OFFICE ERGONOMIC GUIDELINES - EQUIPMENT SET UP
- Visual Display Unit
- Document holders
- Mouse Controls
- Equipment Layout on Desktop
- Office Accessories
- PC Set Up for Bi/tri/multi Focal Wearers
- Adjustable brightness and contrast between the background and the text
- Free from reflections, screen flicker and glare
- Able to rotate and tilt to be easily adjustable
- At an appropriate height above the work surface where the top line of text is just below eye level (15 degrees)
- Legible characters of appropriate size, colour and quality
- No greater than six colours should be simultaneously displayed
The orientation of the VDU will also influence posture, particularly head posture and ease of viewing
See the Posture Checklist for more information.
- Fixed monitor raisers or monitor arms are used at times to enable optimum screen placement.
- Some monitor arms offer increased flexibility in monitor heights. These are often a good consideration for multiple user stations
- Desk top stands often take up more desk space than the monitor arms– a small number have adjustable heights
- Some large monitors may require the desk to pulled out from the wall to ensure it is at a comfortable viewing distance. Care needs to be taken with balancing the equipment to prevent tipping.
- Phone books may provide an adequate short term solution to adjusting monitor height, providing they are not required to be accessed once the monitor is set upon them.
- Alternative light control options should be investigated first eg blinds to reduce glare from the work environment.
- Glass, mesh and plastic filters are available and a correct fit to the screen is important
- Regular cleaning is necessary for optimum long-term use.
The source material should not be positioned flat on the desk or in a position to the extreme side of the monitor. To read a document at such angles requires prolonged bending and twisting of the neck and therefore greater prolonged muscle tension.
Preferences for document holders
- At a comfortable viewing distance in line with the screen
- A3 size document holders located between the keyboard and screen can conserve desk space
- Stable and free from vibration
- Consider as well, the need to turn pages frequently or write on the document
- Select from designs on the basis of document size, weight, legibility of documents and reading distance
Keyboard type and position
- It is preferable that the keyboard be separate from the screen to allow the screen and the keyboard to be independently adjusted. This requirement is essential for intensive users.
- There are various keyboard designs, including split keyboards, compact, "Internet" and "ergonomic". These will need to be trialled to check whether the design matches the hand size, finger reach and keying style of the users.
- A shorter, compact keyboard can sometimes assist in reducing arm and shoulder fatigue in combined keying and mouse tasks as it reduces the reach required when using the mouse. Correct arm posture is also important. See the Posture Checklist for more information.
- The primary part of the keyboard to be used (ie alpha or numeric), should be directly aligned in front of the body
- Laptop screens and keyboards cannot be optimally adjusted and consistent use of these for input work is not recommended.
- Attachment of a standard keyboard and mouse and placement of the lap top unit at a height with the top line of text just below the eye line is important for extended keying.
- Over stretching the fingers to reach shift and function keys should be avoided
- Micro pauses in between program operations are important eg resting hand in lap whilst document saves
- Touch typing skills and keyboard short cuts are advantageous as they can cut down on key strokes and mouse use
The problems associated with intense mouse work and work without breaks cannot be solved by mouse design alone. Consider the following options and seek trial of mouse design before purchase where possible through suppliers or colleagues.
Mouse shape and position
- The slope and shape of the mouse fits you best when it allows your wrist to be aligned with the forearm and not at an angle to either side
- Consider the incline of the mouse to ensure there is minimal bending up of the wrist
- The mouse should be used as close as possible to the keyboard
Mouse movement and use
- Controls that allow a variety of finger movement rather than holding a position on a button are preferred as this ensures better blood flow to the muscles and prevents fatigue
- Easy alternation between the left and right hands is a beneficial consideration if extensive mouse use is required
- Moving the whole forearm and not just the wrist side to side to operate the mouse is also important
- Speed can often be altered through the Control panel or mouse software and should be considered as an option to reduce the demands of maintaining a tense grip to control excess movement
Activation force and grip
- A concerted effort needs to be made to relax the grip on the mouse and release the mouse when not in use
- Minimal activation force for button operation is desirable. Eg: standard Microsoft Mouse requires minimal force
- Scroll wheels can reduce prolonged holding down of mouse buttons eg during web searches
- Take care the wheel use does not cause extra finger strain
Track ball controls
- The mouse with the trackball on the top at the middle often places the wrist at an excessive angle and requires the fingers and thumb to stretch when operating the ball. This may cause problems for those with high levels of use, and for people with small hands
- Sitting too long in any chair will lead to fatigue and stress on the spinal column.
A chair needs to maintain the curves of the spine by providing adequate support to the lower back curve. The backrest should be sufficiently padded and contoured to fit and support the small of the back.
- Individual chair needs are different.
Purchase of standard chairs for the whole work group is not recommended without considering people who are shorter, taller or larger than the average. For larger workers a longer seat base is often more comfortable to support the weight and length of the legs.
- Varied postures are important.
Consider a chair which allows alternation between a semi-reclined and upright posture throughout the day, eg when on the phone.
- Adjustable in height whilst seated
- Stable under normal operating conditions at all heights
- Have backrest adjustable in height and tilt whilst seated on the chair
- Allow close access to the desk. Some armrests impede correct arm posture whilst keying
- Select styles to suit task requirements eg. Sit-stand stools, glides rather than castors for vinyl floors, easy care covering, draughting style for high desktops
- Some people prefer a higher back rest which can offer a good opportunity to change posture and lean back when reading
- The backrest width should not impede keying posture by causing the arms to be held out to the side
- Chairs may not move easily across some surfaces leading to extra strain on the upper limbs in pulling and pushing the worker towards or away from the desk
- Use of a plastic or vinyl floor mat over carpet can be of assistance
Castors or glides
- Glides are recommended if chairs are on linoleum or similar floors, as castors may present a hazard by rolling too freely
- Lockable castors may be used on linoleum floors. These are free rolling when there is no weight on the chair, and lock in position when weight is applied
When selecting a desk design, consider the tasks to be performed and the adjustability required to meet the range of sizes of users and the diversity of task performed at the desk.
Desk top size
Desk top sizeAdequate width and depth of desk top allows for correct posture at the keyboard. If there is insufficient space for source documents, muscles can be strained by holding or balancing documents. Australian Standard 3590.2-1990 Screen based Workstations, defines the following minimum desk top sizes;
- Mixed tasks eg computer and clerical - 1500 X 900mm
- Singe tasks eg computer only - 1200 X 900mm
Large monitors may necessitate the need for larger space.
- Older style desks are often too high for most employees compared to those designed for computer use. With increased desk height there is a tendency to tense the shoulders to key or write
- Adjustable desks are an advantage where desks are shared by different sized workers
- Australian Standard 3590.2-1990 states fixed height keyboard desks should be in the height range of 680 mm to 710mm
Standing height benches
For standing height benches such as laboratory benches or reception counters, adjustable height is preferred to suit workers of different heights. In most offices, having a higher work area is often useful to provide safe and efficient working postures for layout, sorting and collating of documents. Australian Standard 3590.2-1990 states;
- Fixed height – approximately 950mm
- Adjustable height – at least adjustable between 900 and 1100mm
Leg Well Space
The underside of the desk should be free from obstruction to the knees and shins through items such as under desk CPU holders and drawer units. Australian Standard 3590.2-1990 recommends the following for leg well spaces;
- Minimum depth 550mm
- Minimum width 800mm
- The desk top and supporting frame should be a maximum thickness of 30mm to allow for adequate leg clearance.
Cutout keyboard platforms (part of the desk structure)
- Can assist with establishing a relaxed shoulder position whilst keying by lowering the keyboard
- Designs which adequately fit the mouse control on the same level are preferred as raising the shoulder and over reaching to the mouse must be minimised
Attached keyboard extensions (located under the desk on a moveable arm)
- Purchase of desks fitting the standard depths rather than this equipment is the preferred option thus allowing monitor and keyboard location on the desk top
- Fittings may obstruct leg space
- Need to look for designs that fits mouse at same level
Desk top raise
- Extended periods of reading or writing at a desk may cause flexed and uncomfortable postures. Bringing the material up to the worker on a sloping work surface with a desk top raise may be helpful. Various sizes are available.
- Generally the items most frequently handled should be within easy reach
- Less frequently used equipment and materials should be placed within the distance reached by the outstretched arm
- Telephones are ideally positioned on the non-dominant side to allow pick up and holding in the non-dominant hand while writing or keying with the dominant hand
- Holding the handset between the shoulder and ear creates excessive muscular tension in the shoulder and neck
- When phone answering is frequently combined with keying and or writing a phone head set should be considered
- The footrest should be stable, height adjustable and large enough to comfortably accommodate both feet.
- Repetitive, forceful and awkward hand and wrist postures whilst using office accessories also needs to be avoided as this can also lead to discomfort
- Non routine processes involving prolonged tasks such as stapling, hole punching, flipping through heavy lever arch files, guillotining, handling of heavy reference texts and large mail outs should only be performed for short intervals, at a relaxed pace. Staff are often not conditioned to perform these tasks for extended periods and are therefore at higher risk of injury.
- As we age it is natural for our visual capacities to decline. It is important to have you eyes checked regularly. Current advice from the Australian College of Opthamology states the use of computers does not cause damage to an employee's vision.
- For those who wear bi/tri or mutli focal spectacles, the standard set up of the monitor may not be adequate and may contribute to poor neck posture.
- The monitor must be positioned low enough to allow the user to correctly utilise their spectacles without having to raise their chin to look at the screen.
- The monitor distance from the user needs to match the focal length of the spectacles.
- It is vital you inform your eye practitioner regarding your work activities to ensure the spectacles prescribed suit the primary tasks performed at work.