Introduction: Assessment of respiratory muscle strength (RMS) is a key step in pulmonary rehabilitation and several clinical conditions. Objective: To verify the concurrent validity among three instruments (digital manometer, aneroid and expiratory negati

Abstract

Introduction: Assessment of respiratory muscle strength (RMS) is a key step in pulmonary rehabilitation and several clinical conditions. Objective: To verify the concurrent validity among three instruments (digital manometer, aneroid and expiratory negative pressure) for RMS evaluation. Methods: Cross-sectional study with healthy adults submitted to maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) measurements with three instruments following standardized protocol. Results: Thirty-two individuals were evaluated (mean age 24.3 ± 4.2 years). The results showed strong correlation between instruments, with correlation coefficients r > 0.80 for MIP and MEP. Conclusion: The three instruments showed adequate concurrent validity and can be used interchangeably in clinical practice, with the digital manometer being the reference standard.