A Method of Investigation of Diaphragmatic Movements and Corresponding Tidal Volumes: A study in healthy males and females

Abstract

Hauge, Bodil Nexmand. A Method of Investigation of Diaphragmatic Movements and Corresponding Tidal Volumes. Scand. J, clin. Lab. Invest. 19 45–55, 1967. A new procedure for radiological examination of the diaphragmatic movements with simultaneous recording of the tidal volume by spirometry is described. The method makes it possible to investigate the vertical movements of the diaphragm both at rest and following standard exercise, as well as on maximal inspiration and expiration. The influence of photographic enlargement is calculated, and the accuracy of the method together with the reproducibility of the measurements, exemplified by duplicate examinations, are discussed.

Using the technique described, the author investigated 20 healthy men and 13 healthy women. The investigation showed that the men and women had equally large diaphragmatic excursions at rest, following exercise and on maximal in- and expiration. There was some correlation between the vital capacity and the size of the corresponding vertical movement of the diaphragm, and between the tidal volumes and diaphragmatic movements at rest and following exercise.

There was positive correlation between diaphragmatic movements at rest and following exercise, but no correlation between resting movements and maximal diaphragmatic movements.

It is concluded that the technique has certain advantages over previously described methods of investigation of the diaphragmatic movement. Using a simple apparatus and with no discomfort to the patient, an objective numerical value is obtained of a single diaphragmatic movement and the corresponding tidal volume. The present study has shown that the diaphragmatic movements in men and women are of the same extent, and thus disproves the old clinical assumption of a sex difference in respiratory type.