A chair is a piece of furniture consisting of a seat, legs, back, and sometimes arm rests, for use by one person. Without back and arm rests it is called a stool. A chair for more persons is a couch, sofa, settee, loveseat or bench. A chair mounted in a vehicle or in a theatre is simply called a seat.

The back often does not extend all the way to the seat to allow for ventilation. Likewise, the back and sometimes the seat are made of porous materials or have holes drilled in them for decoration and ventilation.

The back may extend above the height of the head. There may be separate headrests. Headrests for seats in vehicles are important for preventing whiplash injuries to the neck when the vehicle is involved in a rear-end collision.

Table of contents
1 Types of chairs
2 Design and ergonomics
3 Standards and specifications
4 Accessories
5 History of the Chair
6 Phrases relating to chairs
7 References

Types of chairs

An Aeron chair is an ergnomic trademarked chair.

A barber's chair swivels and has easily adjusted heights to make it easy for the barber. It may also recline for washing hair. It typically has footrests as the height may be adjusted and raise the patron's feet off the floor. For children's barbershops, the chairs may come in fanciful shapes such as horses and cars to distract the children while their hair is cut.

A Barcelona chair class="external">[1 is a proprietary chair characterized by leather upholstery, backward sloping seat, reclined back and no armrests.

A barrel chair [1] is a chair with a high round back like half a barrel. It is large and upholstered.

Beanbag chairs are fabric bags of beans in the shape of a chair. They are usually filled with foam chips today and made of colourful fabric for children.

A butterfly chair class="external">[1 is composed of a single piece of fabric suspended from a light metal frame.

A captain's chair was originally a low back wooden chair [1]. Today it is often applied to adjustable individual seats in a car with arm rests.

A club chair [1] is a plush easy chair with a low back. The heavy sides form armrests that are usually as high as the back.

A Cogswell chair [1] was a brand of upholstered easy chairs. It has a sloping back and curved and ornamental front legs. The armrests are open underneath.

A deck chair class="external">[1 is a folding chair with an extended seat that is meant to be used as a leg rest. There are usually armrests. It is meant for lounging.

Dentist chairs are deeply reclining chairs to allow the dentist easy access to the patients mouth. The reclining position adjusts as well as the overall height of the chair. Associated with the chair are usually a variety of dental equipment, often including a small tap and sink for the patient to rinse his or her mouth.

A director's chair class="external">[1 is a folding chair used by movie directors. It folds side-to-side and can fold that way because the seat and back are usually fabric, typically canvas. The back is usually low and there are usually armrests.

An easy chair [1] is any large comfortable chair. It is typically upholstered.

The Eames chair [1] is a trademark for molded plywood chairs, contoured to fit the shape of a person.

An electric chair is a device for capital punishment by electrocution.

A fighting chair[1] is a chair on a boat used by anglers to catch large saltwater fish. The chair typically swivels and has a harness to keep the angler strapped in should the fish tug hard on the line.

Folding chairs collapse the back to the seat. Some further collapse the feet up to the back. This is useful for mobility and storage. Folding chairs are typically designed to stack on top of each other when folded and may come with special trolleys to move stacks of folded chairs. Stacking chairs simply stack for storage and do not collapse.

A glider offers the same motions as a rocking chair but without the dangers. A frame rests on the floor and the chair is supported by swing arms within the frame so that moving parts are less accessible.

A high chair is a children's chair to raise them to the height of adults for feeding. They typically come with a detachable tray so that the child can sit apart from the main table. Booster chairs raise the height of children on regular chairs so they can eat a the main dining table. Some high chairs are clamped directly to the table and thus is more portable.

Plastic inflatable chairs are usually children's toys. Ikea briefly marketed them as serious furniture upholstered in fabric. Some are designed for use as floating lounge chairs in swimming pools.

Kneeling chairs or knee-sit chairs [1] are chairs that are meant to support someone kneeling. This is puportedly better for the back than sitting all day. The main seat is sloped forward at the about 30 degrees so that the person would normally slide off; but there is a knee rest to keep the person in place.

A lawn chair is usually a light folding chair for outdoor use on soft surfaces. The left and right legs are joined along the ground into a single foot to make a broader contact area with the ground. Individual feet would otherwise dig into soft grass.

A Morris chair [1] was a proprietary easy chair with adjustable back, cushions and armrests.

An office chair typically swivels and is on castor wheels. It may be very plushly upholstered and in leather and thus characterized as an executive chair or come with a low back and characterized as a steno chair. Office chairs often have a number of ergonomic adjustments: seat height, armrest height and width, back reclining tension.

A pushchair [1] is a British English term for a stroller.

A recliner [1] is a chair whose back reclines. They are typically armchairs and may come with a footrest that unfolds from the chair when the back is reclined.

A rocking chair has the legs mounted on a curved rocker so that the chair can sway back and forth. Rocking chairs can be quite dangerous for small children and pets as the rocker can crush feet as it rotates. Sometimes the rocking chair is on springs to avoid this danger.

A patio chair is any outdoor chair meant for use on a hard surface. (Contrast with lawn chairs.) They are designed so as to not collect water and dry quickly after rain.

A potty chair [1] often abbreviated simply as "potty" is a training toilet for children.

Revolving chair is an older term for swivel chair.

A sedan chair is a chair on carrying poles. The occupant is carried by two or more porters. The chair may be enclosed.

A side chair [1] is a chair with a straight back and without armrests. It is usually matched with a dining table.

A sit-stand chair [1] allows the person to lean against this device and be partially supported. It is better than standing all day.

A steno chair is a simple office chair meant for secretarial staff usage.

Swivel chairs swivel about a vertical axis. They are often on castors as well.

A visitors chair is a chair used for a visitor to someone's office. It is usually less comfortable and ornate than the main office chair.

Wheelchairs are chairs on wheels for those who cannot walk.

A wicker chair is a chair made of wicker and is thus ventilated and useful in humid conditions. Likewise a cane chair.

A Windsor chair class="external">[1 is a classic wooden chair characterized by a high-spoked back, outward-sloped legs. The seat is saddled for the contours of the human buttocks.

A wing chair[1] is an upholstered easy chair with large "wings" for armrests.

Design and ergonomics

Chair design considers intended usage, ergonomics (how comfortable is it for the occupant), as well as non-ergonomic functional requirements such as size, stackability, foldability, weight, durability, stain resistance and artistic design. Intended usage determines the desired seating position. "Task chairs", or any chair intended for people to work at a desk or table, including dining chairs, can only recline very slightly; otherwise the occupant is too far away from the desk or table. Dental chairs are necessarily reclined. Easy chairs for watching television or movies are somewhere in between depending on the height of the screen.

Ergonomic designs distributes the weight of the occupant to various parts of the body. A seat that is higher results in dangling feet and increased pressure on the underside of the knees ("popliteal fold"). It may also result in no weight on the feet which means more weight elsewhere. A lower seat may shift too much weight to the "seat bones" ("ischial tuberosities").

A reclining seat and back will shift weight to the occupant's back. This may be more comfortable for some in reducing weight on the seat area, but may be problematic for others who have bad backs. In general, if the occupant is suppose to sit for a long time, weight needs to be taken off the seat area and thus "easy" chairs intended for long periods of sitting are generally at least slightly reclined. However, reclining may not be suitable for chairs intended for work or eating a table.

The back of the chair will support some of the weight of the occupant, reducing the weight on other parts of the body. In general, backrests come in three heights: Lower back backrests support only the lumbar region. Shoulder height backrests support the entire back and shoulders. Headrests support the head as well and are important in vehicles for preventing "whiplash" neck injuries in rear-end collisions where the head is jerked back suddenly. Reclining chairs typically have at least shoulder height backrests to shift weight to the shoulders instead of just the lower back.

Armrests will also support part of the body weight through the arms. They further have the function of making entry and exit from the chair easier. Armrests should support the forearm and not the sensitive elbow area. Hence in some chair designs, the armrest is not continuous to the chair back, but is missing in the elbow area.

A kneeling chair adds an additional body part, the knees, to support the weight of the body. A sit-stand chair distributes most of the weight of the occupant to the feet.

Padding will not shift the weight to different parts of the body (unless the chair is so soft that the shape is altered). However, padding does distribute the weight by increasing the area of contact between the chair and the body. A hard wood chair feels hard because the contact point between the occupant and the chair is small. The same body weight over a smaller area means greater pressure on that area. Spreading the area reduces the pressure at any given point. In lieu of padding, flexible materials, such as wicker, may be used instead with similar effects of distributing the weight. Since most of the body weight is supported in the back of the seat, padding there should be firmer than the front of the seat which only has the weight of the legs to support. Chairs that have padding that is the same density front and back will feel soft in the back area and hard to the underside of the knees.

There may be cases where padding is not desirable. For example, in hot climates, padding with fabric or plastic covers is often uncomfortable against the skin. Where padding is not desirable, contouring may be used instead. A contoured seat pan attempts to distribute weight without padding. By matching the shape of the occupant's buttocks, weight is distributed and pressure at any given point is reduced.

Actual chair dimensions are determined by measurements of the human body or anthropometric measurements. Individuals may be measured for a custom chair. Anthropometric statistics may be gathered for mass produced chairs. The two most relevant anthropometric measurement for chair design is the popliteal height and buttock popliteal length.

For someone seated, the popliteal height is the distance from the underside of the foot to the underside of the thigh at the knees. It is sometimes called the "stool height". (The term "sitting height" is reserved for the height to the top of the head.) For American men, the median popliteal height is 16.3 inches and for American women it is 15.0 inches[1]. The popliteal height, after adjusting for heels, clothing and other issues is used to determine the height of the chair seat. Mass produced chairs are typically 17 inches high.

For someone seated, the buttock popliteal length is the horizontal distance from the back most part of the buttocks to the back of the lower leg. This anthropometric measurement is used to determine the seat depth. Mass produced chairs are typically 38-43 cm deep.

Additional anthropometric measurements may be relevant to designing a chair. Hip breadth is used for chair width and armrest width. Elbow rest height is used to determine the height of the armrests. The buttock-knee length is used to determine "leg room" between rows of chairs. "Seat pitch" is the distance between rows of seats. In some airplanes and stadiums the seat pitch is so small that there is sometimes there is no leg room for the average person.

For adjustable chairs, the aforementioned principles are applied in adjusting the chair to the individual occupant.

Standards and specifications

Design considerations for chairs have been codified into standards. ISO 9241-5:1988[1], "Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 5: Workstation layout and postural requirements " is the most common one for modern chair design.

There are multiple specific standards for different types of chairs. Dental chairs are specified by ISO 6875. Bean bag chairs are specified by ANSI standard ASTM F1912-98[1]. ISO 7174 specifies stability of rocking and tilting chairs. ASTM F1858-98 specifies lawn chairs. ASTM E1822-02b defines the combustibility of chairs when they are stacked.

The Business and Institutional Furniture Manufacturer's Association (BIFMA) defines BIFMA X5.1 for testing of commercial-grade chairs. It specifies things like[1]:

  • chair backstrength of 150 pounds
  • chair stability if weight is transferred completely to the front or back legs
  • leg strength of 75 pounds applied one inch from the bottom of the leg
  • seat strength of 225 pounds dropped from six inches above the seat
  • seat cycle strength of 100,000 repititions of 125 pounds dropped from 2 inches above the seat
The specification further defines heavier "proof" loads that chairs must withstand. Under these higher loads, the chair may be damaged, but it must not fail catastrophically.

Large institutions that make bulk purchases will reference these standards within their own even more detailed criteria for purchase [1]. Governments will often issue standards for purchases by government agencies (e.g. Canada's Canadian General Standards Board CAN/CGSB 44.15M [1] on "Straight Stacking Chair, Steel").

Accessories

In place of a built-in footrest, some chairs come with a matching ottoman. An ottoman is a short stool to be used as a footrest but can sometimes be used as a stool. If matched to a glider, the ottoman may be mounted on swing arms so that the ottoman rocks back and forth with the main glider.

A chair cover is a temporary fabric cover for a side chair. They are typically rented for formal events such as wedding receptions to increase the attractiveness of the chairs and decor. The chair covers may come with decorative chair ties, a ribbon to be tied as a bow behind the chair. Covers for sofas and couches are also available for home with small children and pets. A brief fad in the late 20th century were custom clear plastic covers for expensive sofas to protect them.

Chair pads are cushions for chairs. Some are decorative. In cars, they may be used to increase the height of the driver. Orthopedic backrests provide support for the back. Obus Forme is a major brand in this category and helped develop this market niche. Car seats sometimes have built-in and adjustable lumbar supports.

Remote control bags can be draped over the arm of easy chairs or sofas and used to hold remote controls. They are counter-weighted so as to not slide off the arms under the weight of the remote control.

History of the Chair

The chair is of extreme antiquity, although for many centuries and indeed for thousands of years it was an article of state and dignity rather than an article of ordinary use. “The chair” is still extensively used as the emblem of authority in the House of Commons and in public meetings. It was not, in fact, until the 16th century that it became common anywhere. The chest, the bench and the stool were until then the ordinary seats of everyday life, and the number of chairs which have survived from an earlier date is exceedingly limited; most of such examples are of ecclesiastical or seigneurial origin. Our knowledge of the chairs of remote antiquity is derived almost entirely from monuments, sculpture and paintings. A few actual examples exist in the British Museum, in the Egyptian museum at Cairo, and elsewhere.

Egyptian chairs

In ancient Egypt they appear to have been of great richness and splendour. Fashioned of ebony and- ivory, or of carved and gilded wood, they were covered with costly materials and supported upon representations of the legs of beasts or the figures of captives. An arm-chair in fine preservation found in a tomb in the Valley of the Kings is astonishingly similar, even in small details, to that "Empire" style which followed Napoleon’s campaign in Egypt. The earliest monuments of Nineveh represent a chair without a back but with tastefully carved legs ending in lions’ claws or bulls’ hoofs. Others are supported by figures in the nature of caryatides or by animals.

Greek and Roman chairs

The earliest known form of Greek chair, going back to five or six centuries before Christ, had a back but stood straight up, front and back. On the frieze of the Parthenon Zeus occupies a square seat with a bar-back and thick turned legs; it is ornamented with winged sphinxes and the feet of beasts. The characteristic Roman chairs were of marble, also adorned with sphinxes. The curule chair was originally very similar in form to the modern folding chair, but eventually received a good deal of ornament. The most famous of the very few chairs which have come down from a remote antiquity is the reputed chair of St Peter in St Peter’s at Rome. The wooden portions are much decayed, but it would appear to be Byzantine work of the 6th century, and to be really an ancient sedia gestatoria. It has ivory carvings representing the labours of Hercules. A few pieces of an earlier oaken chair have been let in; the existing one, Gregorovius says, is of acacia wood. The legend that this was the curdle chair of the senator Pudens is necessarily apocryphal. It is not, as is popularly supposed, enclosed in Bernini’s bronze chair, but is kept under triple lock and exhibited only once in a century. Byzantium, like Greece and Rome, affected the curule form of chair, and in addition to lions’ heads and winged figures of Victory and dolphin-shaped arms used also the lyre-back which has been made familiar by the pseudo-classical revival of the end of the 18th century.

Medieval chairs

The chair of Maximian in the cathedral of Ravenna is believed to date from the middle of the 6th century. It is of marble, round, with a high back, and is carved in high relief with figures of saints and scenes from the Gospels—the Annunciation, the Adoration of the Magi, the flight into Egypt and the baptism of Christ. The smaller spaces are filled with carvings of animals, birds, flowers and foliated ornament. Another very ancient seat is the so-called “Chair of Dagobert” in the Louvre. It is of cast bronze, sharpened with the chisel and partially gilt; it is of the curule or faldstool type and supported upon legs terminating in the heads and feet of animals. The seat, which was probably of leather, has disappeared. Its attribution depends entirely upon. the statement of Suger, abbot of St Denis in the 12th century, who added a back and arms. Its age has been much discussed, but Viollet-le-Duc dated it to early Merovingian times, and it may in any case be taken as the oldest faldstool in existence.

To the same generic type belongs the famous abbots’ chair of Glastonbury; such chairs might readily be taken to pieces when their owners travelled. The faldisterium in time acquired arms and a back, while retaining its folding shape. The most famous, as well as the most, ancient, English chair is that made at the end of the l3th century for Edward I., in which most subsequent monarchs have been crowned. It is of an architectural type and of oak, and was covered with gilded gesso which long since disappeared.

Passing from these historic examples we find the chair monopolized by the ruler, lay or ecclesiastical, to a comparatively late date. As the seat of authority it stood at the head of the lord’s table, on his dais, by the side of his bed. The seigneurial chair, commoner in France and the Netherlands than in England, is a very interesting type, approximating in many respects to the episcopal or abbatial throne or stall. It early acquired a very high back and sometimes had a canopy. Arms were invariable, and the lower part was closed in with panelled or carved front and sides—the seat, indeed, was often hinged and sometimes closed with a key.

That we are still said to sit “in” an arm-chair and “on" other kinds of chairs is a reminiscence of the time when the lord or seigneur sat “in his chair.” These throne-like seats were always architectural in character, and as Gothic feeling waned took the distinctive characteristics of Renaissance work.

Renaissance

It was owing in great measure to the Renaissance that the chair ceased to be an privilege of state, and became the customary companion of whomsoever could afford to buy it. Once the idea of privilege faded the chair speedily came into general use. We find almost at once began to reflect the fashions of the hour. No piece of furniture has ever been so close an index to sumptuary changes. It has varied in size, shape and sturdiness with the fashion not only of women’s dress but of men’s also. Thus the chair which was not, even with its arms purposely suppressed, too ample during the several reigns of some form or other of hoops and farthingale, became monstrous when these protuberances disappeared. Again, the costly laced coats of the dandy of the 18th and early 19th centuries were so threatened by the ordinary form of seat that a “conversation chair” was devised, which enabled the buck and the ruffler to sit with his face to the back, his valuable tails hanging unimpeded over the front. The early chair almost invariably had arms, and it was not until towards the close of the 16th century that the smaller form grew common.

The majority of the chairs of all countries until the middle of the 17th century were of oak without upholstery, and when it became customary to cushion them, leather was sometimes employed; subsequently velvet and silk were extensively used, and at a later period cheaper and often more durable materials. Leather was not infrequently used even for the costly and elaborate chairs of the faldstool form—occasionally sheathed in thin plates of silver—which Venice sent all over Europe. To this day, indeed, leather is one of the most frequently employed materials for chair covering. The outstanding characteristic of most chairs until the middle of the 17th century was massiveness and solidity. Being usually made of oak, they were of considerable weight, and it was not until the introduction of the handsome Louis XIII chairs with cane backs and seats that either weight or solidity was reduced.

English chairs

Although English furniture derives so extensively from foreign and especially French and Italian models, the earlier forms of English chairs owed but little to exotic influences. This was especially the case down to the end of the Tudor period, after which France began to set her mark upon the British chair. The squat variety, with heavy and sombre back, carved like a piece of panelling, gave place to a taller, more slender, and more elegant form, in which the framework only was carved, and attempts were made at ornament in new directions. The stretcher especially offered opportunities which were not lost upon the cabinet-makers of the Restoration. From a mere uncompromising cross-bar intended to strengthen the construction it blossomed, almost suddenly, into an elaborate scroll-work or an exceedingly graceful semicircular ornament connecting all four legs, with a vase-shaped knob in the centre. The arms and legs of chairs of this period were scrolled, the splats of the back often showing a rich arrangement of spirals and scrolls. This most decorative of all types appears to have been popularized in England by the cavaliers who had been in exile with Charles II. and had become familiar with it in the north-western parts of the European continent. During he reign of William and Mary these charming forms degenerated into something much stiffer and more rectangular, with a solid, more or less fiddle-shaped splat and a cabriole leg with pad feet. The more ornamental examples had cane seats and ill-proportioned cane backs. From these forms was gradually developed the Chippendale chair, with its elaborately interlaced back, its graceful arms and square or cabriole legs, the latter terminating in the claw and ball or the pad foot. George Hepplewhite, Thomas Sheraton and Robert Adam all aimed at lightening the chair, which, even in the master hands of Thomas Chippendale, remained comparatively heavy. The endeavour succeeded, and the modern chair is everywhere comparatively slight. Chippendale and Hepplewhite between them determined what appears to be the final form Of the chair, for since their time practically no new type has lasted, and in its main characteristics the chair of the 20th century is the direct derivative of that of the later 18th century.

18th century chairs

The 18th century was, indeed, the golden age of the chair, especially in France and England, between which there was considerable give and take of ideas. Even
Diderot could not refrain from writing of them in his Encyclopédie. The typical Louis Seize chair, oval-backed and ample of seat, with descending arms and round-reeded legs, covered in Beauvais or some such gay tapestry woven with Boucher or Watteau-like scenes, is a very gracious object, in which the period reached its high-water mark. The Empire brought in squat and squabby shapes, comfortable enough no doubt, but entirely destitute of inspiration. English Empire chairs were often heavier and more sombre than those of French design. Thenceforward the chair in all countries ceased to attract the artist. The art nouveau school has occasionally produced something of not unpleasing simplicity; but more often its efforts have been frankly ugly or even grotesque. There have been practically no novelties, with the exception perhaps of the basket-chair and such like, which have been made possible by modern. command over material. So much, indeed, is the present indebted to the past in this matter that even the revolving chair, now so familiar in offices, has a pedigree of something like four centuries.

Phrases relating to chairs

If a movie or a story keeps you on the edge of your chair, the story is very exciting and you want to know what happens next.

If you nearly fall off your chair, you are very surprised.

References


A seat is also a seat of office, authority, or dignity, such as the chairperson of a professorship at a college or university, or the individual that presides over business proceedings.

The seating position of a particular musician in an orchestra may also be referred to as a chair.

As slang, "The Chair" refers to the electric chair.

Also referred to as chairs are the blocks that supports and hold railroad track in position, and similar devices.


See also definition at http://wiktionary.org/wiki/chair