ratio of word probabilities predicted from brain for skirt and chair

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skirt

chair

top 10 words in brain distribution (in article):
wear form century body culture time light type woman produce top 10 words in brain distribution (in article):
material design form century wood type time common size produce

top 10 words in brain distribution (not in article):
tea horse tooth cell pearl shoe kite foot design drink top 10 words in brain distribution (not in article):
tea build fiber tooth city pearl kite shoe sheep culture

times more probable under skirt 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under chair
(words not in the model)

A skirt'" is a tube- or cone-shaped garment that hangs from the waist and covers all or part of the legs. In European culture, skirts are usually considered women's clothing. However, there are exceptions. The kilt is a traditional men's garment in Scotland, and some fashion designers, such as Jean-Paul Gaultier, have shown men's skirts. At its simplest, a skirt can be a draped garment made out of a single piece of material (such as pareos), but most skirts are fitted to the body at the waist and fuller below, with the fullness introduced by means of dart, gores, pleats, or panels. Modern skirts are usually made of light to mid-weight fabrics, such as denim, jersey, worsted, or poplin. Skirts of thin or clingy fabrics are often worn with slips to make the material of the skirt drape better and for modesty. The hemline of skirts can be as high as the upper thigh or as low as the ground, depending on the whims of fashion and the modesty or personal taste of the wearer. Some medieval upper-class women wore skirts over 3 metres in diameter at the bottom. At the other extreme, the miniskirts of the 1960s were minimal garments that may have barely covered the underwear when seated. Costume historians typically use the word "petticoat" to describe skirt-like garments of the 18th century or earlier. History. Skirts have been worn by men and women from many cultures, such as the lungi, kanga and sarong worn in South Asia and Southeast Asia, and the kilt worn in Scotland. The earliest known culture to have females wear miniskirts were the Duan Qun Miao, which literally meant "short skirt Miao" in Chinese. This was in reference to the short miniskirts "that barely cover the buttocks" worn by women of the tribe, and which were "probably shocking" to Han Chinese observers in medieval and early modern times. Skirts in the 19th century. During the nineteenth century the cut of women's dresses in western culture varied more widely than in any other century. Waistlines started just below the bust (the Empire silhouette) and gradually sank to the natural waist. Skirts started fairly narrow and increased dramatically to the hoopskirt and crinoline-supported styles of the 1860s; then fullness was draped and drawn to the back by means of bustles. Skirts in the 20th and 21st centuries. Beginning around 1915, hemlines for daytime dresses left the floor for good. For the next fifty years fashionable skirts became short (1920s). then long (1930s), then shorter (the War Years with their restrictions on fabric), then long (the New Look), then shortest of all during the 1960s, when skirts became as short as possible while avoiding exposure of underwear, which was considered taboo. Since the 1970s and the rise of pants for women as an option for all but the most formal of occasions, no one skirt length has dominated fashion for long, with short and ankle-length styles often appearing side-by-side in fashion magazines and catalogs. Male wear. There are a number of male garments which fall under the catergory of "skirt" or "dress." These go by a variety of names and form part of the traditional dress for men from various cultures. Usage varies- the dhoti is part of everyday dress on the Indian subcontinent while the kilt is more usually restricted to occasional wear and the foustanella is used almost exclusively as costume. Robes, which are a type of dress for men, have existed in many cultures, including the Japanese kimono, the Chinese cheongsam, the Arabic thobe, and the African Senegalese kaftan. Robes are also used in some religious orders, such as the cassock in Christianity and various robes and cloaks that may be used in pagan rituals. Examples of men's skirts and skirt like garments from various cultures include: In the Western world skirts, dresses and similar garments are considered primarily women's clothing today although historically that was not the case. The wearing of skirts by men in these areas is generally seen as cross-dressing although some fashion designers such as Jean-Paul Gaultier have produced skirts for men and kilts are widely accepted in some situations. A chair'" is used to sit on, commonly for use by one person. Chairs often have the seat raised above floor level, supported by four legs. A back or arm rests in a "'stool'", or when raised up, a bar stool (adults) or high chair (young children). A chair with arms is an "'armchair'" and with folding action and inclining footrest, a recliner. A permanently fixed chair in a train or theater is a "'seat'" or airline seat; when riding, it is a saddle and bicycle saddle, and for an automobile, a car seat or infant car seat. With wheels it is a wheelchair and when hung from above, a swing. The design may be made of porous materials, or be drilled with holes for decoration; a low back or gaps can provide ventilation. The back may extend above the height of the occupant's head, which can optionally contain a "headrest". A chair for more than one person is a couch, sofa, settee, or "loveseat"; or a bench. A separate footrest for a chair is known as an "ottoman", "hassock" or "pouffe". History of the Chair. The chair is of extreme antiquity. Although for many centuries and indeed for 1000s 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 in the United Kingdom and Canada, and in many other settings. Committees, boards of directors, and academic departments all have a 'chairperson'. Endowed professorships are referred to as chairs. 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. In ancient Egypt chairs appear to have been of great richness and splendor. Fashioned of ebony and ivory, or of carved and gilded wood, they were covered with costly materials, magnificent patterns and supported upon representations of the legs of beasts or the figures of captives. The earliest known form of Greek chair, going back to five or six centuries BCE, had a back but stood straight up, front and back. During Tang dynasty (618- 907 AD), a higher seat first started to appear amongst the Chinese elite and their usage soon spread to all levels of society. By the 12th century seating on the floor was rare in China, unlike in other Asian countries where the custom continued, and the chair, or more commonly the stool, was used in the vast majority of houses throughout the country. In Europe, it was owing in great measure to the Renaissance that the chair ceased to be a privilege of state, and became a standard item of furniture whoever could afford to buy it. Once the idea of privilege faded the chair speedily came into general use. We find almost at once that the chair began to change every few years to reflect the fashions of the hour. The 20th century saw an increasing use of technology in chair construction with such things as all-metal folding chairs, metal-legged chairs, the Slumber Chair, moulded plastic chairs and ergonomic chairs. The recliner became a popular form, at least in part due to radio and television, and later a two-part. The modern movement of the 1960s produced new forms of chairs: the butterfly chair, bean bags, and the egg-shaped pod chair. Technological advances led to molded plywood and wood laminate chairs, as well as chairs made of leather or polymers. Mechanical technology incorporated into the chair enabled adjustable chairs, especially for office use. Motors embedded in the chair resulted in massage chairs. Design and ergonomics. Chair design considers intended usage, ergonomics (how comfortable it is for the occupant), as well as non-ergonomic functional requirements such as size, stack ability, fold ability, 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 design 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 supposed 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 at 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. Some chairs have foot rests. A stool or other simple chair may have a simple straight or curved bar near the bottom for the sitter to place his or her feet on. 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. Many chairs are padded or have cushions. Padding can be on the seat of the chair only, on the seat and back, or also on any arm rests and or foot rest the chair may have. 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 chairs that are intended primarily for outdoor use. 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 maximum pressure is reduced. Actual chair dimensions are determined by measurements of the human body or anthropometric measurements. 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 when seated. For American men, the median popliteal height is 16.3 inches and for American women it is 15.0 inches. 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 15-17 inches 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 leg room (the seat pitch less the thickness of the seat at thigh level) is so small that it is sometimes insufficient for the average person. For adjustable chairs, such as an office chair, the aforementioned principles are applied in adjusting the chair to the individual occupant. Armrests===. A chair may or may not have armrests; chairs with armrests are termed "armchairs". In French, a distinction is made between "fauteuil" and "chaise", the terms for chairs with and without armrests, respectively. If present, armrests will support part of the body weight through the arms if the arms are resting on the armrests. Armrests further have the function of making entry and exit from the chair easier (but from the side it becomes more difficult). 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 couch, bench, or other arrangement of seats next to each other may have armrest at the sides and or arm rests in between. The latter may be provided for comfort, but also for privacy e.g. in public transport and other public places, and to prevent lying on the bench. Arm rests reduce both desired and undesired proximity. A loveseat in particular, has "no" armrest in between. See also seats in movie theaters, and pictures of benches with and without arm rests. Chair seats. Chair seats vary widely in construction and may or may not match construction of the chair's back (backrest). Standards and specifications. Design considerations for chairs have been codified into standards. ISO 9241, "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. ISO 7174 specifies stability of rocking and tilting chairs. ASTM F1858-98 specifies plastic 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: 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. Governments will often issue standards for purchases by government agencies (e.g. Canada's Canadian General Standards Board CAN CGSB 44.15M on "Straight Stacking Chair, Steel" or CAN CGSB 44.232-2002 on "Task Chairs for Office Work with Visual Display Terminal"). Accessories. In place of a built-in footrest, some chairs come with a matching ottoman'". An ottoman is a short stool intended 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 homes with small children and pets. In the second half of 20th century, some people used custom clear plastic covers for expensive sofas and chairs 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. Some manufacturers have patents on their designs and are recognized by medical associations as beneficial. Car seats sometimes have built-in and adjustable lumbar supports. "'Chair mats'" are plastic mats meant to cover carpet. This allows chairs on wheels to roll easily over the carpet and it protects the carpet. They come in various shapes, some specifically sized to fit partially under a desk. "'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. "'Chair glides'" are attached to the feet of chairs to prevent them from scratching or snagging on the floor.

skirt	chair
top 10 words in brain distribution (in article): wear form century body culture time light type woman produce	top 10 words in brain distribution (in article): material design form century wood type time common size produce
top 10 words in brain distribution (not in article): tea horse tooth cell pearl shoe kite foot design drink	top 10 words in brain distribution (not in article): tea build fiber tooth city pearl kite shoe sheep culture
times more probable under skirt 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under chair (words not in the model)
A skirt'" is a tube- or cone-shaped garment that hangs from the waist and covers all or part of the legs. In European culture, skirts are usually considered women's clothing. However, there are exceptions. The kilt is a traditional men's garment in Scotland, and some fashion designers, such as Jean-Paul Gaultier, have shown men's skirts. At its simplest, a skirt can be a draped garment made out of a single piece of material (such as pareos), but most skirts are fitted to the body at the waist and fuller below, with the fullness introduced by means of dart, gores, pleats, or panels. Modern skirts are usually made of light to mid-weight fabrics, such as denim, jersey, worsted, or poplin. Skirts of thin or clingy fabrics are often worn with slips to make the material of the skirt drape better and for modesty. The hemline of skirts can be as high as the upper thigh or as low as the ground, depending on the whims of fashion and the modesty or personal taste of the wearer. Some medieval upper-class women wore skirts over 3 metres in diameter at the bottom. At the other extreme, the miniskirts of the 1960s were minimal garments that may have barely covered the underwear when seated. Costume historians typically use the word "petticoat" to describe skirt-like garments of the 18th century or earlier. History. Skirts have been worn by men and women from many cultures, such as the lungi, kanga and sarong worn in South Asia and Southeast Asia, and the kilt worn in Scotland. The earliest known culture to have females wear miniskirts were the Duan Qun Miao, which literally meant "short skirt Miao" in Chinese. This was in reference to the short miniskirts "that barely cover the buttocks" worn by women of the tribe, and which were "probably shocking" to Han Chinese observers in medieval and early modern times. Skirts in the 19th century. During the nineteenth century the cut of women's dresses in western culture varied more widely than in any other century. Waistlines started just below the bust (the Empire silhouette) and gradually sank to the natural waist. Skirts started fairly narrow and increased dramatically to the hoopskirt and crinoline-supported styles of the 1860s; then fullness was draped and drawn to the back by means of bustles. Skirts in the 20th and 21st centuries. Beginning around 1915, hemlines for daytime dresses left the floor for good. For the next fifty years fashionable skirts became short (1920s). then long (1930s), then shorter (the War Years with their restrictions on fabric), then long (the New Look), then shortest of all during the 1960s, when skirts became as short as possible while avoiding exposure of underwear, which was considered taboo. Since the 1970s and the rise of pants for women as an option for all but the most formal of occasions, no one skirt length has dominated fashion for long, with short and ankle-length styles often appearing side-by-side in fashion magazines and catalogs. Male wear. There are a number of male garments which fall under the catergory of "skirt" or "dress." These go by a variety of names and form part of the traditional dress for men from various cultures. Usage varies- the dhoti is part of everyday dress on the Indian subcontinent while the kilt is more usually restricted to occasional wear and the foustanella is used almost exclusively as costume. Robes, which are a type of dress for men, have existed in many cultures, including the Japanese kimono, the Chinese cheongsam, the Arabic thobe, and the African Senegalese kaftan. Robes are also used in some religious orders, such as the cassock in Christianity and various robes and cloaks that may be used in pagan rituals. Examples of men's skirts and skirt like garments from various cultures include: In the Western world skirts, dresses and similar garments are considered primarily women's clothing today although historically that was not the case. The wearing of skirts by men in these areas is generally seen as cross-dressing although some fashion designers such as Jean-Paul Gaultier have produced skirts for men and kilts are widely accepted in some situations.	A chair'" is used to sit on, commonly for use by one person. Chairs often have the seat raised above floor level, supported by four legs. A back or arm rests in a "'stool'", or when raised up, a bar stool (adults) or high chair (young children). A chair with arms is an "'armchair'" and with folding action and inclining footrest, a recliner. A permanently fixed chair in a train or theater is a "'seat'" or airline seat; when riding, it is a saddle and bicycle saddle, and for an automobile, a car seat or infant car seat. With wheels it is a wheelchair and when hung from above, a swing. The design may be made of porous materials, or be drilled with holes for decoration; a low back or gaps can provide ventilation. The back may extend above the height of the occupant's head, which can optionally contain a "headrest". A chair for more than one person is a couch, sofa, settee, or "loveseat"; or a bench. A separate footrest for a chair is known as an "ottoman", "hassock" or "pouffe". History of the Chair. The chair is of extreme antiquity. Although for many centuries and indeed for 1000s 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 in the United Kingdom and Canada, and in many other settings. Committees, boards of directors, and academic departments all have a 'chairperson'. Endowed professorships are referred to as chairs. 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. In ancient Egypt chairs appear to have been of great richness and splendor. Fashioned of ebony and ivory, or of carved and gilded wood, they were covered with costly materials, magnificent patterns and supported upon representations of the legs of beasts or the figures of captives. The earliest known form of Greek chair, going back to five or six centuries BCE, had a back but stood straight up, front and back. During Tang dynasty (618- 907 AD), a higher seat first started to appear amongst the Chinese elite and their usage soon spread to all levels of society. By the 12th century seating on the floor was rare in China, unlike in other Asian countries where the custom continued, and the chair, or more commonly the stool, was used in the vast majority of houses throughout the country. In Europe, it was owing in great measure to the Renaissance that the chair ceased to be a privilege of state, and became a standard item of furniture whoever could afford to buy it. Once the idea of privilege faded the chair speedily came into general use. We find almost at once that the chair began to change every few years to reflect the fashions of the hour. The 20th century saw an increasing use of technology in chair construction with such things as all-metal folding chairs, metal-legged chairs, the Slumber Chair, moulded plastic chairs and ergonomic chairs. The recliner became a popular form, at least in part due to radio and television, and later a two-part. The modern movement of the 1960s produced new forms of chairs: the butterfly chair, bean bags, and the egg-shaped pod chair. Technological advances led to molded plywood and wood laminate chairs, as well as chairs made of leather or polymers. Mechanical technology incorporated into the chair enabled adjustable chairs, especially for office use. Motors embedded in the chair resulted in massage chairs. Design and ergonomics. Chair design considers intended usage, ergonomics (how comfortable it is for the occupant), as well as non-ergonomic functional requirements such as size, stack ability, fold ability, 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 design 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 supposed 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 at 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. Some chairs have foot rests. A stool or other simple chair may have a simple straight or curved bar near the bottom for the sitter to place his or her feet on. 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. Many chairs are padded or have cushions. Padding can be on the seat of the chair only, on the seat and back, or also on any arm rests and or foot rest the chair may have. 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 chairs that are intended primarily for outdoor use. 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 maximum pressure is reduced. Actual chair dimensions are determined by measurements of the human body or anthropometric measurements. 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 when seated. For American men, the median popliteal height is 16.3 inches and for American women it is 15.0 inches. 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 15-17 inches 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 leg room (the seat pitch less the thickness of the seat at thigh level) is so small that it is sometimes insufficient for the average person. For adjustable chairs, such as an office chair, the aforementioned principles are applied in adjusting the chair to the individual occupant. Armrests===. A chair may or may not have armrests; chairs with armrests are termed "armchairs". In French, a distinction is made between "fauteuil" and "chaise", the terms for chairs with and without armrests, respectively. If present, armrests will support part of the body weight through the arms if the arms are resting on the armrests. Armrests further have the function of making entry and exit from the chair easier (but from the side it becomes more difficult). 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 couch, bench, or other arrangement of seats next to each other may have armrest at the sides and or arm rests in between. The latter may be provided for comfort, but also for privacy e.g. in public transport and other public places, and to prevent lying on the bench. Arm rests reduce both desired and undesired proximity. A loveseat in particular, has "no" armrest in between. See also seats in movie theaters, and pictures of benches with and without arm rests. Chair seats. Chair seats vary widely in construction and may or may not match construction of the chair's back (backrest). Standards and specifications. Design considerations for chairs have been codified into standards. ISO 9241, "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. ISO 7174 specifies stability of rocking and tilting chairs. ASTM F1858-98 specifies plastic 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: 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. Governments will often issue standards for purchases by government agencies (e.g. Canada's Canadian General Standards Board CAN CGSB 44.15M on "Straight Stacking Chair, Steel" or CAN CGSB 44.232-2002 on "Task Chairs for Office Work with Visual Display Terminal"). Accessories. In place of a built-in footrest, some chairs come with a matching ottoman'". An ottoman is a short stool intended 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 homes with small children and pets. In the second half of 20th century, some people used custom clear plastic covers for expensive sofas and chairs 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. Some manufacturers have patents on their designs and are recognized by medical associations as beneficial. Car seats sometimes have built-in and adjustable lumbar supports. "'Chair mats'" are plastic mats meant to cover carpet. This allows chairs on wheels to roll easily over the carpet and it protects the carpet. They come in various shapes, some specifically sized to fit partially under a desk. "'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. "'Chair glides'" are attached to the feet of chairs to prevent them from scratching or snagging on the floor.