GB2352627A - Therapeutic seating system - Google Patents

Abstract

A therapeutic seating system comprises a base 17, (101, Fig. 2) adapted to support a seat 11, (110, Fig. 2), wherein a spacer member is provided to maintain the seat and the base in a vertically spaced apart relationship, the spacer member comprising a resiliently deflectable portion which facilitates forward/backward and/or side-to-side movement of the seat with respect to the base. The deflectable portion is preferably a coil spring 15, (120, Fig. 2) or a resilient rod. The seating system may be configured as a stool 10 having one or more ties 22-24 extending between the seat and the base to limit the amount of movement possible. The base may also comprise retaining straps 20-21 to secure the feet of a user. Alternatively, the seating system may be in the form of an armchair (100, Fig. 2), wherein the base may include an upstanding back support (102, Fig. 2) with armrests (103-104, Fig. 2).

Description

2352627 A Therapeutic Chair The present invention concerns the general

field of chairs or stools for supporting seated persons. In oarticular the invention concerns a chair which is caoable of inducing physio-therapeutic movement in a person seated thereon.

It is well known that lower back pain is a well known I source of discomfort in adult humans and may become a problem at an early age. Back pain may be exacerbated by the person suffering the pain spending long periods seated on chairs, such as occurs at school, the workplace or when relaxing at home. In severe cases the sufferer is unable to work and may become bedridden until the pain subsides. Short of major surgery and its consequent risks nere is little which can be done to alleviate back pain.

-Ln the modern world back pain is a cause of significant absenteeism form work and discomfort for a large number of people.

In an attempt to alleviate, or prevent, the onset of back pain in habitually seated persons it is known to provide conventional seats which may swivel and may be adjustable for height and backrest angle. This does not prevent 2 people from adopting inappropriate posture, particularly slouching which puts pressure on the lower back.

A radical alternative to the conventional chair is known in the form of a seat or stool which does away with the backrest. The seat is configured so that the user kneels on one support pad while the bottom is supported on another pad. This arrangement encourages the seated person to adopt what is, for some people, a beneficial posture. However not everyone f inds this arrangement satisfactory or comfortable and the problem of back pain remains widespread.

The inventor of the present invention noticed that his 1- back pain was substantially reduced during the course of a long sailing voyage. In helming the sailing boat the seated helmsman continually moves in response to the continual motion of the boat on the sea. This continual motion was seen to be beneficial to the lower back and resulted in a disappearance of back pain during the course of the voyage. As a result of this observation the inventor developed the chair of the present invention which encourages the continuous movement of the lower back of the seated person in an attempt to prevent or )5 alleviate back pain in seated people, as well as provide 3 a physio-therapeutic benefit to people with injured backs.

According to one aspect of the present invention there 5. is provided a therapeutic chair comprising a seat upon which a person may sit, a base for supporting the seat above a floor or ground surface, and spacer means for maintaining the seat and base in vertically spaced apart relation, characterised in that the spacer means comprises a resiliently deflectable portion which permits resiliently constrained forward/backward and/or side to side travel of the seat with respect to the base.

The degree of seat travel may be varied by selecting a I suitable resilience for the deflectable portion. A typical travel range permits at least 5 mm. of lateral travel from an undeflected rest position during normal use, and preferably at least 10 mm, of travel.

2 Preferably the resiliently deflectable portion is adapted to permit fore-aft and side to side travel over an imaginary spherical or spheroidal surface located above the base and having a radius located between the base and the seat.

4 The chair is therefore to a limited extent unstable and requires balance activity from the seated person to maintain a correct seated posture. Furthermore, the seat encourages motion in the hips and lower backs of the seated person. This motion is beneficial to the back of the user because it exercises the lower back, discourages slouching and encourages the adoption of a correct upright seated posture.

The resiliently deflectable portion may comprise an upstanding member which is compliant so that it deflects by bending along its length to permit travel of the seat.

The deflectable portion comprises for example a coil spring, or a resilient rod. In one embodiment the deflectable portion comprises a Cprofile spring, mechanically connected at each end between the seat and base.

The deflectable member may have an upstanding orientation and may be compliant so that it deflects by bending along its length to permit travel of the seat portion.

In a preferred arrangement the deflectable member 5 comprises a coil spring. The coil spring is preferably sufficiently axially stiff to support the weight of an average human without collapsing. The spring should be bendable in response to weight shifts of the user of t he chair. The coil spring has the advantage of providing limited extent bending motion under loading, whilst having no moving parts or bearings to wear. Hence the spring is very reliable. In a preferred embodiment the spring is attached at one end thereof to the seat portion and at another end thereof to the base portion.

The spacer means may comprise a rigid strut extending between the underside of the seat portion and an upper end region of the deflectable member. The rigid strut is an extension which accentuates the travel of the seat 1 portion in response to a given deflection of the deflectable member.

Preferably the rigid strut is joined to the deflectable member at a junction located about half the distance between the seat and a surface upon which the chair is placed.

The chair may be provided with restraining means for limiting the degree of travel of the seat fore/aft and/or from side to side.

6 The restrain-Ling means may comprise one or more ties extending between the base portion and the seat portion.

The chair may be configured as a stool. However in a preferred arrangement the base portion is provided with a generally upstanding back support. The base portion may be provided with arm rests disposed on each side of the seat portion, thereby to give an armchair configuration.

M The base portion may be provided with foot retainers for securing the feet of the seated person during travel of the seat. This helps prevent the user from falling off the chair during travel of the seat portion. In addition the user can;,--hereby anchor his/her feet to force travel of the seat.

The spacer means may be provided with adjustment means f or altering the spacing between the seat portion and the floor or ground. This permits adjustment of the chair for the individual height requirements of the user. Conventional height adjustment means are well known in the art and are not therefore described further.

The base portion may comprise a plate or board which sits 25 on the floor surface. Preferably the plate or board 7 provides a substantial "footprint" which helps prevent unwanted over- balancing of the chair during use.

Alternativelv the base portion comprise a plurality of rigid legs.

The base portion may be provided with rollers or wheels for permitting travel of the base portion over a floor surface.

Following is a description by way of example only and with reference to the drawings of methods of putting the present invention into effect.

In the drawings:- Figure 1 JLs a perspective view of a chair according to the present invention configured as a stool.

Figure 2 is a perspective view of a chair according to the present invention configured as an armchair.

Stool A stool according to the present invention is indicated 25 generally as 10 in figure 1. The chair comprises a 8 cushioned seat 11 of generally square plan. The seat has a wooden base portion (not visible) which is provided with an upholstered cushion on an upper surface thereof.,-..n upper end of a square section seat post 12 is attached to a central underside surface of the seat base portion by means of bolts. A lower end of the seat post is formed with a flange 13. The flange is bolted onto a face of an octahedral plate 14. An underside of the plate is fixed by means of clamping tabs (not shown) to a top end of an I upstanding coil spring 15. A lower end of the coil spring is fixed by means of clamping tabs 16 to a wooden laminate base plate 17.

The base plate has a form which is generally circular in plan at one end 18 and provided with an elongate extension tongue 19 at an opposite end. The coil spring is attached to a point on the base plate surface corresponding to the centre of the circular end 18. A wooden stiffening rod is loosely accommodated in the bore of the coil spring. The rod prevents buckling of the spring under extreme loading and limits the extent of flexing of the coil spring.

The extension tongue is provided with two side by side,5 spaced apart foot stirrups 20,21. The stirrups are formed 9 by a length of nylon webbing. The webbing is attached at each end to opposite sides of the tongue portion, and clamped in the middle thereof to the tongue portion upper surface. This forms two foot loops which define the stirrups.

Three rope restrainers 22, 23 & 24 limit the throw of the stool seat portion fore - aft and from side to side.

In Armchair An armchair is shown generally as 100 in figure 2. The armchair comprise a wooden base portion 101 and a seat portion 110. The base portion includes a ladder frame back support 102 comprising three dowels and two I Z; generally upstanding, rearward inclined back members 105,106. Extending forward from the respectiveback members are two arm rests 103,104. The arm rests are supported by inverted arch members 107,108. An apex of each inverted arch member is attached to an upright apex of respective left and right arched leg members 109,111.

A front foot region of each leg member is attached to a respective end of a rearwardly lain arched base member 112. A rear foot region of each leg member is attached to respective ends of two forwardly lain arched base members 113 and 114. One of the arched base members 114 passes through the rearwardly lain arched base member, thereby forming an eye shaped frame 115. The frame accommodates a wooden plate 116. Attached to a top surface of the wooden plate is an elongate upstanding coil spring 120. A top end of the coil spring is attached to a wooden block 121. A top surface of the wooden block is fixed to the underside of a cushioned seat member 122.

The present invention provides a chair which encourages I lower back mobility. The chair requires the user actively to balance his/her posterior on the seat and gives a therapeutic action to stiff backs, as well as helping to prevent back trouble for people spending long periods of time seated, e.g. computer operators, office workers or television viewers.

Claims (16)

1. A therapeutic chair comprising a seat upon which a person may sit, a base for supporting the seat above a floor or ground surface, and spacer means for maintaining the seat and base in vertically spaced apart relation, characterised in that the spacer means comprises a resiliently deflectable portion which permits resiliently constrained forward/backward and/or side to side travel to of the seat with respect to the base.

2. A chair as claimed in claim 1 wherein the deflectable portion permits forward /backward and side to side travel over an imaginary spherical or spheroidal surface located above the base and having a radius between the base and the seat.

3. A chair as claimed in claim 1 wherein the resiliently deflectable portion comprises an upstanding member which 2 is compliant so that it deflects by bending along its length to permit travel of the seat.

4. A chair as claimed in claim 2 or claim 3 wherein the deflectable portion comprises a coil spring, or a resilient rod.

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5. A chair as claimed in any preceding claim wherein the deflectable portion comprises a C-profile spring.

6. A chair as claimed any preceding claim wherein the spacer means further comprises a rigid spacer portion connecting an underside region of the seat portion and an upper end region of the deflectable portion.

7. A chair as claimed in claim 6 wherein the rigid spacer I portion extends about half of a vertical spacing between the seat underside and a floor engaging surface of the base portion.

8. A chair as claimed in any preceding claim and provided with restraining means for limiting the degree of travel of the seat fore/aft and/or from side to side.

9. A chair as claimed in claim 8 wherein the restraining means comprises one or more ties extending between the base and the seat.

10. A chair as claimed in any preceding claim and configured as a stool.

11. A chair as claimed in any of claims 1 to 9 wherein the base is orovided with a generally upstanding back support.

12. a chair as claimed in claim 11 wherein the base is provided with arm rests on each side of the seat portion, thereby to give an armchair configuration.

13. A chair as claimed in any preceding claim wherein the base portion is provided with foot retainers for securing the feet of the seated person during travel of the seat.

14. A chair as claimed in any preceding claim wherein the spacer means is provided with adjustment means for altering the spacing between the seat portion and the floor or ground.

15. A chair as claimed in any preceding claim wherein the base comprises a plate or board or frame which sits on the floor surface.

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16. A therapeutic chair substantially as hereinbefore described with reference to the drawings.