Week 02 - Ergonomics

Question 1

What is ergonomics?

Answer 1

an applied science concerned with designing and arranging things people use so that the people and things interact most efficiently and safely

Question 2

Effective application of ergonomic changes to the workplace should eliminate a number of aspects that are undesirable. List the 5

Answer 2

Decreasing fatigue, inefficiency, apathy, the risk of injury, and other difficulties

Question 3

Ergonomic improvement to work systems can be achieved by doing what?

Answer 3

• Designing the user-interface to be more compatible with task and the user
• Change work environment to make it safer and task specific
• Change task to suit user characteristics
• Organise work to accommodate psychological and social needs for people

Question 4

Why is the science of anthropometry an important component of ergonomics?

Answer 4

To know the average body composition and dimensions help aid design of work stations, products to suit majority of people, or target specific groups

Question 5

Explain what a percentile score is and how they are used in ergonomics.

Answer 5

• Describes how far an observation is away from the mean as a function of the SD. (designs must accomodate 5th to 95th percentiles)

Question 6

Explain the difference between postural stress and task-induced stress.

Answer 6

Postural stress:
- Denotes mechanical load on the body by virtue of its posture

Task induced stress:
- Denotes on mechanical effort needed to perform the task

Question 7

What is posture and how is it controlled?

Answer 7

• Some posture aspects happen voluntarily and some outside postural awareness (posture sometimes or losing balance)
• Breakdown in this awareness (conscious or subconscious) :

Question 8

Why is it incorrect to instruct a worker to maintain a “straight back”?

Answer 8

Repeated positioning over time will start producing stress even if its a “correct” posture

Question 9

What are the 4 main risk factors for musculoskeletal disorders in the workplace?

Answer 9

• excessive force/weight
• Posture
• Repetition
• Duration/length of task

Question 10

Explain the “pros” and “cons” of standing and sitting posture in the workplace.

Answer 10

Standing:
- Reach capacity is greater, requires less leg room
- BW can exert forces
- legs are good at reducing vibration
- Lumbar disc pressure is low
- maintained with little muscle activity and no concentration
- trunk muscle power twice as large in standing.
Sitting:
- Requires 20% less energy (very insignificant)
- More precise for fine motor skills
- High injury risk

Question 11

Why is it important to have ergonomic seating in the workplace?

Answer 11

• More precise for fine motor skills, higher effectiveness, more stable
• Economics behind it, lots of money lost
• But 80% of people will develop / experience / injure their back

Question 12

List several myths of ergonomic seating.

Answer 12

• Doesn’t always requires 90 degree angle (upright), this produces more pressure on discs
• You can’t judge how ‘good’ it is by how it feels
• You shouldn’t be able to adjust everything
• Users actually need training
• One chair design will not fit all users

Question 13

Name at least 5 key features of ergonomic chair design.

Answer 13

• Lumbar support (adjustable)
• Back rest
• Arm rests
• pedestal
• accurate chair dimensions

Question 14

• How might an ergonomist use anthropometry in designing or modifying a work task/environment?

Answer 14

• Design equipment to suit the 5th to 95th percentile, add modification accessible for the other 10%, or if equipment not able to be adapted, have screening tests before individuals use the equipment (test if they are strong enough)