Cervical pillow and cervical pillow kit

Abstract

The present invention aims to maintain and restore the inward curvature of the lumbar vertebrae and to provide a lumbar support that is more comfortable to use. The lumbar support has a height of 9 to 11 cm and is provided with an outer cushioning member formed of semi-rigid foam and an inner cushioning member formed of semi-rigid foam having a lower hardness than the outer cushioning member. A dome-shaped hollow space is formed in the outer cushioning member. The inner cushioning member has the same cross-sectional shape as the hollow space. When the lumbar support is placed under the lumbar region of a user lying in a supine position, the load X applied to the lumbar support by the user is equal to the weight W of the user multiplied by a factor of 0.59. A preferred range of displacement relative to the load is determined. The comfort of the lumbar support is determined on the basis of a sensory evaluation including a texture evaluation during use, and the lumbar support can be used for a long period of time. By providing a number of set values to visualize the physical properties to provide an approximately linear load-displacement line, any user is enabled to select a suitable pillow regardless of gender and weight.

Description

TECHNICAL FIELD

[0001] The present application relates to a lumbar pillow and a lumbar pillow set. Specifically, the present application relates to a lumbar pillow that can be used for preventing, improving symptoms, and treating discogenic low back pain, and a lumbar pillow set that combines a lumbar pillow and a knee pillow. BACKGROUND

[0002] When a person walks, the S-shaped curve of his or her spine absorbs the gravitational force acting on his or her body. Although the lumbar vertebrae are curved inward, if a person continuously performs an action or maintains a posture that loses this curvature, he or she can develop low back pain. Therefore, maintaining the inward curvature of the lumbar vertebrae can prevent low back pain. In addition, restoring the inward curvature of the lumbar vertebrae can treat or prevent low back pain. According to Non-Patent Literature 3, the inward curvature of the lumbar vertebrae in the supine position is 2 to 3 cm.

[0003] In overseas low back pain treatment, an exercise for restoring the inward curvature of the lumbar vertebrae (also known as McKenzie therapy) has been widely supported. McKenzie therapy involves an exercise of bending the body backward, and was established by Robin McKenzie, a New Zealand physiotherapist, around 1956. Specifically, the therapy involves first lying on the stomach with the face forward, and then placing the hands on the ground like doing a push-up, straightening the elbows to gradually raise the upper body. At this time, the waist and legs are relaxed. To maximize the backward bending of the waist, the arms are stretched as much as possible while exhaling. This posture is maintained for 5 to 10 seconds for one set, and a number of sets are performed every day. There is also a therapy that is done while standing.

[0004] Conventionally, in the field of discogenic low back pain treatment in Japan, many professionals including orthopedic surgeons held an outdated view that bending the waist backward exacerbates low back pain. As a result, treatment of bending the waist backward has not been performed until recently. The conventional treatment method is described on pages 124 and 212 of Non-Patent Literature 1.

[0005] In 2015, “3 Byo! Kore Dake Taiso” (3 seconds! One small exercise) was disclosed in Non-Patent Literature 2. Later, in 2019, the details of the exercise were broadcast by the television network NHK. In view of this information, experts began to praise the exercise of bending the waist backward as a revolutionary treatment method. In Non-Patent Literature 2, it is explicitly stated that the “one small exercise” of bending the waist backward is based on the McKenzie theory, and the mechanism behind low back pain is also described. In addition, it is emphasized that in order to treat low back pain, it is necessary to restore the inward curvature of the lumbar vertebrae (i.e., to restore the lumbar vertebrae to the original position).

[0006] It is now clear that both McKenzie therapy and the “one small exercise” of bending the waist backward are effective in preventing and treating discogenic low back pain.

[0007] The mechanism of intervertebral disc-derived low back pain will be described. The intervertebral discs between the vertebral bodies that make up the spine serve as a cushion and contain a gelatinous substance called the nucleus pulposus. Normally, the nucleus pulposus is located in the center of the intervertebral disc. However, if a person maintains an improper posture or a posture with the back bent forward for a long time or twists the back by overstretching, the intervertebral disc of the waist is compressed, which causes the nucleus pulposus to shift (slide) from the center to the rear side. This movement causes low back pain. If the nucleus pulposus remains in this shifted state without returning to the center, the low back pain can become chronic. Therefore, it is important not to ignore the shift of the nucleus pulposus but to return the nucleus pulposus as soon as possible (restore).

[0008] Prior to the disclosure of Non-Patent Literature 2, the inventors filed Japanese Patent Application No. 2011-246898, which relates to a pillow for restoring the inward curvature of the lumbar vertebrae and a method of using the pillow, which was registered as Japanese Patent No. 5626657 (Patent Literature 1). The inventors also filed Japanese Design Application No. 2014-023488, which relates to the design of a pillow for restoring the inward curvature of the lumbar vertebrae, which was registered as Japanese Design No. 1535266 (Patent Literature 2).

[0009] There are many other exercises and osteopathic treatments that involve bending the waist backward, which indicates that the importance of this backward bending has finally been recognized.

[0010] Related Art Documents

[0011] Patent Literature

[0012] [Patent Literature 1] Japanese Patent No. 5626657

[0013] [Patent Literature 2] Japanese Design No. 1535266

[0014] Non-Patent Literature

[0015] [Non-Patent Literature 1] YAMAGUCHI, Yoshiomi, “Yotsu, Koshite Naosu”, Shufunotomosha, Co., Ltd., 1990

[0016] [Non-Patent Literature 2] MATSUDAIRA, Ko, “3 Byo! Kore Dake Taiso”, Makino Shuppan, “Anshin”, October 2015

[0017] [Non-Patent Literature 3] KOHARA, Jiro, “Interia Ningen Kogaku”, Gaia Books SUMMARY

[0018] Problem to be Solved by the Invention

[0019] The lumbar pillow disclosed in Patent Document 1 (hereinafter referred to as a conventional lumbar pillow) has a semi-rigid cushioning material, and thus strongly presses the lumbar vertebrae. Therefore, it can be used for a short time, but has a disadvantage that the body pressure distribution of the lumbar portion is concentrated in a small area, and thus the pillow cannot be used for a long time.

[0020] When different body shapes and weights of people use the conventional lumbar pillow, it is not clear to what extent the body pressure distribution area is set and how much displacement is optimal with respect to the load. Therefore, it is necessary to determine the physical properties of the lumbar pillow that can be used by an unspecified number of people of different body shapes and weights. It is also necessary to determine the shape of the lumbar pillow that can be used by Asians, Westerners, or people of various body shapes.

[0021] With the conventional lumbar pillow, in the initial stage of lying on the lumbar pillow in a supine position, a small number of people feel a slight discomfort (this discomfort is also referred to as "texture" hereinafter) when the lumbar pillow comes into contact with the skin, or feel a slight discomfort when subjected to a reaction force from the lumbar pillow. Measures need to be taken to alleviate the discomfort of these users.

[0022] When the conventional lumbar pillow is used in a supine position, it is not clear whether or not it is possible to prevent discogenic low back pain.

[0023] The present invention aims to solve the above problems, and the object is to maintain and restore the inward curvature of the lumbar vertebrae and to provide a lumbar pillow that is more comfortable to use.

[0024] Means for Solving the Problem

[0025] The present invention relates to a lumbar pillow.

[0026] The lumbar pillow according to the present invention maintains the inward curvature of the lumbar portion of a user in contact with the user in a supine position or a sitting position, and has a height of 9 to 11 cm, and includes:

[0027] an outer cushioning member formed of semi-rigid foam; and

[0028] an inner cushioning member formed of semi-rigid foam having a hardness lower than that of the outer cushioning member, wherein

[0029] the outer periphery portion of the outer cushioning member has a partial cylindrical shape provided with a horizontal bottom surface and a top surface composed of curved surfaces having three or more different radii of curvature, and a hollow space in the shape of a dome is formed in a central portion of the cross section, wherein the top surface composed of curved surfaces having two different radii of curvature is formed on a vertical side surface at a different height from the horizontal bottom surface,

[0030] The inner cushioning member has the same cross-sectional shape as the hollow space,

[0031] The outer and inner cushioning members have a constant shape in the longitudinal direction,

[0032] When the lumbar support is placed under the user's waist in a supine position, the load X applied to the lumbar support by the user is equal to the user's body weight W multiplied by a factor of 0.59, and

[0033] In the following equation (1) representing the range Y of the displacement amount of the lumbar support with respect to the load X,

[0034] (Equation 1): Y (mm) = {Y0+tanα×X(kg)}±8

[0035] When the load X is 26 kg to 41.5 kg,

[0036] Y0= 37 (constant, unit: mm),

[0037] tanα = Y1-Y0 / X1-X0= 0.97 (coefficient),

[0038] Load X = increased load from X0 to any given point (unit: kg),

[0039] Also, when the load X is 41.5 kg to 65 kg,

[0040] Y0= 52 (constant, unit: mm),

[0041] tanα = Y2-Y1 / X2-X1= 0.68 (constant),

[0042] Load X = increased load from X1 to any given point (unit: kg).

[0043] The inventor found that the preferred height of the lumbar support is 9 to 11 cm, and the load applied to the lumbar support is equal to the user's body weight multiplied by 0.59; and also found that this allows the load applied to the lumbar support and the displacement amount to be quantified, and an optimal displacement amount range can be provided.

[0044] The present invention also relates to a lumbar support kit having a lumbar support and a knee support.

[0045] The lumbar support kit according to the present invention comprises:

[0046] The lumbar support according to the foregoing;

[0047] The knee support, which has a constant shape in the longitudinal direction and a cross-section of a cut-off apex isosceles triangle, and is formed of a cushioning member of semi-rigid foam; and

[0048] An adjustable-length strap for connecting a lumbar pillow and a knee pillow.

[0049] The lumbar pillow and the lumbar pillow kit according to the present application are based on the same lumbar pain treatment and prevention theory as the McKenzie therapy and "one small exercise", and can be expected to be effective in the prevention and treatment of discogenic low back pain.

[0050] The use of the lumbar pillow or the lumbar pillow kit consisting of a lumbar pillow and a knee pillow according to the present application eliminates the doubts of patients suffering from low back pain about "whether it can be prevented". Therefore, this greatly helps to reduce the number of patients suffering from low back pain. In other words, by using the pillow in a supine position every day, the nucleus pulposus does not move too much, and even if it does, it recovers by the end of the day, which reduces the occurrence of low back pain.

[0051] Effects of the present application

[0052] By the synergistic effect of the combination of the internal and external cushioning members having different hardness and the shape of the top surface consisting of a curved surface, the lumbar pillow according to the present application does not concentrate the body pressure distribution of the waist. In addition, the amount of displacement of the lumbar pillow is quantified and increases in proportion to the load on the lumbar pillow, so that within its range, the discomfort at the contact portion is low, and the texture is pleasant.

[0053] The lumbar pillow according to the present application quantifies the relationship between the load from the user and the weight of the user, and provides an optimal displacement amount range, thereby solving the drawback of the conventional lumbar pillow that "the body pressure distribution of the waist is concentrated in a small area, so the pillow cannot be used for a long time". In other words, by optimizing the amount of displacement when the user applies a load to the lumbar pillow, the concentration of the body pressure distribution of the waist is avoided, and the body pressure distribution becomes optimal. Therefore, the pillow can be used for a long time.

[0054] In addition, Asians, Westerners, men, women, and overweight people are classified by weight and body type to quantitatively exhibit the optimal body pressure distribution and displacement amount. Therefore, it is easier for the user to select a pillow that suits him or her, thereby allowing the user to comfortably use the lumbar pillow according to the present application.

[0055] The lumbar pillow kit according to the present application can be used by placing the lumbar pillow in contact with the lumbar spine portion and the knee pillow in contact with the knee. Compared to using only the lumbar pillow, using the lumbar pillow kit "reduces" the load applied to the pillow by moving to the hip area, and reduces discomfort by increasing the number of support points. Therefore, the lumbar pillow kit exhibits the effects of reducing body pressure and reducing discomfort during use. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 is a perspective view of a lumbar pillow according to the present application;

[0057] Figure 2 This is a cross-sectional view of the lumbar pillow according to the present invention;

[0058] Figure 3 This is a perspective view of the lumbar pillow kit according to the present invention;

[0059] Figure 4 The illustration shows an example of body pressure distribution test results for the lumbar pillow according to the present invention;

[0060] Figure 5 This is a graph showing the preferred displacement range of the lumbar pillow according to the invention relative to the load; and

[0061] Figure 6 This is a graph showing all preferred displacement ranges of the lumbar pillow according to the invention relative to the load. Detailed Implementation

[0062] First, the operation of the lumbar pillow and lumbar pillow kit according to the invention will be described. Then, a preferred embodiment of the lumbar pillow and lumbar pillow kit will be described with reference to the accompanying drawings.

[0063] Operation of lumbar pillows and lumbar pillow sets

[0064] Lower back pain occurs when the intervertebral disc is compressed due to prolonged poor posture or overextension and back strain, causing the nucleus pulposus to shift posteriorly from the center. One way to prevent lower back pain is to not ignore the shift and to restore it as soon as possible, or to prevent the shift altogether. The lumbar pillow according to the present invention can maintain or restore the inward curvature of the user's lumbar spine by contacting the user's lumbar spine when lying supine or sitting.

[0065] The shape of the lumbar pillow

[0066] Figure 1 This is a perspective view of the lumbar pillow D according to the present invention. Figure 2 This is a cross-sectional view of the lumbar pillow D according to the present invention. The total height T of the lumbar pillow D according to the present invention is 9 to 11 cm. The lumbar pillow D has an outer cushioning member 1 and an inner cushioning member formed of a semi-rigid foam with a lower hardness than the outer cushioning member 1. The cross-sectional shape of the outer periphery of the outer cushioning member is partially cylindrical, which has a horizontal bottom surface and a top surface composed of curved surfaces with three or more radii of curvature. In the central part of the cross-section, an approximately dome-shaped hollow space 3 is formed, wherein the top surface composed of curved surfaces with two different radii of curvature is formed on a vertical side surface at a different height from the horizontal bottom surface, and the inner cushioning member 2 has the same shape as the hollow space 3 and is housed within the hollow space 3. The outer cushioning member 1 and the inner cushioning member 2 have a constant shape in the longitudinal direction.

[0067] The shape of the top surface of the outer cushioning member 1 is formed according to the shape of the lumbar vertebrae. Therefore, the radius of curvature of the surface in contact with the upper back of the user is greater than that of the surface in contact with the waist of the user, thereby forming a gently curved surface. Hereinafter, the distance from the top of the hollow space 3 in the outer cushioning member 1 to the vertex of the top surface is also referred to as the vault thickness 4.

[0068] The semi-rigid foam constituting the outer cushioning member 1 and the inner cushioning member 2 is a foamed plastic material in which the elastic modulus E of the resin is 700 to 7000 kgf / cm 2 , or the thickness is reduced by 2 to 10% after 50% compression and release. The most common semi-rigid foam is polyurethane foam.

[0069] In other words, the lumbar pillow D according to the present application has an outer cushioning member 1 made of semi-rigid foam. The cross-sectional shape of the outer cushioning member 1 is an asymmetrical arch shape near the top, and has a partially cylindrical hollow space 3 at the center. The outer cushioning member 1 extends linearly in the longitudinal direction. The inner cushioning member 2 made of semi-rigid foam with slightly lower hardness is seamlessly inserted into the hollow space 3 of the outer cushioning member 1. Optionally, a removable cover not shown here can be used to cover the lumbar pillow.

[0070] According to the results of the displacement amount comparison test between the case where the inner cushioning member 2 having the same shape as the hollow space 3 is seamlessly inserted into the hollow space 3 and the case where a gap exists between the hollow space 3 and the inner cushioning member 2, there is a difference greater than the gap. In other words, the case where a gap exists exhibits a greater displacement amount than the gap. Therefore, in order to eliminate unnecessary displacement, it is preferable to seamlessly insert the inner cushioning member 2 into the hollow space 3.

[0071] Shape of the lumbar pillow kit

[0072] Figure 3 is a perspective view of the lumbar pillow kit 10. In addition to the lumbar pillow D, the lumbar pillow kit 10 has a knee pillow Z and a strap P. The knee pillow Z has a constant shape in the longitudinal direction, a cross-sectional shape of a scalene triangle with the apex cut off, and is formed of a cushioning member of semi-rigid foam. The strap P has an adjustable length and connects the lumbar pillow and the knee pillow to each other.

[0073] The knee pillow Z is a member for relieving the user's discomfort, and is optionally covered with a removable cover. Preferably, two length-adjustable straps P are used in parallel to connect the lumbar pillow D and the knee pillow Z to each other. The straps P are provided in parallel at both ends of the lumbar pillow D, and can fasten the two pillows to each other after adjusting the distance to the knee pillow Z. The user places the lumbar pillow D under his or her lumbar vertebrae, and places the knee pillow Z under his or her knees at the desired distance and position.

[0074] The shape and material of the strap P need not be limited, and any connecting member can be used.

[0075] By making the shape of the knee pillow Z an isosceles triangle with the apex cut off, people of different knee heights and leg lengths can change the use side of the pillow, thereby adjusting the position and texture of the leg. In addition, by cutting off the apex of the knee pillow Z, the concentration of the sub-knee load (foot weight) can be alleviated.

[0076] Optimizing body pressure distribution of a lumbar pillow

[0077] Reference Figures 4 to 6 Optimization of the body pressure distribution of a user when the user is in a supine position and the lumbar contacts the lumbar pillow will be described. For a harder lumbar pillow D, the body pressure distribution is concentrated on a smaller area; while for a softer lumbar pillow D, the body pressure distribution is on a larger area. In the lumbar pillow D according to the present invention, the area is not used as an index, but the hardness of the lumbar pillow D is adjusted in order to optimize the relationship between the load applied to the lumbar pillow D and the amount of displacement of the lumbar pillow, thereby optimizing the body pressure distribution on the lumbar pillow D.

[0078] The size and physical properties of the lumbar pillow D for preferred body pressure distribution satisfy the following relationship.

[0079] First, the total height T of the lumbar pillow D is set in the range of 9 to 11 cm. The lighter the user, the lower the lumbar pillow D used. Conversely, when the user is heavier, a higher lumbar pillow D is used.

[0080] Second, by optimizing the shape and material of the outer cushioning member 1 of the lumbar pillow D according to the present invention, the load X applied to the lumbar pillow D is equal to the value obtained by multiplying the user's weight W by the coefficient 0.59. The relationship between the user's weight and the load applied to the lumbar pillow was determined using the results of a usage test, which was conducted by using a B-pillow (a pillow having physical properties represented by the dashed line in the B-pillow of Figure 5 and the test piece of the lumbar pillow D according to the present invention by users of different weights, and the results converged on the coefficient 0.59. As one example, Figure 4 a user with a body weight of 66.3 kg lying in a supine position and the body pressure of the B-pillow under the lumbar spine was measured using an instrument that measures body pressure distribution. The measured load X of the result was 39 kg, and the body pressure distribution area was 426 cm 2 These results roughly converge on the ratio of the user's weight to the body pressure of the lumbar spine portion being 1.0:0.59.

[0081] Third, when the user is lying in a supine position and the lumbar pillow is under his or her waist, the amount of displacement of the lumbar pillow according to the present invention can be represented by the following equation (1).

[0082] (Formula 1): Displacement amount range Y (mm) = {Y0 + tan a x load X (kg)} ± 8

[0083] wherein,

[0084] when the load X is 26 kg to 41.5 kg,

[0085] Y0= 37 (constant, unit: mm),

[0086] tan a = Y1 - Y0 / X1 - X0 = 0.97 (coefficient),

[0087] Load X = increased load from X0 to any given point (unit: kg),

[0088] and, when the load X is 41.5 kg to 65 kg,

[0089] Y0= 52 (constant, unit: mm),

[0090] tan a = Y2 - Y1 / X2 - X1 = 0.68 (constant),

[0091] Load X = increased load from X1 to any given point (unit: kg).

[0092] In addition to the comfort during use in the supine position and the maintenance of the inward curvature of the lumbar vertebrae, the preferred height of the lumbar pillow D can be determined by considering the relationship between the body weight and the load X applied to the lumbar pillow D. For a user having a body weight of 44 to 70.3 kg, a lumbar pillow having a preferred height of 9 cm is preferable. For a user having a body weight of 70.3 to 94 kg, a lumbar pillow having a preferred height of 10 cm is preferable. For a user having a body weight of 94 kg or more, a lumbar pillow having a preferred height of 11 cm is preferable.

[0093] Even when a lumbar pillow having a preferred height is used, if the displacement amount of the lumbar pillow D with respect to the body weight of the user is too small, the user will feel uncomfortable and will not be able to use the lumbar pillow for a long time. Conversely, if the displacement amount of the lumbar pillow D with respect to the body weight of the user is too large, the lumbar pillow D will be compressed to the extent that it cannot maintain the inward curvature of the lumbar vertebrae. Similar to the body pressure distribution test, users of different body weights use the lumbar pillow D, and the preferred displacement range of the lumbar pillow D with respect to the body weight of the user is determined. Figure 6 The preferred relationship between the load and the displacement amount range of the lumbar pillow is illustrated in a graph of the preferred displacement range Y (mm) of the lumbar pillow D with respect to the load X (kg).

[0094] Figure 6 The relationship between the load and the displacement amount in the lumbar pillow D satisfies the relationship in Formula 1. As a result of various tests shown in the following examples, when a lumbar pillow having a preferred height of 9 cm is used for a user having a body weight of 44 to 70.3 kg, a lumbar pillow having a preferred height of 10 cm is used for a user having a body weight of 70.3 to 94 kg, and a lumbar pillow having a preferred height of 11 cm is used for a user having a body weight of 94 kg or more, the user can use the lumbar pillow for a long time without feeling uncomfortable. Figure 6The user is more likely to feel discomfort when using a lumbar support with a displacement amount lower than the lower limit line J of the displacement amount (i.e., a hard lumbar support). On the other hand, when using a lumbar support with a displacement amount greater than the upper limit line I of the displacement amount (i.e., a soft lumbar support), there is a risk that the inward bending of the user's lumbar vertebrae cannot be maintained, and no effect can be obtained. Therefore, with respect to the load, it is preferable that the lumbar support have physical properties within the range between the lower limit line J and the upper limit line I of the displacement amount, as shown in Figure 6 Figure 6

[0095] Example

[0096] The following describes an example of a user of the lumbar support and the lumbar support kit according to the present application in more detail. Figure 5 The displacement of the lumbar support D is substantially proportional to the load applied to the lumbar support D. This operation is a combined effect of the strength of the outer cushion member 1, the strength of the inner cushion member 2, and the vault thickness 4. By making the displacement of the lumbar support D substantially proportional to the load applied to the lumbar support D means that the displacement changes linearly with respect to the load displacement (a relationship of a linear function). Hereinafter, a graph showing the displacement value with respect to the load is also referred to as a "load-displacement line". By adopting a portion of the load-displacement line that is substantially a straight line, a preferable body pressure distribution is achieved.

[0097] The preferred measurement value of the vault thickness 4 is 20 to 25 mm. If the vault thickness 4 exceeds 25 mm, the user feels hard when in contact with the lumbar support, resulting in a lower sensory evaluation score due to discomfort and poor texture, etc. However, in addition to the vault thickness 4, the physical properties and shape of the outer cushion member 1 and the inner cushion member 2 must also be considered important for the sensory evaluation.

[0098] Research on texture discomfort

[0099]

[0100] It is also described that a preferred displacement range of the pillow with respect to the load (displacement direction range H) is provided for users of different genders and weights. The lines indicating the range are the upper limit line I of the displacement amount, the center line L of the displacement range, and the lower limit line J of the displacement amount. Which of these three lines is considered for conducting a survey on sensory impressions (such as texture) is considered. It was found that a displacement line close to the lower limit line J of the displacement amount (the boundary of the preferred displacement range) would facilitate the survey and statistical observation. A lumbar support with such a close displacement line is the test pillow B described below. Figure 5

[0101] ​​​For a conventional lumbar pillow, many users report feeling discomfort when subjected to the reaction force of the pillow, and alleviating this discomfort is considered important. Therefore, a test pillow B having a displacement of 39 mm with respect to an average-weight Asian male (manufactured by a conventional method and having a height T of 9 cm and an arch thickness 4 of 2 cm) was manufactured, and an investigation was conducted using the pain scale described below. As a result, a plurality of responses reported no feeling of pain, so the physical properties were close to the lower limit line J of the displacement amount. From this, the focus was placed on the lower limit line J of the displacement amount that can be evaluated, and the order was set to J, I, L.

[0102] Investigation results and evaluation of pillow B for setting the lower limit line J of the displacement amount

[0103] Test pillow B was evaluated to have physical properties close to the physical properties of the lower limit line J of the displacement amount, and further monitoring was conducted on a large number of test subjects (49 Japanese). This investigation was conducted on 49 Japanese test subjects, and there was no distinction between lumbar pain patients and non-lumbar pain patients, nor was there a distinction between genders. The scale was divided into 1 to 4 levels, with level 1 being pain, level 2 being slight pain, level 3 being tolerable, and level 4 being no pain. After 40 days of use, the results were as follows: 0 people at level 1, 4 people at level 2, 9 people at level 3, 33 people at level 4, and 3 people with no response.

[0104] From a statistical observation, 8% of the people reported feeling pain, and 18% of the people reported feeling slight pain; since most of them were women, it was seemingly reasonable that they expressed their skin sensitivity. However, in this investigation, only the results were used at the time of evaluation, so the test pillow B displacement was at the B pillow line in Figure 5 , and was evaluated to be slightly lower than the lower limit line J of the displacement amount.

[0105] Figure 5 Indicates the preferred displacement range of the pillow with respect to the load, and the displacement of the pillow with respect to the load increases or decreases approximately in proportion to the load. Figure 5 is a graph that visualizes the physical properties, so that any user can select a suitable pillow regardless of gender and body weight.

[0106] Ratio of body weight to load applied to the lumbar pillow

[0107] The ratio of body weight (kg) to body pressure on the lumbar portion of the lumbar pillow D (kg) is 1:0.59. The body pressure on the lumbar portion of the lumbar pillow D applied thereto is also referred to as "load X" hereinafter. Figure 5 The values shown in the upper portion of the horizontal axis in indicate the body pressure applied to the lumbar portion of the lumbar pillow D as "load".

[0108] Determination of pillow type for each body weight

[0109] The body weight of a person with low back pain is estimated to be about 44 to 110 kg. The lower limit value of 44 kg corresponds to the average body weight of a 12-year-old child in the National Health and Nutrition Survey of Japan (2016) announced by the government, and users below this weight are estimated to be rare. Meanwhile, the upper limit value of 110 kg is a value equal to an increase of 35% in the average body weight of Westerners, and users above this weight are estimated to be rare. Considering the relationship in which the load X is equal to the value obtained by multiplying the body weight W of the user by the coefficient 0.59, the load X of the lumbar region corresponding to this weight range is about 26 to 65 kg on average. Considering formula (1), the displacement Y of the lumbar pillow D corresponding to this value is 3.7 to 6.8 cm on average. In order to achieve the operational effect in which the displacement of the lumbar pillow D increases or decreases in proportion to the load X, the average body pressure of the lumbar region of 26 to 65 kg is divided into three parts, and the total height T of the lumbar pillow for each partition is determined. In the load range of 15 to 23.5 kg, a linear load-displacement relationship is achieved. Based on this, the load applied to the lumbar pillow D, that is, the body pressure of the lumbar region, is divided into three categories: a pillow for Asians, a pillow for Westerners, and a pillow for an overweight population.

[0110] Average body weight of women and men related to a pillow for Asians

[0111] Since there is little difference in the body weight of Asians and Japanese, the estimated value of the data of Japanese is also used for Asians. Based on the 2010 edition of the Physical Fitness and Motor Ability Survey announced by the Ministry of Education, Culture, Sports, Science and Technology and the Agency for Cultural Affairs, excluding people under the age of 20 and people 90 years of age or older, the simple average of men and women is calculated, and this value is set as the average body weight of women and men for a pillow for Asians.

[0112] (Average body weight of women: 52.0 kg, average body weight of men: 66.3 kg)

[0113] Average body weight of women and men related to a pillow for Westerners

[0114] Since there is little difference in the body weight of Westerners and Americans, the estimated value of the data of Americans is also used for Westerners. Based on an Internet search of "average height and weight of Americans by age" conducted on August 7, 2017, excluding people under the age of 20 and people 90 years of age or older, the simple average of men and women is calculated, and this value is set as the average body weight of women and men for a pillow for Westerners.

[0115] (Average body weight of women: 74.8 kg, average body weight of men: 88.4 kg)

[0116] The body weight of the overweight population is specifically expressed as 100 kg and 110 kg.

[0117] In the load direction (horizontal axis of the graph) within these ranges, there are places where the displacement line of the lumbar pillow bends, and this boundary is close to 41.5 kg, which is approximately the midpoint between Asians and Westerners. Therefore, this boundary is set as the boundary line X1 within the horizontal range.

[0118] Set the appropriate displacement range of the lumbar support relative to the load.

[0119] To establish suitable lower displacement limit J and upper displacement limit I, 12 pillows D for monitoring were manufactured using a polyurethane raw material injection molding method as the manufacturing method employed, and measured using an instrument for measuring load-displacement. For example, pillow D has a base width of 18.6 cm (length corresponding to the user's body height direction), a pillow height T of 9.0 cm, and a dome thickness of 2 to 2.3 cm, and weighs 850 to 1050 g. This pillow was manufactured for monitoring purposes and is not intended to limit the scope of the invention. Then, based on the measurements of pillow D, the measurements of pillow B, and their evaluation, (1) the lower displacement limit J, (2) the upper displacement limit I, and (3) the displacement range center line L were set in sequence.

[0120] Set the lower limit line J for displacement

[0121] As stated in the survey results and evaluation regarding pillow B, the load-displacement curve of pillow B is evaluated as slightly below the lower limit of displacement J. Therefore, test pillows 20-33 are outside the displacement direction range, while test pillow 23-Y is within the displacement direction range, with a margin of ±8 mm. The lower limit of displacement J is set as follows: Figure 5 As shown. However, in statistical observations, the percentage of people reporting pain (8%) and those reporting mild pain (18%) was considered to have decreased, but the problem was not yet solved. It is certain that using the lumbar pillow described below and reducing the duration of use is a sufficient solution.

[0122] Set upper limit line for displacement I

[0123] The upper limit line I for displacement is determined taking into account the curvature of the lumbar region when lying supine. According to Non-Patent Literature 3, the curvature is 2 to 3 cm when lying supine, therefore the maximum displacement of the pillow is within the range of the lumbar pillow height T to 3 cm, and the upper limit line I for displacement is set as the line connecting the maximum displacement of the pillow at X0, X1, and X2. To determine whether this upper limit line I for displacement provides a suitable pillow, the load-displacement measurements of pillow D were analyzed. It was found that test pillows 23-2 and 20-4 were within the displacement direction range, and test pillow 26-2 exceeded the upper limit line I for displacement. After comprehensive evaluation, this setting was determined to be suitable.

[0124] determining a displacement range center line L

[0125] The test pillow 23D-2 has a load-displacement line approximately in the center, and is evaluated as a preferred pillow. There is about 16 mm between the lower limit line J of the displacement amount and the upper limit line I of the displacement amount, and thus the displacement direction range H is set to 16 mm, and the center line thereof is set to the displacement range center line L.

[0126] Pillow height for a user with a body weight of 110 kg or more

[0127] The pillow height T in the example is set to 9 cm for Asians, 10 cm for Westerners, and 110 cm for an overweight population, but the height is not limited thereto. Even for a person with a body weight of 110 kg or more, the pillow height T can be changed to be higher, Figure 5 The upper limit line I of the displacement amount and the lower limit line J of the displacement amount in the above can each be extended, and the displacement direction range H can be set. In other words, even for a person with a body weight of 110 kg or more, a pillow having a suitable body pressure distribution can be achieved by setting the displacement direction range H.

[0128] Based on the above results, suitable physical properties of a pillow for a corresponding user are as follows.

[0129] For a user with a body weight of 52 kg, which is the average body weight of an Asian female, the load on the pillow is 31 kg, and the suitable displacement range is 42±8 mm.

[0130] For a user with a body weight of 66.3 kg, which is the average body weight of an Asian male, the load on the pillow is 39 kg, and the suitable displacement range is 50±8 mm.

[0131] For a user with a body weight of 74.8 kg, which is the average body weight of a Western female, the load on the pillow is 44 kg, and the suitable displacement range is 54±8 mm.

[0132] For a user with a body weight of 88.4 kg, which is the average body weight of a Western male, the load on the pillow is 52 kg, and the suitable displacement range is 59±8 mm.

[0133] For a user with a body weight of 100 kg, which is classified as overweight, the load on the pillow is 59 kg, and the suitable displacement range is 64±8 mm.

[0134] Effect of the lumbar pillow kit

[0135] The invention lumbar pillow kit is to improve the quality of using a pillow in a supine position, as reported in the investigation regarding the B-pillow (single lumbar pillow D). In the investigation, 4 people reported slight pain, while 9 people reported tolerable pain.

[0136] For the purpose of reducing discomfort, a lumbar pillow kit 10 was manufactured, in which the knee pillow Z is connected via the strap P. The lumbar pillow kit 10 helps to bend the lumbar spine portion while reducing and dispersing body pressure, thereby further reducing discomfort. When those participants who felt pain when using only the lumbar pillow D were monitored again, a good response was received, reporting that the discomfort had improved.

[0137] Reference sign explanation

[0138] D lumbar pillow

[0139] Z knee pillow

[0140] P strap

[0141] 1 outer cushioning member

[0142] 2 inner cushioning member

[0143] 3 hollow space

[0144] 4 vault thickness

[0145] T height of the lumbar pillow

[0146] 10 lumbar pillow kit

Claims

1. A lumbar support pillow that maintains the inward curvature of a user's lumbar region by contacting the user's lower back in a supine or sitting position, the lumbar support pillow having a height of 9 to 11 cm, and the lumbar support pillow comprising: External cushioning components, which are formed of semi-rigid foam; as well as The internal cushioning member is formed of a semi-rigid foam with a lower hardness than the external cushioning member, wherein... The outer periphery of the external buffer member has a partially cylindrical cross-section. This partially cylindrical section has a horizontal bottom surface and a top surface composed of surfaces with three or more different radii of curvature. An approximately dome-shaped hollow space is formed at the center of the cross-section. The top surface, composed of surfaces with two different radii of curvature, is formed on a vertical side surface at a different height from the horizontal bottom surface. The internal buffer component has the same cross-sectional shape as the hollow space. The outer buffer member and the inner buffer member have a constant shape in the longitudinal direction. When the lumbar support is placed under the lower back of a user lying in a supine position, the load X exerted by the user on the lumbar support is equal to the user's weight W multiplied by a coefficient of 0.

59. In the following formula (1), which represents the range Y of the displacement of the lumbar pillow relative to the load X, Y = {Y0 + tanα × X} ± 8 (1) Where: Y is in mm, and X is in kg; when the load X is 26 kg to 41.5 kg, Y0=37, in mm, tanα=0.97; when the load X is 41.5 kg to 65 kg, Y0=52, in mm, tanα=0.

68.

2. A lumbar support set, comprising: The lumbar pillow according to claim 1; A knee pillow, having a constant shape in the longitudinal direction and a cross-section of an scalene triangle with its vertices cut off, and formed of a semi-rigid foam cushioning member; and An adjustable strap is used to connect the lumbar pillow and the knee pillow.

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