Study of Influence Factor on Maximal Mouth Pressure Part I. -Influence of Posture-

Abstract

It is clear that maximal mouth pressure (PEmax, PImax) is influenced by sex, aging, anthropometric data, lung function and activities. However, the influence of posture has not been studied, and in this study we studied the influence of postures 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. Maximal mouth pressure was assessed in the sitting, sitting with elbow on knee (the orthopneic position), standing and supine postures. Changing posture was significantly related to maximal mouth pressure. PEmax and PImax in the orthopneic position were stronger than in other postures, and in the comparison of supine and standing posture, PEmax while standing was significantly lower than PEmax while sitting. It was concluded that respiratory muscle strength changes with posture because of the tension generated by changing interabdominal pressure, and muscle length change with changing posture.