GB2122905A - Inflatable splint - Google Patents

Abstract

An inflatable splint for straightening a joint bent by a muscle spasm has two chambers 19, 20 forming an inflatable region within the angle of the bent joint which abut on inflation to force the joint open. Elongate inflatable chambers 39 (40, Fig. 2) on the opposite side of the joint are shaped to rigidify on inflation thereby continuing the straightening of the joint commenced by the chambers 19, 20. The inflation of chambers 19, 20 and the chambers 39, (40) thus provides opposing forces which co-operate to straighten even a joint bent by a severe muscle spasm. Additional inflatable chambers 18, 21, 34 hold the splint in place around the joint. <IMAGE>

Description

SPECIFICATION Inflatable splint The present invention relates to an inflatable splint.

The joints of humans or other animals are prone to a number of defects. One of these is muscle spasm (or the less intense muscle contraction) in which the muscle controlling the joint undergoes a sudden and powerful contraction, thereby bending the joint. If the joint is not straightened quickly then after a few hours it may be extremely difficult to straighten it completely. Such muscle spasms or contractures afflict both elderly and neurologically disabled patients and are particularly likely to occur around a knee joint. In the case of a muscle spasm, the hamstring muscles pull the lower leg back to an angle of 900 or more.

The present invention seeks to provide a way of straightening the joint after a muscle spasm, by providing an inflatable splint which fits around the joint and has two inflatable regions, one of which is intended to lie within the angle of the joint and to expand on inflation to bend the joint open to a first angle and the second of which is to lie opposed to the first and act to bend the joint to a second angle greater than the first. The "first angle" and "second angle" will depend on the specific design and the joint in question but the first may normally be 900#1 200 and the second approximately 1800.

The first inflatable region may be a pair of expanding wedges whilst the second may be a tubular region or regions which tend to straighten on inflation. The tubular region(s) are preferably wider adjacent the joint than at their ends, to increase the force they apply directly to the joint.

Inflatable stockings or sleeves are known which are simple tubular structures for fitting around a limb. The inflation of such a stocking or sleeve massages or reduces swelling of the limb but none of these are suitable for opening out a severely bent joint. The present invention has the subsidiary effect of treating such swelling, but also it has been found that the application of a splint of the present invention to a joint reduces the severity of muscle spasm.

When uninflated, the splint can be applied easily to a bent joint and subsequently inflated by a small air pump. Rather than have the joint permanently supported by the splint, it is preferable to inflate and deflate the splint intermittently, thereby gradually opening the joint and preventing it from "setting" in its bent position, and to reduce the risk of pressure sores.

An embodiment of the present invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a splint according to the present invention uninflated and unfastened; Figure 2 is a perspective view showing the fastening of the splint of Figure 1 around a person's leg; Figure 3 is a side view of the splint when fitted around a person's leg, the splint being partially inflated; Figure 4 is a side view of the splint fitted around a person's leg, the splint being fully inflated; and Figure 5 is a plan view of a splint fitted around a person's leg, the splint being fully inflated.

Referring first to Figure 1, an inflatable splint 10 is formed of two approximately rectangular sheets of plastics material which are located one on top of the other and secured together at their edges and at various other positions to form a number of chambers between the sheets. In the middle of the rectangle welds 11, 12 and 13 secure the sheets together in a direction-extending along the rectangle and welds 14, 15, 1 6 and 17 secure the sheets across the rectangle to form four chambers 18 to 21 indicated by dot and dash lines. The welds 11 to 17 do not meet and the gaps 22 to 31 between them permit air to pass from one chamber to another. Welds 32. 33 extending across the rectangle form, together with welds 14 to 16, two longitudinal chambers 34 and 35 extending across the rectangle.

The ends 36, 37 of the rectangle are provided with strips 38 of e.g. Velcro (Trademark) in order to enable the two ends to be secured together when the splint is fitted around a person's leg. On the outer surface of the splint 10, adjacent each end 36, 37 a corresponding chamber 39, 40 respectively is provided extending across the rectangle. These chambers are wider at their central region than at their ends, the reason for which will be explained later. Tabs 41 of e.g.

Velcro (Trademark) are provided on these chambers 39, 40 to enable them to be secured together.

A branched air line 42 extending from a pump (not shown) leads to the chambers 34, 35 and 39, 40. When air is pumped into the splint it inflates these chambers and also inflates the chambers 16 to 21 by air movement through gaps 22 to 31.

To fit the splint around a leg bent by severe muscle spasm, the splint 10 is wrapped around the leg with the end 36 overlapping the end 37 as shown by arrow 43 in Figure 2 so that the strips 38 on ends 36, 37 come into contact, thereby securing the ends 36, 37 together. Then the chambers 39, 40 are folded inwardly in the direction of arrows 44, 45 respectively and secured together by the overlapping of tabs 41.

When the splint is inflated around a leg contracted by a severe muscle spasm, expansion of chambers 19 and 20 (which are located behind the knee) causes them to form two wedges pressing against each other. The two chambers 19 and 20 therefore form a first inflatable region, the expansion of which in the direction of arrow 46 forces the knee joint to straighten.

Once the knee has begun to straighten the inflatable chambers 39, 40 in front of the knee begin to expand and their tubular shape gives them a natural tendency to straighten with increasing air pressure. Hence there are two separate forces acting on the knee joint, one from in front of the knee and one from behind the knee, and these forces form couples in opposite directions on the tigh and calf of the leg respectively thereby straightening the knee joint as shown in Figures 4 and 5. It can be seen from those figures that the chambers 39, 40 are shaped to have maximum thickness at the knee joint, both on the vertical direction a in Figure 4 and the horizontal direction b in Figure 5 so that they exert maximum force at that point with a minimum bulk.

it has been found that a pressure of 1 w to 2+ pounds per square inch (10 to 17 x 103 No~2) are suitable to force a severely flexed knee to straighten.

The other inflatable chambers 18, 21, 34 and 35 help to keep the splint in place over the joint, but also have the effect of pressing the leg thereby reducing swelling and reducing the risk of muscle spasm.

A soft lining of e.g. sheepskin may be provided on the inside of the splint to increase the comfort of the user.

As described, the splint is inflated via a single air line 42. It is also possible to have each chamber separately inflatable so that different pressures can be obtained in the chambers, or so that the chambers may be inflated consecutively rather than simultaneously.

Although illustrated for use in straightening a knee joint the present invention is also applicable to the straightening of any joint.

Claims (10)

1. An inflatable splint adapted to be fitted around a bent joint and straighten that joint on inflation, the splint having two inflatable regions, a first of which regions is locatable within the angle of the bent joint and the second of which regions is locatable on the opposite side of the joint to the first inflatable region, inflation of the first inflatable region causing the bending open of a joint to a first angle and inflation of the second inflatable region causing the bending open of a joint to a second angle greater than the first angle.

2. An inflatable splint according to Claim 1, wherein the first angle is 900 to 1200.

3. An inflatable splint according to Claim 1 or Claim 2, wherein the first inflatable region comprises two inflatable chambers, surfaces of which abut on inflation of the splint on a bent joint.

4. An inflatable splint according to any one of Claims 1 to 3, wherein the second inflatable region comprises at least one elongate chamber extending longitudinally along the splint.

5. An inflatable splint according to Claim 4, where the elongate chamber(s) are wider at a central part than at either end, the central part being adjacent the joint when the splint is fitted.

6. An inflatable splint according to Claim 4, or Claim 5 having two elongate chambers, the splint having a sealable opening between the two elongate chambers to facilitate the fitting of the splint.

7. An inflatable splint according to any one of the preceding Claims, wherein the inflatable regions are inflatable in common.

8. An inflatable splint according to any one of Claims 1 to 6, wherein the inflatable regions are individually inflatable.

9. An inflatable splint according to any one of the preceding Claims having two sheets of a plastics material secured together at a plurality of elongate sites thereby to form the inflatable regions between the sheets.

10. An inflatable splint substantially as herein described with reference to and as illustrated in the accompanying drawings.