Orthesis for the carpal tunnel syndrome

The invention relates to an orthesis for the prevention and/or treatment of carpal tunnel syndrome, comprising a substantially rigid hand fixation brace having two ends, one of which is provided with a part to be fastened to the wrist and underarm while the other is provided with a finger coupling part. The finger coupling part which is formed as a finger supporting brace, preferably only engages the index and middle finger, while the top of the finger supporting brace is open to allow finger movement in the upward direction.

BACKGROUND OF THE INVENTION 
Field of the Invention 
Brief Summary of the Invention 
The present invention relates to an orthesis for the prevention and/or 
treatment of carpal tunnel syndrome. 
Due to excessive use of the fingers and the thumb, for instance when making 
gripping movements or when typing, the nerve tendons and flexing tendons 
that control these finger movements, may become irritated. Such an injury 
caused by excessive use is also known as RSI (Repetitive Strain Injury). 
At the base of the hand palm, nerve tendons and flexing tendons of the 
fingers run through a tunnel, the carpal tunnel, which has a length of 
approximately 2 cm, and is defined at the dorsal side by bone and at the 
palmar side by a tendon plate. The irritation of the nerve tendons and 
flexing tendons may cause swelling of the tendon sheaths, thereby pinching 
the nerves in the carpal tunnel which in turn interferes with the 
functionality of the tendons. The resulting pain and unusual feeling in 
the hand palm and fingers caused by this irritation of the tendons at the 
base of the hand palm are known as the carpal tunnel syndrome. 
Naturally, it is preferable to prevent the occurrence of carpal tunnel 
syndrome. Very often, when a person does suffer from such symptoms, a long 
period of absolute rest is prescribed, which in terms of working hours and 
loss thereof, is very costly. 
A very drastic treatment is the operative splitting of the tendon plate of 
the carpal tunnel, to relieve the pressure on the tendons. However, this 
is rather a major and complicated operation without the guarantee of 
improvement. 
Another possible treatment is the application of a splint to the wrist and 
hand palm. This treatment, together with a finger-less glove made of 
elastic material, is known from WO-94/27528, but only partly prevents the 
tendon's movement in the carpal tunnel. 
The object of the invention is to maximally reduce the movements of the 
tendons in the carpal tunnel in order to prevent or treat carpal tunnel 
syndrome. To this end the orthesis according to the invention comprises a 
substantially rigid hand fixation brace having two ends, one of which is 
provided with a part to be fastened to the wrist and underarm while the 
other is provided with a finger coupling part. 
Due to its uncomplicated construction, the manufacture of such an orthesis 
is simple, and due to its size, a modest amount of material is required, 
making the orthesis attractive from an economic point of view. 
In a favourable embodiment, the finger coupling part only engages the index 
and middle finger. From a functional viewpoint these are the most 
important fingers. Restricting the movement of these fingers almost 
completely reduces the tendon movement. Therefore the design of the 
orthesis may be extremely compact. This further increases the 
applicability and further simplifies manufacture. 
Preferably the finger coupling part is formed as a finger supporting brace, 
which is an effective and simple manner of forming a link with the 
fingers. 
In a preferred embodiment the top of the finger supporting brace is open to 
allow finger movement in the upward direction. The finger brace now only 
restricts the downward movement of the fingers. This results in a 
substantially maximal reduction of the tendon movement, without unduly 
restricting the use of the hand. Although this prevents gripping, it is 
still possible to operate the keyboard. This makes the orthesis according 
to the invention very user-friendly. 
Optionally the part to be fastened to the wrist comprises a brace to be 
fitted around the wrist, which in cross section is a substantially 
half-round or half-oval brace and, attached to the brace, a band or strap 
for fastening. In another embodiment the part to be fastened to the wrist 
comprises a curved plate to be fitted on the wrist and, attached to the 
plate, a band or strap for fastening. These are simple and effective ways 
of providing a fastening around the wrist and/or underarm. 
The band or strap for fastening is preferably elastic, which makes the 
orthesis more comfortable in wear and use. 
Furthermore, the band or strap is preferably secured by means of Velcro 
fastening. This provides a secure fastening which is easily adaptable to 
the size of the user's wrist or underarm. 
In a preferred embodiment the supporting parts of the orthesis are made in 
one piece. This simplifies manufacture and results in a smooth orthesis 
without any projections that could irritate the hand.

The orthesis shown in the drawings, for the prevention and/or treatment of 
carpal tunnel syndrome, comprises a hand fixation brace 10, a part 20 to 
be fastened to the wrist and a finger coupling part 30. The fastening part 
20 is located at one end of the hand fixation brace 10 and serves to 
firmly fix the orthesis to the wrist. The finger coupling part 30 is 
located at the other end of the hand fixation brace 10. Into said finger 
coupling part 30 a number of fingers are placed when using the orthesis. 
The drawings show an orthesis to be used on the right hand. A similar 
orthesis can be made for the left hand and an orthesis that may be used on 
both hands is equally well possible. 
When the orthesis is fitted, bending and rotating movements of the hand are 
prevented and the hand is fixed in a position determined by the form of 
the orthesis. To a large extent this prevents the movement of the tendons 
through the carpal tunnel. At the same time the hand's gripping movements 
are hindered, which further reduces the movements of the tendons. 
The finger coupling part 30 shown in the Figures, comprises a finger 
supporting brace consisting of two finger braces 31, as can be best seen 
in FIG. 1. This finger supporting brace accommodates the index and middle 
finger. From a functional viewpoint these are the most important fingers 
and their fixation results in a further reduction of the movements of the 
tendons in the carpal tunnel. The movements of the other fingers are now 
also more or less automatically restricted. 
At the top, the finger braces 31 are an upwardly curved open arc to allow 
the fingers to move in the upward direction. In this way the hand retains 
a great deal of its functionality. For instance, it is possible to type 
while using the orthesis. The likelihood of sustaining the carpal tunnel 
syndrome with this kind of occupation is considerable. However, the use of 
the orthesis with these occupations is a remarkably effective means of 
preventing carpal tunnel syndrome of RSI. 
The fastening part 20 shown in the figures comprises an in cross section 
substantially half-oval brace 21 for fitting around the wrist and a 
fastening band or strap 22 attached to the brace. By means of said band or 
strap 22 the brace 21 is fixed around the wrist. The band or strap 22 are 
fitted and fastened in a manner known as such, for instance, by means of 
Velcro fastening. The comfort in wear can be increased by using an elastic 
material for the band or strap 22. 
In an alternative embodiment the fastening part 20 consists of a plate to 
be fitted on the wrist which plate is fixed into place by means of a band 
or strap 22 attached to the plate. This band or strap 22 is also fitted 
and fastened in a manner known as such. 
In the embodiment shown, the hand fixation brace 10, the brace 21 and the 
finger coupling part 30, that is to say the supporting parts of the 
orthesis, are made in one piece of a metal such as, for example, aluminium 
or titanium, or of a plastic. 
The above-described embodiments are not to be considered as a limitation to 
the invention. There are various possible embodiments for the orthesis for 
the prevention and/or treatment of carpal tunnel syndrome, all within the 
scope of the present invention and the appended claims.