Note: Descriptions are shown in the official language in which they were submitted.
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Gymnastics Band
The present invention relates to an exercise band
(gymnastics band) made of a flexible, elastic material for
strengthening musculature, ligaments and tendons of the
locomotor system, which is used especially in medical
treatment.
Conventional exercise bands are made of rubber (natural
rubber) or latex. Latex is associated with a number of
disadvantages, however. For example, it is known that many
people experience an allergic reaction to latex, which can
result, for example, in local skin irritation, such as
eczema, when latex-containing exercise bands are used.
Furthermore, latex tends to have a tacky consistency and is
therefore often dusted with powder or the like in order to
prevent the exercise band from sticking to itself. The
application of powder to latex gives cause for considerable
concern on health grounds, however, because the powder
itself can act as an allergy-triggering substance on the
skin. In addition, the powder easily passes into the air
when the exercise band is being used and can be inhaled,
often loaded with latex particles, and enter the user's
lungs, so that powder and/or latex in the lungs are able to
trigger systemic allergic reactions. A further disadvantage
of latex is that many people find its odour unpleasant.
When being extended or stretched, latex is also distin-
guished by non-linear force-displacement characteristics
which, as is known to medical therapists, result in a solely
auxotonic load on the musculature, that is to say as the
amount by which the exercise band is stretched increases the
tensile resistance with which the exercise band opposes
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being stretched rises super-proportionally. That is not
always desirable, however, because, as a result, the range
of movement of joint parts when the exercise band is
stretched can be severely limited if the strength of the
muscles is insufficient to stretch the exercise band
sufficiently.
In order to ensure a sufficient range of movement in the
case of weaker muscles, it is therefore necessary to select
an exercise band having a relatively low tensile resistance,
which, if the material remains the same, has hitherto been
achieved solely by varying the thickness of the exercise
band or by modifying the Shore hardness of the rubber-like
material. Conversely, an exercise band having a tensile
resistance that is too low for a specific muscle can readily
develop small cracks, which can result in sudden and abrupt
tearing of the exercise band, which in turn can lead to
injury.
The aim of the present invention is to provide an exercise
band with which the disadvantages mentioned at the beginning
can be avoided.
That aim is achieved according to the invention by the
features of claims 1, 2 or 4. Advantageous configurations of
the invention are given in the subsidiary claims.
The present invention relates to an exercise band for
strengthening musculature, ligaments and tendons of the
locomotor system, which is made of a flexible, elastic band
material. The exercise band comprises at least one
thermoplastic (preferably at room temperature), elastomeric
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material (a) and a further material (b) that is different
from the thermoplastic elastomer.
The material (b) especially comprises silicone or Teflon.
Preferably the materials (a) and (b) are present in
different layers.
It is further preferred that at least one layer comprises
silicone or Teflon and another layer of the thermoplastic
elastomer different from silicone or Teflon.
Alternatively or in addition, the exercise band comprises at
least one thermoplastic elastomeric material and has on at
least one side (that is to say on one side or on both sides)
depressions in the form of channels along t-he longitudinal
direction (lengthwise relative to the direction of
stretching) of the band.
According to the invention, the exercise band is made of a
band material which comprises at least one elastic
- preferably at room temperature (that is to say at, for
example, about 21°C) - thermoplastics material or thermo
plastic elastomer, referred to hereinbelow as a thermo
plastic elastomer or thermoplastic elastomeric material.
Examples of thermoplastic elastomers are, for example,
styrene block copolymers (TPE-S), SEBS, thermoplastic
copolyesters, polyether esters (TPE-E), thermoplastic poly-
urethanes (TPE-U), polyether-polyamide block copolymers
(TPE-A). Such thermoplastic elastomers are thermoplastic and
elastic per se, that is to say also without addition of
further materials.
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Thermoplastics materials have, in principle, lower elastic-
ity than elastomers. According to the invention, however, it
is also possible to use thermoplastics materials that are
provided with elastic properties by addition of appropriate
materials known per se, such as, for example, fillers and/or
plasticisers. The thermoplastic elastomers used according to
the invention can generally be combined with fillers and/or
plasticisers such as, for example, waxes, Aerosil (highly
disperse silicic acid), colourings, glidants (oleic acid
amide, erucamide), anti-oxidants (hydroquinones, pyrocatech-
ols, gallates etc.) or barium sulfate.
The use of a thermoplastic elastomer advantageously makes it
possible to dispense with the use of allergy-triggering
latex or the powders applied thereto. Since thermoplastic
elastomers do not age as quickly as latex, the additional
advantage is obtained that the exercise band has a consid
erably reduced risk of tearing in the event of over
stretching, so that injuries can be avoided.
According to the invention, the thermoplastic elastomers can
be mixed with other, especially elastic, materials (prefer-
ably with crosslinked materials). Preferred here are, for
example, addition-crosslinked or condensation-crosslinked
silicones (especially silicones addition-crosslinked under
platinum catalysis), EADM rubber, NBR rubber and other
irreversibly crosslinkable materials.
In a further advantageous embodiment of the invention, the
exercise band has a layered structure and has at least two
layers of different materials. When the exercise band has
such a layered structure, the stretching properties or
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tensile resistance of the exercise band can be influenced in
the desired manner in an especially simple way by the
selection of suitable layer materials. It is also possible
thereby to improve the chemical resistance of the thermo-
s plastic elastomeric materials with respect to oils and
solvents (such as are present, for example, in nail varnish
removers or disinfectants) and also to stabilise them with
respect to elevated temperatures. Especially advantageous is
a layer of at least one thermoplastic elastomer that is
combined, for example, with a layer of Teflon or a layer of
silicone and/or mixtures thereof. Preferably, the
thermoplastic elastomer is coated on both surfaces with a
layer of a different material (especially silicone or
Teflon). It is also possible for one side of the band to be
coated with one material, for example silicone, and the
other side of the band with a further material, for example
Teflon. Special preference is given to the thermoplastic
elastomer being completely covered or encapsulated by a
layer of a different material (preferably silicone and/or
Teflon). This can be effected, for example, by coating in a
dipping bath or during extrusion. By means of such a
coating, the chemical resistance and thus the durability of
the band material is improved. The band can accordingly also
be more easily disinfected in order to avoid the risk of
contact infection of users.
The layer comprising a thermoplastic elastomer preferably
has a layer thickness of from 50 ~m to 2 mm, especially from
100 ~m to 1 mm, more especially from 200 ~m to 600 Vim. The
further layer (s) can have a thickness of from 5 ~m to 2 mm;
if the layer containing the thermoplastic elastomer is
coated with Teflon, the Teflon layer preferably has a thick-
ness of from 10 ~m to 15 Vim. When the band comprises a first
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layer containing a thermoplastic elastomer and a second
layer containing silicone, the layer thickness of the second
layer is preferably from 5 to 100 0 of the layer thickness
of the first layer.
It is also preferable for the exercise band of the present
invention to have on one or both sides an absorbent surface
which is especially in the form of a flock coating having
absorbent fibres or in the form of an applied fleece.
Examples of absorbent fibres are cellulose, synthetic fibres
and viscose. The absorbent surface can be produced, for
example, by electrostatic flock coating or by pressing a
fleece onto the hot thermoplastic elastomer (for example
after extrusion). Preferably the absorbent surface is not
applied to the thermoplastic elastomer using an adhesive.
The band material can comprise only one thermoplastic
elastomer or a mixture of thermoplastic elastomers.
In accordance with a preferred embodiment, the exercise band
of the present invention comprises in one layer a mixture of
at least one thermoplastic elastomer (a) and a material (b)
that is different from a thermoplastic elastomer, preference
being given to a ratio by weight (a) . (b) of from 30:70 to
95:5 o by weight, especially from 85:15 to 95:5 o by weight.
Examples of the mentioned materials which are different from
thermoplastics material are: silicone (especially addition-
crosslinked or condensation-crosslinked silicones), Teflon,
acrylonitrile-butadiene rubber (NBR), EPDM rubber (for
example Santoprene), polyurethanes, polystyrenes and other
irreversibly crosslinkable materials that form a three-
dimensional structure. The term silicone denotes, for
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example, higher molecular weight compounds having a three-
dimensional framework composed alternately of silicon and
oxygen atoms. Silicon atoms in silicones that do not achieve
their electron octet by the formation of bonds to oxygen are
saturated with organic radicals R. The framework can be
linear or highly branched. An, example are polymeric
compounds composed of repeating units of the general formula
R2Si0, the radicals R being the same or different and being
customary radicals known to the person skilled in the art.
Examples of radicals R are hydrogen, methyl, vinyl or phenyl
groups.
By means of the channels present in a preferred embodiment
it is possible, by virtue of the associated "weakening" of
the band material, for the tensile resistance of the
exercise band on stretching to be reduced selectively in an
extremely advantageous manner. In other words, by virtue of
the surface structuring, specific desirable force-displace-
ment characteristics can be imparted to the exercise band on
stretching. For example, the surface structuring can impart
linear force-displacement characteristics to the exercise
band.
The channels, which are preferably provided, also bring
about a reduction in the contact surface area of the surface
plane of the exercise band. Because thermoplastic elastomers
can also have tacky properties, the channels can advant
ageously also prevent the exercise band from sticking to
itself by reducing the surface plane having the tacky
effect.
Furthermore, at a force that is comparable in relation to a
plain band, raised longitudinal structures between the
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channels prevent sudden (abrupt) tearing of the band and
therefore provide a considerable contribution to the
protection of the user/patient.
In a preferred embodiment, at least one of the two surfaces
of the band has a plurality (at least 2) of depressions
(channels) which, starting from the surface plane of one
side, extend in the direction of the remote side. Such
depressions can have, in each case perpendicular to the
surface plane, a rectangular, especially square, or round
cross-section. The depressions (channels) advantageously
extend along the direction of stretching of the band.
In accordance with a further embodiment, the exercise band
can have a honeycomb-like surface structure. Such a
structure imparts to the band similar properties to those of
a woven material, that is to say a high degree of flexib-
ility and a low tendency to bulge or form folds, combined
with a high resistance to tearing. This is brought about by
the "ridges" remaining between the honeycombs of an exercise
band so constructed. The ridges advantageously extend at
right-angles to one another, so that the depressions in the
surface plane have a rectangular, especially square, cross-
section. This imparts a substantially uniformly character-
istic stretching behaviour to the band. Alternatively, the
depressions can each have in the surface plane a hexagonal,
especially a regular hexagonal, cross-section.
The two surfaces or the surface structures of the exercise
band according to the invention can be identical or
different.
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The depressions can, for example, be produced by stamping of
the finished exercise band. Alternatively, it is also
possible, for example, to provide the depressions as early
as at the stage of manufacturing the exercise band, for
example by means of suitable raised portions during moulding
or extrusion.
In accordance with a further preferred embodiment, the
exercise band according to the invention comprises at least
one longitudinal reinforcement strip of a material different
from the band material in order further to reduce the risk
of sudden tearing. Such a reinforcement strip, which is
preferably tear-resistant, can have, for example, a length
corresponding to the length of the band when stretched by
the maximum extent; it can be arranged in or on the band in
a zig-zag shape or in loops, for example.
It is also preferable for the exercise band of the present
invention to comprise an indicator that displays the level
of force applied. The indicator can be, for example, a
colour indicator or a strain gauge, such as is used in
scales. The indicator can consist of a piezoelectric
material. The use of such an indicator advantageously
enables the force applied to be monitored and therefore
allows regulated treatment.
The exercise band according to the invention can be produced
by melting and subsequent solidification, as is customary
also in the case of conventional latex exercise bands. It is
preferable according to the invention, however, for the
exercise band to be produced by extrusion, which is
considerably more economical. For that purpose, the band
material should preferably be an extrudable material.
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In a preferred configuration of the invention, a band
material is used which, on being stretched in the band
direction, exhibits substantially linear force-displacement
characteristics even without the use of additives. That is
to say, when the exercise band is stretched the tensile
resistance increases substantially in proportion to the
stretching of the exercise band; preferably, therefore, the
band substantially complies with Hooke's Law. A band
material having such behaviour can be used in an especially
advantageous way for strengthening muscles, ligaments and
tendons of the locomotor system: as already mentioned above,
in contrast to conventional exercise bands it allows a
greater range of movement of joint parts, so that, in
particular, the mobility of joints under load can be
trained. In addition, because the increase in the tensile
resistance as the exercise band is stretched is smaller than
in the case of conventional exercise bands, the risk of
unintentional overloading of the locomotor system of the
user is avoided, for example where tendons are weak or have
been previously injured, such as, for example, after rupture
of a tendon. As a result, not only can renewed damage to the
tendon, for example as a result of microscopic cracks that
would otherwise occur, be avoided, but also the progress of
a treatment can be beneficially influenced.
In accordance with a further advantageous embodiment, the
ends of the exercise band according to the invention can be
in the form of loops, which can be produced, for example, by
fusing to itself. Alternatively, the ends of the band can be
joined to one another (for example by fusing together the
ends) in order to obtain an endless loop. If desired, the
exercise band can be provided with grips at the ends.
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As has been explained, the exercise band according to the
invention has excellent properties in respect of resistance
to tearing and stretching behaviour. In addition, the exer-
cise band can be manufactured economically by means of
extrusion.
The invention will now be described with the aid of exemp-
lary embodiments, reference being made to Fig. 1.
Fig. 1 shows a diagrammatic view in cross-section in the
band direction of an exemplary embodiment of the
exercise band according to the invention.
Fig. 1 shows a portion of an exercise band according to the
invention in a cross-section in the band direction, the
section being made perpendicular to the plane of the band.
The exercise band 1 is made of the thermoplastic elastomer
TPE-S and produced by extrusion. Both surfaces of the
exercise band are provided with a surface structure. The
surfaces have a plurality of depressions 4 which, starting
from the surface planes 2, 3 of the two sides, extend in the
direction of the remote side. The depressions 4 are channel-
like in shape, the channels extending along the band
direction of the exercise band 1. By means of the channels
4, the raised areas 5 adjacent to the channels 4 are formed.
The surface structures of the two sides of the exercise band
have been produced by stamping of the exercise band which
has been produced by extrusion. By means of the surface
structure in channel form, selective weakening of the
tensile resistance of the exercise band 1 on stretching can
be achieved.
