What it is and what it’s for
The ROSA method allows for a structured assessment of postural factors in offices using computer screens. It is based on observing how the individual interacts with common elements of their workstation. The results help identify intervention priorities and document which conditions require further review.
It is one of the available ergonomic assessment methods and should be chosen based on its suitability for the task. It is not a universal method for industrial work, manual handling, or any seated activity. Before applying it, it is advisable to verify that the observed scenario corresponds to the type of workstation for which it was developed.
Elements that are observed
ROSA considers the chair, including aspects of the seat, backrest, and armrests, as well as the use of the screen, telephone, keyboard, and mouse. It also incorporates usage time through its scoring criteria. The conditions are combined according to the method’s tables, not through a free sum designed by the evaluator.
The analysis must reflect actual usage. A properly adjustable chair may be misused because the desk prevents it from getting close enough. A mouse may be correctly positioned initially but end up being displaced by documents or other equipment. These interactions explain why simply observing empty furniture or reviewing only sales data sheets is insufficient.
Prepare a representative observation
It’s important to identify tasks, their duration, changes in position, and shared equipment. The person should work in their usual way, avoiding assuming an artificial posture just for the assessment. Their explanations help identify difficulties that don’t appear for a few minutes, such as switching between screens, consulting papers, or taking calls while entering data.
When different activities are involved, a single image may not accurately describe the exposure. It is necessary to justify which situations are observed and how their differences are interpreted. In shared workspaces or remote work, it is also important that the available adjustments and equipment allow the workstation to be adapted to each user and the specific context of use.
Scoring and interpretation
The final score for the method is expressed on a scale of 1 to 10 and guides the level of action required. It should be obtained using the corresponding version and tables, keeping the partial scores. These allow for an understanding of why a particular result was achieved and which specific elements need improvement.
A single score provides little guidance. Two positions may obtain similar scores for different reasons and require different solutions. Nor should a low score be interpreted as a guarantee of the absence of any risk. ROSA does not diagnose an injury or prove that a symptom is solely due to a posture observed during the assessment.
Turning results into improvements
The measures taken should address the observed causes: seat adjustment, equipment positioning, workspace, or the need for assistive devices. Anthropometry helps verify whether the dimensions and adjustment ranges are suitable for the users. Simply buying a new chair does not resolve an issue of a surface being unsuitable for the task.
Training on adjustments is useful when the physical conditions allow for their implementation. It’s advisable to test the solutions with those working at the workstation to ensure they don’t simply shift the problem. For example, moving the keyboard closer shouldn’t leave no room for frequently consulted documents or force users into an awkward posture.
Practical example
A person uses a laptop for most of the day, alternating between documents and calls. Observation reveals that moving the screen closer forces the keyboard to be raised, while positioning it comfortably leaves the screen too low. The analysis also shows a lack of space for organizing reference materials.
The improvement combines separate input devices, proper screen positioning, and a reorganization of the work area. The entire task is then observed again, and the relevant assessment is repeated. The goal is not simply to lower a number, but to verify that the overall approach allows for working with less postural strain and without creating new difficulties.
Scope within display screen workstation assessment
The assessment of visual display units must also consider aspects not fully covered by ROSA, such as visual demands, lighting, glare, organization, mental workload, and environmental conditions. In Spain, preventive obligations arise from applicable regulations, not from the mention of a specific method in a report.
Workplace sedentary behavior cannot be resolved simply by improving sitting posture. Duration, variation in activity, and movement possibilities must be analyzed. Follow-up should verify whether the measures are being implemented and review changes in equipment, tasks, or any discomfort reported by users.
Common mistakes
Common mistakes include using ROSA as a certificate of conformity for furniture, scoring a staged photograph, or modifying the tables without explaining that the methodology has been altered. It is also a mistake to evaluate only one user when the position is shared among people with clearly different needs.
A useful application maintains traceability between observation, scoring, and preventive measures. It should identify the version used, the conditions studied, and limitations. If the main problem falls outside its scope, the assessment should be supplemented with other techniques, rather than forcing all job risks into a single postural score.
