FACTOR-ANALYSIS AND SOMATOTYPING, ARE THESE 2 PHYSIQUE CLASSIFICATIONMETHODS COMPARABLE

The aim of this study was to investigate the correspondence of physiqu e structures estimated by the Heath-Carter anthropometric somatotyping method and a Factor analysis based on the same set of 10 variables us ed by Heath-Carter. The investigation was carried our on a group of 20 0 healthy young adults of 20 years of age who were students of physica l education. The mean somatotype was 2.7-4.6-3.0 for the males and 3.1 -3.4-3.1 for the females. The 73% of the total variance in males and 7 5% in females were represented by three factors. They were identified as muscular, fatness and skeletal factors in the males, and in the Fem ales as muscular-trunk fatness, skeletal and limb fatness factors. A P CA gives different results depending on the measurements used for the calculation. The same set of variables as For the somatotyping method were used intentionally to extract the PCA factors and to evaluate the possible correspondence between these factors and the Heath-Carter co mponents. On the basis of the correlation between the factors and the somatotype components, one can conclude that there is: (1) a high corr espondence between endomorphy and fatness factors in both sexes; (2) t hat mesomorphy correlated positively with the muscular factor in males and negatively with the skeletal factor in both sexes; and (3) that e ctomorphy was highly positively correlated with the skeletal factor an d negatively with the other two factors in both sexes. Factors and som atotype components do not correspond exactly which leads to the follow ing conclusions: (1) The three somatotype components cannot be identif ied as orthogonal Factors in a factorial analysis based on the same me asurements as for the somatotype, e.g. the ectomorphy component is not an independent factor in males or in females; (2) The muscle measurem ents and bone width used to estimate mesomorphy in somatotyping scored in two independent factors; and (3) The factor structure of the 10 me asurements was sex dependent.