RESUMEN
Musculoskeletal and emotional disorders are important causes of reported diseases, causing medical absences, and eventually earlier decrease of work ability. This paper reports the results of a study carried out among practical nurses working at the Orthopedics and Trauma Institute. The objectives of the study were: (a) to describe the routine activities performed during day and night shifts, and (b) to compare the work activities performed in different wards during these shifts. A Brazilian version of the Work Ability Index--WAI (TUOMI et al., 1994) was answered by 83 practical nurses. Forty-three of them (52%) reported pains or musculoskeletal diseases, either based on their own opinion or diagnosed by a physician. These nurses were invited to join the second phase of the study and twenty-nine accepted it. All work activities performed in 29 shifts were observed and recorded. The results showed that day shifts were far more demanding in terms of the number of activities related to patients' care than afternoon and night shifts. Also, body postures associated with day work activities demanded important physical efforts. The number of nurses in charge during night shifts was substantially lower than during day shifts. This could lead to an overload and affect the health of the nurses.