Studies of total pulmonary capacity and its subdivisions. III. Changes with body posture

Abstract

It has been known for nmany years that the posture of the body has an influenice on pulmonary capacity. More than 25 years ago Bohr (3) andl Plesch (10) found that the residual air increases in the recumbent l)ositioll. Christie and Beams (6) \e have shown in a previous paper (8) that there is a definite correlation between the total capacity and its sulbdivisions andl the size of the chest cavity. It will be interestinig, therefore, to discover whether clhanges in position are also accompanied by similar and(I proportional alterations in size and expansion of the chest. Hamiltoni and -Morgan (7), in a recent communicatioln, reported that in five normiial subjects there was nio chanlge in the volume of resi(lual air in the recumbent position, but they observed a moderate (lecrease in the vital cap)acity, an(l consequenitly a corresponding dimintution in the total capacity when lying was compared with the sitting l)osture. These investigators, nmeasuring the lateral anid anteroposterior