What is ergonomics?
The INSST (National Institute for Safety and Health at Work) adopts the international definition of ergonomics or human factors: it studies the interactions of people with other elements of the system and applies theory, principles, data, and methods to design. Its dual objective is to improve well-being and the overall outcome of the system. This requires considering the entire task: objectives, tools, information, time, environment, coordination, and human variability.
Ergonomics doesn’t aim for an “average person” that everyone must conform to. It considers anthropometric differences, experience, age, abilities, time constraints, laterality, and accessibility needs. A robust design allows the intended population to work safely and accommodates adjustments, breaks, learning, and recovery without relying on awkward postures or overexertion.
Physical, cognitive and organizational ergonomics
Physical ergonomics analyzes body dimensions, postures, forces, repetitive movements, load handling, vibrations, and environmental conditions in relation to activity. Cognitive ergonomics studies perception, attention, memory, mental workload , decision-making, interfaces, and errors. Organizational ergonomics addresses communication, coordination, shift work, task allocation, work rhythms, and sociotechnical design.
The three dimensions intersect. A poorly designed screen can increase mental workload and lead to static postures; an imposed pace can prevent the use of mechanical aids; an organization with constant interruptions can generate errors and muscle strain. Therefore, an assessment that only measures body angles or furniture may be insufficient. The analysis must link exposure, task, organization, and user population.
Differences with safety, hygiene and psychosocial factors
Workplace safety typically focuses on conditions that can cause accidents; industrial hygiene , on exposure to hazardous agents; and psychosocial factors, on organizational and social factors that affect health. Ergonomics is distinguished by its approach to system adaptation and design, although it shares problems and methods with these specialties. They are not isolated disciplines.
Ergonomics is not synonymous with comfort. A task can be uncomfortable without posing the same level of risk as another, and a comfortable solution can introduce errors or hazards. Even a chair labeled as ergonomic does not guarantee a suitable workstation. Suitability depends on the individual, the task, the duration of use, the available adjustments, the workspace, the information available, and the organization of the work.
How to perform an ergonomic analysis
The analysis begins by defining the actual activity and the population exposed. The entire cycle is observed, those performing it are interviewed, and variations, peaks, incidents, and informal strategies are collected. Then, physical, cognitive, and organizational demands are identified, and appropriate and validated methods are selected; a generic list is not applied without verifying its scope.
The results are interpreted in conjunction with duration, frequency, recovery, and combination of factors. The intervention prioritizes eliminating unnecessary demands, redesigning heights and reaches, mechanizing or assisting, improving interfaces and layout, varying tasks, and adjusting timelines. Participation allows for testing solutions before generalizing them. Finally, the outcome is verified through observation, exposure indicators, discomfort, errors, and performance, reviewing whether new risks emerge.
Why is it important?
Inadequate design can contribute to musculoskeletal disorders, fatigue, errors, accidents, mental overload, and inclusion difficulties. EU-OSHA notes that work-related musculoskeletal disorders can affect the back, neck, shoulders, and limbs, ranging from minor discomfort to problems requiring sick leave or treatment. Not every disorder has a single cause; prevention focuses on modifiable workplace factors.
Ergonomics also improves reliability: it makes system limitations visible, reduces unnecessary steps, and makes the right action the easiest. Productivity improvements should not be achieved by intensifying work. The key is sustainable operation that maintains health, quality, and responsiveness throughout the workday and over time.
Practical example
In an order picking area, heavy boxes are stored at floor level, and high-turnover items require repeated turning and reaching. The analysis examines weights, frequencies, heights, distances, space, carts, pace, and variability between shifts. Workers explain that mechanical assistance is underutilized because it is too far away and delays the daily target.
The solution combines redesign: heavy items stored between knee and shoulder height, bringing materials closer together, an adjustable table, accessible assistance, reduced distances, and revised work-rate targets and task rotation that allows real recovery. It is tested with people of varying sizes and experience levels. Afterward, postures, effort, times, errors, and discomfort are assessed. Training in “lifting correctly” would be insufficient without correcting the design that creates the problem.
Regulatory framework in Spain
Law 31/1995 includes among its preventive principles adapting work to the individual, particularly with regard to workstations, equipment, and methods, and mitigating monotonous and repetitive work. The assessment and planning provisions of Royal Decree 39/1997 provide the general framework. There is no single standard that covers all aspects of ergonomics: specific provisions apply depending on the risk and the activity.
Royal Decree 487/1997 regulates the manual handling of loads that pose a risk, especially to the lower back. Royal Decree 488/1997 addresses work with display screens . Royal Decree 486/1997 establishes minimum workplace requirements. The INSST guidelines develop technical criteria. Technical standards can support design, but their application must be relevant and does not replace the assessment of actual work.
