Ischial sitting cushion

Abstract

To provide an ischial sitting cushion, when being used for ischial sitting, expected to have a positive effect on the trunk of a user, by preventing an increase in a hip joint flexion angle or accentuating the physiological lordosis of the lumbar spine due to a lumbar support part, and by allowing the user to maintain a neutral posture with the pelvis upright by appropriately activating the user's own muscles such as deep muscle groups of the trunk without excessively depending on a support for the lumbar part.SOLUTION: An ischial sitting cushion C1 formed of a material with a prescribed strength and resilience, includes: an inclined upper plate 1; a rear base part 11 that supports the inclined upper plate 1 at a rear portion in a prescribed inclined state together with a front portion of the inclined upper plate and whose upper surface inclined downward at a prescribed angle forward, supports a user's buttocks from behind; and ischial support parts 3 and 3a that are arranged side by side at a prescribed interval on the left and right sides, and have slits 30 and 30a penetrating in upper / lower surface direction at prescribed positions of the inclined upper plate 1 avoiding the rear base part 11, to form an outer shape into an elongated oval shape that is long in the left and right directions, with their connected except for a portion of the front part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ischial cushion, specifically an ischial cushion that allows the user to maintain a neutral posture with the pelvis upright by appropriately activating the user's own deep core muscles without excessively relying on something to support the lower back, and is expected to have a positive effect on the core of the user when using this ischial cushion. [Background technology]

[0002] Modern people spend a lot of time sitting in chairs due to various aspects of their lives, such as work, and poor posture is said to be the cause of chronic illnesses such as lower back pain. One solution to this problem is the so-called ischial sitting position.

[0003] For example, when sitting in a chair, if you place the ischial tuberosities of your sitting bones (hereafter referred to simply as the ischia) on the seat of the chair, your pelvis will also be upright, and your spine will also form an ideal S-shape, allowing you to sit comfortably without strain. This is widely recommended not only in various sources such as magazines and the Internet, but also in medical institutions.

[0004] However, it is generally considered difficult to maintain this ischial sitting position for a long period of time without any assistance, and various cushions have been proposed over the years that are said to help people to assume this position and maintain correct posture. The cushion described in Patent Document 1 is one such cushion.

[0005] This conventional cushion has a lumbar support section behind the buttocks support section that supports the user's lower back, and the lumbar support section has a sacrum support section that supports the sacrum from behind.The buttocks support section is provided with a pair of ischial support sections, and when the user sits down, the ischial area is dropped into the ischial support sections to stabilize the cushion, thereby preventing the ischial bones from shifting position when sitting. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-55605 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the cushion described in Patent Document 1 has the following problems. In other words, all of the cushions listed in Patent Document 1 have a structure in which the buttocks support section is dropped deep backward, which may result in an uncomfortable sitting posture when the user sits down due to an increase in the hip joint flexion angle or an emphasis on the physiological lordosis of the lumbar spine by the lumbar support section.

[0008] For this reason, even if the ischial bones were dropped into the ischial housing and the sacrum was supported from behind by the sacral support part, it was difficult to actually keep the pelvis upright. This made it difficult to achieve the ideal ischial sitting posture, in which the spine forms an S-shape, and even if it was possible to achieve it, it was difficult to maintain that posture for long periods of time.

[0009] Furthermore, if there is reliable support from behind, such as in the lumbar support or sacral support, the user's body becomes dependent on it, weakening the function of their own muscles (deep core muscles) which should be working properly even while sitting. For this reason, while it would be fine if this cushion could be used all the time, in other environments without it, it would be impossible to maintain posture, and as a result, it could not be expected to have a positive effect on the user's core.

[0010] Furthermore, the distance between the ischial tuberosities varies from person to person depending on factors such as gender and individual bone structure, and with the structure of the ischial tuberosity housing portion of the cushion described above, it is possible that the ischial tuberosities may not fit properly within the pockets of the ischial tuberosity housing portion, making it quite likely that the purpose of stabilizing the position of the ischial bones will not be achieved.

[0011] The present invention was devised in light of the above points, and aims to provide an ischial sitting cushion that does not increase the hip joint flexion angle or accentuate the physiological lordosis of the lumbar spine due to the lumbar support part, as occurs with cushions that have a buttock support part that drops deep backward, and that allows the user to maintain a posture with the pelvis in an upright neutral position by appropriately activating the user's own muscles, such as the deep core muscles, without relying excessively on something to support the lumbar area, so that ischial sitting using this cushion can be expected to have a positive effect on the user's core. [Means for solving the problem]

[0012] [1] In order to achieve the above object, the present invention provides an ischial cushion made of a material with a predetermined strength and elasticity, comprising an inclined upper plate of a predetermined shape, a rear support part that supports the inclined upper plate at a predetermined inclination together with its front part at the rear, with its upper surface sloping downward at a predetermined angle to the front and supporting the user's buttocks from behind, and ischial support parts that have a slit penetrating the inclined upper plate in the vertical direction at a predetermined position avoiding the rear support part, giving it an outer shape that is long from side to side, and are arranged side by side at a predetermined interval on the left and right with the front part connected except for a portion.

[0013] When the ischial tuberosity cushion of the present invention is placed on a support surface, the inclined upper plate is inclined downwards at a predetermined angle toward the front relative to the support surface. First, when the user sits on the ischial tuberosity cushion with their buttocks resting on it and aligns their ischial tuberosity at the bottom of their pelvis with the ischial support part and applies their weight, the inclined upper plate is pushed by the part that corresponds to (or is equivalent to) the ischial tuberosity and deforms to be slightly bowed upward.

[0014] The ischial support parts, which have an overall elongated shape, are arranged side by side at a specified distance on the left and right, with only a portion of the front part remaining connected, making it easy to accommodate and accommodate differences in the size and spacing of the ischial tuberosities due to differences in the user's physique, etc. When more weight is placed on the ischial support parts, the ischial support parts separate from the rest of the inclined upper plate at the slit, deforming so that they drop downward and come into contact with the support surface.

[0015] At this time, the ischial support section is held down by the ischial tuberosities, becoming parallel to the support surface and roughly flat, and the ischial tuberosities are stable when placed on the ischial support section. Furthermore, as the inclined upper plate deforms upward, slightly weakened portions are created along the front ends of each slit, and the inclined upper plate bends upward from these weakened portions. Furthermore, because the user's buttocks are in contact with the inclined upper plate, significant upward deformation of the rear support section is prevented.

[0016] In this case, the rear end of the rear base itself is slightly raised from the undeformed resting state, and the angle of inclination with respect to the resting surface and the amount of lift of the rear end of the bottom surface increase, resulting in a settled state. This deformed state of the ischial sitting cushion will be maintained in approximately the same shape as the ischial sitting cushion as long as the user continues to sit on their ischial bones.

[0017] In this position, the user's buttocks are supported forward by the upper surface of the rear support, which is inclined upward at the rear. This support force is not very strong because the contacting upper surface is inclined downward at the front, which allows the force to easily escape, and only provides light support for the buttocks from behind. Because the support force is light, the user is less likely to rely on it excessively when trying to maintain ischial sitting during use, and the user is able to moderately work their own muscles, such as their deep core muscles.

[0018] Furthermore, when the cushion for ischial sitting is deformed, the front side remains approximately horizontal, so for example, there is no increase in the hip joint flexion angle due to the buttocks support part dropping deep backward, or the lumbar support part accentuating the physiological lordosis of the lumbar spine, making it easier to assume the ideal posture for ischial sitting, that is, a neutral position with the pelvis upright.

[0019] Furthermore, as mentioned above, the upper surface of the rear support provides rear-to-front support for the user's buttocks, making it relatively easy to maintain an ischial sitting position for long periods of time. This also means that ischial sitting using an ischial sitting cushion effectively trains the user's deep core muscles, which is expected to have a positive effect on the core.

[0020] [2] The ischial support cushion of the present invention may be configured so that the ischial support portion has a horizontally long, approximately oval shape.

[0021] In this case, the area of ​​the ischial support where the ischial tuberosities rest is relatively large, allowing for smoother deformation when the ischial tuberosities rest on it. Also, the ischial support that becomes nearly flat allows the ischial tuberosities to move freely, making it easy for the user to adjust it to their preferred position.

[0022] [3] The ischial cushion of the present invention may be configured such that the inclined upper plate has a weak portion on at least the upper surface along the partially connected portion continuing from the cut that forms the ischial support portion, which helps the ischial support portion to deform downward.

[0023] In this case, when the ischial support portion is deformed by the weight of the user, the weakened line naturally causes the necessary amount of flexural deformation, preventing the ischial support portion from being damaged by excessive deformation.

[0024] [4] The ischial cushion of the present invention can also be configured as a two-layer structure in which the upper surface of the inclined upper plate is made of cork, and the lower surface and the rear base are made of foamed synthetic resin.

[0025] In this case, cork retains the properties of a natural material, namely, it is highly flexible and does not crack easily even when deformed significantly, and also has the property of being moderately non-slip even when worn through clothing. The upper layer has moderate cushioning properties, and the lower layer has the sufficient elasticity of foamed synthetic resin, making it a rational material that can be used as is for an ischial cushion.

[0026] [5] The ischial cushion of the present invention may be configured to include a fixing means for fixing it to the seat of a chair.

[0027] In this case, the ischial sitting cushion can be fixed to various types of chairs, so that the ischial sitting cushion that can help with ischial sitting can be used in many places.

[0028] [6] In order to achieve the above object, the present invention provides an ischial sitting cushion made of a material having a predetermined strength and elasticity, comprising an inclined upper plate of a predetermined shape, a rear support part that supports the inclined upper plate at a predetermined inclination together with its front part at the rear, with its upper surface sloping downward at a predetermined angle to the front and supporting the user's buttocks from behind, and ischial support parts that have a slit penetrating the inclined upper plate in the vertical direction at a predetermined position avoiding the rear support part, giving it an outer shape that is long from side to side, and are arranged side by side at a predetermined interval on the left and right with the front part remaining connected. The cushion is deformed when a user sits on it, and comprises: an inclined upper plate that is pushed by the weight of the user and deforms so as to bend upward; the rear base portion that is tilted upward at a higher angle as the inclined upper plate bends upward from weak parts that occur along the front ends of each slit as a result of the inclined upper plate being pushed upward by the weight of the user; and the ischial support portion that is pushed by the part that corresponds to the ischial tuberosity of the user and deforms so as to sink downward, separating from the other parts of the inclined upper plate at the slits, and becomes approximately flat when it comes into contact with the support surface.

[0029] With the ischial cushion of the present invention, the user's buttocks are supported forward by the upper surface of the rear support, which slopes upward at the rear. This support force is not very strong because the contacting upper surface slopes downward at the front, making it easy for the force to escape, and it only provides light support for the buttocks from behind. Because the support force is so light, the user is less likely to rely too heavily on it when trying to maintain ischial sitting during use, and instead moderately engages their own muscles, such as the deep core muscles.

[0030] Furthermore, because the front side of the cushion for ischial sitting remains roughly horizontal, it does not result in, for example, an increase in the hip joint flexion angle due to the buttocks support part dropping too far back, or the lumbar support part emphasizing the physiological lordosis of the lumbar spine, making it easier to adopt the ideal ischial sitting posture, i.e., a posture with the pelvis in an upright neutral position.

[0031] Furthermore, as mentioned above, the upper surface of the rear support provides rear-to-front support for the user's buttocks, making it relatively easy to maintain an ischial sitting position for long periods of time. This also means that ischial sitting using an ischial sitting cushion effectively trains the user's deep core muscles, which is expected to have a positive effect on the core.

[0032] [7] In order to achieve the above object, the present invention provides an ischial sitting cushion made of a material having a predetermined strength and elasticity, the inclined upper plate being deformed so as to bend upward when pressed by the weight of the user, the rear base portion being tilted upward at a predetermined high angle as the inclined upper plate bends upward from weak parts that are created along the front ends of each slit as the inclined upper plate is deformed so as to bend upward from the weak parts that are created along the front ends of each slit, and the ischial support portion being deformed so as to bend downward at the part that corresponds to the ischial tuberosity of the user, separating from the other parts of the inclined upper plate at the boundary of the slit, and becoming approximately flat when it comes into contact with the support surface.

[0033] In this case, when the user sits on the ischial sitting cushion, the buttocks are supported forward by the upper surface of the rear support, which slopes upward at the rear. This support force is not very strong because the contacting upper surface slopes downward at the front, making it easy for the force to escape, and it only provides light support for the buttocks from behind. Because the support force is light, the user is unlikely to rely too heavily on it when trying to maintain ischial sitting during use, and the user is able to moderately work their own muscles, such as their deep core muscles.

[0034] Furthermore, because the front side of the cushion for ischial sitting remains roughly horizontal, it does not result in, for example, an increase in the hip joint flexion angle due to the buttocks support part dropping too far back, or the lumbar support part emphasizing the physiological lordosis of the lumbar spine, making it easier to adopt the ideal ischial sitting posture, i.e., a posture with the pelvis in an upright neutral position.

[0035] Furthermore, as mentioned above, the upper surface of the rear support provides rear-to-front support for the user's buttocks, making it relatively easy to maintain an ischial sitting position for long periods of time. This also means that ischial sitting using an ischial sitting cushion effectively trains the user's deep core muscles, which is expected to have a positive effect on the core. [Effects of the Invention]

[0036] The present invention can provide an ischial sitting cushion that, for example, prevents an increase in the hip joint flexion angle due to the buttocks support section being dropped too far back, or an emphasis on the physiological lordosis of the lumbar spine due to the lumbar support section, and allows the user to maintain a posture in which the pelvis is upright and neutral by appropriately activating the user's own muscles, such as the deep core muscles, without relying excessively on something to support the lumbar region, and is expected to have a positive effect on the user's core when sitting on the ischial bones. [Brief explanation of the drawings]

[0037] [Figure 1] 1A and 1B are explanatory views showing a first embodiment of an ischial sitting cushion of the present invention, in which (a) is a perspective view and (b) is a side view. [Figure 2] FIG. 2 is a plan view of the ischial cushion shown in FIG. [Figure 3] FIG. 2 is a bottom view of the ischial cushion shown in FIG. 1. [Figure 4] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 5] FIG. 10 is an explanatory diagram showing the ischial cushion fixed to the seat of a chair with a fastening band. [Figure 6]FIG. 1 is an explanatory diagram of a state in which a user sits on an ischial sitting cushion fixed to the seat of a chair. [Figure 7] 10A and 10B are explanatory diagrams showing the state in which the cushion for ischial sitting is deformed into a shape suitable for ischial sitting when the user sits on the ischial bones, where (a) is an oblique view and (b) is a side view. [Figure 8] 1A and 1B are explanatory views showing a second embodiment of the ischial sitting cushion of the present invention, in which (a) is a perspective view and (b) is a side view. DETAILED DESCRIPTION OF THE INVENTION

[0038] An embodiment of the ischial cushion of the present invention will be described in more detail with reference to Figures 1 to 8. In the following description, the terms "front, back, left, right" may be used to specify directions and positions, but these are based on the directions when the user is using the cushion, with "front, back" representing the left in Figure 1 and "rear" representing the right, and "left and right" representing the right in Figure 2.

[0039] 1 to 7, a description will be given of an ischial sitting cushion C1 according to a first embodiment of the present invention. The ischial sitting cushion C1 is entirely made of a material with a predetermined strength and elasticity. In this embodiment, the material used for the inclined upper plate 1 is a two-layer plate with a lower layer made of foamed synthetic resin and an upper layer made of cork sheet.

[0040] Note that elasticity includes the meaning of "ability to return to its original shape after deformation," but here it is used to mean that it is easy to deform appropriately when force is applied, and has excellent ability to return to its original shape after deformation.

[0041] This material has a moderate shape retention property that prevents excessive deformation even when subjected to the weight of a single person, and has the ability to return to approximately its original shape when the weight is released after deformation.It may be a single material or a composite of multiple types of materials.

[0042] The ischial sitting cushion C1 has an inclined upper plate 1, which is a flat plate with a planar shape (the rear edge is a double mountain shape extending left and right, and the front edge protrudes forward at both left and right ends), and its size is formed to roughly match the shape of the surface that comes into contact with the buttocks when sitting. In this embodiment, the inclined upper plate 1 has an inclined portion 10 made of a slightly hard foamed synthetic resin with a thickness of about 7 mm, and at the rear of the inclined portion 10 is formed a rear base portion 11 that is thicker than the inclined portion 10 and has a total thickness of about 23 mm (see Figure 1(a)).

[0043] The rear base 11 has a stepped portion 111 whose front end surface is formed linearly across its entire width in the left-right direction, aligned with the rear ends (upper ends in FIGS. 2 and 3) of each slit 30, 30a (described later). The inclined portion 10 is inclined at a predetermined angle by contacting a corner 112 of the stepped portion 111 of the rear base 11 together with a lower corner (reference number omitted) at the tip of the inclined portion 10 with the surface on which it is placed (see FIG. 1(b)). Note that the angle of the bottom surface of the rear base 11 may be changed so that it is approximately parallel to the surface on which it is placed, thereby expanding the contact area and improving stability.

[0044] At this time, the inclination angle of the bottom surface of the rear support portion 11 relative to the surface on which it is placed is approximately 9°, and the amount of rise of the rear end of the bottom surface is approximately 10 mm (see Figure 1 (b)). Note that although the rear support portion 11 has a solid structure in this embodiment, it can also have a hollow structure with partial spaces. Furthermore, the inclination angle of the inclined portion 10 of the inclined upper plate 1 relative to the surface on which it is placed is not particularly limited, but can be set appropriately within the range of 5 to 13°, for example.

[0045] Additionally, a cork top sheet 12, approximately 1 mm thick, is stretched over the entire top surface of the inclined portion 10 (see Fig. 1(a) and Fig. 4). Although the top sheet 12 is a thin sheet, it retains the properties of natural cork, which is a material with excellent usability and does not feel strange even when indirectly touching the user's buttocks through clothing. For example, it is highly flexible and does not crack even when significantly deformed. It also has the property of providing adequate slip resistance even through clothing, and provides adequate cushioning.

[0046] In this embodiment, the inclined upper plate 1 is made of a two-layered plate material, but is not limited to this. For example, a plate material made by bonding upper and lower layers of different thicknesses can be used. Alternatively, a plate made of a single material, either foamed synthetic resin or cork, can be used, or even a material other than these (one that has at least the above-mentioned predetermined strength and elasticity) can be used.

[0047] Two ischial support portions 3, 3a are provided at approximately the center of the inclined upper plate 1 in the front-to-rear direction, avoiding the rear support portion 11, with a specified distance between them on the left and right. The ischial support portions 3, 3a are formed by cutting slits 30, 30a that penetrate the top and bottom surfaces of the inclined upper plate 1 and have a roughly U-shape (an inverted U-shape in Figures 2 and 3) that resembles an oval cut in half in the short direction. As mentioned above, the rear end portions of the slits 30, 30a are flush with the step portion 111 (see Figure 3).

[0048] Next to the cuts 30, 30a, on the front side, roughly U-shaped weakened lines 31, 31a that are symmetrical to the cuts 30, 30a are provided on the top and bottom surfaces of the inclined upper plate 1. The weakened lines 31, 31a are actually shallow cut grooves that do not penetrate through and continue from the cuts 30, 30a on the top and bottom surfaces, but in the drawings, they are shown by chain lines (dotted lines) for convenience of illustration and to distinguish them from the cuts 30, 30a (see Figures 2 and 3).

[0049] (action) Here, referring to FIG. 5, an example of a method for attaching the ischial cushion C1 to the chair 4 will be shown, and referring to FIGS. 6 and 7, the method of use and operation will be explained.

[0050] The ischial sitting cushion C1 is connected here by passing both ends of fastening bands 5 through holes 14 provided on both the left and right ends of the front part, and the fastening bands 5 are then passed around under the seat 42 of the chair 4 and tightened to secure it in place. Note that it is also possible to use a method combining a magnet with the ischial sitting cushion C1 or other known method, such as embedding a magnet in the bottom of the cushion and attaching a fastening band 5 with a magnet to the chair 4 for magnetic attachment.

[0051] When the ischial sitting cushion C1 is fixed to the seat 42, the inclined upper plate 1 is inclined downwards at an angle of, for example, 9° with respect to the upper surface of the seat (reference numeral omitted) (see FIG. 1(b)). First, as shown in Figure 6, when a user 6 sits on the ischial sitting cushion C1 with his or her buttocks 62 placed on it, the user 6 aligns the ischial tuberosities 61 at the bottom of his or her pelvis 60 with the ischial support parts 3, 3a and applies his or her weight (load), the inclined upper plate 1 is pushed by the part that contacts the ischial tuberosities 61 and deforms so that it bends slightly upward.

[0052] In this case, the ischial support parts 3, 3a, which are approximately oval in shape overall (the cuts 30, 30a and the weakened lines 31, 31a), are arranged side by side in the longitudinal direction, so they can easily accommodate and accommodate differences in the size and spacing of the ischial tuberosities 61 due to differences in the physique of the user 6.

[0053] When weight is further placed on the ischial support portions 3, 3a, the ischial support portions 3, 3a separate from the rest of the inclined upper plate 1 at the slits 30, 30a, deform so as to drop downward and come into contact with the upper surface of the seat portion 42. At this time, the ischial support portions 3, 3a naturally undergo the necessary amount of flexural deformation due to the weakened lines 31, 31a, preventing damage due to excessive deformation. The ischial support portions 3, 3a are then held down by the ischial tuberosities 61, becoming parallel to the upper surface of the seat portion 42 and approximately flat, and the ischial tuberosities 61 are also stable when placed on the ischial support portions 3, 3a (see Figure 6).

[0054] Furthermore, as described above, as the inclined upper plate 1 deforms in an upward warping manner, slightly weakened fold lines 13 are created along the front ends of the slits 30, 30a, which are essentially shortened by dividing the left and right width into three parts, and the inclined upper plate 1 bends upward from these fold lines 13. Furthermore, because the buttocks 62 are placed on the inclined upper plate 1, the upward deformation of the rear base part 11 is stopped, and the boundary between the inclined upper plate 1 and the rear base part 11 bends in an approximately "V" shape.

[0055] Even in this case, the rear end of the rear base 11 itself rises slightly from the resting state before deformation, the angle of inclination with respect to the resting surface becomes higher at about 13°, and the amount of rise of the rear end of the bottom surface is about 15 mm (see Figure 7(b)). In this way, the state in which the ischial sitting cushion C1 is transformed into the ischial sitting cushion Ca is the settled state, and as long as the user 6 continues to sit on the ischial bones, the ischial sitting cushion Ca will maintain approximately the same shape (structure).

[0056] In this state, the buttocks 62 of the user 6 are supported in the forward direction by the upper surface (reference numeral omitted) of the rear support part 11, whose rear end is inclined upward. This support force is not very strong, as the abutting upper surface is inclined downward in the front, and the force is easily dissipated, so the buttocks 62 are only lightly supported from behind.

[0057] However, even if the user 6 does not lean against the backrest 41 of the chair 4, the support is effective due to the anti-slip effect of the cork upper sheet 12 stretched over the upper surface of the rear support portion 11. Although the support force provided by the upper surface of the rear support portion 11 is light, it is effective, so that the user 6 is unlikely to rely excessively on the support force when trying to maintain ischial sitting during use, and the user 6 is able to moderately work his or her muscles, such as the deep core muscles.

[0058] Furthermore, when the ischial sitting cushion C1 (or Ca) is in use, the front side is kept roughly horizontal (roughly parallel to the upper surface of the seat), so for example, there is no increase in the hip joint flexion angle due to the buttocks support part being dropped too far back, or the lumbar support part not emphasizing the physiological lordosis of the lumbar spine, so it is easy to assume the ideal ischial sitting posture, that is, a posture in which the pelvis 60 is upright and in a neutral state.

[0059] Moreover, as described above, the upper surface of the rear support 11 provides rear-to-front support to the buttocks 62 of the user 6, making it relatively easy to maintain an ischial sitting position for long periods of time. Furthermore, this leads to ischial sitting using the ischial sitting cushion C1 (or Ca) effectively training the deep trunk muscles of the user 6, and is expected to have a positive effect on the trunk.

[0060] The ischial sitting cushion Ca may be configured with elasticity so that it returns to approximately its original shape when the load is released, or once it has been deformed into the shape of the ischial sitting cushion Ca, it may be configured so that it hardly returns to its original shape, or it may be configured so that it remains almost the same as the ischial sitting cushion Ca even with repeated use.

[0061] It should be noted that, unlike the ischial sitting cushion C1 of this embodiment, the ischial sitting cushion C1 does not need to be deformed through use to assume its intended shape, but can instead be prepared in its intended shape from the beginning. This ischial sitting cushion Ca will assume approximately the same shape (structure) as the ischial sitting cushion C1 when used, deforming under the weight of the user 6, and therefore a description thereof will be omitted here.

[0062] Here, an ischial sitting cushion C2, which is a second embodiment of the present invention, will be described with reference to Figure 8. The ischial sitting cushion C2 has a structure substantially identical to that of the ischial sitting cushion C1, so identical parts are denoted by the same reference numerals, and the description of the ischial sitting cushion C1 will also be used, with only the differences from the ischial sitting cushion C1 being described here.

[0063] In the ischial sitting cushion C2, the slits 30, 30a that form the ischial support parts 3, 3a are roughly oval in shape, and the straight portions in the left-right direction at the front ends of the ischial support parts 3, 3a form weakened lines 31, 31a. With this structure, the area of ​​the part of the ischial support parts 3, 3a that rests on the ischial tuberosities 61 is larger than in the ischial sitting cushion C1, and the weakened lines 31, 31a are also shorter, which has the advantage of allowing for smoother deformation when the ischial tuberosities 61 rests on it.

[0064] Furthermore, the fold line 13 when the inclined upper plate 1 deforms is located at the weakened lines 31, 31a at the front ends of the ischial support portions 3, 3a, and the entire, approximately oval, ischial support portions 3, 3a come into contact with the upper surface of the seat portion 42. This has the advantage of making it easier to accommodate and accommodate differences in the size and spacing of the ischial tuberosities 61 due to differences in the physique of the user 6. Furthermore, because the ischial support portions 3, 3a are approximately flat, the ischial tuberosities 61 resting on the ischial support portions 3, 3a are more stable.

[0065] Furthermore, the shape of the front of the inclined upper plate 1 prevents an increase in the hip joint flexion angle or the lumbar support from emphasizing the physiological lordosis of the lumbar spine, and the support from behind by the rear base 11 allows the user to moderately work their own muscles, such as the deep core muscles, without relying excessively on something to support the lumbar area, and maintain a posture with the pelvis in an upright neutral position.As with the ischial sitting cushion C1, it is expected that sitting on the ischial bones using this will have a positive effect on the user's core.

[0066] The terms and expressions used in the present specification and claims are merely for explanatory purposes and are not limiting in any way, and are not intended to exclude terms and expressions equivalent to the features described in the present specification and claims and parts thereof. It goes without saying that various modifications are possible within the scope of the technical idea of ​​the present invention. [Explanation of symbols]

[0067] C1 Sit-up cushion 1 Sloped top plate 10 Slope 11 Rear section 111 Stepped section 112 Corner 12 Top sheet 13 Line 3, 3a Ichial support 30, 30a break 31, 31a line of weakness 14 through holes 5. Tightening band 42 Seat area 41 Backrest 6 User 60 Pelvis 61 Ischial tuberosity 62 Buttocks Ca Sciatica Cushion C2 Sit-up cushion

Claims

1. It is made of a material with a certain strength and elasticity, an inclined upper plate having a predetermined shape; a rear support portion that supports the inclined upper plate at a rear portion together with its front portion in a predetermined inclined state, and whose upper surface is inclined downward at a predetermined angle toward the front and supports the user's buttocks from behind; The inclined upper plate has a cut penetrating in the vertical direction at a predetermined position avoiding the rear base portion, so that the outer shape is long in the left and right directions, and ischial support portions are provided in parallel on the left and right at a predetermined interval while connecting the front portion except for a part of the front portion. Cushion for sitting on the ischial bones.

2. The ischial support portion has a horizontally long, approximately oval shape. The ischial cushion according to claim 1.

3. In the inclined upper plate, a weakened portion that helps the ischial support portion to deform downward is provided on at least the upper surface along the partially connected portion that continues from the cut that forms the ischial support portion.

3. The cushion for sitting on the ischial bones according to claim 1 or 2.

4. The upper surface of the inclined upper plate is made of cork, and the lower surface and the rear base are made of foam synthetic resin.

3. The cushion for sitting on the ischial bones according to claim 1 or 2.

5. Equipped with a fixing means for fixing to the seat of a chair 3. The cushion for sitting on the ischial bones according to claim 1 or 2.

6. The cushion is made of a material with a predetermined strength and elasticity, and has an inclined upper plate of a predetermined shape, a rear support part that supports the inclined upper plate at a predetermined inclination together with its front part at the rear, with an upper surface that slopes downward at a predetermined angle forward to support the user's buttocks from behind, and ischial support parts that have slits that penetrate the inclined upper plate in the vertical direction at predetermined positions avoiding the rear support part, giving the outer shape a long shape in the left and right directions, and are arranged side by side at a predetermined interval on the left and right with the front part remaining connected, and are deformed when the user sits on the cushion, The inclined upper plate is deformed by being pushed by the weight of the user so as to bend upward; the rear base portion is inclined upward at a higher angle as the inclined upper plate bends upward from weak parts generated along the front ends of each slit due to the inclined upper plate being deformed by being pushed by parts corresponding to the ischial tuberosities of the user, and is deformed so as to drop downward, separating from other parts of the inclined upper plate at the slits, and becomes approximately flat when in contact with the placement surface. Cushion for sitting on the ischial bones.

7. It is made of a material with a certain strength and elasticity, The inclined upper plate is deformed upward by being pushed by the weight of the user; The rear base portion is inclined upward at a predetermined high angle by the inclined upper plate being deformed so as to bend upward from weak portions formed along the front ends of each slit due to the inclined upper plate being warped upward; the ischial support portion is pressed by a portion corresponding to the ischial tuberosity of the user, and is deformed so as to drop downward, separated from other portions of the inclined upper plate at the slit, and becomes substantially flat when in contact with the placement surface. Cushion for sitting on the ischial bones.

Images