The important aspect of physical job design is that it fits with how our bodies operate. Points to consider include:
- joints should be in relaxed and comfortable positions. This makes the work of muscles, ligaments and tendons around joints more efficient. Where extreme positions must be used, they should be held for as little time as possible and not repeated often;
- the work should be kept as close as possible to the body to minimise the stress on the body when reaching to perform a task;
- commonly accessed items should be stored between hip and shoulder height where possible to avoid bending over and reaching up;
- repetitive tasks such as using a keyboard and mouse should be performed for short periods. They are best interspersed with other tasks requiring different postures and movements, e.g. collecting work at the printer, reviewing, photocopying and distributing documents;
- static or fixed postures should only be held for short periods of time and interspersed with different tasks;
- job design should provide the opportunity for people to sit, stand or walk a short distance as a normal part of their duties;
- exertion from the use of excessive force should be avoided; and
- exertion of force should be done in an upright posture, without twisting the spine and preferably using both hands equally.
The core components of an office workstation include a desk, a chair and the equipment used to perform office tasks. Other furniture may include reception desks, paper storage, collation benches and workbenches next to office equipment such as photocopiers, faxes and printers. In the design of office workstations flexibility and adjustability are the key design issues. Individuals can then control how their workstation is set up and organised to meet the changing demands and variety of tasks they perform.
The design of a workstation should be directed by the range of people who may use it, the tasks they perform and the type of equipment to be accommodated.
In addition to adjustability to accommodate the different sizes and statures of people, workstations need to be flexible and large enough to accommodate the growing range of tasks performed and equipment used in offices. The workstation should be easily adjustable and the adjustment mechanism should not create a risk from manual handling. Electric adjustment is the most appropriate.
Posture and movements
The shape and adjustability of a workstation influences the postures people adopt while working. The location and type of equipment used at the workstation also influences the range of movements performed during work. The workstation then is the means of placing people in the best position to enable them to effectively perform their tasks and use their equipment in comfort.
A variety of workstations are used in offices to meet the needs of computer users, including:
- data entry or customer service users – engaged in continuous input tasks such as keying numerical data;
- interactive users – performing a variety of tasks with a considerable proportion of the day interacting with a computer; and
- casual users – using computers on an occasional basis or infrequently during the day.
Workstations should also allow for non-computer tasks, or separate workstations should be available for non-computer work.
In addition to the type of computer usage, the design of a workstation is influenced by the variety of people required to use it:
- multi-user workstations need to be adjustable to meet the needs of different users; and
- single-user workstations need to be adjusted initially to meet the particular dimensions and preferences of the individual. Even after this initial adjustment, the user’s tasks or needs may change requiring further workstation adjustments.
Possibly the most common workstation found in the office combines provision for computing and general administrative duties.
Some office working environments may pose specific risks because of the type of work or the demands of work. Minimising risks in these environments depends on careful assessment of the effects on the people involved. Some examples are listed below.
This workstation usually involves an adjustable chair, a desk, a footrest if needed, desktop computing equipment including a keyboard, a mouse, a hard disk drive and a screen, a document holder, a telephone, and related furniture and equipment. As new technologies and tools are introduced, flexible workstations are required to accommodate the job design changes that occur as a result.
Customer-controlled or ‘call centre’ work
Many office jobs are in telephone call centres, often requiring long periods of time to be spent in a fixed posture. Other OSH issues include hearing problems, what is known as acoustic shock, vocal problems and stress from irate or difficult customers.
The design of call centre workstations and environments is the same in principle as for general office work, but special care must be taken with the design, provision and hygiene of essential equipment such as headsets. Easily adjustable furniture and equipment is important as employees have to move from workstation to workstation both within and between shifts. Given the constrained nature of the work, issues of job design must be carefully considered. These would include introducing some variety into the work, taking adequate breaks and ‘time out’ pauses for operators. In WA there is a specific Code of practice: Occupational safety and health in call centres.
Home-based work is being used increasingly by many large organisations. In addition, many small businesses operate from the home, setting up an office in a section of the house to run the business. A home office may not have the technology available of a large office, for example, a scanner or a photocopier, and repetitive manual work may be increased. Where people work at home, lack of social contact may lead to boredom, lack of motivation and loss of involvement in the decision-making within the organisation. Balance between work at home and contact at work in a larger office setting should be considered.
Some safety and health issues to consider when setting up a home office include:
- the suitability of the range and duration of activities for this environment;
- the suitability of the design of the home office, including workplace layout, provision of furniture, equipment and separation from other areas of the home;
- the environment, e.g. lighting and thermal comfort;
- the selection, motivation and management of staff;
- training in safe working procedures; and
- involvement of the person in the planning and evaluation of work to provide them with control and feedback about their work and prevent isolation.
Policies and procedures should be developed to cover the occupational safety and health issues of working at home, including job design, hours of work, breaks and task variation. Further information on the psychosocial aspects of work is discussed in Psychologically safe and healthy workplaces: Risk management toolkit. Environmental issues are discussed in environmental factors and layout. General information about office workstation design and equipment is discussed elsewhere in this section.
Off-site administrative or audit work
Intensive computer work can be required in circumstances such as reporting proceedings of conferences or corporate meetings, or during audits of organisations. These working environments may be poorly designed for the tasks with inappropriate furniture, lighting, noise and equipment. The work may be highly repetitive over a number of days. A policy should include provision by the host organisation of an appropriate workstation, equipment and environment or the employer should provide portable equipment, e.g. laptop stand, separate mouse and keyboard, and a trolley for equipment transport. Staff numbers should allow for regular breaks from intensive keyboard or mouse use or periods of high concentration.
Reception or counter areas
There are many office jobs which involve interaction with customers or clients. Where work involves a variety of users and tasks, including administrative and computing activities, adjustability is required to accommodate staff. Wider bench surfaces may be required for the placement of delivery items and to improve staff security, but care should be taken to avoid the need for reception or customer service staff to have extended periods of reaching up and forward. Security features, such as screens or emergency buttons, may be required. The design of reception areas should reflect the type of work involved. Desks may need to be low to accommodate discussion and interviews, or high to separate staff from clients or customers. When the desk is high, thought needs to be given to whether staff need to be seated up high, possibly on a high adjustable chair with a footrest, or perhaps a false floor is required to raise the staff to the level of the customer. The height should reflect the type of work and whether the worker is sitting, standing or both at the workstation. AS/NZS 4442 Office desks recommends the appropriate design of counter workstations. Work practices to allow variation in tasks and breaks from constrained posture and customer demands are important.
It is essential that office seating is comfortable, appropriate to the task being undertaken and easy for the operator to adjust. The often held view of the activity of sitting is that people maintain a fixed posture for long periods of time, however, when performing a range of activities, people tend to adopt different positions and postures while seated. This is desirable as it provides variation in loading of the thighs and back and in general can improve seating comfort.
Adjustable office chairs
A chair is the main item of a workstation that provides adjustability for comfort and enables the work heights to be controlled. Key factors to consider when determining if the chair is appropriate for the person and the job are listed as follows:
- it should be adjustable to the task and be easily adjusted from the seated position;
- the seat should be height-adjustable, preferably utilising a gas lift for ease of adjustment;
- the seat should have a curved front edge, to minimise pressure on the underside of the thighs;
- the seat should be able to tilt slightly backwards or forwards;
- it should have a supportive backrest that is adjustable in height, angle and depth;
- both the seat and backrest should be covered by cloth or some other type of material that breathes;
- it should have a five-star base for stability; and
- armrests are optional; they help decrease the forces on the shoulders and back during rest from keying. If provided, armrests should preferably be adjustable in height.
In general, chairs are designed to fit 90% to 95% of the adult population. People outside this range, because they are tall, short or large, may need seating that is tailored to their needs.
Chairs should support the body in a way which minimises awkward postures and provides comfort, however, chair positions may need to be changed often. No chair can provide a perfect position for long periods and it is important to change postures and get up from a chair many times during the day’s work.
Some forms of alternative seating are designed to enable people to sit with the hips at an angle that is believed to reduce pressure on the lower back. These types of seating are not necessarily better or worse than conventional adjustable office chairs, but may not provide the optimum support in a workplace where many hours of the day may be spent in sitting.
There are no current guidelines or design standards for alternative chairs. They should not be used for constant sitting and conventional chairs are also required in the office environment. See Fitness ball not suitable as a chair.
Different seating is sometimes chosen by personal preference e.g. by someone with lower back pain or to look good. Some examples are:
- the ‘kneeling’ chair, a forward tilted chair base with knee support;
- the ‘sit-stand’ or ‘saddle’ chair with a tilted base for ‘propping’ on;
- the ‘physio’ or ‘fit’ ball, an inflated ball which encourages constant small changes in posture to maintain balance; and
- executive chairs, which, as the name suggests, are designed as status furniture for executives and not necessarily designed for practical use.
Their design often provides little in the way of adjustability and seat and backrest design to give support. As most senior managers use computer equipment as a core part of their daily work, executive chairs should include the adjustability and features listed above.
An organisation may choose not to allow alternative seating unless it has been assessed for risks to users or is required by a medical or rehabilitation plan. There are limitations in using these chairs in the workplace, eg:
- the seat is often not able to be adjusted to accommodate different leg lengths or the angle of seat. Some models of the ‘kneeling’ and the ‘sit-stand’ chair do provide adjustments and include an adjustable backrest;
- their use relies on the adoption of a prescribed posture, maintaining the natural curves in the back. Users may need to gradually increase their use of this seating to enable muscles to adapt to the different postures;
- although some of these postures may be preferred for short periods, in general these forms of seating do not provide lumbar support, which leads to the back and abdominal muscles working for long periods of time to maintain the adopted posture if used as a work chair;
- getting on and off and sitting on seats such as the ‘kneeling’ chair and ‘fit’ balls may be awkward, particularly with some types of clothing, and caution is needed; and
- where there is no stable mobile chair base, a person cannot easily move around the workstation as their leg positions are often constrained. They must rely on back and arm strength to move.
Although these chairs allow an upright posture when facing a task, there is a greater degree of reaching, bending and twisting required when accessing other parts of the workstation and there may be risks from loss of balance and extreme postures.
How to correctly adjust an office chair
- The chair height should be set so that the thighs are approximately horizontal and the feet rest comfortably on the floor.
- Combine chair and desk adjustments to position the work at elbow height. Where writing and mouse and keyboard tasks are performed, it may be necessary for the chair height to be adjusted slightly between these two tasks (that is, raised for keying or mouse work and lowered for writing).
- If the chair height is correctly set but the desk is too high, either lower the desk height or raise the height of the chair and use a footrest to make up the height difference .
- The backrest should be adjusted so that its convex curve fits into the curve of the lower back, centred about waist level. A slight backwards tilt of the backrest or forward tilt of the seat will allow an increase in the angle at the hip. This will decrease the force on the lumbar spine.
- If the thighs are wedged between the chair and the under surface of the desk, or the knees bump into the front of the desk then either the desk is too low, the chair is too high, the desk top is too thick or the user is too tall for the chair and desk. An ergonomist can give advice in this situation.
- Small adjustments can be made as often as changes in tasks to adopt the most appropriate posture for the task.
How to decide if you need a footrest
This will depend upon whether your desk is at the required height once you have adjusted your chair to suit your needs. If the desk is too high and it cannot be lowered, then raise the height of the chair and use a footrest to raise the height of the floor by the same amount. Footrests should have height and angle adjustability and be large enough to permit some movement while supporting the feet. A footrest should not be so big that it clashes with the chair base. Using a footrest limits mobility so it is preferable to have full adjustability of the desk and chair to avoid the need for a footrest.
How to decide if you need armrests
Armrests are designed to allow people to support themselves when getting up or sitting down. They are suitable for people who perform a variety of tasks at a workstation, move frequently to and from their chair or sit back in their chair to talk to visitors. Armrests are less suitable for keying work. If the elbows are fixed on the armrests they can cause the shoulders to be raised into an unnatural posture. The desk surface can be used to support the forearms and reduce the effort of supporting the arms. Armrest designs should not limit forward chair movement by touching the desk.
Choosing between castors and glides
Castors allow chairs to be easily moved forwards and backwards, however, they are not suitable for use on non-carpeted surfaces unless fitted with friction brakes. Misuse of a chair with castors, such as standing on it, is hazardous. Glides or castors with friction brakes should be used where chairs do not need to be moved – for example, on visitors’ chairs – or where hard floor surfaces exist. Care must be taken not to provide slippery mats at desks where chairs with castors are in use.
Before purchasing new chairs, it is important to assess use of the chairs and the design features needed. Safe Work Australia’s Ergonomic Principles and Checklists for the Selection of Office Furniture and Equipment provides guidance for the selection of chairs, and the requirements for adjustable height chairs can be found in AS/NZS 4438 Height Adjustable Swivel Chairs . It is the responsibility of suppliers to advise if chairs meet the Australian Furniture Research and Development Institute (AFRDI) Standards. Trial use of chairs in the office is advisable prior to purchase. Be aware that just because a chair meets AFRDI or Australian Standards doesn’t mean that it will be best practice or meet the needs of individual workers. It is important to consider that all workers are different and having a The “one size fits all” policy rarely works due to the variation between individuals and therefore even with adjustable chairs it is worthwhile having a couple of different chair types/brand available to enable workers to select the one that best fits them.
Desks and workbenches
General design considerations
The main factors to consider when choosing desks include:
- tasks to be performed;
- equipment and resources to be accommodated; and
- adjustability to meet the range of different sizes of the users.
Refer to the WorkSafe Australia publication Ergonomic Principles and Checklists for the Selection of Office Furniture and Equipment (1991) and AS/NZS 4443 Office Panel Systems – Workstations for more detailed information on office desks and workstations.
Freestanding height-adjustable desks
These desks are designed to raise and lower the desk surface so that the user can position work at the most comfortable height. They are suitable where different staff use the same desk (multi-user) or where a range of different tasks are performed at the same desk (multi-task).
The length and depth of the desk depends on its use. For example, a computer screen needs to be located at least an arm’s length from the user when sitting in a keying position and the depth of the desk will need to take into account the depth of the screen and the distance required from the user. Where a freestanding desk is used against a wall, it may have to be moved away from the wall to allow the screen to be placed at the rear of the desk and to achieve a suitable distance from the user.
Freestanding fixed-height desks
These desks provide limited flexibility for the user. Chair adjustments are relied on to meet the user and task requirements. In some situations the desk can be modified (raised or lowered permanently) by a trades person; however, this renders the desk unsuitable for use by people of different physical dimensions.
Split desk and keyboard platforms
Some desks used for computing work have an adjustable section to hold a keyboard. These designs limit the range of tasks that can be performed at these desks. If they are used, the selection of a split desk should match the tasks that need to be performed. Adjustment mechanisms located in the leg space under the desk may be hazardous to the knees. A drop down keyboard shelf provides inadequate space for using a mouse, forcing the operator to raise the arm up from the side to use the mouse. Keyboard platforms that slide out from under the desk are not recommended as they cause an increase in the reach distance to other equipment on the desk and generally provide inadequate space for the use of a mouse.
In these workstations, the desk is usually designed to extend along two sides of the partitioning so that it occupies the corner. The corner section usually has a bridging section that is at 45 degrees to the two sides. In some cases the bridging section connects the two sides with a curve to accommodate larger computers, which can be placed in the corner section to take advantage of the increased depth created by the angle. Placement of these larger computers, such as some design and engineering systems, is crucial as they are much deeper than conventional screens and, if placed on one of the side sections of the desk, would be too close to the user.
Corner workstations can be an efficient use of space and often have built-in cable housing. Care should be taken to choose a workstation that does not impose limitations on adjustability or the ability to choose a layout if needs change.
Typical tasks that require a standing-height bench include sorting mail, collating documents, and binding and receiving incoming goods. Drafting workstations may be required for tasks involving drawing or preparing artwork. In some cases, standing-height benches or drafting workstations are used by staff whose capacity to sit for prolonged periods is limited.
Ideally, standing-height benches should be adjustable to accommodate the height differences of the range of people using them. In general, a standing-height bench needs to be between 850mm and 950mm from the floor, but this will depend on the type of task performed. The tasks performed should determine the amount of space required on the bench top. Generally, the length ranges from 1.2 metres up to 3 or 4 metres long. The depth generally ranges upwards from 600mm depending on the tasks to be performed.
Benches are less suitable for seated work, where a desk should be used. Benches usually have limited or no space for the knees, causing a twisted posture. High chairs can be unstable and do not enable a person to place their feet comfortably on the floor or a footrest. Some high desks provide a continuous foot platform to allow for foot support and movement at the workstation.
Sloped work surfaces
Some desk designs incorporate a sloped surface section. Otherwise an angle or sloped board enables the angle of a work surface to be adjusted. It is usually placed on top of a desk and used to raise the height and angle of documents so that the neck is in a more upright posture while reading and writing for prolonged periods.
Eye strain can be decreased by positioning the document at a right-angle to the line of vision. The angle board needs to be adjustable and large enough to support several documents.
General features of desk design
A good desk should have:
- rounded corners with no sharp edges;
- good access for legs with no obstacles under the desk to cause discomfort and possible injury;
- a flat, smooth surface for ease of writing, of a neutral colour with a non-reflective finish; and
- adjustability to fit most users (AS/NZS 4442 Office Desks recommends a range of adjustment for seated tasks of at least 150mm, from 610mm to 760mm in height, easily adjustable from the seated position).
Tips and hints
- When selecting desks and other workstation equipment and furniture, consider:
- tasks to be performed;
- type of equipment and materials to be used;
- adjustability; and
- number of different users.
- Where possible, split desk designs should be avoided as these limit the options for placing equipment and can cause secondary hazards if the user’s legs strike the adjustment mechanism.
- The space under the desk should be free of obstacles to enable safe and comfortable location and movement of the legs.
- Where possible, arrange trials of a variety of desks from suppliers. This allows you to select desks suitable for the variety of tasks performed at each workstation.
- Consider modular workstations that permit flexibility in design and layout.
Data input devices
Of the wide range of input devices used with computers, the ones most commonly used are the keyboard and the mouse. The way in which these devices are used needs to be carefully considered, as repetitive use over an extended period can lead to discomfort and injury.
Use of keyboards in offices varies according to the task. Generally, the more a keyboard is used, the higher the risk of discomfort. This does not mean that people should not use a keyboard extensively in their work. However, job design (including variation in tasks and ability to take breaks from repetitive keying) and adjustable equipment and furniture are important considerations for people who use computers for extensive periods of time.
Safety and health issues also need to be considered for notebook and laptop computers, and small keyboards such as palm types.
To reduce keyboard work, voice recognition and handwriting recognition software can be appropriate for some users.
Placement of the keyboard
The keyboard should be aligned with the computer screen (or document holder if it is the major viewing surface) and directly in front of the user so that there is no need to twist or rotate to use it. It should also be placed near the front edge of the desk to reduce the distance required to reach it.
Reference documents should be placed between the keyboard and the screen or directly alongside the screen. They should not be placed between the keyboard and the front of the desk because this places the keyboard too far away from the user and contributes to poor posture.
Where possible, the feet at the rear of the keyboard should be maintained in a lowered position to minimise the height and angle of the keyboard and reduce unnecessary loading of the shoulder and wrist muscles. There should be sufficient space on the desk so that the keyboard can be easily moved away to create room for another task when it is not in use.
Split keyboards are split in half and angled to enable the joints of the upper limbs to adopt a neutral posture while keying. Keyboards of this type are available commercially but their use is currently not extensive.
Separate numeric pads
As many users do not use numeric pads attached to keyboards, providing a keyboard without a numeric pad can reduce the keyboard width and allow the mouse to be operated closer to the user.
The mouse can come in a variety of shapes and sizes, with features such as a scrolling wheel. The key criteria for the use of a mouse should include:
- placement of the user’s hand and upper limb in as neutral a posture as possible during use;
- support of the weight of the arm by the desk and not by the user;
- keeping the wrist flat during use;
- allowing fingers to rest on the push buttons between actions; and
- ensuring mouse design fits the size of the user’s hand.
Use of a mouse
It is good practice to learn to use a mouse with each hand and periodically change between the hands to reduce or prevent discomfort through prolonged use. Many people are reluctant to try to share the use of the mouse between hands, but if practised the skill to alternate between hands is often developed.
Preventing discomfort when using a mouse
Sustained hand postures during use of the mouse can be reduced by greater utilisation of keyboard shortcuts, changing hands and by moving the mouse towards the middle of the desk and pushing the keyboard back, if the task is primarily a mouse activity.
If used, a mouse mat should be placed immediately beside the keyboard so that reach distance and the risk of discomfort is minimised.
Ease of use and maintenance of the mouse
If the cursor is difficult to control, cleaning the mouse ball and its contents with a suitable solvent (consult the manufacturer’s instructions) and cleaning the mouse pad may make it easier and quicker to use. The computer’s operating system can also be used to alter mouse settings, such as speed and acceleration. An optical mouse, which does not have a ball underneath, can be used.
Alternative cursor controls
Alternatives to the standard mouse are designed to change hand and arm postures and increase efficiency. They include a diverse group of operations, including rollers, pens, balls, pads and glide points. The main difference between a mouse and these devices is that the hand and arm remain stationary while the wrist is at an angle and the fingers or thumb stretch. For long periods of use this way may cause finger, thumb or wrist discomfort. Lifting the hand off the keys while operating the pointing devices is preferable.
Other office equipment
People in offices use telephones to varying degrees. Telephones should be situated so that the user can perform simple tasks, such as taking notes, without the need to twist or support the telephone on the shoulder. A long enough cord is usually sufficient to allow flexible positioning of the telephone to suit the user.
Headsets should be used where the person has to regularly perform tasks such as keying information or taking orders while using the telephone, or does dedicated telephone work, such as in a call centre. Use of a headset can assist in reducing the reach distance and the frequency of handling the receiver and eliminate awkward neck postures.
When a headset is being purchased, the surrounding environment and the need for the user to attend to other signals should be considered when deciding on the design and number of ear pieces.
A hands-free phone may be used for occasions such as a teleconference, but they are not suitable in an open office environment.
Staplers are designed to be used on a bench. With occasional use they do not present a hazard. If thick documents are to be stapled, a stapler appropriate for the task should be used to reduce the need for high levels of force to perform the task. If a stapler is used repeatedly for a prolonged period of time, this may be fatiguing for some people, particularly if they perform the task while seated or the table or bench is at an unsuitable height, requiring them to elevate their shoulders. High usage of a stapler may also result in excessive compression forces to the palm of the hand.
Electric staplers should be used where stapling is frequently required for prolonged periods. The design of an electric stapler should guard against fingers being injured during use and safe work procedures should be implemented.
If use of the stapler is assessed as a risk, control options such as the use of alternative attachment devices (for example, binding, bulldog clips) or the provision of a larger manual stapler or an electric stapler should be considered.
For occasional removal of staples, a small pincer type of staple remover is commonly used in the office. Where this task is identified as a risk, such as highly repetitive staple removing, a lever operated device should be considered.
Removing staples by hand should be avoided. To control the risks associated with staple removing, such as stabbing injuries, some large organisations now ask customers to return documents unstapled. Alternate binding mechanisms should also be considered.
The use of letter openers usually doesn’t present a problem in offices until the level of use increases beyond that used to process personal mail. The slim handle of a knife-like letter opener can be difficult to grasp. A larger handle enables a more solid grip. Repeated handling of mail and the forceful movement required to open mail can be avoided by the use of mechanical letter openers.
A range of hole punches are available – from small lever operated to large electric drill types – and their use should be matched to the thickness of the documents being processed. Longer lever arms enable thicker documents to be punched by a manual hole punch with less force required by the operator. Many photocopiers have a hole punching function. Because of the forceful nature of this work it is preferable to use hole punches at a standing-height bench.
If use of the stapler is assessed as a risk, control options such as the use of alternative attachment devices (for example, binding, bulldog clips) or the provision of a larger manual stapler or an electric stapler should be considered.
Pens and writing implements
Despite the major office tool being the keyboard, a wide range of writing tasks exist in the office. The standard ballpoint pen is suitable for infrequent general use, however, easy ink-flow pens usually require less force to grip and write. A thick grip pen or a triangular attachment to the pen can reduce the overall force required to grip the pen.
Writing for long periods may result in hand or forearm soreness. If this occurs, these periods may need to be reduced or interspersed with other activities.
Wrist or forearm rests
Wrist or forearm rests are incorporated in some keyboard designs or provided to support the forearm during pauses in keying work. In practice, however, people often use the rest while typing, causing the fingers to reach to the keys rather than the whole arm generating that movement. This may cause strain of the muscles and tendons at the wrist. The use of a wrist rest also places the keyboard further away from the user, which can increase sustained load on the shoulders and cause discomfort or muscular strain. Wrist rests should not be required if a workstation has been adjusted to meet the needs of the user.
Reading source documents resting on the surface of the desk for prolonged periods may cause neck and shoulder strains through the adoption of poor posture. Document holders are designed to hold reference material so that they can be positioned according to the visual needs of the user.
Upright movable document holders can be positioned next to the screen at the same height and visual distance from the user as the screen. A-frame or flat document holders can be positioned between the screen and keyboard to support multiple or bulky papers. A-frames need sufficient adjustment to raise, lower and angle documents to accommodate different screen heights.
Screens may need to be raised above desk height to reduce postural strain to the user’s neck muscles. The top of the screen should generally be level with the user’s horizontal eye level and at a distance of approximately one full arm length when the operator is sitting in their usual position for keying. A variety of stands are available to raise screens above desk height. Fixed-height stands tend to be suitable for single user workstations where the height of the monitor suits the individual’s needs and the employee performs varied tasks, including keying, throughout the day. Adjustable height and movable stands can be used to meet the needs of a variety of users or to provide space for other tasks an individual may perform over the day.
As our society progresses to using increasing amounts of digital technology, the number of monitors used by staff is also increasing. When setting up multiple monitors it is important to assess what they are being used for and which screen is used the most. Computer monitors should be of the same size/shape, resolution and contrast so the eyes are not having to continuously adjust as the worker glances between the two screens which can increase visual demand and therefore fatigue. In this situation the staff member needs to look at how they plan on using the screens and setting them up appropriately so their body maintains a ‘neutral’ posture for as much of the time. Having multiple monitors also affects where data input devices are positioned. It is often good to go back to the basic principles of having frequently used items closest to the person and the less frequently used items further away.
Notebook and laptop computers
Laptop computers were designed for short-term or mobile use. The portable nature of the laptop and notebook results in them being used in a wide variety of situations and settings where there is limited capacity to adjust the desk. This can result in the work height being unsuitable. Lack of adjustability of the screen and keyboard can result in the arms being held too high or the neck bent to view the screen. If this position is adopted frequently or for long periods, discomfort may result. If the screen is tilted upwards to reduce the need to bend the neck to view the screen, reflections can be a problem with some screens.
The adverse effects of working on a laptop computer may be prevented by:
- docking the laptop or notebook into a desktop computer at an adjustable workstation;
- connecting into existing computing equipment, such as the screen, keyboard and mouse;
- transferring information from the notebook to the desktop computer for more extensive periods of work;
- being aware of the importance of posture when using the notebook and frequently rotating between keying and other activities; and
- becoming keyboard literate to avoid periods of time looking down at the keys, which can contribute to neck discomfort.
The portable nature of these computers also means that they are frequently used where there is no suitable or adjustable workstation, for example, sitting the computer on the lap or on a kitchen table or using the computer in a cafe or motel. Prolonged use may contribute to discomfort.
Carrying laptop computers may also contribute to back and neck problems. The introduction of laptop computers to school children from an early age, and in some cases for some hours use per day, may mean that problems with portable computers may affect employees even before they enter the workplace.
Ipads/ tablets/ pdas
These and other small electronic devices are normally used for short periods of time. Extended use of this type of keyboard is not recommended. Tablet type devices often encourage excessive neck flexion and cramped hand positioning therefore increase risk of injury. If these are to be used regularly or for longer duration it is worthwhile connecting them to other devices or using external screen and/or keyboard.
Computer docking stations
Docking stations enable use of portable computers in a variety of locations without the need to continually transfer information to a desktop computer once at the office. The advantage of docking stations is the capacity to easily connect the portable computer to other peripheral devices, such as the screen and conventional size keyboard. This can improve the posture, actions and overall comfort of the user.
Mobile phones are common for both office work and home use. Safety hazards, such as loss of concentration leading to accidents, arise when people try to perform additional activities at the same time as using a mobile phone, e.g. while driving. Noise in the office caused by ringing phones should be controlled by a policy of reducing volumes of phones in the workplace. There is some limited evidence on the risks from exposure to radiation sources and noise from mobile phones and it is recommended that mobile phone use is restricted and that phones are stored away from the body.
Voice recognition transfers voice information to an electronic format. This technology has limited application at present, but if the voice becomes one of the major means of entering and controlling computer data, then reliance on the keyboard for input will be reduced.
Software programs for OSH in the office
There are a number of software products on the market aiming to improve safety in the office. For example, there are screen savers which prompt rest breaks or promote good working postures or exercises; programs for assessing or improving workstations; and various checklists and user surveys for assessing OSH in the office. A poorly designed program may interrupt work and raise the user’s annoyance levels. It is important to trial these in your own organisation before purchasing to ensure they will meet your needs.
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