Ergonomics: History and Definition

• Ergon means work, nomos means laws or standards.
• Ergonomics is the science of adapting machines, furniture, and tools to the person who uses them regularly to achieve greater comfort and efficiency, while respecting their physical, physiological, psychological, and social limits.
• Frederick Taylor is considered the father of industrial engineering and the founder of the "Scientific Organization of Work," which includes disciplines like quality, safety, hygiene, and optimization.
• Walt Disney propelled ergonomics forward.
• Frank and Lilian Gilberth, precursors of ergonomics, created "Therblings," methodologies of work in small and specific movements where the production of products repeats.
• Humans began creating stone weapons and using fire to meet their needs and evolve.
• In the Middle Ages, inventions were devised and sciences were used for human benefit.
• During the Industrial Revolution and World War I, countries created repeated production methods for the high demand for weapons, techniques incorporated into the principles of Industrial Engineering, such as manufacturing and optimization.
• Initially, the Scientific Work Organization sought to adapt the man to the machine, making the machine an authority that subjected the worker.
• Ergonomics seeks to solve problems such as inadequate handling of loads, environments, chemical-environmental conditions (toxicity), use of protective equipment, personal interactions, work times, and their repetitiveness.
• The Human Factors Society in the USA emerged in 1957, International Ergonomics Association is its representation and holds congresses on different themes.

Types of Ergonomics

• Physical Ergonomics: Focuses on anatomy, anthropometry, physiology, and human biomechanics for the proper functioning of production processes, including body measurements, organ functions, and natural movements.
• Cognitive Ergonomics: Focuses on mental processes such as perception, memory, reasoning, and motor response.
• Organizational Ergonomics: Focuses on optimizing sociotechnical systems, collectivity, design, cooperation, and quality management.
• Man-Machine System: Includes at least one human element attending to a need. The machine is the physical object used to perform an activity with a specific purpose. The environment consists of political-legal, economic-financial, sociocultural, technological-scientific, and ecological-geographical factors.
• Ergonomics in Man-Machine systems optimize the synergy of components, improve performance, and integrate all characteristics.

Universal Ergonomic Design Principles

• Equitable Use: Useful and marketable to people with disabilities.
• Flexibility in Use: Accommodates a wide range of individual preferences and abilities.
• Intuitive Use: Easy to understand, eliminating complexities.
• Perceptible Information: Considers the user and their sensory capacity
• Tolerance to Error: Minimizes risks and consequences of accidents
• Low Physical Effort: Efficient use causes minimal fatigue
• Size and Space for Approach and Use: Communicates conditions of use and mobility

Occupational Risk Factors

• Physical factors include noise, temperature, radiation, and biometric pressures.
• Chemical factors include particles, dust, gases, mists, vapors, and fumes.
• Biological factors include viruses, bacteria, fungi, and parasites.
• Ergonomic factors include forced postures, repetitive movements, and manual lifting of loads.
• Psychological factors include work stress, interaction with people, and work overload.

Safety Standards

• NOM 001: Safety standard focused on buildings, premises, facilities, areas, and work centers, considering employers' and employees' obligations, surveillance, safety requirements, conformity evaluations, ventilation, etc.
• NOM 011: Health standard focused on safety and hygiene conditions in work centers where noise is generated, considering employers' and employees' obligations, maximum 95 decibels with personal protective equipment, determines acoustic pressure and resistance to noise.
• NOM 012: Health standard focused on safety and hygiene conditions in work centers where ionizing electromagnetic radiation is generated, identifying risks and sources of exposure, as well as placing appropriate signs and emergency plans.
• NOM 013: Health standard focused on safety and hygiene conditions in work centers where non-ionizing electromagnetic radiation is generated (microwaves, lasers), identifying risks and sources of exposure, as well as placing appropriate signs and emergency plans.
• NOM 015: Health standard focused on safety and hygiene conditions in work centers with elevated or reduced thermal conditions that affect the worker's health by altering their body balance.
• NOM 024: Health standard focused on safety and hygiene conditions where vibrations are generated that affect the body, muscles, or bone structure, as well as the worker's balance.
• NOM 025: Health standard focused on safety and hygiene conditions regarding lighting in work centers, expressed in lux according to the area of the work plan.
• NOM 030: Health standard focused on safety and hygiene conditions in the search for accident prevention and safety at work, seeks to prevent diseases and comply with safety standards, training for emergencies and evacuation routes, fire fighting and first aid
• NOM 035: Health standard focused on safety and hygiene conditions in work centers with psychosocial risk factors, such as anxiety disorders, severe stress, maladjustment, violence, severe traumatic events, etc.
• NOM 036: Health standard focused on safety and hygiene conditions in work centers with ergonomic risk in the manual handling of loads, with consequences such as fatigue, accidents, occupational illnesses developed by incorrect back strain

Virtual and Auditory Boards

• Boards for transmitting information indicate the conditions of the machine, performance, and productivity through striking messages accompanied by lights or sounds, seeking to draw attention to operators and prevent failures and accidents.

Rules for Developing Boards

• Should reflect complete performance, marking ideal limits and appropriate efforts
• Includes signals for decision-making and implementation of control actions.
• Are simple and understandable for the operators.
• Make failures or malfunctions evident.

Types of Boards:

• Dynamic Boards: Change continuously over time, usually indicating temperature and pressure, such as CRT displays (radar, sonar, TV, cinema).
• Qualitative Scales Indicate non-exact values, including graphics and inferences.
• State Indexes reflect basic conditions in which a machine is found (off, on, etc.)
• Static Boards: Unalterable, include signs, tables, graphics, physical labels, or written material.
• Quantitative Scales: reflect exact values and quantities.
• Alarm Indicators: Indicate when there is a state of insecurity or emergency.

Human Factors

• Human factors include people in life and work situations, their relationship with machines, procedures, environments, and their relationships.
• Visual and auditory performance, reaction times, olfactory performance, touch, attention, and surveillance tasks are all human factors.
• Ergonomics studies circadian rhythms, those that regulate biological activity during the 24 hours of the day, and what happens when they are affected.

Aspects of Organizations and Work

• Organization and Management: Working times, shift design, staff selection.
• Work Groups: Formal and informal interactions, leadership processes.
• Work Situations: Risk and accident control, use of PPE, alarm systems.
  • Individuals: Fatigue, dissatisfaction, excessive errors, delays, professional ailments.

Anthropometry

• Science studies the measures and proportions of the human body to adapt machines to their operators.
• Studies methods and techniques for obtaining magnitudes, statistical processing of data, use of data for the design of objects for human use.
• Applied in industrial design, consumer product design, machines, tools, workstations, and work stations, considering anatomical, anthropometric, physiological, biomechanical, psychological, and sociocultural factors.
• Cineanthropometry: Discipline that deals with the size, shape, and composition of the human body to understand all processes involved in growth, physical exercise, and athletic performance.
• Lack of anthropometric adequacy is the most frequent cause of Discomfort, Fatigue, Errors, Dissatisfaction, and Musculoskeletal Injuries, even causing bone deformities during growth.

Types of Anthropometry

• Static Anthropometry: Measures the body while it is fixed in a position, allowing measurement of the skeleton.
• Dynamic Anthropometry: Assesses movements as complex systems, with the skeleton analogous to articulated links, with muscles as springs
• Workers should not make unnecessary efforts to observe informative devices and manipulate controls.
• Lack of information prevents having parameters for the design and construction of tools, machinery, and equipment that prevent damage to worker health.

Equipment Considerations for Workplace Design

• Dimensional Factors: Compatibility between dynamic anthropometric measurements of potential users, design objects, and dimensions, shapes, structures.
• Informative Factors: Compatibility between the capacity for the perception of information by workers before and during work, analyzed from censoring the perception.
• Ambient Factors: Atmospheric factors like humidity, temperature, ventilation, among others.
• Social Factors: Compatibility of interpersonal relationships among team members
• Organizational Factors: Mark the hierarchies among the members.
• Cultural Factors: Compatibility of the individual psychosocial aspects and the cultural environment where it develops.

Areas of ergonomic design application

• Industrial Design: Design of products such as furniture, tools, medical equipment, and automobiles that are easy to use and safe.
• Interior Design: Optimization of workplaces, homes, and public spaces to maximize comfort and efficiency.
• Web Design: Design of websites and digital interfaces that are easy to navigate, accessible, and user-friendly.
• Occupational Ergonomics: Adaptation of jobs and tasks to reduce the risk of injuries and increase productivity.
• Transport Design: Design of vehicles and transport systems that are comfortable, safe, and easy to use.
• Minimum height of an office or desk is 71-79 cm to allow for free movement of legs when sitting.
• Spine curves unnaturally if desks are lower than the recommended height.

Consequences of Poor Posture

• Lumbar discomfort
• Neck and shoulder pain
• Breathing difficulties and exhaustion
• Dizziness and migraines
• Digestive issues
• Weakened abdominal muscles
• Vertebral frailty

Considerations in development processes

• Anthropometry and biomechanics
• Adjustment to avoid uncomfortable postures
• Control management
• Perceptual Sensitivity
• Durability of Materials
• User Safety
• Ergonomic test stages
  • Establish test objectives
  • Determine relevant measurements.
  • Determine the Sample population.
  • Construct a test protocol.
  • Develop test tools
  • Train test personnel
  • Prepare physical and equipment resources.
  • Obtain participants
  • Conduct test pilot phase
  • Conduct main test
  • Determine if requirements are met

Principles of Universal Design

• Equitable use
• Flex usability
• Simplify user input
• Tolerance for error
• Low burden of exertion
• Appropriate size and space

Protocol Parts

• problem Definition
• Objectives
• Performance evaluation metrics
• profile of usability participants
• procedure

Documentation used for testing:

• Participant Evaluation Form: Used when selecting participants.

• Background Questionnaire: Used to see if they have used similar products.

• Musculoskeletal disorders are associated with risk factors where damage accumulates over a period of time.

• Work-related musculoskeletal disorders (WMSDs) are injuries or disorders of the muscles, tendons, ligaments, nerves, peripheral, joints, cartilages.

• Trauma causes WMSDs by a working physical impact, in static and/or strained positions, repetitive movements and vibrations.

• Injuries result in fatigue, muscle pain, numbness, weakness, etc.

Common lesions due to overexertion:

• Tendonitis
• Tenosynovitis
• Trigger finger
• Epicondylitis
• Ganglion cyst
• Bursitis
• Carpal tunnel syndrome
• Hernia
• Cervical syndrome
• Lower back pain

Preventing Lesions:

• Ergonomic design of workspaces
• Avoid sustained postures
• Periodic changes of employment
• Micro-breaks with extension
• Provide area clearance
• Use automated tools if available
• Occupational Biomechanics is the study of the human body through a mechanical lens.

Body Components

• Bones, tendons, joints, and muscles

• Main bone types

  • Compact
  • Spongy

• Joint classifications

  • Synovial
  • Non-synovial

• Considerations for designing work stations

  • Body size
  • Energetic consumption
  • Ergonomic Principles