Confirmation of Secular Trends in Physique and Motor Fitness of Preschool Girls

- Analysis Based on Least Square Approximation Polynomial -

Abstract

　In this study we applied least square approximation polynomials to the physique and physical fitness of preschool girls in 10-year spans for the 40 years from 1969 to 2009, and investigated the behavior of these mathematical functions. Height, weight, and BMI were measured as parameters for physique, and the 20 m dash, tennis ball throw, standing long jump, one-leg hop, and hanging from a horizontal bar were measured as parameters of motor performance. No further shifts toward earlier or larger growth were seen among parameters of physique. Among parameters of motor performance, declining trends were seen in the tennis ball throw and hanging from a horizontal bar, suggesting decreased upper body muscle strength. A decreasing trend was seen in the 20 m dash and increasing trends were seen in the standing long jump and one-leg hop, although that rising trend has leveled off in recent years. These findings suggest that lower body strength may also shift to a declining trend in the coming years.