2020 年 20 巻 p. 26-39
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.