Taking a closer look at Ergonomic Seating
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Contents Ergonomic Seating is only average Body Volume and BVI The Shape of Individuals in the future Ergosomatonomics: Shape not Size Ergonomic Seating Basics Conventional Seating Solutions Humanfactor Seating Solutions Realising your Aims
3 4 5 6 8 9 10 11
HF2, HF4, HF5; seating solutions for medium sized individuals HF2, HF4; seating solutions for larger individuals HF3; seating solutions for shorter individuals HF7; seating solutions for taller individuals
12 14 16 18
Humanfactor seating solutions Model Number Codex Body Shape Assessment Web Assessment Humanfactor and Status Seating
20 21 22 23
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Ergonomic seating is only average It is estimated that during the course of an average office worker’s career he or she will have sat in more than 3 but less than 15 different types of office chairs. Statistics don’t actually tell you much really. Some workers stay in the same job for many years and develop a personal attachment to their office chair. Others move between jobs. Over decades office chair design has been driven by the need to comply with adjustable functionality based on Anthropometric guidelines. These averaged body and limb measurements obtained from small samples of evenly-gendered subjects from the UK (or more recently from sample data collected around Europe, or in some studies aggregated from data sourced from around the World) set the limitations on component and product design. We are supposed to accept that statisticians can predict a standard deviation around the mean average of a small sample population and that the guidelines will suit 90% of office workers. That is the basis on which the minimum standards are calculated. Even in the USA, the hotbed of much of the 3-Dimensional anthropometric modelling research that has driven ergonomic seating design into the 21st Century, seating adjustability has been calculated on a sample of only 4431 individuals compiled from studies across the US and Europe. The resulting industry norms, through the application of inferential statistics, have led to the creation of products purporting to suit the mass market – the 5th to 95th percentiles of an inferred normal distribution. However, at the sharp end, when you are up close and personal with the individual user, things can often look and feel very differently. The vast majority of office chairs, designed specifically to fit the guidelines, allow for only the standard deviation of adjustability. In reality there are many individuals that are not average. The effect of only matching standard international guidelines for chair design is that the specific needs of individuals are obfuscated during the average measurement process. The challenges of allowing for adjustability for a user’s height, for longer or shorter limbs, may have been taken into account when designing the chair, but what about body mass, body volume, or the natural laws of gender, ethnicity, age, proportion or well-being? What about the personal stature, shape or combination of shapes that makes the human being the individual? What about the physical displacement of the person’s body volume? This deeply affects our personal interface with the office chair, has no statistical link with body height or limb length and can adversely affect our sense of comfort or support whilst sitting. If you have ever been out at the coalface talking to people about their personal chair nightmare you will know that every individual has a different story, a different sub-set of problems, a different body shape; a different solution from the average.
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Body Volume and BVI What is the Body Volume Index (BVI)? Based on individual body shape rather than one standard measurement technique for all people, BVI divides the body shape of an individual into sections so that the body volume of the body parts and body composition can be analysed. This allows BVI to differentiate between people with the same Body Mass Index (BMI) rating.
Scans of 8 Women with a BMI of 30.0 but with different Body Volume Measurements
BVI is the world's first dedicated computer based anthropometric system and allows a healthcare professional to:• Measure a patient in less than 6 seconds without any radiation or intervention whilst being comfortable for the patient. • Measure the differences in body shape between patients with the same BMI rating or waist circumference. • Objectively track an individual’s data over time to assess changes in a patient's body shape. • Use a health risk indicator by combining a person’s 3D shape with their medical statistics, height, weight, age and gender. How does a BVI scanner work? A patient walks into the 7ft scanner and is scanned in their underclothes to ensure that the contours of the skin are correctly measured - the system is perfectly safe as no radiation is involved and the whole process takes 2-3 minutes from start to finish. BVI data is captured using a 3D camera, but in reality is better described as a 'Human Photocopier' - copying a person's body shape to get measurements that simply can't be done by the human hand. The scan is saved on a secure server anonymously to be accessed by authorised healthcare professionals, takes less than 6 seconds and can extract an infinite combination of measurements for healthcare analysis. Body Volume Imaging is perfectly safe and uses white light only, reflected on the body to create an exact ‘virtual’ image of a person’s shape and weight distribution. BMI is based on height and weight only, but the BVI system automatically measures BMI, waist circumference and waist-hip ratio (WHR) in addition to highly sophisticated volumetric and body composition analysis. It is projected that the scientific and technical development of BVI may follow a similar timescale to BMI, so 2020 is the current projected date for adoption and delivery on the scale required. BVI has undergone clinical trials in the USA and Europe as part of a three year collaborative project, the results of which were presented in October 2010 at a publicly funded launch in Birmingham, UK, with scientific research and evaluation continuing into 2012. 2013 saw 6 scientific and 7 academic institutions involved in the evaluation and validation of BVI as a potential new health risk measurement and indicator. Developments in 2013 included initial benchmarking of BVI values for children aged 4-17 and the collation of 3D data in the US and Europe for normative reference data for BVI in male and female adults and development of an on-line BVI measurement system, allowing it to be used on the same basis as the BMI (Body Mass Index). Until the time when BVI allows us to better measure weight distribution, the implication for office seating is clear – the more precisely that individuals can describe their body shape now the more definitive will be their furniture requirements.
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The Shape of Individuals in the future There are now several scanning techniques employed to create 3-Dimensional imaging or Whole Body Surface Anthropometry. However, the TC2 body scanners used by “Size USA” or the white light BVI scanners used at the University of Aston in association with Select Research will eventually result in a bank of real statistical data that will be representative of all types of individuals dependent on body shape– not an inferred statistical assumption. The data is being collected to provide indicators of potential illness or disease and is used extensively by the UK National Obesity Centre at Heartlands Hospital in Birmingham, but is equally useful in considering furniture design or selection. These new techniques are measuring the body including the soft tissues – an existing science known as Somatometry – and creating a new set of predictable natural laws for understanding body shape – Somatonomics. International research will continue for some years yet, but for now there are just tantalising glimpses of what the ergonomic seating sales foot-soldiers and ergonomic assessors have known for many years: • • • •
Individuals do not always have classical (average) body proportions. In general the action of sitting for women is different from men due to physiology. Body Volume displacement is different between gender, ethnicity and occupation. As we reach middle age our body shape changes due to spinal degeneration and Body Volume distribution.
These issues do not change the need for all individuals to require a comfortable back support when sitting, or that movement is always better for the body than long periods of sitting, but it creates a challenge for designers to identify the specific needs of an individual rather than fitting the individual into a chair designed for the average user. In a world where individuals are working for longer, sitting for longer, and subjecting our bodies and minds to increasing stress it is ever more important to find the right work chair for the individual. The science of understanding an individual’s personal body shape and how it can affect the interaction in his or her personal working environment is upon us. It is more than Ergonomics. It is Ergosomatonomics. It might only be a few years before employers are placing orders for an ergosomatonomic chair to suit an individual subject of pre-determined BVI Body Type F14T-PAC, (or some other such categorisation), that may mean nothing to us today, but will define a person’s gender-specific body shape, life expectancy, insurance category and credit risk.
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Ergosomatonomics: Shape not Size In order to more correctly understand how Office Seating must adapt for the future we need to have a better understanding of the additional factors that will change our self-reflected view of our body shapes and work requirements. Ergonomic Seating already looks at how to provide functional adjustments for people of heights and limb lengths a standard deviation away from the average, but when it comes to fitting a chair to an individual there are more combinations to consider. Body Shape and BMI. Since 1850 it has commonly been proposed that a person’s health and general body structure could be assessed by comparing their weight in accordance with their height – the Body Mass Index or BMI. Many recent surveys and scientific studies have criticised this generalist measure. In particular much research in the 21st Century has tried to establish whether or not there are new body shapes that we should be referencing instead of just tall or short, fat or thin. The fashion industry was quick to latch on to the possibilities of new types of statistical measurement using 3-D technology resulting in a plethora of new size terminology – pear, apple, diamond, hour-glass, ad infinitum. Note that the imagery in Figure 1 is a stereotypical indicator suggesting that people might be obese or underweight proportionately in all body areas. The reality is often a combination of body section shapes. Proportions Ever since Leonardo da Vinci’s sketch of the Vitruvian man, anthropometric measurements have indicated that average body proportions are common. In real life there are a wide range of proportions – long legs with short torsos, short legs with long torsos, wide or thin hips etc.; much more variation than can be determined through a small sample and a normal distribution. Gender and Body Volume Distribution Research has indicated that long periods of sitting affect women differently from men. For women in sedentary office-based occupations body volume gravitates towards the buttocks and thighs. For men, body volume builds up more at the front of the body. In the general population, other research has corroborated that this body volume displacement has a distinct impact on the depth of fleshy support that pear-shaped women experience when they are sitting. It is believed that the fat cells in this part of the body become more dense and supportive and that this body volume acquisition could lift their body more than 25mm higher from the seat than men of similar BMI and also affect their popliteal measurements. Put together, both of these factors will influence or actively affect the desired position of a lumbar support, and the requirement for density and comfort of supportive seat upholstery for women in general and for larger women in particular.
Figure 1
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Gender and Body Flexion Several studies have implied that, due to the different nature and construction of the female hip and joints, men sit differently from women. For men it is natural to sit with legs apart and hips part-rotated. For women, sitting involves rotating the hips a little more (about 5%) pushing back into the seat and raising the position of the lumbar vertebrae. Scandinavian research has outlined that a woman’s erectus spinea contains a higher frequency of Type 1 muscle fibres, which means that they have greater endurance, but they also have greater discomfort when their joints deviate from their neutral posture. Size USA anthropometric research suggested that the lumbar position for a group of men and women is usually within a few millimetres. However the sample in this study also tells us that the males were on average 100mm taller than the females. By implication, if you were to compare a male and female of similar height the female lumbar area is situated higher when seated. The Effects of Age As more people continue to work into their 60’s and beyond it becomes clear that office furniture should reflect the reality that spines change shape over time due to degeneration. There is a stronger risk today of encountering more instances of the need for Back Care chairs for older users regardless of whether or not they have suffered years of previous back-care neglect. The spine naturally shrinks and becomes more stiff and shaped with age, requiring improved support. Ethnic Diversity Researchers in the US also recently discovered that body volume displacement also varies ethnically – and in particular between female ethnic groups. A study showed that Hispanic women and Black women tended to develop more fat on their thighs and buttocks, but less fat on their stomachs than caucasian women. This study was designed to support Waist Hip Ratio (WHR) analysis as an indicator of health. Whereas BMI would suggest that both groups of women would suffer similar health risks, those with higher levels of body fat around their stomachs (the caucasian group) were more likely to develop bowel diseases than those where the body volume distribution was in the anterior areas. Occupation Of course all anthropometric studies select a sample with a wide variety of subjects in order to artificially match prescribed socio-demographic distributions in age, weight and gender. However, one has to question whether this selection is likely to be representative of an office population? By their nature office workers are more sedentary than labourers or service-industry personnel and this is known to affect their body shapes.
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Ergonomic Seating Basics Human Factors and Ergonomics (HF&E) is a multidisciplinary field incorporating contributions from psychology, engineering, industrial design, graphic design, statistics, operations research and anthropometry. In essence it is the study of designing equipment and devices that fit the human body and its cognitive abilities. The two terms "human factors" and "ergonomics" are essentially synonymous. HF&E is employed to fulfil the goals of health & safety and productivity. It is relevant in the design of such things as safe furniture and user-friendly machine and equipment interfaces. Proper ergonomic design is necessary to prevent repetitive strain injuries (RSIs) or associated musculo-skeletal disorders, which can develop over time and can lead to long-term disability.
Obtaining benefit from current Seating Ergonomics primarily means three things: 1. that the office chair fits the user and has appropriate adjustability options. 2. that the office chair enables and stimulates a variety of sitting positions. 3. that the office chair is userfriendly towards a cognitive understanding of the use of the functional controls that might allow for repeated use.
Central to the design of good ergonomic seating is the ability to adjust the back support and seat angle of the chair so as to tilt the user’s pelvis and allow the spine to adopt a natural “S-shaped� lordotic curve, allowing the body weight to be borne by the skeletal structure rather than the muscles.
Avoid problems incorrectly:
that may
arise
Continuous periods of sitting in an incorrectly supported position can result in degeneration of the spinal cartilage (discs) situated between the vertebrae. Lumbar area support has been the traditional method of promoting a lordotic posture. from
sitting
1. Head - Your head weighs as much as a bowling ball - unsupported it can lead to strains in your neck. Poor blood flow also leads to poor concentration. Create a supportive posture and consider additional support. 2. Organs - Poor posture restricts the function of your organs from stomach digestion to lung functions. Improve posture through better seat mechanics and enforcing a lordotic (S-shaped) spinal curve. 3. Back - Poor posture (kyphotic back shape) leads to disc pressure, constricted blood flow and excessive strain on your back resulting in weakening and fatigue. Ensure that the vertebrae line up as if standing by assuming a good posture with correct support for the lumbar area. 4. Arms - Unsupported arms can use up to 80% more effort leading to tendinitis in the wrist, strain in the shoulders, and upper back problems. Adjustable armrests provide support. 5. Legs - 80% of your weight when seated goes through your ischial tuberocities and one of your largest veins runs at the back on the knee. Constricted blood flow creates fatigue. Ensure that the seat pad is of suitable dimensions.
1.
2. 3.
4. 5.
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Conventional Seating Solutions In order to offer new ways to provide adjustability and good posture whilst sitting in office chairs, seating manufacturers are continually pressing to innovate on existing designs and to create new ways for improving the well-being of office workers. Here is a selection of the most common adjustable functions:
Height-Adjustable lumbar vertebrae Support (Backrest height adjustment) To provide comfort and support for the lumbar area of the spine, with the aim of inducing a lordotic S-shaped spinal curve; adjustable in height to suit different users. The Humanfactor chairs are provided with the patented Chiropod®, Therapod® and C-Pod® backrest mechanisms.
Multi-functional Adjustable Armrests To provide support (and direction) of the forearms in order to provide weight-bearing and relieve stress from the shoulder muscle. Humanfactor offer Heavy Duty (HD), height, width and depth-adjustable (3D), or height, width, depth and twist (4D). For some workstations, armrests restrict body movement and should be avoided.
Depth-Adjustable Seat (Slide Seat) To provide the ideal weight-bearing support for the thighs and to prevent a constriction of blood flow caused by compression of the thighs at the front edge of the seat. Humanfactor include a 55mm sliding seat in all chairs, allowing for adjustment between 385mm and 495mm in conjunction with seat size selection.
Shorter and Wider Seats Size also creates a relative feeling of physical perspective. Wider, shorter or longer seat pan lengths are often made available so that the foam on the seat pad is correctly distributed for people of different proportions. All Humanfactor chairs can be fitted with one of four different seat pad sizes.
Adjustable Headrests To provide relief for individuals that are suffering from neck pain, (or to signify authority), headrests are an alternative to larger backrests which can provide additional support to the shoulders for those people with longer trunks. Humanfactor chairs are available with multi-adjustable head rests or a nape pad for the HF7 series.
Back-rake Tension Adjustment Sometimes referred to as “tension control” this adjustment allows the body’s mass to be supported on reclining. For people of different body mass the strength of the support is an aid to finding an equilibrium position where a to-and-fro rocking motion is achievable.
Seat Height Adjustment (Gas Lifts) To suit individuals of different body weights, a selection of gas lifts are available so that chairs can be made suitable for people who weigh from around 45kg up to 150kg. In some cases gas-lifts are used that support body mass up to 220kg. Gas lifts are also available in different height specifications which can help to raise the chair even higher from the floor for those with longer floor-to-knee linear measurements, or for counter, mailroom or laboratory applications. Personal requirements For individuals with specific orthopaedic needs, sensitivities or injuries, the depth and choice of foams can often provide an opportunity to personalise the chair to match requirements. Amputees, pregnant users or people recovering from an accident or injury often find relief from the placement of a cushion or integrated personalised seat pad. One such frequently-requested and recommended item is a Coccyx Cushion or Coccyx Cut-Out where a gap in the foam is created to reduce contact between the sacral vertebrae and the seat pan.
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Humanfactor Seating Solutions Humanfactor seating solutions offer a seating solution for an individual to his or her specific size or shape. Patented back care support Systems and robust tried-and-tested seating assemblies offer the user the possibility of finding a comfortable and supportive seating solution that fits them personally. HF 2 Series: System Chiropod® was developed to provide a robust and effective method of giving flexible support and comfort for the spine to office chair users. Four pre-tensioned straps are located at selected places within a static frame to enable the user to mould their spine into the form of the backrest. There is no access to adjust the strap tension but in practice this has proved to be a perfect solution for multi-occupancy or 24/7 workstations where continual adjustment between shift patterns might be inappropriate. Lumbar force adjustment can be added by the addition of a lumbar pump mechanism. HF 3, HF 5 and HF 7 Series: System Therapod® was developed by Industrial Ergonomist and Biomedical Engineer Kumar Rajaratnam. The System ensures that improved senses of comfort and support can be provided by the personalised adjustment or relaxation of support straps in the backrest. The straps are wrapped into a flexible frame, accessed by unzipping the rear upholstery, and are located so as to support the sacral, lumbar, lower and upper vertebrae, providing a full height backrest support. The entire backrest assembly is also height-adjustable to help to position the straps to the desired position. HF 4 Series: System C-Pod® was launched by Kumar Rajaratnam in 2010 after customer requests to look at a mesh-back version of the same support principle as Therapod®. After 6 years in development C-Pod® was launched with both aesthetic and functional innovations. Adjustable flex-absorption discs link the frame of the mesh to the backrest and thereby provide a dorso-kinetic support without challenging its strength. The ratchet-based mesh-torsioning straps provide the ability to adjust resistance firmness in five locations corresponding with the sacral, lumbar, lower, middle and upper thoracic vertebrae. There are 16 possible adjustments per strap with audible clicks and Braille zones. In order to provide physical encouragement for the automatic adoption of the S-shaped curvature of the spine required for a correct posture, Humanfactor chairs are supplied with a choice of two mechanisms. The Synchronous mechanism moves the seat and backrest together in a prescribed relationship. A ProBax® foam under-layer increases the foam density at the rear of the seat without affecting comfort. The ProBax® foam thus promotes a slight forward tilt of the seat support (around 4 ). Alternatively, the Independent seat-and-back mechanism allows the creation of a personalised combination with a similar or increased angle of forward seat tilt (up to 7 ).
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Realising your aim In the target below, individuals of medium height and medium body volume are represented by the intersection point A between the axes of Body Height and Body Volume. They would find most office chairs suitable for their use. The degree of comfort or personal suitability might depend on the provision of adjustments available for the chair. Points B and C on the target represent shorter people with medium (B) or high (C) body volume. Point D represents medium height individuals with higher body volumes. Points E, F and G represent taller people with high, medium and low body volumes. Remember that individuals often have a combination of shape characteristics – for example a higher body volume on the lower (sitting) part of the body, with a medium body volume in the trunk. See page 21 for an indication of Somatometric Body Assessment.
BODY HEIGHT
F
G
E
A
B
D
BODY VOLUME
C
When choosing an office chair for an individual based on their body shape, or when restricted on choice by the nature of their Body Volume displacement, the key guideline measurements begin with the back and lower limb lengths. This determines a suitable backrest height and seat depth. For example, at Points E, F and G seat depth would be longer and backrest higher. At Points C, D and E the seat depth needs to be wider and at Point C also shorter. When selecting an office chair for an individual that has suffered back or leg injury, illness or limb loss, then the personal options have to be managed more precisely. In many cases a standard chair can be used, perhaps with alterations through adding alternative upholstery etc. Since Ergonomic seating is also beneficial as a means of preventing back pain injury for any shape or stature of user the majority of our sales are in Target Area A.
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HF 2 Series HF 4 Series HF 5 Series
for medium sized individuals
About 75% of our Back Care chair sales are to users of medium size and build. Perhaps they have recently had a new back problem or have had a flare-up of a historical complaint. Perhaps they have had an industrial or traffic accident. More often than not they are people who are struggling to find the right posture in their existing chair and have been recommended a chair with a System Therapod® or System C-Pod® backrest after an independent workplace assessment. These chairs are also perfect for those individuals consciously seeking to actively prevent back injury.
A
A
Body Volume: Seat Size:
Medium Medium
Medium Medium
Models:
HF 2/HF 4/HF 5 series
192 cm – 165 cm –
HF 2 Series chairs for this group are fitted with a medium sized seat and the System Chiropod® backrest which is ideal for multi-use or 24/7 applications. HF 4 Series chairs for this group are fitted with a medium sized seat and the System C-Pod® backrest. HF 5 Series chairs for this group are fitted with a medium sized seat and the System Therapod® backrest.
0 cm –
Available Options: • Independent Seat/Backrest Mechanism for greater choice of body posture and seat/back angle combinations. • With or without 3-dimensional, 4-dimensional or Heavy Duty multi-functional armrests; dependent on chair selection. • Additional independently-adjustable Head Rest. • Optional Coccyx Cut-out foam cushion. • Inflatable Lumbar Pump (for Chiropod® only). • Polished Aluminium Spider 5-star base.
Technical Details: • 685mm black nylon spider 5-star base. • 60mm twin-wheeled castors. • 150kg (23.5 stone) rated gas lift – 110mm adjustment. • Advanced synchronous mechanism - 21 recline. • Lockable in 5 positions. • Side-activated backrest tension control. • Sliding seat – 55mm depth adjustment. • Pressure-sensitive layer of CMHR seat foam. • ProBax® seat foam layer promoting a 4 posture. • Quick-lift 70mm height-adjustable ratchet backrest.
A
Dimensions in mm: Overall height of chair from ground MIN Overall height of chair from ground MAX
HF 2*30 995 1190
HF 4*30 1060 1255
HF 5*30 995 1190
Back height from seat MIN Back height from seat MAX Back width
565 635 525
630 700 495
565 635 525
Seat height from floor MIN* Seat height from floor MAX* Seat pad depth Seat depth adjustment (55mm) Seat pad width
430 555 475 425-480 510
430 555 475 425-480 510
430 555 475 425-480 510
Height of arm-pad from seat† Inner distance between armrests† Outer distance (Total chair width)†
160-260 460 670
160-260 460 670
160-260 460 670
* Seat height depends on mechanism choice. † Measurements depend on arm choice.
Please see Page 20 for an explanation of the Model Codex
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Model HF 2030/AL/PMP
Model HF 5030
Model HF 4140/HR
Optional Pump-Up Lumbar Support for HF 2 Models
Independent mechanism tension control
Synchronous mechanism tension control
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HF 2054 HF 5054 for larger individuals A small number of those who need assistance with finding safe and comfortable chairs are individuals with excess body volume. Additional foam layers and wider seats provide more comfort whilst the use of alternative gas lifts and heavy duty mechanisms allow us to construct a product that can help to provide comfort and suitable back and body volume support.
D 192 cm – 170 cm –
HF 2054 chairs are fitted with a wide seat and a thicker foam System Chiropod® backrest. HF 5054 chairs are fitted with a wide seat and a thicker foam System Therapod® backrest. Technical Details: • 685mm black nylon Spider 5-star base. • 60mm twin-wheeled castors. • 150kg (23.5 stone) rated gas lift – 110mm adjustment. • Advanced synchronous mechanism - 21 recline. • Lockable in 5 positions. • Side-activated backrest tension control. • Sliding seat – 55mm depth adjustment. • Pressure-sensitive layer of CMHR seat foam. • ProBax® seat foam layer promoting a 4 posture. • Quick-lift 70mm height-adjustable ratchet backrest. • V-rated flexible PU CMHR foam in Chiropod® or Therapod®. • With a pair of heavy duty multi-functional armrests.
D
0 cm – Body Volume: Seat Size:
Large Wide
Models:
HF 2054 or HF 5054
Available Options: • Additional independently-adjustable Head Rest. • Optional Coccyx Cut-out foam cushion. • Inflatable Lumbar Pump (for Chiropod® only). • Polished Aluminium Spider 5-star base.
Dimensions in mm: Overall height of chair from ground MIN Overall height of chair from ground MAX
HF 2*54 995 1190
HF 5*54 995 1190
Back height from seat MIN Back height from seat MAX Back width
575 645 535
575 645 535
Seat height from floor MIN* Seat height from floor MAX* Seat pad depth Seat depth adjustment (55mm) Seat pad width
430 555 490 440-495 570
430 555 490 440-495 570
Height of arm-pad from seat† Inner distance between armrests† Outer distance (Total chair width)†
165-245 565 765
165-245 565 765
* Seat height depends on mechanism choice. † Measurements depend on arm choice.
Please see Page 20 for an explanation of the Model Codex
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HF 2054 and HF 5054 backrests are made with a thicker foam depth (left) than the thinner backrest of the HF 2 or HF 5 chairs. This is to provide both physical comfort and psychological reassurance for the larger user whilst also maintaining optical proportions when the chair is assembled with a larger seat pad.
Model HF 5054
Adjustment straps inside the HF 5054 Therapod速 backrests.
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HF 3 Series for shorter individuals Around 12.5% of our sales are for people who are shorter than average. In some cases due to the nature of sedentary work in offices there is a build-up of body volume in the lower and anterior areas of the body disproportionate to the height of these individuals.
B
C
Body Volume: Seat Size:
Medium Short
Large Short/Wide
Models:
HF 3**3
HF 3**5
165 cm – 150 cm –
Finding an appropriate support for the sacral and lumbar areas of shorter people is a consistent problem for chair manufacturers although the back care systems we offer are very effective in pain prevention. Shorter seats are intended to ensure contact between the user’s back and the chair backrest. HF 3**3 chairs are fitted with a shorter seat and a thinner foam backrest. HF 3**5 chairs are fitted with a shorter but wider seat and a thicker foam backrest. Both chairs are fitted with System Therapod®. The Flat 5-star base allows the seat height from the floor to be as low as 410mm. Technical Details: • 685mm black nylon Flat 5-star base. • 50mm twin-wheeled castors. • 150kg (23.5 stone) rated gas lift – 50mm adjustment. • Shorter System Therapod® backrest. • Advanced synchronous mechanism - 21 recline. • Lockable in 5 positions. • Side-activated backrest tension control. • Sliding seat – 55mm depth adjustment. • Pressure-sensitive layer of CMHR seat foam. • ProBax® seat foam layer promoting a 4 posture. • Quick-lift 70mm height-adjustable ratchet backrest. • V-rated flexible PU CMHR foam.
B
C
0 cm –
Available Options: • Independent Seat/Backrest Mechanism for greater choice of body posture and seat/back angle combinations. • With or without 3-dimensional, 4-dimensional or Heavy Duty multi-functional armrests; dependent on chair selection. • Additional independently adjustable Head Rest. • Optional Coccyx Cut-out foam cushion. • Polished Aluminium Flat 5-star base.
Dimensions in mm: Overall height of chair from ground MIN Overall height of chair from ground MAX
HF 3*33 880 1010
HF 3*35 890 1020
Back height from seat MIN Back height from seat MAX Back width
470 540 525
480 550 535
Seat height from floor MIN* Seat height from floor MAX* Seat pad depth Seat depth adjustment (55mm) Seat pad width
410 470 435 385-440 475
410 470 435 385-440 570
Height of arm-pad from seat† Inner distance between armrests† Outer distance (Total chair width)†
160-260 425 635
160-260 520 730
* Seat height depends on mechanism choice. † Measurements depend on arm choice.
Please see Page 20 for an explanation of the Model Codex
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Model HF 3055/AL
Model HF 3033
Individuals of a shorter stature may need to consider using a height adjustable desk.
Or a footrest to support their feet if they are seated at a 740mm high desk.
Adjustment straps inside the HF 3 Therapod速 backrest.
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HF 7 Series for taller individuals Around 12.5% of our sales are for individuals that are tall. It is not unusual for us to be asked to supply chairs for people over 200cm tall. In this instance the individuals might be thin, requiring a narrow seat, but as soon as we encounter tall people of medium or large body volume then their body size and body mass have usually become an issue for chair selection and long-term durability. The chairs therefore have to be manufactured to exacting standards. There is often a high incidence of neck pain for taller people and many years ago we developed a higher backrest that provides both shoulder and neck support for taller people. As an option the HF 7 Series chairs are provided with a neck pad support that fits into the nape of the neck. All HF 7 Series chairs can be fitted with a selection of seat sizes in accordance with body volume. They are supplied as standard with a high backed version of the System Therapod® backrest.
E
F
Body Volume: Seat Size:
Large Wide
Medium Medium
Thin Short
Models:
HF 7**4
HF 7**0
HF 7**3
210 cm – 190 cm –
0 cm –
Technical Details: • 685mm black nylon Spider 5-star base. • 60mm twin-wheeled castors. • 150kg (23.5 stone) rated gas lift – 110mm adjustment. • Advanced synchronous mechanism - 21 recline. • Lockable in 5 positions. • Side-activated backrest tension control. • Sliding seat – 55mm depth adjustment. • Pressure-sensitive layer of CMHR seat foam. • ProBax® seat foam layer promoting a 4 posture. • Quick-lift 70mm height-adjustable ratchet backrest. • V-rated flexible PU CMHR foam in Therapod®.
G
F E
G
Available Options: • Independent Seat/Backrest Mechanism for greater choice of body posture and seat and back angle combinations. • With or without multi-functional 3-dimensional or 4-dimensional armrests. • Optional Coccyx Cut-out foam cushion. • An adjustable neck pad or nape support. • Polished Aluminium Spider 5-star base.
Dimensions in mm: Overall height of chair from ground MIN Overall height of chair from ground MAX
HF 7*54 1180 1375
HF 7*30 1180 1375
HF 7*33 1180 1375
Back height from seat MIN Back height from seat MAX Back width
750 820 505
750 820 505
750 820 505
Seat height from floor MIN Seat height from floor MAX Seat pad depth* Seat depth adjustment (55mm)* Seat width*
430 555 490 440-495 570
430 555 475 425-480 510
430 555 435 385-440 475
Height of arm-pad from seat† Inner distance between armrests† Outer distance (Total chair width)†
165-245 565 765
160-260 460 670
160-260 425 635
* Measurements for 3 seat sizes – see codex † Measurements depend on arm choice.
Please see Page 20 for an explanation of the Model Codex
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Model HF 7140/AL
Individuals of a taller stature may need to consider using a height adjustable desk.
HF 7 chairs can be supplied with a black vinyl heightadjustable nape support.
Adjustable straps inside the Therapod速 back.
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Model Codex Identity Code
HF
First Number Backrests Chiropod® Low Back Therapod® C-Pod® Therapod® High Back Therapod®
Second Number Mechanisms 2 3 4 5 7
Synchro
Independent
0
1
Third Number Armrests No Arms
0
Fourth Number Seat Width Medium
0
3D Arms
3
Shorter Seat
3
4D Arms
4
Wider Seat
4
HD Arms
5
Short/Wide
5
Additional Notes 1. All chairs have a code following the format HF ****. 2. For Armrest options; Chairs with Seat width 4 or 5 will always be HD armrests. 3. All chairs are supplied as standard with a Heavy Duty gas-lift fitted into a black nylon spider-style 5-star base; a flat base for HF 3 chairs. All chairs are also fitted with a sliding seat as standard. 4. The HF 2 Chiropod backrest chairs have an option for a Lumbar Pump (/PMP). 5. All chairs (except HF 7*** High Back Therapods) can also have an optional Headrest (/HR). 6. The High Back Therapod can be supplied with a Neck/Nape Support by adding code (/NP). 7. All chairs can be fitted with an optional polished aluminium 5-star base (/AL). 8. All chairs can be fitted with a Permanent Coccyx Cushion (/PC) which can also be purchased separately for additional support (/CC).
HF 4140/HR
HF 5030
HF 7140/AL
HF 2030
HF 2030/HR/AL/PMP
HF 4140/HR
HF 5030
HF 7140/AL
HF 2030
HF 2030/HR/AL/PMP
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Body Shape Assessment Anthropometric Measurements What body size are you? Do the lengths of your limbs or torso influence the adjustability of your chair or workstation?
A The widest part of the hips or thighs (width between armrests). B From the rear of your back to behind the knees when sitting upright (seat depth). C From the heel to the under side of your thighs (seat height). D From the base of the thigh to the small of the back (lumbar vertebrae) whilst sitting (lumbar support height). E From the seat to the top of the shoulders (backrest height). F From the seat to under your elbow with your arm slightly bent (armrest choice). G Keyboard or Desk Height (requirement for foot stool or heightadjustable desk).
What weight are you? This has an influence on the performance specification of the selected chair? Do you have any specific injuries or medical conditions that affect the way that you sit?
Somatometric Measurements What body shape are you? How do your body proportions or body volume displacement affect your interface with your chair? A = Upper Body Volume, B = Lower Body Volume, C = Proportional Body Volume.
1
F E M A L E
2
1
1
3
3
2
2
4
3
5
4
4
6
5
5
7
6
6
7
1
2
3
4
5
6
7
A
B
1
1
7
C
2
4
3
2
3
4
6
5
5
6
7
7
M A L E
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Web Assessment If you have understood the principles outlined in this document and you would like to direct a colleague, client or friend towards a simplified selection procedure, please search www.humanfactorseating.co.uk/assessment and follow the steps to determine which Humanfactor Seating chair would be most likely to suit their requirement.
BODY HEIGHT
F
G
E
A
B
D
BODY VOLUME
C
Of course it is always preferable to get advice from an independent or company-appointed health professional, ergonomic assessor or orthopaedic furniture agent. They are able to work with specific cases and may be able to offer a variety of sample chairs for an extended trial period. The web assessment is meant only as an indicative guide as it relates to the suitability of our products. You can also complete one of our Anthropometric and Body Volume Data Sheets available to download from the website at www.humanfactorseating.co.uk/datasheets to provide us with a more detailed revision of your needs.
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Humanfactor and Status Seating Humanfactor Seating is a range name within Status Seating, the umbrella sales brand of JFC Engineering Ltd of High Wycombe. Status Seating were founded in 1985 and have been supplying the System Therapod® chairs into the UK since that time.
Other brands being offered under the Status Seating brand include Malmstolen of Sweden and Ergoeconomix® from the UK. JFC Engineering Ltd manufactures steel chair and desk components for many of the UK’s office furniture manufacturers as well as owning Envosort - the specialist mailroom and reprographic office furniture company.
Height-Adjustable Workstations JFC Engineering are manufacturers of manually and electrically operated height-adjustable workstations and control room furniture. For shorter and larger individuals the only acceptable workstation solution is to have a height-adjustable work surface or desk. Similarly these can be an imperative for individuals for whom mobility issues present a problem at work. Since the impact of the Disability Discrimination Act in 1996 there has been a proliferation in available desks of this type. Individuals who like to alternate between working standing up and sitting down, either through flexion problems or personal choice, also find Sit-Stand working to be invaluable.
Foot Platforms or Foot Rests For shorter individuals who find that sitting comfortably on a chair at a desk leaves their feet dangling in mid-air, producing pressure on the back of the lower thigh and constricting the blood vessels located behind the knee, it is also recommended that a foot platform is made available. A suitable platform or Foot Rest should be height-adjustable, wide enough to allow for support during swivelling movements of the task chair and sturdy enough to allow for it’s use as an aid to alighting from the chair.
Quality of Manufacture JFC Engineering Ltd of High Wycombe has worked with Bureau Veritas for many years as its independent assessor of quality control management. JFC Engineering Ltd holds ISO 9001 and ISO 14001 certification. It also holds SSIP certification through CHAS. Chairs manufactured by Status Seating comply with BS EN 1335 pts 1-3 and also many chairs are certificated to BS5459:2000.
Status Seating Limited Berna House, Hillbottom Road, Sands Industrial Estate, High Wycombe, Buckinghamshire, HP12 4HJ
T +44 (0) 1494 686500 F +44 (0) 1494 530258 W www.statusseating.co.uk E sales@statusseating.co.uk