Differences in Physical and Motor Traits Between Boys of Advanced, Normal, and Retarded Maturity

Abstract

The purpose of this study was to determine if significant differences in structural measures, muscular strength tests, and explosive muscular power exist between boys who are advanced, normal, and retarded in maturity. The subjects were 273 boys 9, 12, and 15 years of age; the three maturity groups at each age were formed on the basis of skeletal age assessed from wrist-hand X rays. The following results were noted. (1) In all instances where the differences were significant, the more mature group had the higher mean; (2) the highest and most significant differences between the means were obtained at 15, 12, and 9 years of age in that order; (3) a greater difference was found between the mean body weights at all ages than for any other test variable, followed by hip width, grip strength, sitting height, upper arm girth, and calf girth; (4) in general, when advanced 12 and retarded 15 and advanced 9 and retarded 12 year old boys were compared, the chronologically older boys were taller and stronger.