The significance of sitting height as an index of leg length

Abstract

From the idea of a relationship betwen intestinal area and sitting height as part of the Nem System of Feeding proposed by Clemens Pirquet associated with the theory of nutrition, it is thought that the growth of bones is caused by the development of internal organs during the process of body growth. According to this idea, it is hypothesized that there is a significant positive correlation or a direct proportion of sitting height to leg length (=height-sitting height). The purpose of this study was to investigate the significance of sitting height as an index of the process of body growth from the viewpoint of the relationship between sitting height and leg length. The study was done in three parts. The first involved comparison of the growth curves for sitting height with those for leg length of subjects from five different generations (born in 1930, 1942, 1954, 1966, and 1978). The second was a comparison among the relationships of sitting height to leg length in subjects aged 6, 15, 17, and 20 born in each year from 1930 to 1990. The third was a comparison among the relationships of sitting height to leg length for subjects of a specific age with the same subjects of other specific ages in the future. The data were obtained from annual nationwide statistics for mean standing height and sitting height since 1937, when measurement of sitting height was started in schools. The measurement was authorized by the Ministry of Education as part of the School Health Examination and Physical Fitness Tests. The subjects ranged in age from 6 to 24 yr, although the data from 1940 to 1948 were missing because of the World War II. The study conclusions were : 1. Sitting height at the age of 6 yr is the most effective index for predicting leg length at subsequent ages. 2. Sitting height is a valuable index of not only intestinal area but also body growth. 3. However, sitting height in adults is not a useful index because of the small differences it shows.