Using the OVAKO working posture analysis system in cleaning occupations

BACKGROUND: Cleaning workers experience severe musculoskeletal symptoms. OBJECTIVE: The objective of this paper was to examine musculoskeletal symptoms in cleaners of different heights to evaluate the effects of height on working postures in the work environment (schools). METHODS: We used a three-stage method including using the Nordic Musculoskeletal Questionnaire (NMQ) to evaluate musculoskeletal symptoms, a task analysis to confirm typical cleaning tasks, and the OVAKO Working Posture Assessment System (OWAS) for posture analysis. Multinomial logistic regression was performed to evaluate the adjusted effects of individual characteristics on painful body regions, using individuals without any pain as the reference category. RESULTS: This study found that the prevalence of musculoskeletal symptoms is very high for cleaners, especially in the shoulders, elbows, and lower back. Odds ratios for the accumulation of two or more risk factors were higher among men and were inversely associated with national economic indicators. The relatively high prevalence of musculoskeletal symptoms may stem from the multiple operations involved in cleaning tasks, such as trash collecting, floor mopping, toilet cleaning, and mirror polishing. Workers of different heights had differential work loadings for different tasks. CONCLUSIONS: This paper proposes recommendations for job adaptations and occupational safety training. Cleaners of different heights execute the typical tasks via different postures, and awkward postures often result in musculoskeletal symptoms. Cleaners should be provided with specific tools and training regarding working postures on the basis of height. These findings can be used as a reference for related operation designs and task improvements to ensure correct tool usage and safer working postures during cleaning.