7-11, wherein there is a pair of outer elements and these each have a chamfered peg that snaps into a hole in the side below the top of the slot, this being to secure the brace from slipping out vertically as in a fall.

13. A leg brace, as in claims 1-7, wherein there is also a hinge close to the ankle and this is comprised of inward facing pegs attached to the bottom of the arms of the brace and able to 'pop fasten' into holes in the sides of a U shaped piece that attaches to the back of footwear, as claimed in claims 10 and 11.

14. A leg brace, as claimed in claim 1-7, wherein there is also a hinge close to the ankle and this comprises inward facing pegs that pop fasten, or slide, into holes made for them in the sides of a ski boot.

15. A leg brace, as claimed in any of the claims 1-14, wherein a cleat allows variable tension to be created in the elastic support elements and also allows it to be released after an external lever is pushed down.

16. A leg brace, as claimed in any of the claims 1-14, wherein the cleat simply comprises a slot, cut in a strong hoop, to allow stops on the tensioning cord to be hooked into this and be released by pressing the stop out of the hoop.