ergonomics principles and guidelines

7/28/2019 Ergonomics Principles and Guidelines

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Ergonomics Principles and

Guidelines

For Area OHS Supervisors

UNSW SCHOOL OF PHYSICS OHS MANAGEMENT SYSTEM

Based on UNSW Ergonomics Principles and Guidelines


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WHAT IS ERGONOMICS?

ERGONOMICS is the scientific study ofhuman performance at work

WHY IS IT IMPORTANT?Application of ergonomics principles to work

practices allows prevention and control

musculoskeletal injuries arising from repetitiveor forceful movement or/and maintainingawkward or constrained postures


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Examples of Musculoskeletal Disorders

Injuries: sprains, strains, tears, degeneration

Symptoms: discomfort, pain, muscle fatigue,swelling, stiffness, inflammation, numbness,tingling, burning sensation, heaviness,weakness or clumsiness in hands

Disorders: Repetitive strain injury, Occupationaloveruse syndrome, Tendonitis, Carpal tunnelsyndrome, Degenerative disc disease, etc


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Area OHS Supervisors Responsibilities

Implementing and maintaining ergonomic principles Ensuring that people in your area are properly

trained in ergonomic principles Ensuring that people in your area follow safe

ergonomic practices Actively practicing and developing positive attitudes

towards ergonomic issues Ensuring that people in your area use the

ergonomic equipment provided Considering workplace layout, ergonomics and

individual needs when allocating tasks to people inyour area


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Responsibilities of Individuals

Complying with ergonomic safety instructions oftheir Area OHS Supervisors

Not putting themselves or other at risk by their

actions or omissions Making proper use of ergonomic equipment

provided

Using training received in applying ergonomic

principles to their tasks Reporting potential ergonomic hazards and

problem to their Area OHS Supervisors


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Work with Computers: What to

Consider Job design

Work practices: work breaks, keyboarding

duration, task rotation

Workstation: posture, chairs, desks,computer monitors, computer mouse,

ergonomic accessories


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Work with Computers: Job designand Task rotation

If possible, the job should be designed toallow rotation of work and inclusion oftask not involving repetitive and dynamic

muscle movement.

Work with Computers: Keyboarding

A safe working level of 4 hours ofintensive keyboard work per day (notincluding breaks) should not be exceeded


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Work with Computers: Work breaks

Where the job does not provide adequatebreaks through task variety, it isrecommended that short frequent breaksshould be taken during periods ofintensive computer use, i.e. 2-3 minutesevery 20-30 minutes. These breaks should

include whole body movement. Forexample, fatigue in the back is relived bystanding up and walking around


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Work with Computers: Posture

The feet are supported on the floor, or a footrest (if kneesare at greater that 900 )

No pressure caused by the front edge of the chair seatunder the thighs

The upper body is upright with the lower back firmlysupported by the backrest

The shoulders are relaxed and not hunched

The elbows and upper arm are close to the body

The head is upright or slightly inclined forward withminimum of strain on the neck

Forearms are horizontal and the wrists are straight whenthe fingers are on the keyboard


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Stable (a 5 star base)

Adjustable height range suited to the desk

A stable, independently adjustable backrest Freely moving castors when used on carpet or

glides for use on a hard floor surface

Armrests are not recommended as they arelikely to interfere with the ability to move thechair close enough to the desk

Work with Computers: Chairs


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Work with Computers: Desks

Height adjustable desks are the preferred option. Theheight to the top if the work surface should be between580mm and 730 mm above floor level

For a fixed height desk: between 680mm and 720mm The minimum work surface area: 1500mm x 900mm and

the maximum bench thickness 25mm The volume of leg space: minimum of 800 wide x

550mm deep x 580mm high The viewing distance to work: between 350 mm and 780

mm No sharp edges, protrusions or rough surfaces It is recommended that work surface be continuous due

to increase mouse usage, keyboard and mouse are onthe same level


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Work with Computers: Monitors

It is recommended that the screen is located

at approx arms length away from the

user

Directly in front of the user

Eye level and the bottom can be readwithout a marked inclination of the head

No glare and reflections


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Work with Computers: Mouse

To minimise fatigue when using the mouse:

Place the mouse on the a mouse pad to restrictthe area of movement for the hand and arm

Ensure the mouse is used with a straight wrist

The mouse pad should be placed as close aspossible to the keyboard to avoid over-reachingwith impact on shoulder/neck muscles


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Work with Computers: Ergonomic

AccessoriesConsider the following when trying to

address the ergonomic issues

A footrest

Document holder

Monitor stands and Monitor arms

Screen filter


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Look out For Other Repetitive

Actions or Sustained PosturesExamples:

Laboratory tasks, e.g. pipetting

Workshop task, e.g. repetitive hammering,repetitive lifting

Electronic workshop, e.g. soldering


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Environment: Lighting

Suitable light levels based on Australian Standard AS 16801990 Interior Lighting:

General background 200 Lux

Routine office work (typing, filing) 400 Lux

Work with poor contrast (proof reading) 600Lux

Overhead lighting should be fitted with glare reducing diffusersand light should fall from the side rather than from the front to

avoid reflection

Windows should be on the side of the user if possible, notdirectly behind or in front of the screen


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Work with Computers: Ventilation

Air movement of less than 0.1 meter per secondcan lead to stuffy rooms whereas air movementof more than 0.2 meters per second causes

droughts to be felt.

Australian Standard AS 1668.2 1991 Mechanicalventilation for acceptable indoor-air qualitysets

the minimum rate of 10 liters per second perperson for general office space or 10 liters persecond for every 10 square meters of floorspace


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Work with Computers: Indoor

Climate A comfortable temperature range for sedentary

work is between 210 and 240 C

The optimum range of relative humidity is 40-50%. Relative humidity below 20% can causedryness of the eyes, nose, throat and build up ofstatic charges. Humidity above 80% can cause

fatigues Draughts around the neck and the feet can

cause muscle contraction

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