Abstract
We studied the influence of posture on maximal mouth pressure in Part I. The study of Part II was aimed at determining the influence of trunk flexion on maximal mouth pressure. Nineteen healthy, young adult students from WCMAS comprised a STANDING study group, and 27 healthy, young adult students from IUHW comprised a LYING study group (same subjects of Part I). Maximal expiratory mouth pressure (PEmax) and maximal inspiratory mouth pressure (PImax) were measured at 0, 30, and 60 degrees of trunk flexion. Posture changes were significantly related to maximal mouth pressure values, and trunk flexion from the standing posture statistically influenced maximal mouth pressure. PEmax and PImax in standing were enhanced with trunk flexion. Respiratory muscle strength changes with trunk flexion, because respiratory muscle tension occurs with the change in interabdominal pressure and the muscle length-tension relationship.
