WO2005009782A1 - Head rest for whiplash prevention - Google Patents

Abstract

A head rest simultaneously brought into contact with the lower surface part of the rear head part, upper cervical vertebrae part, and fifth cervical vertebrae part of an occupant for supporting these parts when a vehicle is bumped from a rear side and a method of using the head rest, the head rest wherein the trichoid connective tissues and the rear vertical ligaments of the cervical vertebrae parts are prevented from being damaged when a torque about the cervical vertebrae parts is suddenly applied to the head part of the occupant by an impact at the time of a rear-end collision, whereby a whiplash can be effectively prevented from occurring.

Description

 Description Headrest for whiplash prevention

 The present invention relates to a headrest for a motor vehicle. More specifically, the present invention relates to a novel shaped headrest for preventing an occupant from having a so-called whiplash due to the impact of a car collision. Background art

Until the 1950s, car seats were not equipped with a bed rest as standard. Probably because there were relatively few car collisions. Most passenger cars since the 1980's have been equipped with headrests. What has become a hot topic in Japan during this transitional period is the so-called "whiplash". Whiplash is a symptom that occurs when the trunk is pressed forward and the neck is shocked backwards, such as when the vehicle is hit by a car, causing damage to muscles, ligaments, joints, and sometimes the spinal cord. (Kojien Fifth Edition), but it is medically said to be traumatic cervical syndrome, and, of course, its definitive treatment methods, as well as its outbreak theory and defense methods, have not yet been fully established. Is the current situation. However, the number of automobile collisions is increasing steadily, and whiplash has not been shown to decrease at all, despite the fact that almost all vehicles have a headrest as standard equipment. This demonstrates that the headrests currently used in many passenger cars are extremely insufficient to prevent whiplash. Therefore, the development of a headrest that effectively prevents whiplash that easily occurs due to a rear-end collision is needed. Coveted. Headrests that have been developed to prevent whiplash have not been spared. For example, as an attempt to absorb the impact of a collision with the headrest material, a headrest body has a bag body filled with liquid and a seat body has a liquid discharge portion capable of receiving the liquid. A headrest for draining liquid in the headless body into a seat in the event of a collision to reduce the impact (for example, see Patent Document 1); a cushion member attached to a headrest frame; A headrest in which a part of the cushion member is deformed under a low-speed load but has a small amount of deformation under a high-speed load when the outer periphery is surrounded by a skin member (for example, see Patent Refer to Reference 2), so that at least the occupant's head contact part of the head restraint is close to the occupant's head due to the impact at the time of a rear-end collision In a headless train mounted on a vehicle seat that protrudes by a fixed distance, a cavity is provided inside the headless train, and the head of the occupant when the rear-end collision hits the headless train A headless train equipped with air bleeding means for rapidly bleeding air from the cavity by operation (for example, Patent Document 3), a headrest in which a support member enters the headrest body from the outside, and the headrest is There is a headrest set so as to have an angle inclined forward of the vehicle body from the vertical direction (for example, see Patent Document 4). However, considering the mechanism of onset of whiplash described below, it is not considered that these inventions effectively prevent onset of whiplash. Attempts to mechanically absorb the impact of a collision include, for example, For example, when an impact from the rear of the vehicle such as a rear-end collision occurs, the fixture is released due to the inertia of the weight, and the upper part of the headrest falls forward to support the occipital part of the person on the panel due to the force of the panel. A headrest that is supported by a pole of a seat pack of a seat, and the headrest is supported by the pole so as to be rotatable in the front-rear direction. A holding member for holding the headrest at a predetermined rotational operation position is provided, while a sensor member for detecting a rear collision is provided on the headrest. A headrest provided with a previous operating member for forcibly operating the headrest last time (for example, see Patent Document 6), is provided on a vehicle seat, and is provided for a seated occupant. A pillow that supports the pillow, a pillow attitude control mechanism that controls the attitude of the pillow, a contact pressure sensor that is provided on the pillow, detects a head contact pressure of a seated occupant, and is provided on the vehicle. An impact sensor that senses an impact at the time of a rear-end collision, and feedback control of the pillow attitude control mechanism so that an output of the contact pressure sensor matches a preset contact pressure reference value, and an output of the impact sensor is preset. And a tongue roller for fixing a pillow posture controlled by the pillow posture control mechanism when the collision impact reference value exceeds a predetermined rear impact collision reference value (for example, see Patent Document 7). A headrest attached to the backrest of the seat provided on the vehicle and supporting the head of the occupant sitting on the seat, the headrest being strong only when the vehicle is stopped or running at low speed. A headrest (for example, see Patent Literature 8) configured to be moved forward to make an abutment is fisted. As these inventions mechanically attempt to reduce the impact at the time of rear-end collision, the equipment becomes complicated and expensive, and the effect is hard to expect as described below. Further, although not intended to prevent whiplash caused by impact at the time of a rear-end collision, an invention relating to a headrest for a chair with less muscle fatigue around the neck has been disclosed (see Patent Document 9). Since the present invention discloses a headrest similar to the present invention, it is necessary to clarify the differences. The headrest according to the present invention is characterized in that, in a headrest attached to the upper part of the chair back so that the upper and lower positions can be adjusted, the upper part of the headrest is formed and the lower part of the headrest is formed rather than the part supporting the back of the head. The part that supports the cervical vertebra is made to protrude toward the seating side, and bulges are provided on both sides of the part that supports the cervical vertebra with at least a gap to accommodate the neck, and the bulge is provided. The headrest for chairs is characterized in that the headrest is extended toward the upper part of the headrest so that the distance between them increases. The purpose of this headrest is to provide a headrest for a chair with less muscle fatigue around the neck and is suitable for a chair with a swaying vehicle. It is intended to provide the most comfortable headrest assuming the use condition of the headrest. However, the invention disclosed in Patent Document 9 does not intend to prevent occurrence of whiplash when a sudden impact such as a rear-end collision is given. Therefore, it is difficult to prevent whiplash at the time of rear-end collision by using this headrest. This is because the headrest described in claim 1 of the present invention is designed such that the comfort from normal use results in that the occupant's neck to the back of the head fits perfectly between the side bulges. It has a shape. In this configuration, the occupant's occipital area, the mastoids of the temporal bones on both sides, the lower occipital area, and the cervical vertebrae all fit perfectly in the recess of the headrest and are cheap. Will be placed. When such a headrest is used, the headrest surface sandwiches the mastoids (bulges behind the ears) of the front of the occipital region and the temporal bones on both sides during a rear-end collision, causing a forward impact. As a result, the occupant's head protrudes violently forward, generating a forward rotational moment about the neck, causing neck damage and causing whiplash. To prevent this, the headrest must not contact the occipital posterior surface of the occupant and the mastoid of the temporal bones on both sides. Also, as in the invention described in Patent Document 9, when the occupant's occipital region, the mastoids of the temporal bones on both sides, the lower surface of the occipital region, and the cervical vertebrae are all settled in the headrest, the driver does not move from the occipital region. The cervical vertebrae is fixed to the headrest, and if you drive in this state, you will not be able to move freely, and you will drive the part of the cervix head away from the headrest. And many will spin the cervical spine away from the headrest. This is most notably shown in FIG. 11, which is used in the description of claim 3 of Patent Document 9. In this use, only the top of the headrest is in contact with the occupant's occiput, and the cervical spine is not in contact with the headrest. If used in this state, it is impossible at all to prevent whiplash at the time of a rear-end collision.

As outlined above, effective and inexpensive headrests to prevent the onset of whiplash due to the impact of a rear-end collision have not yet been developed, and the need for such development is increasing. Can be. [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-29083

 [Patent Document 2]

 Unexamined Japanese Patent Publication No. 2000-1—3 3 3 8 3 2

 [Patent Document 3]

 Unexamined Japanese Patent Publication No. Hei 11-132

 [Patent Document 4]

 Japanese Patent Application Laid-Open No. 2000-1905

 [Patent Document 5]

 Japanese Patent Application Laid-Open No. 10-27648

 [Patent Document 6]

 Japanese Patent Application Laid-Open No. 2000-01-375777

 [Patent Document 7]

 Japanese Patent Application Laid-Open No. 8-1 8 7 1 3 9

 [Patent Document 8]

 Japanese Patent Application Laid-Open No. Hei 8-1828570

 [Patent Document 9]

 SUMMARY OF THE INVENTION Problems to be Solved by the Invention

 Accordingly, an object of the present invention is to develop and provide a headrest that can effectively and inexpensively prevent the occurrence of whiplash due to a rear-end collision accident. Means for solving the problem

SUMMARY OF THE INVENTION The present inventors have solved the above-mentioned problem by providing a cervical vertebra of a normal person (first Fig. 2) and the typical cervical vertebrae of a whiplash patient (Fig. 2). The position of the pressure applied to the cervical vertebrae by the impact of a rear-end collision, The effect of the headrest on the cervical spine movement was examined. The largest load supported by the spine is the head. In the case of a normal person, as shown in Fig. 3, the weight of the head is transmitted to the atlas (first cervical vertebra), the lordosis of the cervical vertebra (from the first cervical vertebra to the first thoracic vertebra), and the kyphosis of the thoracic vertebra (the second cervical vertebra). From the thoracic vertebra to the ninth thoracic vertebra), the lumbar lordosis (from the 10th thoracic vertebra to the 5th lumbar vertebra) and the sacral kyphosis are transmitted sequentially, and are transmitted from the sacroiliac joint to the iliac lower limb and escape to the ground. Is done. The posterior longitudinal ligament that extends to the posterior side of the vertebral body protects the basic form of lordosis and kyphosis. In other words, the lordosis and kyphosis play the role of the panel. In addition, the spine is not just a superposition of columnar bones, but a circular or octagonal hole surrounded by a vertebral arch extends behind the columnar vertebral body, inside which an important central nervous trunk called the spinal cord is placed. I'm in it. The spinal cord, along with the brain, is wrapped in a tough membrane called the dura mater, soaked in cerebrospinal fluid. During inspiration, the spine moves as shown in Fig. 5 and returns the cerebrospinal fluid to the head side by squeezing the dura mater through the posterior longitudinal ligament and hair-like connective tissue (see Fig. 4). Let me. Conversely, during exhalation, the spinal column moves as shown in Fig. 6, and also squeezes the cerebrospinal fluid by squeezing the dura mater through the posterior longitudinal ligament and hair-like connective tissue (see Fig. 4). To reflux. The cells of the central nervous system (brain and spinal cord) receive sugar (glucose) and other nutrients from this cerebrospinal fluid, and receive oxygen from blood vessels to live. If this flow of cerebrospinal fluid stops flowing smoothly, it will interfere with all functions of the central nervous system, and will cause headaches, dizziness, nausea, decreased motivation, tinnitus, poor vision, general malaise, etc. Causes a variety of intractable symptoms. This is called hypomedullary syndrome. Whiplash Patients present with such various symptoms as well as neck pain. One of the main causes of such central nervous system symptoms is distortion in the alignment of the spine caused by head bruising and the like. A typical example is whiplash. Central nervous system symptoms called whiplash are caused by distortions in the spine alignment caused by impacts on the head and neck due to collisions and other traffic accidents. As is clear from the comparison between FIG. 1 and FIG. 2, it can be seen that the lordosis of the cervical vertebra of a normal person is damaged and deformed linearly in the cervical vertebra of a whiplash patient. The damage that causes whiplash occurs in the hair-like connective tissue that secures the posterior longitudinal ligament and the dura behind it (see Figure 4). When this part is damaged (see Fig. 7), the circulation of cerebrospinal fluid, which is driven by respiratory movement, is impaired, and the sugar supply to the central nervous system (brain and spinal cord) becomes insufficient. Various symptoms appear. This fact has received little attention so far. When the spine arrangement is distorted, the above-mentioned mechanism that supports gravity from the head collapses, causing scoliosis torsion in the spine. This causes compression of the peripheral nerves and impaired muscular blood circulation, causing muscle tension in the neck, shoulders, back, and hips, as well as pain and stiffness. Normally, the ligaments play a major role in supporting the body weight, so if it breaks down, a muscular system that has only one-third of its ability to support it will not be able to support the weight for 24 hours. You will not be able to take the basic stance of standing and sitting for a much shorter time than when you are healthy. This is because they get tired quickly. As described above, whiplash is a damage to the hair-like connective tissue that fixes the posterior longitudinal ligament and the dura behind it, as a result of head bruises or hyperextension of the neck due to a rear-end collision, etc. It is thought to be caused by Fig. 8 shows a typical example of the headrest currently in use.However, when the occipital region is brought into contact with the headrest, the occipital region only touches the protruding part of the occipital region, and 5 No contact with cervical spine. Therefore, when a rear-end collision occurs, the head suddenly moves forward, and at the same time, receives a rotational moment about the upper cervical vertebra and the fifth cervical vertebra, resulting in damage to the longitudinal ligament and hair-like connective tissue. . Therefore, to prevent whiplash, it is necessary to develop a headrest that is shaped to prevent damage to the posterior longitudinal ligament and hair-like connective tissue even if the head or neck is bruised. In order to prevent whiplash in the event of a collision, it is essential that the occupant keep the lower back of the occipital region, the upper cervical vertebra and the fifth cervical vertebra in contact with the headrest, as described later. It was found that Of course, even if the passenger does not touch the head and neck to the headrest just before the accident, the possibility of whiplash is minimized if the headrest is properly set. it can. In other words, there is no problem if the headrest of the present invention contacts the lower surface of the occipital region, the upper cervical vertebra and the fifth cervical vertebra at the moment of impact. However, depending on the speed and magnitude of the impact, a bruise to the neck may be possible. In order for the passenger to use the lower occipital region, upper cervical vertebra and fifth cervical vertebrae in contact with the headrest, the lower occupant lower surface of the occupant, upper cervical vertebra, and Obviously, the fifth cervical vertebra must contact the headrest, but the rest of the occupant's head Rather, it is preferable to be away from the headrest. This will effectively prevent whiplash in rear-end collisions. Thus, during normal use, the present inventor has found that only the lower surface of the occipital region of the occupant, the upper cervical vertebra and the fifth cervical vertebra are in contact with the surface of the headrest, and the occipital protrusion of the occupant and the temporal bones on both sides are reduced. I came up with a headrest (a conceptual diagram is shown in Fig. 9) with a shape that cannot or does not easily contact the surface of the headrest. In this case, the impact at the time of the rear-end collision first applies to the upper cervical vertebra and the fifth cervical vertebra of the occupant. At this time, a rotational moment is generated rearward on the occupant's head, but this is supported by the surface of the headrest in contact with the lower surface of the occipital region. Next, the neck and head are integrated with the torso from the waist to the neck (in a rod shape) and rotate forward around the hip joint. In this way, unlike the conventional headless case, the occipital region is first subjected to an impact and a rotational moment about the neck is generated, so that a large impact is prevented from being applied to the neck and whiplash is prevented. It is done. Thus, in the present invention, the shape of the headrest is different from the shape of the headrest disclosed in Patent Document 9, and the portion extending to the mastoid of the temporal bone and the posterior surface of the parietal bone on both sides of the occupant is formed by the headrest. The shape does not touch the surface. This is the biggest difference, with a totally different result in a rear-end collision. Disclosure of the invention

 The outline of the present invention is as follows.

The present invention relates to a headrest which can be attached to the upper part of a chair backrest so that the position can be finely adjusted up and down, wherein the headrest is in contact with the lower surface of the occipital region of the occupant, the upper cervical vertebra and the fifth cervical vertebra at the same time. A headrest having a shape that does not have a bulge on the surface in contact with the lower surface of the occipital region About. The present invention relates to a headrest which can be attached to the upper part of the backrest of a chair so that the position of the headrest can be finely adjusted vertically, and the headrest simultaneously contacts the lower surface of the occupant's occipital region, the upper cervical vertebra and the fifth cervical vertebra. A headrest that has a shape that fits and that has no bulging surface in contact with the lower back of the occipital region when the lower back surface of the occupant, upper cervical vertebra, and fifth cervical vertebra simultaneously contact the headrest. It relates to a headrest in which there is a gap of less than 4 cm, preferably less than 3 cm, more preferably less than 2 cm between the occiput's occipital projection and the opposing surface of the headrest. The present invention relates to a headrest which can be attached to the upper part of a backrest of a chair so that the position can be finely adjusted vertically, and the headrest simultaneously contacts the lower surface of the occipital region of the occupant, the upper cervical vertebra and the fifth cervical vertebra. A headrest having a shape that is in contact with the lower surface of the occipital region and having a shape that does not have bulge, wherein the cervical vertebra contact surface of the headrest is 2 cm to 1 cm larger than the surface facing the occipital projection. For headrests that protrude to the seating side up to 5 cm. The present invention relates to a headrest which can be attached to the upper part of the backrest of a chair so that the position can be finely adjusted vertically, and the headrest simultaneously contacts the lower surface of the occipital region of the occupant, the upper cervical vertebra and the fifth cervical vertebra. A headrest having a shape that is in contact with the lower surface of the occipital region and has a shape that does not have swelling, wherein the cervical vertebra contact surface of the headrest is 3 cm to 1 cm larger than the surface facing the occipital protrusion. It protrudes to the seating side within a range of up to 2 cm. Headrest. The present invention relates to a headrest which can be attached to the upper part of a chair backrest so that the position can be finely adjusted up and down, wherein the headrest is in contact with the lower surface of the occipital region of the occupant, the upper cervical vertebra and the fifth cervical vertebra at the same time. A headrest having a shape in which the surface in contact with the lower surface of the occipital region has no swelling, wherein the cervical vertebra contact surface of the headrest is 4 cm to 8 cm larger than the surface facing the occipital projection. Regarding the headrest that is protruding to the seating side in the area. The present invention relates to a headrest which can be attached to the upper part of a chair backrest so that the position can be finely adjusted vertically, and the headrest simultaneously contacts the lower surface of the occupant's back of the head, the upper cervical vertebra and the fifth cervical vertebra. In a headrest that has a shape that erodes and has a shape that does not bulge in contact with the lower surface of the occipital region, the surface that erodes the upper cervical vertebra and the fifth cervical vertebra does not contact the seventh cervical vertebra As described above, wherein the headrest is retracted with respect to the seating side. The present invention is further characterized in that the headrest of the present invention is used by being fixed to a seat back so that the headrest, the upper cervical vertebra and the fifth cervical vertebra are simultaneously in contact with a passenger sitting on the seat. It also relates to how to use the headrest. The present invention provides the headrest of the present invention by adjusting the distance between the headrest of the present invention and the backrest, so that the headrest of the individual occupant can be positioned on the lower back of the head. The present invention relates to a method of using the headrest of the present invention, which is adjusted so as to simultaneously contact the cervical vertebra and the fifth cervical vertebra and then fixed to the backrest. Brief Description of Drawings

 Figure 1 is a lentogen photograph of the cervical spine of a normal person.

 Figure 2 is a radiograph of the cervical spine of a whiplash patient.

 Figure 3 is an illustration showing the shape of the main skeleton from the head to the waist of a normal person.

 FIG. 4 is a schematic view of a cross-sectional view of a spine. The relationship between hair-like connective tissue, posterior longitudinal ligament and vertebral bodies is shown. In the figure, 1 1 is hair-like connective tissue, 1 2 is posterior longitudinal ligament, 13 is vertebral body, 14 is intervertebral disc, 15 is dura, 16 is spinous process, 17 is cerebrospinal fluid, 18 Represents the spinal cord, respectively.

 Fig. 5 shows the physiological movement of the spinal column during inspiration and the direction of cerebrospinal fluid return in the spinal canal. In the figure, the white arrow (21) indicates the direction of cerebrospinal fluid return.

 FIG. 6 shows the physiological movement of the spinal column during exhalation and the direction of cerebrospinal fluid return within the spinal canal. In the figure, the white arrow (22) indicates the direction of cerebrospinal fluid return. FIG. 7 is also a cross-sectional view of the spine, showing the hair-like connective tissue broken. In the figure, 19 indicates a damaged portion of the hair-like connective tissue.

 FIG. 8 is a schematic diagram showing a state of contact between a normal headrest and a passenger's head. In the figure, 1 indicates an occipital projection.

FIG. 9 shows that the lower back of the occupant's head, the upper cervical vertebra and the fifth cervical vertebra are simultaneously in contact with the headrest of the present invention and effectively supported when the headrest of the present invention is used. FIG. In the figure, 1 is the occipital posterior projection, 2 is the lower back of the head, 3 is the upper cervical vertebra, 4 is the 5th cervical vertebra, 5 represents the seventh cervical vertebra, respectively. FIG. 10 is a perspective view of one example of the headrest of the present invention. FIG. 11 is a side view of an example of the headrest of the present invention. Surfaces A to H to G and B shown by dotted lines are cross-sectional views of the head contact surface of the conventional headrest. The cross-sectional view of the head contact surface of the headrest according to the present invention is added for comparison with A to H to E to F and B. The dotted line E-G indicates the length of the E-F surface protruding from the headrest surface (HA ah surface) behind the occipital protrusion to the seating side. In the figure, H is a portion facing the occipital projection of the headrest of the present invention, and E to F are surfaces in contact with the upper cervical vertebra and the fifth cervical vertebra of the headrest of the present invention. Is a surface that comes into contact with the lower surface of the back of the head of the present invention.

 FIG. 12 is a front view of the headrest of the present invention.

 FIG. 13 is a top view of the headrest of the present invention.

 Fig. 14 is an illustration showing the impact on the body of an occupant who is not using a headrest when the vehicle is impacted from behind.

 Fig. 15 is an illustration showing the impact of the body of the occupant using a normal headrest when the vehicle is impacted from behind.

 FIG. 16 is an illustration showing an impact received by the occupant's body when using a headrest of the type that comes into contact with the occipital region of the occipital region and the temporal bone mastoid as in Patent Document 9. In general, results similar to those in FIG. 15 are obtained. In the figure, reference numeral 20 denotes a temporal bone mastoid.

FIG. 17 is an illustration showing the force received by the occupant using the headrest of the present invention when the vehicle is hit from behind. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a headrest of the present invention will be described in detail based on an embodiment shown in the accompanying drawings. FIG. 9 is a conceptual diagram showing how the headrest of the present invention makes contact from the head to the neck of the occupant. That is, when the headrest of the present invention is used, the lower surface of the occupant's occipital region, the upper cervical vertebra and the fifth cervical vertebra come into contact with the headrest surface, and the occipital protruding portion of the occupant and the mastoid of the temporal bone become the headrest surface. Does not come into contact with The distance between the occipital projection and the headrest surface is usually less than about 4 cm, preferably less than about 3 cm, more preferably less than about 2 cm, and even more preferably less than about 1 cm. On the other hand, most of the conventional headrests are in contact with the occupant's head at one location, that is, only at the protruding part of the back of the head, as shown in a typical example in FIG. No headrests in contact with the upper cervical vertebrae and the fifth cervical vertebra were found, much less the occipital protuberance and the temporal bone mastoids, but only on the lower occipital region, the upper cervical vertebra and the fifth cervical vertebra. There is no headrest in contact with and supporting this. Therefore, in the case of a headrest that is currently used, if a rear-end collision occurs, a strong rotational moment about the cervical vertebrae is generated by a hard hit of the occipital region by the headrest, and the posterior longitudinal ligament of the cervical vertebra and the hard ligament behind it. This results in damage to the hair-like connective tissue anchoring the membrane (see FIG. 4) (see FIGS. 7 and 15). In contrast, the headrest of the present invention can The head is once subjected to a rotational moment backward because the impact force is applied only to the upper cervical vertebra and the fifth cervical vertebra, but this is first supported by the headrest surface in contact with the lower back of the occipital region. The head is pushed forward by the headrest surface behind the back of the occiput with a moment delay, so that the entire spine from the head to the abdomen receives a forward force, and the entire spine is evenly rotated about the hip joint as the rotation axis. (See Figure 17). As a result, the head receives a sudden rotational moment about the upper cervical vertebra and the fifth cervical vertebra as in the case of the conventional headrest, and fixes the posterior longitudinal ligament of the cervical vertebra and the dura behind it. It is possible to prevent the hair-like connective tissue from being damaged, and to effectively prevent the onset of whiplash due to a rear-end collision. FIG. 10 is a perspective view of an example of the headrest of the present invention. The headrest of the present invention contacts the lower surface of the occupant's back of the head, the upper cervical vertebra and the fifth cervical vertebra (hereinafter also referred to as the head and neck), but contacts the occipital protrusion of the occupant and the mastoid of the temporal bones on both sides. It is important to note that when using the headrest of the present invention, the surface of the headrest is the lower surface of the occupant's back of the head, the upper cervical vertebra, and the fifth cervical vertebra. It must be used to touch parts. Also, even if the passenger uses the head and neck away from the headrest, if the headrest pushes the head and neck from behind at the moment of a collision, the headrest may At the moment of contact with the neck, it is necessary to set the height of the headrest so that it is in the same condition as above. Otherwise, passengers cannot be protected from whiplash in a rear-end collision. The shape of the headrest is Considering the case where each passenger actually uses the vehicle, even if the conditions are satisfied, there is a difference in sitting height between the passengers, so that the cervical vertebra contact portion of the headrest of the present invention and the passenger are seated in the vehicle seat. It is indispensable to adjust the height of the headrest of the present invention so that the position of the cervical vertebrae in the case of the present invention exactly matches. Therefore, when the headrest of the present invention is mounted on a seat of a vehicle, it is essential to provide a mechanism between the headrest and the seat that can freely adjust the height of the headrest. Headrests equipped with a height adjustment mechanism that can be used for such purposes are already commercially available, and by using any of these headrest height adjustment mechanisms, the capability of the headrest of the present invention can be improved. The effects of the present invention can be exerted to the fullest extent. As is clear from this, the headrest of the present invention can be mounted on the occipital lower surface contact portion and the cervical vertebra contact portion of the headrest of the present invention by adjusting the height of the headrest according to the occupant. The contact with the lower surface of the occipital region, the upper cervical vertebra and the fifth cervical vertebra is satisfied, and a headrest having the same shape as the headrest of the present invention is fixedly attached to a vehicle seat, or Even if the seat back itself has a shape similar to the headless of the present invention, the headrest of the present invention generally has a whiplash-preventing effect, except in rare cases where the occupant's sitting height satisfies the above conditions. It is clear that no fruit is produced. The shape of the headrest and the shape of the back, side, and bottom that are above the contact part of the occipital posterior surface of the headrest and do not come into contact with the occupant's head, unless there is an obstacle to the use of the headrest. Any shape may be used. The shape of the upper part and the shape of the back or side of the headrest of the present invention shown in FIG. 10 does not limit the shape of the headrest of the present invention. The shape of the bottom surface is similarly not limited. FIG. 11 is a conceptual view of a side view of an example of the headrest of the present invention, FIG. 12 is a conceptual view of a front view of an example of the headrest of the present invention, and FIG. 1 is a conceptual diagram of a top view of a headrest according to an example of the present invention. Hereinafter, the present invention will be described in more detail with reference to FIGS. 910, 11 and 12. The part surrounded by ABCD in Fig. 11 is a conceptual diagram of a side view of a conventional headrest. In the conventional headrest, the surfaces A to B in Fig. 11 (8 and 8 in Fig. 12), that is, the surface of the headrest that comes into contact with the occipital projection of the occupant are convex or concave in the center. It may be curved, but most of it is almost flat. In the headrest of the present invention, the position where H in FIG. 11 (approximately the center of H—h in FIG. 12) faces the protruding portion of the occupant's occipital region (contact with the occipital protruding portion during a rear-end collision, etc.) (Possible position). If the occupant touches the lower back of the occipital region, the upper cervical vertebra and the fifth cervical vertebra at the same time, the H does not come into contact with the occipital posterior protrusion and is usually less than about 4 cm, preferably less than about 3 cm More preferably, a gap of less than about 2 cm is present therebetween. The H-E plane in Fig. 11 (HE eh plane in Fig. 12) is the plane that comes into contact with the lower surface of the occupant's back of the head. As is evident from Fig. 9, the skeleton of the human occipital region forms a curve, so that the lower surface of the occipital region and the E-H surface in Fig. It is preferable to be raised upward as going to. Furthermore, it is preferable that the planes E to H in Fig. 11 be concavely curved so as to draw a curve in the direction of E-H that matches the curve of the lower surface of the occupant's lower head. Yes. However, in the E-e direction, there must not be large bulges on both sides. Especially, there must not be bulges that touch the mastoid of the temporal bone. Even in the case of a curved surface, it should be limited to a concave curve toward the center in order to stabilize the contact with the lower surface of the occipital region. The E to F planes in FIG. 11 (E e F f planes in FIG. 12) are the planes in contact with the upper cervical vertebra and the fifth cervical vertebra. The feature of the present invention is that the E to F planes in FIG. 11 (E e F f planes in FIG. 12) are larger than the A to H planes in FIG. 11 (Hh G g planes in FIG. 12). It is protruding forward. In the conventional headrest, the planes E to F in Fig. 11 (EeFf plane in Fig. 12) are on the same plane as the planes H to G in Fig. 11 or conversely. 11 The planes H to G in FIG. 11 protrude forward from the planes E to F in FIG. 11, and the lengths of E to G are almost 0 cm or minus. In the headrest, the planes E to F in Fig. 11 project forward from the planes H to G, and the length of E to G in Fig. 11 is usually from about 2 cm to about 15 cm. Ranges from about 3 cm to about 12 cm, more preferably from about 4 cm to about 8 cm. The E to F planes in Fig. 11 (E e F f planes in Fig. 12) may be flat, but are concavely curved toward the center along the line E- e. It is preferable. This is to make the head and neck stable and comfortable to use when the head and neck are brought into contact with the headrest. Further, the length of E—F (e−f) in FIG. 11 is a length that allows simultaneous contact with the upper cervical vertebra and the fifth cervical vertebra, usually from about 2 cm to about 15 cm, preferably about It is from 3 cm to about 10 cm, more preferably from about 4 cm to about 8 cm. The length of HG in FIG. 11 indicates the vertical distance between the height of the occipital protrusion of the occupant and the upper end of the contact surface of the upper cervical vertebrae, and may be generally 3 cm or more.

The distance between the headrest surface behind the occipital projection of the occupant and the occipital projection is usually less than 4 cm, preferably less than 3 cm, and more preferably less than 2 cm. If the planes E to F in Fig. 11 extend beyond the upper cervical vertebra and fifth cervical vertebra and reach the seventh cervical vertebra or above, move downward along the line EF from the point beyond the sixth cervical vertebra. As it goes, it is preferred that the surface be retracted posteriorly so that the E e F f surface of FIG. 12 does not contact the seventh cervical vertebra. This is to eliminate discomfort caused by the headrest surface pressing on the seventh cervical vertebra. Therefore, in this case, it is preferable that the length of FB (f-b) is shorter than the length of EG (eg). The feature of the headrest of the present invention is the shape of the surface of the headrest that simultaneously contacts the lower surface of the occupant's back of the head, the upper cervical vertebra, and the fifth cervical vertebra. Therefore, the shape of other parts of the headrest is not particularly limited. For example, the width of the headrest can be freely designed as long as it does not interfere with its use as a headrest, usually from about 15 cm to about 40 cm, preferably from about 20 cm to about 20 cm. It is in the range of about 30 cm. If the height of the headrest does not affect the normal use of the headrest, an arbitrary height can be set above H in Fig. 11. The C c D d surface on the back of the headrest and the A a C c surface on the top of the headrest Any shape can be used as long as it does not affect normal dressing. Also, the shape of the left and right side surfaces of the headrest can be freely designed as long as it does not hinder the use as a normal headrest. The shape of the bottom of the headrest is not particularly limited. Normally, two support rods are attached to the bottom to fix the headrest to the seat, but it can also be attached using conventional methods. As described above, since it is a reality that passengers have various sitting heights, to use the headrest of the present invention, the surface of the headrest of the present invention, the lower surface of the occipital region of the passenger, and the upper cervical vertebrae are used. It is indispensable to adjust the distance between the upper surface of the backrest of the seat seat and the headrest so that the cervical vertebrae and the fifth cervical vertebra can be contacted simultaneously. For this purpose, the stepless height adjustment mechanism of the headrest used in a normal headrest can be used as it is. Note that the height of the backrest of the seat to which the headrest of the present invention is attached is limited to the shoulder of a low-seat passenger, and in the case of a high-seat passenger, the height of the headrest is adjusted to adjust the cervical spine of the headrest. It is preferable that the contact part and the occupant's cervical vertebra are fitted together. The materials for manufacturing the headrest of the present invention are the same as those used for manufacturing a normal headrest. For example, the core material includes polyurethane foam, polystyrene foam, ABS foam, vinyl chloride resin foam, and polyethylene foam. Rigid foams such as polypropylene foam, phenolic resin foam, and urea resin foam may be used. It may be covered with a flexible or semi-rigid foam such as polyurethane foam, vinyl chloride resin foam, polyethylene foam or polypropylene foam. Further, the surface may be covered with cloth, natural leather, synthetic leather, artificial leather, or the like. The invention's effect

By using the headrest of the present invention, the upper cervical vertebra and the 5th cervical vertebra are subjected to an impact on the head and cervix from the rear due to a rear-end collision, etc. As a result, the entire upper body is integrally fixed and receives a rotational moment about the hip joint, and as in the case of a conventional headrest, a large forward force is applied only to the back of the head, There is no generation of a rotational moment about the cervical vertebra and the fifth cervical vertebra, and the occurrence of so-called whiplash can be effectively prevented. Hereinafter, the effects of the present invention will be described in detail with reference to FIGS. 14 to 17. First, what happens when a rear-end collision occurs when there is no headrest will be described with reference to FIG. At the moment of the rear impact, the lower cervical, thoracic and lumbar vertebrae and the upper sacrum are pushed forward, the entire head is pushed backwards, the upper head is pushed backwards, and the lower head is pushed forward and upwards. The lower part of the sacrum is pushed upward. At this time, the lower part of the fifth cervical vertebra is pushed forward, and the head is left behind while generating a moment of rotation backward, so that the upper part is pushed out posterior and lower from the fourth cervical vertebra, and the vertebral body The posterior longitudinal ligament, which secures the posterior aspect of the cervical vertebra, is damaged, causing the fourth cervical vertebra to slip backwards and lose cervical lordosis. Thus, the occipital bone shifts forward, and the joint with the first cervical vertebra shifts more forward than usual. Fourth cervical vertebral body, especially its lower end, compresses the posterior dural space, obstructs cerebrospinal fluid circulation, and has various symptoms such as headache, dizziness, nausea, decreased motivation, tinnitus, poor vision, and general malaise The following describes what happens when a rear-end collision occurs when a conventional headrest is installed. As shown in FIG. 15, the lower cervical and thoracic vertebrae are pushed forward. However, the entire head is once pushed out backward, but since there is a headrest in contact with the upper part of the head, only the upper part of the head is pushed forward by the headrest. Receives a rotational moment in the forward direction. Therefore, the first to fifth cervical vertebrae all shift posteriorly. Then, at the time of restoring the posture, the curved portions (lordosis) of the fourth and fifth cervical vertebrae disappear and become straight, or a reverse curve, that is, cervical kyphosis occurs. Of course, the posterior longitudinal ligament is also damaged, especially in the fourth and fifth cervical vertebrae. In this case, the joint between the occipital bone and the first cervical vertebra can be either an anterior shift (overextended) or a posterior shift (hyperflexion) relative to the cervical vertebra. Also, the lumbar spine and sacrum are weakened in kyphosis in response to the head, the upper sacrum shifts backward, and the lower sacrum and ischium shift forward. Again, the major damage is likely to be in the loose hair-like connective tissue between the posterior longitudinal ligament and the dura. In addition, the possibility of low back pain increases due to the imbalance of the spine. When using a headrest such as that of Patent Document 9 that encloses the entire occipital bone and temporal bone mastoid, the mastoid is pushed largely forward at the beginning, so that the head has a normal headrest Even more, a large forward rotation moment is generated, and the human body is seriously damaged as shown in Fig. 16 It causes whiplash and is dangerous. Now, the newly developed headrest of the present invention completely solves all the above problems. The headrest of the present invention has a shape that simultaneously contacts the lower surface of the occupant's back of the head, the upper cervical vertebra, and the fifth cervical vertebra. Therefore, when a rear-end collision occurs, as shown in FIG. 17, the occupant of the vehicle equipped with the headrest of the present invention firstly has the upper cervical vertebra and the fifth cervical vertebra, followed by the occipital protuberance. From the vertebrae of the upper spine (cervical vertebra), the kyphosis of the middle part (thoracic vertebra) and the lordosis of the lower part (lumbar vertebrae) in an instant. It is fixed in its original shape, thus avoiding the occurrence of any destructive moment under the rear-end collision described above. From the head to the sacrum and even the coccyx, they are united as if they were a single rod. The whole upper part is pushed together and pushed forward while being pushed out by the back of the seat and the headrest. In this way, the rear-end collision safety of the passenger is ensured.

This mysterious defense response of the human spine is always easy to reproduce. It can be seen by supporting the upper cervical vertebra to the fifth cervical vertebra by hand from the back of the person sitting on the chair and pushing it forward. The human body is always integrated and only leans forward about the hip joint (see Fig. 17). On the other hand, when a person sitting on a chair also supports the occipital bone projection from behind and pushes forward, the head produces a rotational moment in the forward direction, and the neck is forced to bend tightly (No. 15). See figure). If you do poorly, this experiment (the latter) alone may even hurt your neck. Mankind has long been running a car society without realizing this important defense response. As a result, it can be said that it has continued to produce many victims suffering from whiplash. In addition, hands on the mastoid as well as on the back of the head It can also be seen that when the palm is touched and pushed forward, the same forward rotation moment as in Fig. 15 is produced.

 The present invention was invented and developed based on the fact that the applicant, a physician, discovered from clinical experience the overall defense reaction of spinal column integration that occurs when the inferior occipital region, upper cervical vertebra, and fifth cervical vertebra were fixed. It is a thing. Industrial applicability

 By using the headrest of the present invention for a vehicle seat or the like, damage to the hair-like connective tissue of the cervical vertebrae and damage to the posterior longitudinal ligament at the time of a rear-end collision of a car, which is seen when a conventional headrest is mounted, In the event of a rear-end collision of a car, etc., it is possible to reliably and inexpensively prevent the occurrence of so-called whiplash caused by the application of a strong rotational moment about the cervical spine to the head.

Claims

The scope of the claims  1. A headrest that can be attached to the upper part of the backrest of the chair so that the position can be adjusted up and down so that the headrest can contact the upper cervical vertebra and the fifth cervical vertebra simultaneously. A headrest having a shape and a shape that does not have swelling on a surface in contact with the lower surface of the occipital region.  2. When the lower surface of the occupant's occipital area, upper cervical vertebra and fifth cervical vertebra simultaneously contact the headrest, there is a gap of less than 4 cm between the occupant's occipital protuberance and the opposing surface of the headrest The headrest according to claim 1, wherein  3. The surface that contacts the lower surface of the occiput protrudes forward from the upper part to the lower part, and its lowermost end is in contact with the uppermost end of the contact surface of the cervical vertebrae. 2. The headrest according to claim 1, wherein the contacting surface projects forward from a surface facing the occipital projection.  4. The headrest according to claim 1, wherein the cervical vertebra contact surface of the headrest protrudes toward the seating side in a range of 2 cm to 15 cm from a surface facing the occipital projection.  5. The headrest according to claim 1, wherein the cervical vertebra contact surface of the headrest protrudes to the seating side in a range of 3 cm to 12 cm from a surface facing the occipital projection.  6. The headrest according to claim 1, wherein the cervical vertebra contact surface of the headrest protrudes toward the seating side in a range of 4 cm to 8 cm from a surface facing the occipital projection. 7. The vertical length of the cervical vertebral contact surface of the headrest is 2 cm to 15 c. The headrest according to any one of claims 1 to 6, wherein the headrest ranges from m to m.  8. The headrest according to any one of claims 1 to 6, wherein the vertical length of the cervical vertebral contact surface of the headrest is in a range of 3 c to 10 cm. '  9. The headrest according to any one of claims 1 to 6, wherein a vertical length of the cervical vertebral contact surface of the headrest is in a range of 4 cm to 8 cm.  10. The surface in contact with the upper cervical vertebra and the fifth cervical vertebra, wherein the surface retreats from the seating side so as not to contact the seventh cervical vertebra. Headrest as described in. 11. The seat back according to any one of claims 1 to 10 so that the headrest of the occupant sitting on the seat, the upper cervical vertebra and the fifth cervical vertebra are simultaneously contacted. The use of a headrest, characterized in that it is fixed to the head.  1 2. By adjusting the distance between the headrest and the seat back, the headrest was adjusted to simultaneously contact the lower back of the occipital region, the upper cervical vertebra and the fifth cervical vertebra of each passenger. 12. The method according to claim 11, wherein the method is fixed to the backrest of the rear seat.