This study aimed to clarify the developmental characteristics of orientation and differentiation abilities in early childhood jumping movement by focusing on jumping tasks under different conditions and analyzing the mean value of the error and performance on each test by category.
Therefore, the jumping tasks were such that the heels of both feet were aligned on a line 40 cm away, with the tasks performed twice each under the two conditions of without an obstacle (condition A) and with an obstacle (condition B). The participants comprised 308 infants 3‒6 years of age. The main results obtained were as follows.
1）Accuracy by analysis of the mean value of the error:
・Changes were seen in the absolute error. In condition B, young four-year-olds (early 4s) showed a performance improvement in the second test. In addition, it was shown that both conditions A and B reached a certain level of performance in the late 4s, and remained at the same level until the early 6s.
・Performance in conditions A and B was not significantly correlated up to the late 4s but was significantly correlated in the early 5s and late 5s.
・Changes were seen in the constant error. In condition B, late 3s and early 4s tended to go beyond the target line.
2）Accuracy by category analysis of performance:
・Regarding the difference in the ratio of performance levels, the ratios of the upper and middle ranks increased, and those of the lower ranks decreased, as age increased in conditions A and B.
・Interrelationships were observed between performance patterns and age. The late 4s tended to show the “immature” and “unstable” patterns, and the early 5s and late 5s tended to show the “stability” and “unstable” patterns.
From the above, the following were shown as the developmental characteristics of orientation and differentiation abilities required for the jumping task of this study. The mean value of the error significantly improved after the late 4s, and it was confirmed that orientation and differentiation abilities reached a certain level. In addition, regarding the category analysis of performance, the frequency of performance above a certain level increased from the early 5s to the late 5s, thereby suggesting a stable exhibition of orientation and differentiation abilities.