Early in the history of medicine clinicians recognized that the shape of the chest varies in disease. Thus the emphysematous or "barrel-shaped" chest, the phthisical or flat chest, and the various unilateral deformities of pleurisies, etc., are mentioned under various names by eminent writers.
Apparently, however, the fact that the contour of the chest varied in different individuals not subject to disease was not recognized or was considered of no value until in the beginning of the last century, when Chomel1 published the first work on thoracic diameters and insisted that diameters and not circumference were the true basis for estimating lung capacity. The next publication along this line was by Fourmentin,2 who, working along the lines of Chomel, determined the "thoracic index," using the formula adopted by craniologists in determining the cephalic index, i e.:
MALONE FF. THE RELATION OF CHEST CONTOUR TO LUNG CAPACITY.. JAMA. 1904;XLIII(12):783-786. doi:10.1001/jama.1904.92500120002d