RESUMO
OBJECTIVE: To compare the PEFs in healthy, young, non-active subjects in seated, supine, and prone postures. METHODS: A total of 30 healthy volunteers (15 male, mean age 22.7 years, non-smokers, sedentary) underwent a physical examination, spirometry to confirm normal pulmonary function, and PEF using the Mini-Wright Peak Flow Meter while wearing a nose clip. PEF measurements were repeated three times in each of three positions (seated, prone, and supine) in random order and differed by less than 20 L/min for a given position. Paired Student's t-tests were used to analyze the results, and the significance level was set at 5%. RESULTS: The PEF values obtained when the study participants were in a seated position (481.0 ± 115.1 L/min) were higher than those obtained when participants were in prone (453.7 ± 112.1 L/min) or supine (453.2 ± 114.3 L/min) positions (p < 0.05). No significant difference in PEF values was observed between the prone and supine positions. CONCLUSION: Body posture affects PEF in healthy, young, non-active subjects. PEFs are higher when subjects are in a seated position compared to prone or supine positions, but no difference in PEF is observed between the prone and supine positions.