Physiological Factors in Design
- Designers consider physiological factors to ensure products meet ergonomic needs
- They do this by focusing on user safety, health, comfort, and performance.
Definition
Physiological factors
Physiological factors refer to the physical characteristics and capabilities of the human body that influence how we interact with products.
Physiological factors refer to the physical characteristics and capabilities of the human body that influence how we interact with products.
Key Physiological Factors
Designers use a range of physiological data to inform their decisions. Some key factors include:
- Muscle Strength
- E.g.: The handles of a suitcase should be designed to require minimal grip strength, ensuring that users can comfortably carry them without excessive strain.
- Endurance
- E.g.: Office chairs should be ergonomically designed to provide lumbar support, allowing users to sit comfortably for extended periods without experiencing back pain.
- Visual Acuity
- E.g.: Road signs should have high-contrast colors and large, clear fonts to ensure drivers can read them quickly, even from a distance or in low-light conditions.
- Tolerance to Hot or Cold Temperatures
- E.g.: Coffee cups should have insulated sleeves to prevent users from burning their hands while holding a hot beverage.
- Hearing Range
- E.g.: Alarm clocks should produce sound frequencies that fall within the human hearing range, ensuring that users can wake up even if they have minor hearing impairments.
- Hand-Eye Coordination
- E.g.: Video game controllers should have well-spaced buttons and responsive joysticks to accommodate quick and accurate hand-eye movements, enhancing the gaming experience.
Tip
Consider how these factors might vary across different user groups, such as children, adults, and the elderly.
Comfort and Fatigue
Comfort
- Comfort is being free of physical pain
- Designers care about this because it influences how users interact with products.
Example
- Think about an office chair that adjusts in height and recline.
- This flexibility caters to different comfort preferences
- Think about the same chair that is built in a single frame but the user has a choice of softer or firmer materials depending on the purpose or comfort preferences
Fatigue
- Fatigue is a feeling of tiredness or weakness that develops over time.
- It can lead to musculoskeletal disorders (MSDs) affecting muscles, nerves, and tendons.
Risks include:
- Exerting force to move or drag heavy items
- Carrying heavy objects
- Stooping or crouching
- Extending arms above the headMaintaining uncomfortable or strained positions
- Repeating identical or similar movements frequently
Note
Designers should consider:
- Performance: Designs should minimize fatigue and allow users to sustain optimal performance for extended periods.
- Health and Safety: Fatigue increases the risk of injuries, which can be permanent or lead to chronic pain.
- Ergonomics: Poorly designed tool handles may encourage unsafe or harmful usage, leading to potential strain or injury.
Biomechanics
- Biomechanics is the study of the mechanical movements of the human body.
- Designers use biomechanics to:
- Develop inclusive designs that consider physical abilities, strength, and movement
- Avoid increasing the risk of musculoskeletal disorders (MSDs)
Key Biomechanical Factors
- Force: The amount of compression, pushing, twisting, or pulling a person can exert
- Repetition: How frequently a task is repeated
- Posture: The position of the body during a task
- Duration: How long a task is performed or repeated
Example
A computer chair designed with lumbar support helps maintain proper posture, reducing strain during long hours of use.
Task Analysis Using AI
- Software like Soter Analytics uses AI to analyze video of users performing tasks. It identifies risky movements that could lead to injury.
Theory of Knowledge
How might cultural differences influence perceptions of comfort and fatigue in design?
Reflection Questions
- What are some physiological factors that designers collect data on to optimize user safety and performance?
- How can designers reduce the risk of musculoskeletal disorders (MSDs) in their designs?
- Think about a task you frequently perform. How might the principles of biomechanics and ergonomics improve your performance and reduce the risk of injury?
