This study elucidates the developmental characteristics of orientation and differentiation abilities of jumping motion in early childhood. Therefore, we conducted the Moving Target Jump (MTJ) test to predict the target movement and jumping in a timely manner. The test was conducted twice per person. On examining the characteristics of changes on the basis of gender, age, and the number of trials, the following results were obtained. (1) With respect to the difference in the absolute value between the first and second tests, the absolute value in the second test was significantly smaller in the late three-year-old children, suggesting a learning effect due to the repetition of the task. (2) In the distribution of movement angles, a large variation was observed between the late three-year-old and the early four-year-old children; however, beyond the late four years of age, there was a tendency to gather around 360°, the reference value. (3) With respect to the gender characteristics, a study of the proportion of premature reaction (355° > movement angle) and delayed reaction (365° < movement angle) suggested that girls had a greater proportion of delayed reactions than boys. Hence, the development of orientation and differentiation abilities to predict the moving targets and time their landing and jumping in early childhood revealed different developmental tendencies between boys and girls, suggesting that the prediction of the moving target or the start of the jump motion tended to be delayed in girls. Additionally, it was suggested that the learning effect of the test task appeared in the late three-year-olds and that orientation and differentiation abilities necessary for the MTJ test were acquired in the late four-year-olds.
This study aimed to detect differences of difficulty of common motor tasks between straddle and squat vaulting in elementary school children. The analysis subjects were 157 elementary school children (73 boys, 84 girls) from the 5th and 6th grades. Students performed straddle and squat vaulting, and we recorded the movements using a video camera from the front and left sides. The study scored the motions using observational motion evaluation criteria for each technique. Using the graded response model of item response theory, we estimated the ability and item parameters for the data of 314 people who combined the evaluation results of the two techniques. Differential item functioning (DIF) was detected by the likelihood ratio test, and we identified the evaluation items that had a significant difference in the difficulty level depending on the technique. The research conclusions were as follows: (1) The common motor tasks with higher differences of difficulty in squat vaulting are supporting and moving weight forward with arm support. (2) The common motor tasks with higher differences of difficulty in straddle vaulting are grounding at the forefoot in taking off, putting both hands together on the box, pushing off the box and raising shoulder. Therefore, consider teaching methods and practice tasks based on the difference in difficulty of common movements, and enhance systematic instruction is important.
The Course of Study for Elementary School, which was revised and announced in March 2017, requires that children learn reasonable and comfortable movements while manipulating their bodies skillfully in the act of running. In recent years, it has been reported that foot-gripping strength is important for sprinting ability, and a number of studies have reported that foot-gripping strength and sprint running ability are related.
Therefore, in the present study, we measured the foot-gripping strength and sprint running ability of elementary school students (1st to 6th years), making adjustments for factors related to growth (i.e., height, weight, age, grip strength). The results revealed that foot-gripping strength was significantly correlated with sprint running ability (r = -0.130, p <0.05) even when factors related to development were adjusted with partial correlation analysis. These results suggest that foot-gripping strength affects sprint running ability in children, although not to a great extent.
The purpose of this study was to develop an assessment standard table of physical activity and exercise among primary and junior high school students. We conducted oral surveys of thirty-five educational professionals recruited from four areas across Japan. Six researchers and educators discussed the results and created an assessment standard table by examining area-wise data from the national survey on physical fitness and motor ability and exercise habits. Ten items were adopted as the assessment standard, and the relative positioning among values representing the whole country and individual prefectures revealed the characteristics of the group. Based on this, an assessment standard table was developed to examine physical activity and exercise among students. Future studies must verify the effectiveness of the promotion of physical activity and exercise.