EFFECT OF DEEP AND QUIET BREATHING ON PULMONARY COMPLIANCE IN MAN*†

Abstract
Convalescent poliomyelitic patients and normal subjects showed a decrease in their pulmonary compliance as measured in the tidal volume range during quiet breathing after a series of deep breaths. This change occurred in the prone, supine, lateral and sitting positions. Compliance decreased 26 to 40%. Two or more deep breaths to the limit of inspiration, after the period of quiet breathing, produced an increase in the compliance; this increase could be eliminated by forced expirations in the normal subjects. It was thought that these changes were probably due to the opening and closing of various units within the lung.