ANATOMICAL ORTHOPAEDIC CRUTCH

BEQUILLE ORTHOPEDIQUE ANATOMIQUE

English Abstract

An unique orthopaedic crutch designed to fit the anatomy of the user and thereby avoid causing harm to the user. The crutch handle is inclined at the average angle of the human wrist to forearm of 14 degrees to the horizontal plus or minus a few degrees. This is unlike all crutches identified to date which generally require the patient's anatomy to fit to the crutches' design, exemplified by handle angles of zero degrees, or 90 degrees to the vertical. The upper part of the crutch is offset from the lower part by the angled handle takes into account all the major anatomical requirements of the human arm by fitting the natural carrying angle of the human arm in respect of the shoulder elbow wrist and hand. The device has an upper arm-support ring, a comfort-designed anatomically accommodating handle, and a shock-absorber in the lower part. The crutch is adjustable with particular ease and speed using an engraved red line for lining up the adjustment mechanisms

French Abstract

Une béquille orthopédique unique conçue et adaptée à l'anatomie de l'utilisateur, cette béquille prévient par conséquent les blessures de l'utilisateur. La poignée de la béquille est inclinée à l'angle moyen du poignet de l'être humain par rapport à l'avant-bras qui est égal à 14 degrés sur la ligne horizontale plus ou moins quelques degrés. Cette béquille est différente des autres connues jusqu'à ce jour et qui exigent en général que l'anatomie du patient s'adapte à la forme des béquilles qui sont généralement dotées de poignées dont l'angle de courbature par rapport à la verticale est égal ou bien à zéro ou bien à 90 degrés. La partie supérieure de la béquille qui se décale de la partie inférieure par la poignée inclinée prend en compte tous les aspects importants de l'anatomie du bras humain et offre un angle naturel pour le bras humain portant des charges par rapport à l'épaule, le coude, le poignet et la main. Cette béquille est dotée d'un repose-bras, d'une poignée anatomiquement adaptée et d'un amortisseur sur la partie inférieure. La béquille peut être réglée avec aisance et rapidité à l'aide des lignes rouges gravées utilisées pour ajuster le mécanisme de réglage.

Claims

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What is claimed is:
1. A walking aid in the form of a crutch comprising a leg with a handle
located
part way up the leg; the leg having a region below the handle which in use may
engage the ground as a user leans onto the walking aid; and a region above
said
handle for supporting the arm of the user, characterised as follows:
a) the handle with an angle of between 0 and 89 degrees being preferably
14 degrees below the horizontal, located between the leg's upper and
lower regions, the leg's handle, upper and lower regions have a
common supporting bar; an arm being located across and beneath the
handle between said upper and lower regions for strength and support,
and the handle has thus an ovoid space between the upper and lower
parts of the handle;
b) the leg's upper region is offset from the leg's lower region by the
handle located between them to accommodate normal human arm
anatomy while allowing space for elbow flexion;
C) the upper region above the handle for supporting the arm incorporates a
circular cuff for supporting the upper arm and is hinged onto the top of
the leg's upper region;
d) a shock absorber is provided at the bottom of the leg at the ground
contact point where the leg has a ribbed rubber insert or stopper inserted
onto it and the leg then inserted into a hollow rubber end cap containing
two washers welded to a spring.
2. A walking aid according to Claim 1, wherein the handle has an anatomical
hand stop and palm-fitting dome and for use when user is stationary.

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3. A walking aid according to Claim 1 wherein the handle has a neoprene
saddle as a handgrip, the saddle being held on by Velcro TM straps and
therefore replaceable as required.
4. A walking aid according to any of the preceding claims 1-3 wherein
the upper and lower regions of said leg are telescopic.
5. A walking aid according to claim four (4) where the telescopic regions
are adjustable using a resilient pin-into-hole locking mechanism, a
scribed line being provided on the upper and lower telescopic regions for
aligning of said mechanism.
6. A walking aid according to Claim 1, wherein the shock absorber is a
pre-cast air bubble at the end of the leg at ground contact point to provide
the shock absorption.

Description

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Title: Anatomical Orthopaedic Crutch
Field of Invention:
This invention relates to walking aids in the form of a crutch designed to
assist
old, infirm, injured and handicapped individuals gain mobility. More
specifically this invention is a crutch designed to accommodate the anatomy of
the human arm for comfort and stability but also to minimize or prevent
harmful damage to parts of the arms when in use.

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1 Background to the invention
While there is a great deal of prior art pertaining to crutches that represent
many variations of their designs such as axillary or underarm support by
Chen, US Pat No 4,865,065, forearm support to Ewing US Pat No 4,869,280,
elbow support and wrist supports, there are embodiments that allow for
folding up, sprung arm supports by Herr 5,458,143, conversion into canes as
by Kelly, US Pat No 5,482,070, Coogan WO 89/00039 and many other
variations. There are no instances identified where the structural anatomy of
the arm has been properly taken into account. The normal carrying angle of
the arm when in the resting position, reveals that the hand to wrist angle is
at
an angle of approximately 14 degrees and the elbow is not straight such that
the hand is positioned anterior to, or in front of, the shoulder and upper
arm.
The fundamental problem with current forearm or 'Canadian' crutches means
that the weight of the body has to be borne through the wrist and hand at a
unnatural angle and this has been recognised to cause inflammation of the
wrist joint restricting the ability to walk comfortably and safely using the
crutches which may lead to consequent arthritic changes or carpal tunnel
syndrome. Similarly pressure on the elbow joint held straight or fully
extended frequently leads to inflammation and pathological joint changes. To
a lesser degree pressure on the arms with the use of forearm crutches has
been shown to cause occasional stress fractures in the ulnar bone, and crutch
use has been implicated in skin inflammation, blood vessel thrombosis and
aneurysms. Furthermore the use of currently designed forearm or 'Canadian'
crutches leads to physical fatigue and a nerve dmamge syndrome causing
numbness in the hands as a result of nerve and circulatory problems.
Even prior art that uses angles in crutch design does not address the
anatomical considerations or the spectrum of anatomical problems incurred
by the user, nor does it approximate the design of this invention in reducing
these conditions. For example Forearm crutch patents by Stockwell, US
Patent No 5,555,904 and Hagberg, US Pat No 5,671,765 show angles to the
elbow. However in the former the angle invoked is merely for support of the
elbow-forearm rest and has no relationship to anatomical structures of wrist
or shoulder, and in the latter the angle of elbow-forearm rest is pointed

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downwards to a vertical handgrip rest which does not address the correct
anatomical angle of the elbow or wrist. A patent converting a crutch to a
walking stick by Coogan et al, PCT WO 89/00039 does not describe or claim
an angle as such and this crutch will not function anatomically as the wrist
is
unnaturally bent, and as with the other patents cited there is no upper arm
support. A Ski-pole type crutch by Owen, US Pat No 4,196,742 while
describing a wrist angle for the handle, but it is rearwards of the upright
pole
at a steep angle of between 40 and 55 degrees and requires the wrist flexing
in use for forward propulsion. In the Owen ski-pole embodiment there is no
offset anteriorly of the wrist to shoulder requiring the excessive flexion of
the
shoulder in use.
The novelty of the current application is in the adherence to the normal
structure, angles and functions of the human arm to provide comfort, stability
and thereby minimising the risk of damage to the users arm when the device
is being used.
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Summary of the Invention
In its broadest independent aspect, the invention provides a walking aid
comprising a leg with a handle located part way up the leg; the leg having
a region below the handle which in use may engage the ground as a user
leans onto the walking aid; and a region above said handle for supporting
the arm of the user; characterised by any one or more of the following
features:
a) the handle is an inclined elongate handle at approximately 14
degrees to the horizontal, located between the leg's upper and
lower regions; the leg's handle, upper and lower regions having a
common supporting bar; an arm being located across and beneath
the handle between said upper and lower regions. The handle
thus has an ovoid space between the upper and lower parts of the
handle to allow for storing small personal items or hanging things
on.
b) the upper region is offset to the handle
c) said region for supporting the upper arm incorporates a cuff
d) a shock absorber is provided in the lower region integral in the cap
at the ground contact point
f) A red line is provided on the telescopic, adjustable upper and
lower regions for rapid and accurate location of the sprung-pin
locking mechanism of the adjustable parts by simply lining up the
red lines.
An anatomical handgrip is provided with a hand grip stop that
anatomically matches the space between the thumb and first
finger.
f) Furthermore the hand-grip stop is domed to match the palm of the

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hand. The handgrip is also may have a thick neoprene handle
attached by Velcro TM or similar mechanism, for comfort and may
be a disposable-replaceable type for hygiene.
Aspect a) is particularly advantageous because the handle is at the
natural carrying angle of the wrist and hand, user comfort is paramount, it
prevents the anatomically related problems from arising as no distortion
or flexion of joints is required, as well as reducing pressure problem on
skin, nerves and blood vessels. Aspect a) allows the walking aid to rely
on the supporting strength of a common supporting bar. Therefore, in
use, the walking aid is less likely to break at joints which would have
been the case in a prior art crutch with several supporting bars. This
configuration also allows an improved construction of the handle region
as compared to the prior art system. It also reduces the number of
components necessary thus rendering the crutch more straightforward to
manufacture at a lower cost.
Aspect b) is particularly advantageous because it allows the normal
anatomical orientation of shoulder to elbow, and elbow to wrist and hand.
Furthermore it is normal for some flexion of the elbow to occur when
suing crutches and it allows the elbow region and/or forearm region of a
user to be less constrained by the upper portion of the crutch in a non-
ergononiic manner.
Aspect c) is particularly advantageous because it allows crutches to
provide good stability and less lateral arm wobble over those with
forearm support only and avoids the brachial plexus nerve damage on
underarm or axillary forms.
Aspect d) has the advantage of softening the ground contact shock which
when unabsorbed is a cause of fatigue in users of walking aids.
Aspect e) is also particularly advantageous because it reduces the
difficulty and stress in adjusting the crutch length as required by one
user, or for use by different users.

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1 Aspect f) is particularly advantageous and provides for hand comfort
against fatigue, a hand stop to prevent the hand moving too far down the
handle, a palmar support for resting the hand on, and a removable
washable neoprene cover for additional comfort, safety and hygiene. The
reduction in pressure related problems of the hand is also minimised
In a subsidiary aspect in accordance with the invention's broadest
independent aspect, at least one of the two handle parts is of plastics
material with webbing reinforcements. This allows the walking aid to be
of minimal weight but of sufficient strength to withstand the periodic
pressure exerted during a user's walk. The plastic injection moulding
may be mass produced and made in two sections that will clamp over and
be attached over the 'S' shape of the tubular aluminium leg of the crutch
with fasteners eg nuts and bolts. This will allow for ease of manufacture
and strength to the crutch.
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Brief Description of the Figures
1
Figures 1 and 2 show the right and left-handed elevations of the crutch
respectively.
Figure 3 shows the right-hand elevation demonstrating the hinged cuff at
the top of the upper region.
Figure 4 shows the front elevation
Figure 5 shows the rear elevation
Figure 6 shows a partly exploded rear elevation
Figure 7 shows a plan view of the top of the crutch
Figure 8 shows a view from below looking upwards
Figure 9 Shows a detailed right-hand elevation of the handle showing the
parts for assembly to the inner tube seen externally as the upper
and lower aluminium crutch body tubes.
21
Figure 10 shows a section through the lower end of the crutch near the
ground contact point showing the end cap with shock absorber
Figure 11 shows a section through the lower end of the crutch near the
ground contact point showing the end cap with air bubble shock
absorber
Figure 12 shows the shape of the neoprene saddle with flaps for attaching
around the handle using Velcro TM.
Detailed Description of the Figures

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Figures 1 and 2 shows the crutch comprising an aluminium pivot 1 and
1 plastic or nylon, upper arm cuff 2 fitted into an upper region 3 made of
an aluminium tube which in turn fits into the aluminium-tube upper
adjustable region 12 showing adjustment holes 7. At collar 8 this
engages the upper handle part 11 containing the palm knob 10 which is
for comfort and to prevent slippage from the handle 11 during use, and
the lower part 9 which provides bracing support for the handle 11, all
these parts are made from plastic or nylon or similar light weight non-
metallic material and may be attached to the aluminium tubular upper
body of the crutch 12 and lower body 17 with a nut and bolt arrangement.
A lower collar 181ocates the connection body 17 to handle 11. The whole
assembly is shown having an optimal angle of 14 degrees indicated by
the dotted line 13. The handle assembly engages the aluminium lower
adjustable region 17 and lower adjustment holes 19, this engages the
aluminium lower part 14 over which fits the rubber or other non-slip
material, end cap 15. The spring pin mechanisms upper 6 and lower 20
are represented by the holes on the adjustment parts and the sprung pin
operates to adjust the length of the crutch portion upper or lower, to fit
the size of the user and operate by locking into a hole in the adjustable
parts 12 and 17. Lower body 17 locates into lower region part 14 at collar
21.
The diagrams also show on the upper crutch part 3 and lower crutch part
14 the Red Line 4 called the Steve Line which is used to facilitate the
engagement of the adjusting mechanisms 7 and 19 with pins 6 and 20
respectively. Velcro TM straps are shown R which engage the saddle for
the handle (Figure 12) to hold he saddle in place, and friction grip
washer/collars 5 upper and 21 lower ensure a tight fit of the adjustment
mechanism parts 3 and 12, and 17 and 14 respectively. The ovoid hole 16
between the lower handle part 9 and upper handle part 10 is used for
hanging storage items.
Figure 3 shows the upper arm cuff 2 hinged upwards on the hinge 1 to
allow for ease of arm entry.

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1 Figures 4 and 5 show rear and front views that show more clearly the
spring clip operating pin 6 upper and 201ower.
Figure 6 shows an exploded view of the upper part 3 with hinge 1 and
cuff 2 separated from upper adjustable part 12 and similarly lower
adjustable part 17 separated from lower part 14.
Figure 7 shows the view from above the hinge 1 and cuff 2 looking down
on the palm knob 10 of the upper handle part 11.
Figure 8 shows the bottom end of the crutch with the foot 15 fitting onto
lower part 14 and adjustable part 17.
Figure 9 shows the parts of the handle, the lower part 9 and upper part
that attach round the central tubular body 12. The preferred average angle
of fourteen (14) degrees is shown with the dotted line 13. The ovoid
hole 16, is for storing or hanging items within the lower handle part 9.
Figure 10 shows the lower part of the leg 14 containing an end plug A
fitted into the end cap 15 containing shock absorber spring B and two
thrust washers C.
Figure 11 is the same as for Figure 10 without the shock absorber spring
and thrust washers, and instead showing the edge Q of the end plug A and
a pre-cast air-pocket bubble D which acts as the shock absorber.
Figure 12 shows the actual size and shape of the neoprene saddle for
fitting over the handle showing the part R which fits on the grip stop and
palm dome 10 (Figure 1) of the handle upper part 11, (Figure 1).

Representative Drawing