PREMUS 2025: 12th International Scientific Conference on the Prevention of Work-Related Musculoskeletal Disorders
Designing a stair chair as a multi-dimensional system to address musculoskeletal disorders in emergency medical technicians
2Institut de recherche Robert-Sauvé en santé et en sécurité du travail, Montréal, Canada
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Introduction: Paramedics are the first responders in the pre-hospital response chain in Québec (Canada). They play an essential role within the community. However, they are affected by musculoskeletal disorders, and one of the activities posing the greatest risk is moving patients up and down stairs using a stair chair. Therefore, it seems necessary to rethink this equipment. The aim of this study is to highlight the main factors influencing the use of the stair chair and to prioritize those that should be considered in the design of a new stair chair.
Method: A secondary analysis of a previous project involving 81 interviews with 50 paramedics (including 11 women) was carried out using Nvivo 14® software. A database of workplace accidents involving stair chairs (n=378) was also consulted. An analysis grid was designed and validated to analyze the content of the verbalizations. A thematic tree was constructed using an inductive and iterative approach. The extracted variables were subjected to an inter-rater reproducibility test (n=10 interviews), then the tree was refined and a second inter-rater reproducibility test was conducted (n=5 interviews). The factors selected were those most frequently cited by the ambulance staff. The order of priority was determined by the difficulty of use reported by paramedics and the nature of accidents involving stair chairs.
Results: The final tree comprises a total of 39 variables. They were categorized into seven main categories of determinants: beneficiary, work activity, teammate, stair chair, environment, organization and others. The factors influencing emergency evacuation were the beneficiary’s characteristics and cooperation, the dynamics between teammates, the stair chair’s effectiveness in vertical and horizontal movements, and environmental constraints.
Conclusion: This analysis shows that moving a patient on a stair chair is a complex multi-dimensional system. A new stair chair version should aim for greater efficiency and the integration of environmental conditions such as the variability of stairs, transit areas, work surfaces and the characteristics of the patient and partners in pairs.
