[Purpose] Normal values for respiratory muscle pressures during development in Japanese children have not been reported. The purpose of this study was to investigate respiratory muscle pressures in Japanese children aged 3-12 years. [Subjects and Methods] We measured respiratory muscle pressure values using a manovacuometer without a nose clip, with subjects in a sitting position. Data were collected for ages 3-6 (Group I: 68 subjects), 7-9 (Group II: 86 subjects), and 10-12 (Group III: 64 subjects) years. [Results] The values for respiratory muscle pressures in children were significantly higher with age in both sexes, and were higher in boys than in girls. Correlation coefficients were significant at values of 0.279 to 0.471 for each gender relationship between maximal respiratory pressure and age, height, and weight, respectively. [Conclusion] In this study, we showed pediatric respiratory muscle pressure reference value for each age. In the present study, values for respiratory muscle pressures were lower than Brazilian studies. This suggests that differences in respiratory muscle pressures vary with ethnicity.
Keywords: Correlated factors; Japanese children; Respiratory muscle pressures.