The Effect Of Position And Abdominal Restriction On Pulmonary Function

Abstract

Lung volumes were measured in eight normal subjects, four males and four females, all between the ages of 18-23. They were studied in three body positions: sitting, standing and supine. The tests were done twice on every subject in each position. The first series of tests were to establish the unrestricted group in which the total lung capacity, vital capacity, functional residual capacity and residual capacity were found to decrease in volume while the inspiratory capacity increased upon assuming the supine position. The second series of tests were then developed to indirectly study the role of the abdominal contents in contributing to the movement of the diaphragm by applying a pressure belt around the abdominal region. Gravity exerts an affect on lung volumes by virtue of its force on the abdominal contents. The effect of gravity varies with position. It was found that when the abdominal area was restricted, each sub-division of lung volume decreased in every position significantly with the exception of the unrestricted supine as compared to the restricted supine in the functional residual capacity and the residual volume. When comparing the sitting and standing positions, It was found that they did not differ significantly in either the unrestricted or restricted group.