GB2274591A

GB2274591A - Progressive gait-correcting orthosis

Info

Publication number: GB2274591A
Application number: GB9301903A
Authority: GB
Inventors: David Hart
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-01-30
Filing date: 1993-01-30
Publication date: 1994-08-03
Anticipated expiration: 2013-01-30
Also published as: GB2274591B; GB9301903D0

Abstract

The orthosis, which provides adjustable support and control to correct the lower limbs of a patient suffering from cerebral palsy or the like, allowing the patient to stand and walk and to progress towards independent mobility, comprises left and right leg members 1 releasably secured to the patient's legs and unmodified footwear and hinged at the ankle to provide natural toe-up and toe-down movement, the latter being controlled by an adjustable stop 4. The leg members are connected by one or more flexible, jointed or rigid linking members such as the member 23 - 31 shown which may be positioned to the front, rear or front and rear of the patient, the height of such linking member as well as its distance forward or rearward of the legs being adjustable. The linking member acts to restrain movement of the legs to that of walking and to that of which the patient has voluntary control. <IMAGE>

Description

PROGRESSIVE GAIT-CORRECTING ORTHOSIS This invention relates to an orthosis to provide adjustable support and control to correct the lower limbs of a patient suffering from cerebral palsy or of similar resultant medical condition, allowing the patient to stand and walk and to make progress towards the point when they no longer need the orthosis.

The cruel effects of cerebral palsy and of other similar resultant medical conditions are many. One of the common effects can be the involuntary activity and tightening of muscles, causing, amongst other things, the legs to cross or close tightly together and one foot to hook behind the heel of the other, an effect that is generally referred to as 'scissoring'. Another effect can be the involuntary throwing of the knees outwards, with the feet turning inwards. These are just two examples of how the condition can affect the sufferer. These effects can vary in severity from patient to patient and in a great many cases prevent the patient from standing and walking.

Many people suffering these effects in a mild form, are able to get themselves upright and take steps, albeit with an untidy and high energy consuming gait. There are available splints, braces and other devices that can provide support and control, but in general, these tend to restrain and immobilise the patient's unruly lower limbs. Aids intended to help the more severely affected sufferer are usually cumbersome and, for many, prove to be ineffective.

According to the present invention there is provided a progressive gait-correcting orthosis comprising: a left and right leg member, a left and right ankle hinge arrangement, means for releasably securing the orthosis to any size of patient or size of unmodified footwear, means for distributing the orthotic working forces upon unmodified footwear, means for releasably securing the arrangement that releasably secures the orthosis to the patient's unmodified footwear to a member pivoting from the orthotic ankle hinge, means for controlling the amount of toe-down movement of each foot of the patient about ankle hinge arrangement, means for adjusting and fixing the amount of toe-down movement of each foot while the patient is wearing the orthosis, a left and right universal size leg trough arrangement, means for securing the leg trough arrangements to their relative leg members, means for adjusting the position of each leg trough arrangement upon each relative leg member, means for adjusting the position of each leg trough arrangement upon each relative leg member while the patient is wearing the orthosis, means for attaching one or more leg-spacing control links between and onto leg members, means for adjusting and fixing the position of the legspacing control link relative to the patient's legs, means for adjusting and fixing the position of the legspacing control link relative to the patient's legs while the patient is wearing the orthosis, means for adjusting and fixing the position of a second leg-spacing control link relative to the patient's legs and to the position of any another leg-spacing control link, means for adjusting and fixing the position of a second leg-spacing control link relative to the patient's legs and to the position of any other leg-spacing control link while the patient is wearing the orthosis, means for reducing the support and control being provided by the orthosis as the patient's involuntary muscle activity subsides and alternative fixed, expanding or flexible leg-spacing control links of which any one or more can be incorporated into the orthosis.

For better understanding of the present invention, reference will now be made by way of examples to the accompanying drawings in which: Figure 1 shows, in perspective, an example of the orthosis being used to prevent scissoring; Figure 2 shows an example of a load distribution member releasably secured to a boot; Figure 3 shows, in perspective, an example of the orthotic arrangement for the left leg and foot; Figure 4 shows, in section, an example of orthotic provision for the left foot and ankle; Figure 5 shows top view of example leg trough assembly; Figure 6 shows, seperated, an example arrangement for releasably securing the footwear-securing load distribution arrangement to the ankle hinge arrangement; Figure 7 shows detail of left end of example expanding legspacing control link;; Figure 8 shows example orthosis with expanding leg-spacing control link when legs of patient are maximum distance apart; Figure 9 shows example orthosis with expanding leg-spacing control link when legs are minimum distance apart; Figure 10 shows example position of patient's feet without orthosis; Figure 11 shows example position of patient's feet when legspacing control link is not set sufficiently forward of the patient's legs; Figure 12 shows example position of patient's feet when legspacing control link is set too far forward of patient's legs; Figure 13 shows example position of patient's feet when legspacing control link is set correctly; Figure 14 shows example position of patient's legs when legspacing control link is set too low; Figure 15 shows example position of patient's legs when legspacing control link is set too high;; Figure 16 shows example position of patient's legs when legspacing control link is set correctly; Figure 17 shows detail of example fixed leg-spacing control link; Figure 18 shows detail of example fixed leg-spacing control link clamping plates; Figure 19 shows example of patient wearing orthosis with legspacing control link positioned to the rear; Figure 20 shows example of patient wearing orthosis with two leg-spacing control links positioned one above the other at the front; Figure 21 shows example of patient wearing orthosis with one leg-spacing control link at the front and a second at the rear; Figure 22 shows example of patient wearing orthosis with one fixed leg-spacing link and one flexible leg-spacing link positioned below;; Figure 23 shows example of patient wearing orthosis with one flexible leg-spacing control link and Figure 24 shows patient wearing orthosis with no leg-spacing control link.

Referring to Figures 1 and 3. The orthosis comprises a left and a right leg member 1 positioned vertically to the outer side of the patient's legs. The leg members are multi-sided, allowing mating components to slide up or down their height, while preventing them from rotating about the section. In this example the leg members are square in cross-section, to the lower end of each is formed, or permanently attached by means of welding or brazing for example, an ankle hinge plate 2, from which the ankle catch steel 5 is free to swing by means of the hinge pivot 3 which, in this example, is a headed rivet.

The amount of toe-down movement achievable by the patient is controlled by an adjustable stop which, in this example, is a cam 4, which is adjusted by rotating about and locked to the upper end of the ankle catch steel 5 by screw 6. Cam 4 stops toe-down movement when making contact with ankle hinge plate 2. The ankle hinge arrangement allows the patient's ankle to function normally within the toe-down limit controlled by cam 4 and provides the means for making the adjustment while the patient is wearing the orthosis.

Referring to Figures 2 and 4. The orthosis is releasably secured to the patient's footwear by means of load distribution plate 9 and an instep bar 7 which, together with foot steel 8, forms a load distribution member, which can be manufactured as one piece or, as in this example and as illustrated in Figure 4, fabricated by way of welding or brazing the components together. Instep bar 7 locates within the instep of the boot or shoe, to the outside end of which is attached the foot steel 8, to which the load distribution plate 9 is attached at an angle so as to align the ankle hinge arrangement pivot 3 with that of the patient's ankle joint and, at a distance between its lower edge and instep bar 7, to form a good location onto the outside welt of the footwear.Load distribution plate 9 is of sufficient length and width to provide a contact area that can distribute any forces, acting between the orthosis and the footwear, along the top face of the welt and the outside face of the footwear, so as not to cause damage to the footwear.

Referring to Figures 1 and 2. The load distribution member is located onto the welt on the outer side of the patient's boot or shoe and held secure by welt clamp 10 located on the welt on the inner side of the footwear; the tightening of screw 11, which is of sufficient length to accommodate wide footwear, located within the threaded hole at the inside end of instep bar 7, which is of sufficient depth to house the length of the screw 11 when fitted to narrow footwear, effectively clamps and secures the load distribution member to the patient's boot or shoe.This method of securing the orthosis to the patient's footwear, alleviates the need for the patient to have special or modified footwear in order to make use of the orthosis, allowing the patient to choose and wear any shoes or boots with a suitable instep and welt and/or, to replace the footwear with a larger size as their feet grow.

Referring to Figures 3, 4 and 6. To help the patient don and doff the orthosis, means for releasably securing the load distribution member arrangement to the ankle hinge arrangement is provided. Figure 6 shows an example arrangement which is seperated. When brought together the slotted end of foot steel 8 locates onto the smaller protruding diameter and under the head of location pin 12, which is riveted into catch steel 5; the slotted end of ankle catch steel 5 locates onto screw 13. The releasable fixing is secured by turning screw 13 until the tapered head locates tightly into the countersink formed at the inner end of the slot in the ankle catch steel 5.

Referring to Figures 1, 3 and 5. The orthosis is located onto the patient's legs by way of a left and a right leg trough arrangement. In this example the leg trough 17 is made from aluminium in the form of a shallow arc, making it a universal size which will fit any patient without the need for sizing.

A soft plastic foam 18 or similar cushioning material is adhered to the inside face of leg trough 17 and continues in sufficient length to wrap around the patient's leg. The patient's leg is releasably secured into the leg trough arrangement by means of strap 19 which, in this example, loops through slots at either end of leg trough 17 and is fastened by way of a buckle 33 to the front.

In this example, the leg trough arrangement is riveted to carrier plate 20 and attached by screws to the lower end of carrier plate 20 is clamp block 14, which locates onto leg member 1 and is fixed in the required position by clamping screws 15 and clamp plate 16. The clamp block 14, being at a lower level than the leg trough arrangement, allows the top end of leg member 1 to protrude with safety above clamp block 14, making provision for increasing the height of the leg trough arrangememt at a later date, to accommodate for the growth of the patient, for example, or, as illustrated in Figure 20, to enable the leg-spacing control link to be fixed to leg member 1 at the same height as the leg trough arrangement.

To correct the involuntary muscle-tightening causing the pulling apart and/or tightening together and/or rotating of the patient's lower limbs, there is provided alternative fixed, expanding and flexible leg-spacing control members, of which any one or two can be used to make up the orthosis, which can be positioned to the front or to the rear or to the front and rear of the patient.

In the example illustrated in figure 1, the orthosis is fitted with one expanding leg-spacing control link which is positioned to the front of the patient and comprises a jointed arrangement at each end of spacing bar 24, which link spacing bar 24 to each respective leg member 1. The link arrangement is the same at each end of spacing bar 24 and for easier understanding the arrangement of just one end will be explained: Referring to Figure 7. The threaded end of spacing bar 24 is located into threaded tube 25; this arrangement provides a means of adjusting the overall length of the assembly which is fixed at the required length by lock nut 26. The threaded end of ball joint 27 is screwed securely into the end of threaded tube 25.Ball joint 27 is linked to ball joint 28 by threaded rod 29; this arrangement provides a means of adjusting the distance between ball joint 27 and ball joint 28 which are then secured with lock nut 30 and lock nut 31.

Referring to Figures 3 and 7. The threaded end of ball joint 28 is located in any one of the holes spaced along the length of arm 23 and is fixed in the required position by lock nut 32. Ball joints 27 and 28 are identical, each having full rotational movement and a maximum of twenty degrees angular movement in any direction from centre position. Arm 23 is secured at the required position to leg member 1 by clamp block 21 and clamp screws 22.

Referring to Figures 8 and 9. Ball joints 27 and 28 allow the leg-spacing control link to extend and flex, enabling the patient to take steps forward, back and to the side. Figure 8 shows the position of the patient's legs when taking a sidestep. Once the length of the leg-spacing control link is set, the amount of movement by which the legs can side-step is controlled by the limited angular movement of ball joints 27 and 28, as shown in Figure 8, preventing the patients legs and feet from coming completely together and scissoring.

Figure 17 shows an example of a fixed leg-spacing link, which is used to make up the orthosis when the patient cannot cope with side movement, or when side movement would prove detrimental to the overall gait-correcting effect of the orthosis for a particular patient.

Referring to Figures 17 and 18. The fixed leg-spacing control link has one ball joint 34 at each end, which can be fixed into any of the holes spaced along the length of each arm 23.

The upper threaded end of bent spacing bars 35 and 39, are located into ball joints 34. The lower arms of bent spacing bars 35 and 39 are each located between clamp plates 36 and 37. This arrangement provides an alternative means of adjusting the overall length of a leg-spacing control link and is secured at the required length by lock screws 38.

A patient making use of the orthosis fitted with the fixed leg-spacing control link is able to step forward and back, but cannot side-step. The positioning and securing of the fixed leg-spacing control link relative to each of the patient's legs, is the same as that for the expanding type link.

The effects of involuntary tightening of muscles in the lower limbs vary considerably from patient to patient and, for a better understanding of how the positioning of a fixed, expanding or flexible leg-spacing link, or any two, upon the orthosis, provides the means to correct the lower limbs of each individual, several examples will be explained: Figure 10 shows the foot position of a patient prior to being fitted with the orthosis. In this example the patient's involuntary tightening of muscles is causing the legs to be tight together, with the toes rotating inwards and one foot hooked behind the heel of the other, indicating that the corrective effect of the orthosis in this example, needs to be that of seperating the patient's knees and feet and rotating the toes outwards from the front, to a degree that establishes a good standing posture for taking steps.

Referring to Figures 1 and 3. Ball joint 28 provides the point about which the patient's leg can rotate from the hip.

Ball joint 28 can be fixed into any one of the cross holes spaced along the length of arm 23; the greater the distance forward of the patient's legs, the greater the effect of counteracting the patient's involuntary tightening of the muscles that force the legs together and rotate the toes inward. The correct setting is achieved when the position of ball joint 28 relative to the patient's leg, causes the inward force of the leg, acting upon this point, to correct the rotation of the foot.

Figure 11 shows the position of the patient's feet whilst wearing the orthosis, the double-headed arrows indicating the position of ball joints 28, relative to the patient's legs.

In this example, the leg-spacing control link is keeping the feet apart, but is not set sufficiently forward of the patient's legs to stop the toes from turning inwards. Figure 12 shows the position of the patient's feet when the legspacing link is set too far forward. Figure 13 shows the position of the patient's feet when the orthosis is set correctly.

Referring to Figures 1 and 3. The height of any leg-spacing control link, relative to the patient's legs, can be adjusted by releasing clamping screws 22, which allows arm 23 and clamping block 21 to slide up and down leg member 1.

Adjustment is aimed at achieving a good standing posture and stepping gait. Figure 14 shows the position of the patient's legs when the leg-spacing control link is set too low and for easier understanding the double-headed arrow indicates the height of ball joints 28.

Figure 15 shows the patient's leg position when the legspacing control link is set too high. Figure 16 shows the patient's leg position when the leg-spacing control link is set at the correct height. Once the correct height has been established, the tightening of clamping screws 22 secures the setting on each leg member 1.

Referring to Figure 19. In cases when the patient's involuntary muscle-tightening is causing the legs and heels to be tight together, with the feet turning outwards, the leg-spacing control link is positioned to the rear of the patient's legs, with arms 23 assembled onto the relative leg members 1, so as to protrude horizontally rearwards. The method of establishing the patient in a good standing posture for taking steps, is the same as when the link is positioned to the front, positioning and securing the leg-spacing control link at the most effective height and distance from the rear of the patient's legs.

In the event of a patient's involuntary muscle-tightening being of a severity that renders the orthosis fitted with one leg-spacing control link inadequate to correct the lower limbs, then two leg-spacing control links can be used. Figure 20 illustrates an example of the orthosis fitted with two fixed leg-spacing control links, positioned one above the other at the front, which control the position of the legs, relative to each other. With some patients it may be necessary to position two leg-spacing control links at the rear, or, as illustrated in Figure 21, position one to the front and the second to the rear to control the distance between and rotational position of the patient's feet.

In most cases a patient will have one lower limb that is stronger than the other, or one lower limb that requires more correction than the other and therefore the correcting position of ball joint 28 for the left limb, may be different from that of the right limb.

In cases when the leg-spacing control link, or an additional leg-spacing control link, is to be used to provide support and control to correct by preventing the legs or feet or legs and feet, from parting only and, when there is no need to provide support and control to correct by preventing the legs or feet, or legs and feet, from coming together, then a flexible leg-spacing control link is used.

Referring to Figures 22 and 23. In this example, the flexible leg-spacing control member comprises of a link 40, which is made from cord or elastic or the like, each end of which is secured at the correct length between and passing through the most effective hole in arm 23, each arm 23 being clamped at the most effective height onto each leg member 1. This provides a simple and lightweight leg-spacing control link, which prevents the legs from parting while the patient stands and takes steps.

As the patient makes use of the orthosis over a period of time, the involuntary activity and tightening of muscles in the limbs will hopefully begin to decrease, making it necessary to periodically adjust the orthosis to decrease the corrective effect to accommodate such.

Referring to Figure 24. In cases when a patient's involuntary muscle activity and tightening has subsided to the point when they no longer need the support and control of a leg-spacing control link, or when the patient only needs support and control to the ankle, then the orthosis can be used without a leg-spacing control link.

It is intended that by making regular use of the orthosis, a patient's involuntary tightening of muscles in the limbs will continue to decrease to the point when the patient no longer needs the orthosis or any part of it.

Claims

1 A progressive gait-correcting orthosis which provides adjustable support and control to correct the lower limbs of a patient suffering from cerebral palsy or of similar resultant medical condition, allowing the patient to stand and walk and to make progress towards independent mobility, wherein a left and a right leg member, located onto and releasably secured to a patient's legs and unmodified footwear, hinged at the ankle to allow a patient to acheive natural toe-up and toe-down movement of each foot about their ankle joint, the amount of natural toedown movement being controlled by an adjustable stop, are connected to one or more common linking members, positioned to the front or to the rear or to the front and rear of the patient, across from the left leg member to the right leg member, the distance forward or rearward and the height of any linking member, relative to each of the patient's legs, being adjustable and the arrangement for connecting the left leg member and the right leg member to a linking member being of such, that the left leg member and the right leg member can move, within the constraints of the linking member, with the patient's legs, allowing the patient to stand and walk, the constraints of the linking member upon the right leg member and the left leg member being of such, so as to restrain the movement of the patient's lower limbs to that of walking and to that of which the patient has voluntary control.

2 A progressive gait-correcting orthosis as claimed in Claim 1 wherein the left leg and right leg members each comprise a vertical rod positioned to the outer side of each of the patient's legs.

3 A progressive gait-correcting orthosis as claimed in Claim 2 wherein each vertical rod is multi-sided.

4 A progressive gait-correcting orthosis as claimed in any preceding claim wherein the linking member ends are each in the form of an arm.

5 A progressive gait-correcting orthosis as claimed in Claim 4 wherein each linking member arm can be attached to the relevant leg member so as to protrude forward or rearward relative to the patient's legs.

6 A progressive gait-correcting orthosis as claimed in Claim 5 wherein each linking member arm is attached to the relevant leg member by way of an arrangement which allows height of the arm to be adjustable relative to the patient.

7 A progressive gait-correcting orthosis as claimed in Claim 6 wherein the arrangement for height adjustment of each linking member arm is by way of location onto the vertical faces of the leg member so as the arrangement can slide up or down the leg member and be secured in desired position by closing the location so as to clamp the arrangement onto the vertical faces of the leg member.

8 A progressive gait-correcting orthosis as claimed in Claim 4 wherein the position of securing the linking member to each linking member arm is adjustable.

9 A progressive gait-correcting orthosis as claimed in Claim 8 wherein the linking member end arms each have a series of spaced cross holes along their length, through any of which is secured an arrangement for linking the arms.

10 A progressive gait-correcting orthosis as claimed in Claim 8 or Claim 9 wherein flexible cord or the like is used to link the arms.

11 A progressive gait-correcting orthosis as claimed in Claim 8 or Claim 9 wherein elastic or other resilient means is used to link the arms.

12 A progressive gait-correcting orthosis as claimed in Claim 8 or Claim 9 wherein jointed members are used to link the arms.

13 A progressive gait-correcting orthosis as claimed in Claim 12 wherein the jointed members comprise a rod and two ball joints.

14 A progressive gait-correcting orthosis as claimed in Claim 12 wherein the jointed members comprise multiple rods and ball joints.

15 A progressive gait-correcting orthosis as claimed in any preceding claim wherein the orthosis is located onto each of the patient's legs by way of universal size leg troughs, each in the form of a shallow arc.

16 A progressive gait-correcting orthosis as claimed in any preceding claim wherein each leg trough assembly locates onto the relative leg member so as to slide up or down the height of the leg member section, but is prevented from rotating about the section by way of the mating faces.

17 A progressive gait-correcting orthosis as claimed in any preceding claim wherein each leg trough assembly is secured to its relative leg member by means of a bridging clamp and screws.

18 A progressive gait-correcting orthosis as claimed in any preceding claim wherein the orthosis is releasably secured to a patient's unmodified footwear.

19 A progressive gait-correcting orthosis as claimed in Claim 18 wherein the means of releasably securing the orthosis to the patient's unmodified footwear incorporates a load-distribution member.

20 A progressive gait-correcting orthosis as claimed in Claim 19 wherein the load-distribution member is located on the upper face of the welt and against the outer side of the patient's boot or shoe, the contact areas being sufficient to distribute the forces between the orthosis and the footwear without causing damage or wear to the footwear.

21 A progressive gait-correcting orthosis as claimed in Claim 20 wherein the load distribution member is releasably secured to the footwear welt by way of being part of a clamping arrangement.

22 A progressive gait-correcting orthosis as claimed in any preceding claim wherein the arrangement for releasably securing the orthosis to the patient's unmodified footwear is releasably secured to the member pivoting from the orthotic ankle hinge.

23 A progressive gait-correcting orthosis as claimed in any preceding claim wherein the amount of toe-down movement acheivable by the patient is controlled by an adjustable stop.

24 A progressive gait-correcting orthosis as claimed in Claim 23 wherein the adjustable stop arrangement for limiting the amount of toe-down movement acheivable by the patient is incorporated into the orthotic ankle hinge arrangement.

25 A progressive gait-correcting orthosis as claimed in Claim 23 or Claim 24 wherein the adjustable stop is a cam.

26 A progressive gait-correcting orthosis as claimed in any preceding claim wherein the length of the linking member can be adjusted.

27 A progressive gait-correcting orthosis as claimed in Claim 26 wherein the length of the linking member is adjusted by means of releasably clamping overlapping parts of the linking member.

28 A progressive gait-correcting orthosis as claimed in Claim 26 wherein the length of the linking member is adjusted by means of releasably securing one part of the member inside another part of the member.

29 A progressive gait-correcting orthosis as claimed in Claim 28 wherein the location of one part of the member inside another part of the member is by means of a screw thread.

30 A progressive gait-correcting orthosis substantially as described herein with reference to Figures 1-24 of accompanying drawings.