Analysis of Changes in Physical Strength over Time in Recent School-Age Students: Proposal for Multi-year Span Evaluation Chart with the O Model

Ken-Ichi Watanabe,Katsunori Fujii,Yuki Kani,Keiko Abe,Kan-Ichi Mimura

doi:10.11648/j.ajss.20210901.13

Abstract

For school-age children to lead healthy lives, they need suitable physical abilities for those lives. Together with this, measurements of physical strength and motor ability to assess those abilities could be considered essential. The physical strength of children has declined in recent years, and City O in the Kansai area of Japan has implemented an action plan to address the problem. This action plan was developed from a survey continued over seven years of the physique, physical strength, and motor abilities of fifth grade elementary school students and second year junior high school (seventh grade) students. To assess the efficacy of City O’s action plan, this study analyzed trends in strength and motor ability over seven years to examine whether trends were rising or falling. The method adopted for this plan was to measure the same items as those in the strength and motor ability survey conducted by the Ministry of Education, Culture, Sports, Science and Technology. The wavelet interpolation model was applied to the multi-year trends in the results obtained over seven years to examine whether they were improving or declining. An improving trend was seen with time in the physical strength and motor ability of second-year junior high school girls. One may infer that behind the improving trend over time were the effects from City O’s action plan. The background for the improving trend seen over the years seen in second year junior high school girls but not boys may include that girls were originally less active than boys and but were encouraged to be active by the action plan. Because the second year of junior high school is the period of late puberty for girls, and is a time when they are approaching their developmental peak in physical strength, it may be inferred that the increase in physical strength was affected by factors in the action plan. In this study, a new evaluation chart that considers trends over years was established using the wavelet interpolation model, and the efficacy of the multi-year span evaluation chart for physical strength is presented as the O model.

Highlights

The problem of decreased physical strength in youth goes back to the finding of decreased physical strength in a conscription survey of American soldiers sent to the Korean civil war between the north and south that broke out on the peninsula in 1950
Physical strength, and motor ability were measured over the years from 2013 to 2019 in boys and girls in the fifth grade of elementary school and the second year of junior high school
Behind the increasing trend over the years in second year junior high school girls but not boys is that while girls originally had lower levels of activity than boys, their activity was stimulated by the action plan. Those years are the years of late puberty for girls, and the time after the peak in physical development velocity in girls, which is around the second year of junior high school, is a time that is approaching the developmental peak in physical strength

Summary

Introduction

The problem of decreased physical strength in youth goes back to the finding of decreased physical strength in a conscription survey of American soldiers sent to the Korean civil war between the north and south that broke out on the peninsula in 1950. Nakai and Demura [1] reported from longitudinal measurements and surveys over three years in male technical school students that continuous exercise increased muscle power, whole-body endurance, and flexibility. That report is somewhat dated, reports by Shimada et al [2, 3] showed improved agility, muscle endurance, and whole-body endurance in groups who performed more continuous exercise. They stated that groups which exercised with lower frequencies had inferior whole-body endurance, muscle endurance, and agility They reported that regardless of age, continuous exercise basically had positive effects on preserving and enhancing physical strength and health, even in elderly people [4]. A picture could be drawn in which further continuous exercise increases physical strength and motor ability in the school years

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Discussion

Conclusion