Ergonomics, Anthropometrics, and Human Factors

Comprehensive flashcards covering key concepts of Ergonomics, Anthropometrics, Physiology, Biomechanics, and Psychological Factors from the lecture notes.

What Greek words do "ergonomics" and "anthropometrics" derive from, and what are their meanings?

"Ergonomics" derives from "ergon" (work) and "nomoi" (natural laws). "Anthropometrics" derives from "anthropos" (man) and "metron" (measure).

What are the primary goals of ergonomics and anthropometrics?

To reduce stress, fatigue, and errors; increase safety; increase ease of use; enhance operational comfort; and improve system performance, reliability, and maintenance.

What are the three main types of ergonomics and their focal areas?

1. Physical ergonomics (posture, layout, repetitive stress, occupational safety). 2. Cognitive ergonomics (mental processes such as perception, memory, reasoning). 3. Organisational ergonomics (communication, work design, work hours, teamwork).

When was the Ergonomics Research Society (ERS) formed, and what was its significance?

It was formed in $1949$ during a meeting of psychologists and physiologists, becoming the first ergonomics society in the world.

How does ergonomic design improve efficiency, usability, and functionality?

Efficiency reduces strain and fatigue to complete tasks faster; usability makes products easier and more intuitive to operate; functionality ensures a product performs well for its intended purpose.

What condition can be caused by frequent use of power tools without vibration-dampening handles?

Hand-arm vibration syndrome (HAVS).

Who was Henry Dreyfuss, and what key figures did he introduce to codify human factors?

An industrial designer who authored "Designing for People" ($1955$) and "The Measure of Man" ($1959$), introducing "Joe" and "Josephine" as average anthropometric representations.

What is the key difference between static and dynamic anthropometric data?

Static (structural) data refers to measurements taken while a subject is in a fixed or standard position, whereas dynamic (functional) data refers to measurements taken during movement or physical activity.

What is volumetric data or kinosphere in dynamic anthropometrics?

The space that can be reached by easily extending limbs, also described as the "gesture reach" or "zone of reach".

What four key factors cause variations in human body dimensions?

Age, gender, ethnicity/regional differences, and disability.

Why are airplane controls designed based on the $5\text{th}$ percentile arm length?

Designing for the $5\text{th}$ percentile ensures that users with the shortest reach can reach all controls, thereby allowing all larger users to reach them as well.

Why is door clearance height typically designed for the $95\text{th}$ percentile or higher?

To ensure that the tallest proportion of the population can fit through without hitting their heads, while shorter people fit easily.

What is the "method of extremes" in anthropometric design?

Using extreme percentile ranges (such as the $2.5\text{th}$ or $97.5\text{th}$ percentile) when designing to ensure safety and protection where there is a real risk of injury.

What is the difference between a "range of sizes" and "adjustability"?

"Range of sizes" refers to producing a product in multiple fixed sizes (e.g., clothing sizes), while "adjustability" allows a single product to be altered by the user to suit their proportions.

What is multivariate accommodation in product design?

Designing to fit several anthropometric variables simultaneously (e.g., sitting height, leg length, and arm reach in a vehicle) so that users are not designed out by conflicting measurements.

What is a workspace envelope, and which percentile group is it designed for?

A 3-dimensional space within which physical work activities are performed from a fixed position, typically designed for the $5\text{th}$ percentile so $95\text{\%}$ of users can reach everything inside it.

What is the difference between physical comfort and psychological comfort?

Physical comfort involves physical ease and usability, while psychological comfort involves sensory feedback (touch, feel, texture, build quality) that gives the brain a perception of quality and ease.

What is fatigue in human factors, and what is its relation to comfort?

Fatigue is a person's sense of physical or psychological tiredness that negatively impacts performance; it is a consequence of discomfort, which ergonomic design aims to prevent.

What four key criteria of biomechanics must designers consider to reduce physical impact on users?

Force, repetition, duration, and posture.

In biomechanics, at what task cycle time is a job considered highly repetitive?

$30\text{ seconds}$ or less.

How can designers accommodate users with colour vision deficiencies (colour blindness)?

By not relying solely on colour to convey information (adding text, symbols, or patterns), ensuring high contrast, and using colour-blind-friendly palettes.

What design considerations support users with limited muscle control or dexterity?

Larger controls that are easy to press, avoiding complex movements like twisting or pinching, and offering alternative inputs like voice commands or motion sensors.

In colour psychology, what emotions or meanings are commonly tied to red and green?

Red is associated with urgency and warnings; green symbolizes eco-friendliness, growth, health, and sustainability.

What is the noise level threshold in the UK at which employers must assess worker risk and provide PPE?

80\n\,dB.

What four environmental factors determine thermal comfort in a workplace?

Air temperature, radiant temperature, air velocity, and humidity.

What is the difference between open-plan offices and defensible spaces in workplace design?

Open-plan offices encourage discussion, collaboration, and communication, whereas defensible spaces provide privacy required for focused thinking.