Physiology
Physiology
Physiology is the study of the human body’s systems and biomechanics, focusing on its responses, capabilities, and physical limitations in relation to product use.
Biomechanics
Research and analysis of the mechanics (operation of our muscles, joints,
tendons, etc.) of the human body.
Key Physiological Factors in Design
Physiology Factors
Human factor data related to physical characteristics used to optimise the
user’s safety, health, comfort and performance.
Visual Accuracy
- Visual accuracy refers to the sharpness or clarity of vision.
- It can be reduced by factors like age, poor lighting, screen glare, or uncorrected vision problems.
- Designs should ensure that text is legible (considering font size, type, and contrast), and that screens and interfaces are easy to read.
Colour Perception
- Users with difficulty distinguishing certain colours (e.g. red-green colour blindness).
- Designs should avoid relying solely on colour to communicate information (e.g. using red for “stop” without a label).
- Use strong contrast, patterns, or icons in addition to colour cues.
Approximately 8% of men and 0.5% of women have some form of color blindness, making it crucial to consider in design.
Strength
- Users vary in strength based on age, gender, health, and fatigue levels.
- Tasks that require too much physical effort can exclude users or lead to strain.
- Levers, grips, and assistive mechanisms can reduce required effort.
Muscle Control
- Fine motor control is the ability to perform precise movements.
- It can be limited in young children, older adults, or users with certain conditions.
- Designs should avoid requiring precise or delicate movements.
- Buttons should be large and well-spaced, avoid requiring high dexterity.
Hearing Thresholds
- Sensitivity to sound declines with age or noise exposure.
- Some users may not hear high-frequency or low-volume sounds.
- Use visual indicators with sound, avoid reliance on high-frequency alarms.
Fatigue
Fatigue
Physical or mental exhaustion during repetitive or prolonged tasks.
Factors That Contribute to Fatigue
- Repetition: Performing the same movement or task continuously without variation or rest.
- Duration: Working for long periods without sufficient breaks.
- Force: Using excessive strength repeatedly (e.g. heavy lifting, tight grip tools).
- Posture: Holding uncomfortable or awkward positions (e.g. reaching, bending, standing).
Think of performing squats as a way to understand the physical causes of fatigue:
- Repetition: Repeating squats without variation leads to muscle overuse and exhaustion.
- Duration: Holding a squat position for too long builds up strain and discomfort.
- Force: Adding weights increases the physical effort required, causing fatigue more quickly.
- Posture: Performing squats with poor form places extra stress on joints and muscles, increasing fatigue and injury risk.
Environment (poor lighting, temperature, noise, or vibration) and mental load (tasks requiring high concentration, decision-making, or emotional strain) can also have an impact on fatigue.
Health Impacts of Fatigue
Prolonged or unconsidered fatigue can lead to:
- Musculoskeletal disorders (MSDs): like lower back pain
- Increased error rates: especially in high-stakes tasks (e.g. surgery, driving, industrial control).
- Reduced reaction time: leading to higher accident risk.
- Chronic fatigue syndrome: in extreme or repetitive strain cases.
- Workplace injury: fatigue is a major contributing factor in industrial and transport-related accidents.
To what extent should designers prioritise physiological data over aesthetic or cultural considerations?
The Hydrate Spark smart hydration bottle is designed to help users track their daily water intake. It features a touch-activated LED display, a sensor that monitors fluid levels, and a Bluetooth connection to a mobile app. The bottle is available in multiple sizes and materials, including stainless steel and BPA-free plastic, and is shaped for easy grip and portability.
Explain how the designer may have collected static anthropometric data and psychological data to aid the development of the Hydrate Spark smart hydration bottle. (6 marks)
Solution
Static Anthropometric Data
- Deals with body measurements when the user is not in motion.
- Collected by measuring a range/percentile of users’ hand sizes or grip spans (primary data), or from books/manuals/software databases (secondary data).
- Used to determine the size, shape, and grip texture of the HidrateSpark bottle to ensure it is comfortable to hold and easy to carry.
Award [1] for explaining how the designer may have collected static anthropometric data to aid the development of the HidrateSpark bottle, up to [3 max].
Psychological Data
- Relates to users’ psychological responses to sensory inputs.
- Collected through user trials or focus groups evaluating the bottle’s visual appeal, LED glow feedback, app interface, and material feel.
- Used to determine the most engaging lighting cues, finishes, and motivational features to encourage hydration.
Award [1] for explaining how the designer may have collected psychological data to aid the development of the HidrateSpark bottle, up to [3 max].
