1.1a Anthropometrics Notes

Anthropometrics helps ensure Appropriate Sizing and Usability for humans in design

1. Imagine sitting in a chair designed for someone twice your size or struggling to use a smartphone with buttons too small for your fingers
2. It would be pretty annoying right?
3. These examples underline the importance of designing products that fit their users. To achieve this, designers rely on anthropometric data—measurements of human body sizes and shapes.
4. By using this data, designers ensure products are both functional and comfortable
5. In this section, we’ll explore how anthropometric data is applied, its types and sources, and the significance of percentiles and adjustability in creating inclusive designs.

Human factors: What are the main aims?

1. Increasing safety
2. Increasing ease of use
3. Make fewer mistakes
4. Enhancing operational comfort
5. Improving system performance, reliability and maintenance

Ergonomics: Physical, Cognitive and Organizational

Physical Ergonomics: Physical ergonomics focuses on the human body's physical interactions with products, tools, and environments to optimize comfort, efficiency, and safety:

1. Improves human posture and fatigue
2. More efficient Worksite development operating layout
3. Easier material handling
4. Reduces repetitive stress, movement, injuries and musculoskeletal disorders
5. Ensures occupational safety and health
6. The aspect of ergonomics that deals with body measurements, particularly those of size, strength and physical capacity

Cognitive Ergonomics: Designers create systems that align with how the human brain processes information, reducing mental strain and improving safety:

1. Easier perception
2. Improved memory
3. Clear reasoning
4. Quicker motor response

Organizational Ergonomics: Systems made to improve overall workforce efficiencies which includes:

1. Communication
2. Work design
3. Shift (work hours) management
4. Crew resource management
5. Teamwork
6. Virtual organizations
7. Telework
8. Quality management

Ensuring Appropriate Sizing for Comfort and Usability

Why Sizing Matters in Design

1. Poor sizing can lead to discomfort, inefficiency, and even safety risks.
2. To avoid these issues, designers must carefully consider the target user group—their age, gender, cultural background, and physical characteristics—when determining product dimensions.
3. This is especially important for products like furniture, clothing, vehicles, and tools, where physical interaction is frequent and critical.

Considering Interaction and Misuse in Design

Understanding Interaction

1. Interaction refers to how users physically engage with a product. Consider the following questions:
   1. How does a person grip a handle
   2. How much force is needed to press a button?
   3. What is the maximum reach distance for accessing controls?
2. Designers must account for both intended use and potential misuse.
   1. Misuse often occurs when a product is used in ways the designer didn’t anticipate, such as a child climbing on a chair not designed for such activity, creating tipping hazards
   2. Poor ergonomics or unclear instructions can exacerbate these issues

Designing to Minimize Misuse

To reduce misuse, designers can:

1. Simplify interactions: Ensure controls and features are intuitive and easy to understand.
2. Design for safety: Incorporate features like fail-safes or mechanisms that prevent hazardous use.
3. Test with diverse users: Observing diverse users interacting with prototypes can help identify potential misuse scenarios.

Accessing Anthropometric Data: Measurements of Human Bodies

1. Anthropometric data helps designers tailor products to human dimensions.
2. It includes measurements of human body weight, leg length, height, waist size etc.
3. Anthropometric data falls into two main categories:
   1. Static and dynamic measurements

Two types of Anthropometric Data: Static and Dynamic

1. Static Data (aka Structural Data):
   1. These are measurements of the body in fixed positions, such as height, arm length, or head circumference
   2. Static data is essential for designing items like chairs, desks, and helmets
   3. Static Data is easier to gather, as people are asked to remain still while measurements are taken

1. Dynamic Data (aka Functional Data):
   1. These are measurements of body movement, such as reach, movement or strength
      1. E.g., stride length, or range of motion
   2. Dynamic data is crucial for products involving motion, such as gym equipment or tools

Sources of Anthropometric Data

Primary Data Collection

1. Primary data is collected directly for a specific design project.
2. This involves measuring a sample group of users using tools like calipers, motion sensors, sitting height meters or 3D body scanners.

Advantages:

1. Tailored specifically to the target user group.
2. Highly accurate for the intended purpose.

Challenges:

1. Time-consuming and expensive.
2. Requires specialized equipment and expertise.

Secondary Data

Secondary data comes from pre-existing datasets, such as national anthropometric surveys or databases like NASA’s Human Factors data.

Advantages:

• Readily available and cost-effective.
• Covers large population groups.

Challenges:

• May not represent specific user groups (e.g., children, elderly).
• Data might be outdated or irrelevant to the design context.

Percentiles and Ranges: Designing for Inclusivity

What Are Percentiles?

1. Percentiles describe the distribution of a population’s measurements. For example:
   1. The 5th percentile represents the smallest individuals (e.g., shortest height).
   2. The 95th percentile represents the largest individuals (e.g., tallest height).
   3. The 50th percentile represents the average.
2. Percentile ranges
   1. For example the range that encompasses 2.5th to 97.5th or 5th to 95th

By using percentile data, designers can ensure their products accommodate a wide range of users.

Applying Percentile Data

1. Clearance Design:
   1. Can be seen as the minimum space required to, enable the user group into or through an area e.g., for emergency exits or safety hatches you'd want the larger folks to be able to go through easily
   2. Designed for the 95th percentile to comfortable use the product / system
2. Reach (aka Workspace Envelope) Design:
   1. The Workspace Envelope is a 3-dimensional space within which you carry out physical work activities when you are at a fixed location
   2. Designed for the 5th percentile of users meaning 95% of users can reach everything placed within that envelope
3. Adjustable Design:
   1. Certain products tend to be available in different sizes or with adjustability built in as there really is no ‘one size fits all’.
   2. E.g, Ironing tables can be adjusted to allow for people of a different height to use comfortably. This has an effect on the design of the legs, as this is how the board is adjusted in height.

Reliability of Anthropometric Data

Challenges in Data Collection

1. Sampling Bias: Data may not represent the target population (e.g., collecting data only from adults excludes children).
2. Cultural Differences: Body sizes and proportions vary across regions and ethnic groups.
3. Measurement Errors: Inaccurate tools or inconsistent methods can lead to unreliable data.

Mitigating Limitations

• Use diverse and representative samples.
• Cross-check data from multiple sources.
• Regularly update datasets to reflect current populations.

Using Percentile Tables: Ensuring Inclusivity

1. Percentile tables help designers interpret anthropometric data
2. For example, a table might show that the 5th percentile female height is 150 cm, while the 95th percentile male height is 190 cm.

Steps to Use Percentile Tables

1. Identify the relevant measurement (e.g., arm length, height).
2. Determine the target population (e.g., children, adults).
3. Select the appropriate percentiles based on the design context.

Adjustability in Design: Catering to Diverse Users

Why Adjustability Matters

1. People vary significantly in size, shape, and strength
2. A fixed-size product may only suit a narrow group of users, whereas adjustable designs can meet the needs of a broader audience
3. This improves both usability and inclusivity

Key Considerations for Adjustability

1. Clearance: Ensure adequate space for larger users.
2. Reach: Allow smaller users to access controls comfortably.
3. Strength: Design mechanisms that are easy to adjust, even for users with limited strength.

Ergonome: 2D models to assess space requirements and user interaction

1. A 2D scaled physical anthropometric model based on a specific percentile human forms are called ergonomes
2. The ergonomes have been scaled from data taken from specific percentile ranges to form a standard human form
3. Ergonomes are used with drawings of the same scale as the model to consider the relationship between the size of an object and people
4. They are used with 2D drawings, mainly for orthographic drawings and also modelling to view field of reach, field of vision, etc.

Manikin: A 3D models used to evaluate ergonomics, posture, reach, and movement

1. A manikin (aka lay figure) is an anatomical 3D model of the human body
2. A jointed model of the human body used by artists, especially to demonstrate the arrangement of draper
3. They are useful for assessing the relationship of body parts to spatial arrangements represented by a 3D model, for example, a chair to a desk.
4. Full scale manikins are generally more expensive than ergonomes and they give a better representation of the overall ergonomics in the design context (such as crash test dummies)

Conclusion: Designing for Humans

1. Anthropometrics forms the foundation of human-centered design
2. By understanding body measurements, interaction patterns, and potential misuse, designers can create products that are comfortable, safe, and inclusive
3. Whether using primary or secondary data, incorporating percentiles, or ensuring adjustability, the ultimate goal is to design for real people with diverse needs.