Analyzing respiratory muscle weakness and thoracopulmonary restriction in subjects with Duchenne muscular dystrophy.

Objective: To analyze the underlying components of reduced maximal static inspiratory (MIP) and expiratory (MEP) pressures in subjects with Duchenne muscular dystrophy.

Methods: Forty-three subjects were assessed based on routine pulmonary function tests. MIP and MEP were measured the subjects performed maximal expirations and inspirations using a snorkel mouthpiece.