GB2525955A

GB2525955A - Ergonomic seat

Info

Publication number: GB2525955A
Application number: GB1500457.5A
Authority: GB
Inventors: Maarit Hiltunen
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-01-15
Filing date: 2015-01-12
Publication date: 2015-11-11
Also published as: GB201500457D0

Abstract

An ergonomic chair with a frame with a seat part 4, a seat support 1 made of a rigid material extending from a front part of the seat part 4 to the rear to support a users thighs wherein a recess 2 is formed between the inner edge of the seat support 1 and the rear of the sea part which is sufficient to allow a users ischial bones to be positioned in it so they arent supported by the chair. The recess 2 may have an adjustable depth and the seat support 1 may be arranged so that it can be inclined. The seat support 1 may be upholstered and a backrest 5 may be provided with two pairs of supports 3a&b which can support a users back with their spine positioned between the supports.

Description

I

ERGONOMIC SEAT

Area of the invention The invention falls within the area of seats, in particular an ergonomic seat, which as a result of its design is intended to prevent back pain by reducing the pressure on the spinal column and pelvic region.

Background of the technology

Existing seats are usually well suited for sitting when the sitting person has no back or pelvic pain or when short-term sitting is involved. However, if the person suffers from various pains in the back or pelvic region, particularly long sitting on conventional seats can present problems.

Sitting discomforts are known in Western countries such as Finland and the USA but also elsewhere throughout the world. It is assumed that back pain is attributable inter alia to the increase in sedentary activities. Also injuries of various type cause back pain, either directly after an accident or gradually with increasing age when the muscles are no longer as powerful, and back and pelvis can no longer support to the same extent as in earlier years.

It is postulated that a functional disorder of the SI joint (sacroiliac joint) is one of the most important triggers of back pain. As a result of a study, most of the pain in the lower back can be attributed to the SI joint. The SI joint lies at the connecting point between spinal column and pelvis, and blockages or displacements are designated as functional disorder. In many people the SI joint can be dislocated for years, as a result of some presumptions, even from birth. A functional disorder of the SI joint causes a skew position of the pelvis.

In order to be able to hold the head uniformly despite the skew position of the pelvis, the spinal column is curved. This can trigger various disorders such as a twisting of the foot, different-sized feet, lordosis of the back, skoliosis, disk prolapse, ischialgia, stiffness and pain in the neck, shoulder and back muscles, numbness in hands and face, blockage in the vertebra, dislocation of the shoulders.

If the sitting person has pain in the back and pelvic area, sitting on a softly or only slightly upholstered seat can be painful. There can be several causes for this, for example, the fact that the person cannot stand up from a softly upholstered seat, or that as a result of the cushioning of the seating surface, pressure is exerted on the problem zones which consequently triggers pain. This can occur, for example, when the person has become set in the area of the SI joint; when Is sitting on a soft seat such as a sofa, armchair, car seat etc., the joint easily slips back into the incorrect position. Frequently the persons are not aware of the incorrect position in the hip area but perceive pain or symptoms in other areas of the body even when this is caused by a functional disorder of the SI joint.

Sitting on a hard seating surface often seems easier to people with back pain, but longer sitting is not possible. People with pain in the SI joint can also find it difficult to shift the centre of gravity onto the ischial bones when sitting.

A Canadian-Scottish study some years ago demonstrated that sitting at a 90 degree angle and a forward-sloping sitting position present a higher loading of the spinal column than a sitting position leaning backwards at an angle of 135 degrees. This finding certainly increases the understanding of the sitting problem by demonstrating that one must lean backwards when sitting but presents no solution as such since numerous aspects of modern society require sitting in a relatively upright position and it would take a long time before we were capable of highly backward leaning sitting positions in various areas and situations, for example, in service professions or when driving vehicles. If one sits permanently in a highly backward leaning position, this can cause problems in the neck region. Changing sitting positions is advantageous during prolonged sitting.

An attempt has been made to resolve various sitting problems by developing various sitting facilities and aids which are aimed at new ergonomic sitting positions, suitable materials, different hardness and adjustability of seating surface and back rest. In all seating furniture work is being carried out to improve sitting ergonomy, but mostly in those which are intended for prolonged sitting such as work chairs and car seats. Despite these efforts, back problems seem to be on the increase. For this reason there is a need for a seat which can better eliminate the pressure on the spinal column and pelvic regions with changing sitting positions and thereby prevent back pain.

The invention is based on the finding that the pressure on the spinal column during standing is significantly lower than when sitting. Thus, the aim is to produce a seat which enables a position in which the spinal column is as free as possible, similarly to when standing and which has a prophylactic effect in healthy people and in particular facilitates the sitting of people with back and pelvic pain. The seat must furthermore be designed so that the ischial bones and/or pelvic bones are located in an unstressed position as far as possible.

Summary of the invention

The aims set out are achieved by means of the characteristic features listed in the protection requirements.

A conventional seat has a seating surface, back rest and foot construction. In the invention the attention is on the opening or recess formed in the seat in which the ischial bone and/or pelvic bone and the spinal cord are positioned when sitting. In order to enable the stress on spinal cord and pelvic region when sitting to be as low as possible, these must be position in or on the opening or recess. In order that ischial bone and/or pelvic bone as well as spinal cord can be positioned as freely as possible in the opening or recess, these must have sufficient dimensions. The sitting position is supported by a seat support lying under the thighs or a seat-support-like part of the seating area and by a backrest which is optionally reinforced with a back support in the area of the lower posterior, lower back and/or back. It is possible to sit on the ergonomic seat without a backrest but the presence of the backrest improves the applicability of the chair and enables changing sitting positions, which is particularly important for prolonged sitting. A back support and/or ergonomically shaped back rest then offer the spinal column most space when the support lies on both sides of the spinal column and pelvis.

The sitting position adopted in the invention enables prolonged sitting, avoids back problems and supports the SI joint so that this does not dislocate.

The seat according to the invention is suitable for all sitting requirements: for vehicle seats, work, office and seating seats, dining room chairs and other chairs such as armchairs and sofas. Ergonomic shape and adjustability ensure sitting comport and enable changing sitting positions and minimise the pressure on the spinal column and pelvic region. The ergonomic seat is also suitable for general use where the seat need not necessarily be adjustable, usage comfort can also be achieved with conventional dimensions. The ergonomic seat is also suitable as a separate aid and even as a bench or stool, even when back support/rest are omitted. The seat can also be fitted with armrests.

List of schematic diagrams The invention will be described in further detail in the following figures in which Fig. 1 shows the sitting person from the side and the positioning of the ischial bone and/or pelvic bone and the spinal column on the ergonomic seat in general which is shown in the form of a car seat, I5 Fig.2 shows the sitting person from the side and the positioning of the ischial bone and/or pelvic bone and the spinal column on the ergonomic seat in general which is provided with supports in the posterior and back area, Fig.3 shows from above the most important parts of the ergonomic seat in general, i.e. seat support/seating surface, back support/back rest as well as opening or recess, opening or recess in the genital area as well as how ischial bone and/or pelvic bone and spinal cord are positioned to the opening, Fig.4 shows from above the most important parts of the ergonomic seat, i.e. seat support/seating surface, back support/back rest which lies on both sides of spinal column and pelvis, as well as opening or recess, opening or recess in the genital area as well as how ischial bone and/or pelvic bone and spinal cord are positioned to the opening.

Description of the favoured embodiment of the invention Figures 1-4 show the seat support 1 which is positioned under the thighs so that edge la lies in front of the ischial bone. The seat support 1 serves as a stable seating surface which comprises non-elastic or semi-elastic material such as wood, plastic, or plastic composite or other non-elastic or semi-elastic material or such a technique; the seat support can be shaped ergonomically. An upholstery layer can be applied to the seat support 1 according to the sitting requirement. The softness can be increased by making the seating surface 4 under the seat support 1 of a more elastic material such as foam or other elastic material or such a technique; in this case the seat support is adapted to the particular manner of sitting.

The edge la, lb of the seat support 1 can be provided with elastic material such as rubber or silicone or other elastic material or such a technique in order to enhance the sitting comfort, even when the edges per se have a rounded shape; the edges can also be more angular.

In the case of seating furniture which is designed for prolonged sitting such as car seats or work chairs, the seat support 1 can be firmly attached or be adjustable in such a manner that it can be moved forwards or backwards and thus the opening or recess 2 is made smaller or enlarged or that the slope of the edges la, lb of the seat support 1 can be adjusted upwards or downwards; this technique can also be used for other seats. At the seat support 1 there can furthermore be an adjusting requirement if the backrest 5 is to be adjusted. In this case, the seating comfort is increased by individual adjustment of the seat support 1 or the entire seating surface 4 by raising/lowering the front and rear edges. In vehicle seats the seat support 1 is integrated as part of the secure and adaptable seat.

The seat support 1 can lie independently of the seat under the seat covering or other material or be visible; it can also be identical with the seating surface 4 insofar as this has the same functional features as the seat support 1.

If the seat is provided for short-term sitting such as, for example, conventional small chairs and dining chairs, the seat support 1 can also be uncovered and not upholstered; the sitting comfort is then achieved by the shape of the seat support 1.

In certain cases it is advantageous the edge la of the seat support 1 Is lying in front of the ischial bone is significantly elaborate, not highly rounded or not necessarily upholstered with elastic material; there can be a need for such a seat among people with SI joint disorders in whom the SI joint tends to turn downwards; the sitting person can clearly feel here how the ischial bones rest against the edge la which increases the feeling of safety; this property can also offer advantages to other people; the edge la must however not produce any unpleasant pressing.

In softly upholstered seating furniture such as armchairs and sofas or other seating furniture which should offer softness, the seat support 1 can be separate or identical with the seating surface 4; it can be well upholstered or the seat support 1 and/or seating surface 4 consists of semi-elastic or elastic material. It is important that ischial bone and/or pelvic bone as well as spinal column are positioned in or on the opening or recess 2; in this case, the person suffering from SI joint pain need not worry that the joint is pressed back into the incorrect position.

Figures 3 and 4 show the opening or recess 7 integrated in the seat support 1 which provides for a reduction in pressure in the genital area. All the seats can be provided with this opening or recess 7.

Figures 1 and 2 show the seating surface 4 which is provided with the seat support 1; the seating area 4 can be identical to the seat support 1, for example, in chairs, armchairs or other seating furniture.

The seating surface 4 can have any shape. In car and other vehicle seats, the exacting usage and safety requirements are taken into account in the design and technical implementation of the seating surface.

Figures 1-4 show the central part of the invention, i.e. the opening or recess 2. In the sitting position spinal column and ischial bone and/or pelvic bone must have sufficient space and be unstressed as far as possible. This is achieved by forming a recess or opening 2 between seat support 1 and/or seating surface 4 and back support 3 and/or back rest 5, which must provide sufficient space for ischial bone and/or pelvic bone and spinal column. The opening or recess 2 must be retained even when the backrest 5 is bent backwards and the seat angle is changed substantially. The size of the opening or recess 2 can be adjusted individually as required in car seats and work seat-like sitting furniture; other seats can also be adjustable. The opening or recess can also be covered/compensated by upholstering and covering or in some other way, but always so that the position of the opening or recess under the weight is softer/more elastic than the surroundings so that the ischial bones have sufficient space to rest without being under stress.

It is also possible to sit on the ergonomic seat without back rest 5 and/or back support 3; however this can enable more stability and flexibility when sitting when the sitting person rests against this.

Figures 1 and 3 show a general view of the back support 3. The back support 3 can be added to the back rest 5 on seating facilities where this is deemed to be necessary such as car seats, work chairs, armchairs and chairs and other seating furniture. The back support 3 in the area of the lower back and upper posterior and possibly in the entire back area provides additional support when sitting; independently of the seat the back support 3 can extend as far as the lowest end of the ischial bone, where it adapts to the posterior and together with the seat support 1 allows space for sitting. The material of the back support varies according to intended use and shape of the seat; the back support 3 can consist of a combination of different materials such as wood or plastic or other non-elastic material or such a technique, which is upholstered with foam or other elastic material or it can already consist of elastic material or elastic technology as such; the shape increases the functionality of the support. The back support 3 can be designed to be elastic whereby the back rest 5 behind the back support 3 is made of elastic material such as foam or other soft material or such a technique.

In sitting facilities which are provided for long-term sitting such as car seats and office chairs which are fitted with an adjustable back rest S and adjustable seating surface 4, the back support 3 can impart significantly more support stability but must not be hard, since the back support 3 must not unpleasantly press the back in the upright and backward-leaning sitting position; in this case a possible adjustment of the seat support 1 according to sitting position is advantageous. In sitting facilities which are provided for long-term sitting but whose back rest 5 and seating area 4 are not adjustable, the adjustability of the back support 3 can increase the sitting comfort; the back support 3 can also be firmly attached to the seat according to the most common dimensions. The back support 3 can also lie under the seat covering or other material or be visible.

In small chairs and armchairs as well as other chairs, the back support 3 can be identical to the back rest 5; back support 3 and/or back rest 5 can be upholstered or non-upholstered, non-elastic or semi-elastic with comfortable ergonomic shape.

The back support 3 and/or back rest 5 can be one-part so that it supports lower back, upper posterior, the same parts of the body as the back support 3a and 3b in Figures 2 and 4, and runs in an arcuate shape on the spinal column so that the spinal column has space. Or it can also be a conventional, straight or shaped part whose main purpose is to support the sitting person. The back support 3 and/or back rest 5 can also be narrower in small chairs or other chairs, only a few centimetres wide, whereby the support rests directly on the spinal column or the back support 3 and/or back rest S can consist of two or more parts which lie on both sides of the spinal column.

Figures 2 and 4 show the back supports 3a, 3b which are suitable for all seats, in particular for sitting furniture which is designed for prolonged sitting and other seats which should enable a sitting position which is as unstressed as possible; and which lie as a pair of back supports on both sides of the spinal column so that the back support 3a lies on both sides of the pelvis in the region of the lower back and upper posterior and the back support 3b lies far higher above the pelvic bone on both sides of the spinal column. The back support 3a supports the sitting position and the back support 3b can be added to support the back as required. The back support 3, 3a, 3b can be attached to seats which are intended for long sitting but also to seats for short-term sitting or they can be fastened to the back rest 5.

Softer sitting furniture such as armchairs and sofas do not absolutely require a seat support 3, the back rest 5 offers sufficient support stability. When sitting on a soft seat a separate accessory can also be provided which has the same functioning principles as an ergonomic seat.

Figures 1 and 2 show the back rest 5 which is required in most sitting furniture, the back rest 5 can be so high that one can lean against it Is with the entire back or it can be flatter. The back rest S in most sitting furniture can form a support unit with seat support 1 and/or seating surface 4 without back support 3, 3a, 3b.

Figures 1 and 2 show the head support 6 which is provided for sitting furniture having a high back rest 5, in particular for seats in which the slope of the back rest 5 is adjustable; whereby the position of the head support can be well adjusted.

Ergonomically designed stools or benches or similar sitting furniture do not necessarily have a back support 3 or back rest 5. The principle is taken as the starting point that the sitting furniture is fitted with an opening or recess 2 which offers space for spinal column and pelvis and a seat support 1/seating surface 4; the sitting position is upright or inclined towards the front; the seats can also have foot rests.

In the case of ergonomic sitting furniture, the feet should also rest stably either on the floor or on a foot support located on the chair or on a separate base; ergonomic seats can also be used when the feet do not reach the floot support or base.

That described previously comprises some possible embodiments of the invention. According to the attributes of the protection requirements, the design of the ergonomic chair can also be accomplished in a different manner. I5

Claims

Claims 1. Ergonomic seat having a frame, a seating surface (4) carried by the frame, characterised in that the seat comprises S a seat support (1) made of a rigid material, locating on the upper part of the seat part and extending from the front part of the seating surface to the rear part over a region that supports the thighs of a sitting person, and an opening or a recess (2) between the inner edge (la) of the seat support and the rear edge of the seating surface which extends so far in the depth direction of the seating surface that at least the ischial bones are positionable on the opening or recess without support by the seat.
2. The ergonomic seat according to claim 1, characterised in that the opening or recess (2) is dimensioned in the depth direction and in the width so that the pelvic bones are positionable on the opening or recess without support by the seat.
3. The ergonomic seat according to claim 1, characterised in that the rigid material of the seat support is one of the following materials: wood, plastic, glass fibre, metal or any composite thereof.
4. The ergonomic seat according to claim 1, characterised in that for adjustment of the opening or recess the seat support (1) can be adjusted in the depth direction of the seating surface (4).
5. The ergonomic seat according to claim 1, characterised in that the seat support (1) can be inclined in the depth direction of the seating surface (4).
6. The ergonomic seat according to claim 1, characterised in that the opening or recess is upholstered with soft material and/or is covered with elastic material.
7. The ergonomic seat according to claim 1, characterised in that a back rest (5) is fastened to the frame.
8 The ergonomic seat according to claim 7, characterised in that the back rest (5) is provided with a back support (3) of stiff material which serves to support lower back and upper posterior.
9. The ergonomic seat according to claim 8, characterised in that the back rest consists of a first pair (3a) of which halves rest on the lower back and in the upper posterior area such that the spinal column lies between the halves and of another pair (3b) of which halves rest above the pelvic bone so that the spinal column lies between the halves.
10. The ergonomic seat according to any of claims 1-9, characterised in that an opening or recess 7 is integrated in the inner edge (la) of the seat support (1) for reducing pressure in the genital area.