The present invention relates to a training device for rehabilitation of a person's neck.

Whiplash or Whiplash-associated disorder (WAD) is an acceleration- deceleration mechanism that can occur when a sudden force affects the neck. It can lead to trauma such a hyperextension and/or straining of the soft tissue in the cervical spine. The typical example is a car crash. If one is hit from behind, the head is thrown backwards and subsequently forward. If one hits something it is the opposite. Here, the head is first thrown forward and subsequently backwards. Generally, the neck is put under further strain if the head is turned. The motions are uncontrolled. Whiplash can also occur at sports injury, for instance when persons run into each other or when diving head first. The sudden and uncontrolled force causes a hyperextension of muscles, tendons and joints that can be compared to a strain injury. As with other strains, the damaged tissue leads to swelling, stiffness and pain. WAD must be followed by rehabilitation as soon as possible. One type of therapy that is offered is neck exercises. They consist in turning the head in different directions, for instance as follows:

- Look to the right, and turn the head slowly in the same direction. Stop, before it hurts.

- Look to the left, and turn the head slowly in the same direction. Stop, before it hurts.

The movements during the exercises can take place lying down with the back of the head placed on a surface, if there is too little control in standing position. In this case, the muscles of the neck must overcome the friction between the back of the head and the surface. The drawback of lying flat on the back with a floor or a carpet as surface is that muscles tighten up and/or that discomfort and pain grow. That means that rehabilitation with these exercises is not possible. To avoid these pains and strains, it is necessary to reduce the friction between the back of the head and the surface.

Known devices for rehabilitation of the neck are very few and do not have a sufficient effect for rehabilitation after a severe whiplash injury. The devices comprise a means for stretching the muscles in the complete spine - US2012/02651 14A1 . However, performing single stretches is not sufficient to remove the muscle tensioning after a whiplash injury. Another known device is meant for rehabilitation of the lower back, the stomach muscles or the ankles - GB2042909 A. this device can cause a lateral movement as the top part can be moved in relation to the bottom part as there are several sets of balls by means of which the top part can be moved in relation to a middle part, and another set of balls by means of which the middle part can be moved in relation to the bottom part. The device is not suited as a training device for rehabilitation of muscles in the neck for a whiplash injury, as the possibility of lateral movement cannot be combined with a circular motion. The device is meant for calisthenics, meaning people that train by means of their own weight and training device, typically outdoors.

Consequently, it is of a strong design and among other things the balls are made of steel so that the device can be used to rotate the body thereon. Another known training device is described in C N201 182862 Y. In this patent specification a training device for training of the waist of a person is described. It is used in the way that one stands on the training device with both feet and tilt up and down while at the same time rotating about oneself, that means not independent of the up-and-down function. The up- and-down function is to be avoided in a training device for training of the neck muscles. The device is also a complicated design, and it is not possible to perform a lateral movement with the device.

The problem that is solved with the present invention is to provide a training device that by active training shortens the treatment period for rehabilitation of a user's neck muscles, connective tissue, cartilage, etc., in case the neck has been exposed to overstrain such as a whiplash injury. At the same time, it must be of a simple design so that it is easy to sterilize and cheap to manufacture. Short description of the invention

The problem is solved by means of a training device that is described in claim 1 , said training device having a top part 1 and a bottom part 2 that are rotatably connected and are rotatable around an imaginary axis that is perpendicular to the parts and having limiting means that are adapted to limit a mutual relative movement of the parts just like the device of

CN201 182862 Y. The device according to the invention is characterized in that the device is configured so that the parts are mutually movable in a plane with the surfaces of the parts by being able to slide laterally on each other, where the lower surface of the top part and the surface of the bottom part both have a static and a dynamic coefficient of friction that is lower than 0.25, and that the device has limiting means for the lateral movement of the surfaces in relation to each other. Furthermore, the device has means that are adapted to build up a force that works against said lateral movement of the top part (1 ) in relation to the lower part (2 or 22-25) in a plane that is perpendicular to the imaginary axis from a first position to a second position.

Claims 2 to 9 describe alternative embodiments of the training device. To give a better understanding of the invention, some examples of the invention will be revealed referring to the following figures, in which Fig. 1 shows a training device according to the invention in a very simple form consisting of two parts, in a side view, a top view, and a bottom view. Fig. 2 shows a training device according to the invention comprising five parts in an exploded perspective side view.

Fig. 3 shows the training device of Fig. 2 in a bottom view (to the left) and a top view (to the right).

Fig. 4 shows the top part of the training device of Fig. 2, uppermost from above and lowermost from below.

Fig. 5 shows the elastic material in the training device of Figs. 2 and 3.

Fig. 6 shows the holding disc in the training device of Figs. 2 and 3.

Fig. 7 shows a side view and a view seen from below of the lower part of the bottom part of the training device of Figs. 2 and 3. The figure shows a click joint edge for joining with the upper part of the bottom part 22, see Fig. 3 to the left, where it is the part in which a hole can be seen.

Fig. 8 shows the fundamental directions in which a training device according to the invention can be moved in in relation to a surface.

Fig. 1 shows a training device according to the invention. With such a device it is possible for the patient to perform controlled movements during exercises such as neck stretch movements, where the areas that are affected are among others the neck, shoulder and back areas. The training device is meant to be used by people that are in treatment, during which there is a need for neck exercises due to soreness, damage or from other reasons, and where neck exercises are necessary for a faster rehabilitation/recovery of muscles, cartilage, connective tissue, etc. Concurrent with this improvement a reduction of nerve nuisances is achieved.

The training device provides less friction between the back of the head and the top part than the friction between the back of the head and a cotton surface, pillow or floor. During recovery, it is essential that it is possible to do exercises with customized load. As a result, the device must be equipped with a further means to cause an opposite force when the external force is removed, so that the force can return the top part to the starting position in relation to the bottom part, and must in the best case also be adjustable according to customer needs. Patients that use this device avoid improper strain, and the treatment is targeted at the areas that need treatment.

Fig. 1 shows an example of a training device. Uppermost, the assembled device is shown in a side view. In the middle is the top part 1 seen from above. Lowermost, the top part 1 is seen from below assembled with the bottom part 2. All training devices according to the invention have a simple form and comprise at least two parts a top part 1 with an upper side on which a force is applied by placing the back of the head of a person, and a bottom part 2 with an upper side 1 that supports the top part on the lower part 1 12 (not shown in Fig. 1 ) thereof, and which can move so that the back of the head can be moved or rotated within an area of the outermost edge of the bottom part. When in contact, the top part 1 and the bottom part 2 move with a friction that is smaller than the friction between the back of the head and for instance a cotton fabric in a plane that is defined by the two opposite surfaces, which gives a resistance during the movement. A low friction could for instance be obtained between two surfaces of Teflon as stated in claim 9. That means that materials with a dynamic coefficient of friction of 0.1 or less are especially suited. An edge on the perimeter of the top part 1 limits the area within which the bottom part 2 can be moved laterally in relation thereto. The lower part of the bottom part 2 abuts against a preferably solid surface.

Fig. 2 shows another example of a training device in a side view. It comprises in addition to a top part 1 and a bottom part that is drawn as its upper part 22, an elastic material 23, a stainless screw, a holding disc 24 and a bottom part 25.

Fig. 3 shows the example of the training device in Fig. 2 in a bottom view (to the left) and a top view (to the right). The upper part 22 of the bottom part comprises a bore. The elastic material 23 is mounted between the upper part 22 and the lower part 15 of the bottom part. In a state of rest, the bottom part 22-25 is centred in relation to the centre of the top part 1 . The elastic material 23 is - possibly rotatably - mounted in one end around a centre part or spigot perpendicular to the surface on the top part, and at the other end to the upper part 22 of the bottom part on the lower side thereof in the perimeter of the bore. A distance defined by the outer edges between the upper part 22 and lower part 25 of the bottom part has the effect that the holding disc 24 can move freely in the cavity between the parts 22 and 25. The holding disc 24 has a circumference that is slightly bigger than the bore in the upper part 22 of the bottom part so that the top part is rotatably connected to the bottom part 22-25. For instance this may be by means of said spigot on the top part that can be provided with a threaded bore for a screw that is located at the centre on the lower side 1 1 of the top part. In this way, the holding disc 24 can move inside the outer edge of the bottom part that is defined by the outer edge of the upper part 22 or the outer edge of the lower part 25.

The top part 1 can move so that the back of the head can be moved or rotated within an area of the outer edge of the bottom part. The two parts 1 and 22-25 move with a friction that is less than the friction between the back of the head and for instance a piece of cotton fabric in a plane that is defined by the lower side 1 12 of the top part and the upper side 221 of the lower part, which are touching and apply resistance during the movement. An edge on the top part 1 limits the area, so the centre of the top part 1 can only move within the outer edge on the bottom part 22-25. When in use, the lower part 25 of the bottom part abuts against a solid surface. The holding disc 24 can move freely in the cavity between the upper part 22 and the lower part 25 of the bottom part.

When later in the treatment a need arises of a controlled larger resistance during exercise, it is possible to alter the resistance between the two upper surfaces by applying another surface with another static and dynamic coefficient of friction.

The device can be placed on a floor, a mat or similar. The device can be mounted on a wall, if it is necessary for the user to be in sitting or standing position.

Fig. 3 also shows the training device of Fig. 2 where the upper part 22 of the bottom part has an upper side 221 and a lower side 222 with an inner click connection edge that fits an outer click connection edge on the lower part 25 of the bottom part, see Fig. 5. Furthermore, a bore in the upper part 22 of the bottom part can be seen.

The lower side 1 12 of the top part and the upper side 221 of the bottom part are made out of a material with low static and dynamic friction. In an alternative embodiment the training device can comprise magnets that are mounted on or in the lower side 1 12 of the top part or on or in the upper side 221 of the bottom part so that a magnetic force resists the applied force/weight from the head or the weight of the head.

Fig. 4 shows the training device of Fig. 2, where the top part 1 has an upper side 1 1 1 and a lower side 1 12. The upper side 1 1 can be constructed of a material that is comfortable to put the back of the head onto. The material on the lower side 1 12 must comply with the demand for a suitably low coefficient of friction where the material is brought into contact with the upper side 221 of the lower part, see Fig. 3. Fig. 5 shows the further means that the training device may comprise. It is an elastic material and in this case an elastic material that provides resistance against lateral movement of the top part 1 in relation to the bottom part 22-25, which adds to the resistance that the friction between the parts 1 12 and 221 creates in for instance the embodiment of Fig. 2 and Fig. 3.

The further means 23 that in Fig. 2, Fig. 3 and Fig. 5 is an elastic material can also be a magnet or another material that enables the top part 1 and the bottom part 22-25 to return to the starting position after a force has been applied on one of them in a lateral direction in relation to the other. The further means can be chosen so that the resistance against lateral movement is as sought. The further means can for instance be springs or other flexible means that will provide a different resistance against movement.

So the mechanism for holding the top part 1 and the bottom part 22-25 together can be an elastic material or for instance magnets or anything else that returns the top part to the starting position in relation to the bottom part after a movement thereof. This mechanism is provided to fix the top part 1 to the bottom part 22-25 and to, simultaneously, function as a centring mechanism for the top part 1 in relation to the bottom part 22-25. Fig. 6 shows a holding disc 24 that can ensure that the bottom part 22-25 is connected to the top part 1 , see Fig. 3. As in this example, a screw can be located centrally, the thread of which fits the thread of a centre spigot on the top part 1 (not shown). The circumference of the holding disc 24 is larger than the bore in the upper part 22 of the bottom part and smaller than the inner diameter of the upper part 22 of the bottom part.

Fig. 7 shows the training device of Fig. 2 where the lower part 25 of the bottom part has an outer click connection edge that fits an inner click connection edge on the inner side 222 of the upper part of the bottom part, see Fig. 3 to the left. Uppermost, the lower part 25 of the bottom part is shown in a side view, lowermost in a bottom view. The upper part 22 of the bottom part is connected to the lower part 25 of the bottom part so that a cavity is formed, in which the holding disc 24 that fixes the top part 1 to the bottom part can move freely. The holding disc can also have different shapes. Furthermore there may be embodiments where there is no need for a cavity, as the connection between the top part 1 and the bottom part 22-25 can be magnetic or consist in that the top part is a socket in which the bottom part can be moved and held fast at the same time. The parts must be designed to be separated and reassembled, so that all parts can be separated to be cleaned, if the training device is to be used in the health sector.

The lower side 252 of the bottom part can be placed on a surface such as a floor, a mat or the like, on which the patient places the back of the head. In an alternative embodiment the upper side, on which the back of the head rests, is constructed in a material that makes the contact with back of the head comfortable. In a simple and useful embodiment, the training device comprises a top part 1 and a bottom part 22-25 that are shaped like discs or another flat element. Fig. 8 shows a training device according to the invention like for instance the embodiment of Fig. 2 and Fig. 3, where the arrows show the fundamental directions in which the top part 1 can be moved in relation to the surface.