Ergonomics Principles and Guidelines

1. UNSW SCHOOL OF PHYSICS OHS MANAGEMENT SYSTEM Ergonomics Principles and Guidelines For Area OHS Supervisors Based on UNSW Ergonomics Principles and Guidelines

2. WHAT IS ERGONOMICS? ERGONOMICS is the scientific study of human performance at work WHY IS IT IMPORTANT? Application of ergonomics principles to work practices allows prevention and control musculoskeletal injuries arising from repetitive or forceful movement or/and maintaining awkward or constrained postures

3. 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, Occupational overuse syndrome, Tendonitis, Carpal tunnel syndrome, Degenerative disc disease, etc

4. Area OHS Supervisor’s 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 in your area

5. Responsibilities of Individuals • Complying with ergonomic safety instructions of their 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

6. 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

7. Work with Computers: Job design and Task rotation If possible, the job should be designed to allow rotation of work and inclusion of task not involving repetitive and dynamic muscle movement. Work with Computers: Keyboarding “A safe working level” of 4 hours of intensive keyboard work per day (not including breaks) should not be exceeded

8. Work with Computers: Work breaks Where the job does not provide adequate breaks through task variety, it is recommended that short frequent breaks should be taken during periods of intensive computer use, i.e. 2-3 minutes every 20-30 minutes. These breaks should include whole body movement. For example, fatigue in the back is relived by standing up and walking around

9. Work with Computers: Posture • The feet are supported on the floor, or a footrest (if knees are at greater that 900 ) • No pressure caused by the front edge of the chair seat under the thighs • The upper body is upright with the lower back firmly supported 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 with minimum of strain on the neck • Forearms are horizontal and the wrists are straight when the fingers are on the keyboard

10. Work with Computers: Chairs • 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 are likely to interfere with the ability to move the chair close enough to the desk

11. Work with Computers: Desks • Height adjustable desks are the preferred option. The height to the top if the work surface should be between 580mm 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 on the same level

12. Work with Computers: Monitors It is recommended that the screen is located • at approx arm’s length away from the user • Directly in front of the user • Eye level and the bottom can be read without a marked inclination of the head • No glare and reflections

13. Work with Computers: Mouse To minimise fatigue when using the mouse: • Place the mouse on the a mouse pad to restrict the 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 as possible to the keyboard to avoid over-reaching with impact on shoulder/neck muscles

14. Work with Computers: Ergonomic Accessories Consider the following when trying to address the ergonomic issues • A footrest • Document holder • Monitor stands and Monitor arms • Screen filter

15. Look out For Other Repetitive Actions or Sustained Postures Examples: • Laboratory tasks, e.g. pipetting • Workshop task, e.g. repetitive hammering, repetitive lifting • Electronic workshop, e.g. soldering

16. Environment: Lighting Suitable light levels based on Australian Standard AS 1680 – 1990 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 diffusers and 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, not directly behind or in front of the screen

17. Work with Computers: Ventilation Air movement of less than 0.1 meter per second can lead to stuffy rooms whereas air movement of more than 0.2 meters per second causes droughts to be felt. Australian Standard AS 1668.2 – 1991 Mechanical ventilation for acceptable indoor-air quality sets the minimum rate of 10 liters per second per person for general office space or 10 liters per second for every 10 square meters of floor space

18. 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 cause dryness of the eyes, nose, throat and build up of static charges. Humidity above 80% can cause fatigues • Draughts around the neck and the feet can cause muscle contraction