{'fraction_non_alphanumeric': 0.05201026518391788, 'fraction_numerical': 0.037125748502994015, 'mean_word_length': 4.080834419817471, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 5, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 14, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Sex and Age-Level Differences in Preschool Children in Walking Times on a Course and on a Balance Beam with Obstacles

This study aimed to examine sex and age-level differences in preschool children with respect to walking times on a course and on a balance beam with obstacles. Subjects were 324 healthy preschool children: 4-year-old boys (51) and girls (51), 5-year-old boys (50) and girls (60), and 6-year-old boys (62) and girls (50). A 5or 10-cm-high obstacle (depth, 11.5 cm; width, 23.5 cm) was set at the halfway point of a course (length, 200 cm; width, 10 cm) that was drawn on the floor and a balance beam (length, 200 cm; width, 10 cm; height 30 cm). The children walked to the end of the course and on a balance beam, and returned as quickly as possible under three conditions: no obstacle, low obstacle, and high obstacle. In all obstacle conditions, children aged 4–4.5 years walked on the course and the balance beam significantly slower than children aged 5 and 6 years, and children aged 4.5–5 years walked more slowly than children aged 5.5–6 years and children aged 6 years. Both walking was significantly slower in children aged 5–5.5 years than children aged 6 years (course: aged 6.5–7 years) in the high-obstacle condition, and was lower in the high-obstacle condition than in the no-obstacle condition in children aged 4 years. No significant sex difference was found in children in either walking time in all obstacle conditions. The walking time on the course showed a significant curvilinear regression with age in boys except for the noand low-obstacle conditions. All balance beam walking times showed a significant curvilinear regression with age in both sexes in all obstacle conditions. Finally, 4-year-old children walked more slowly than 5and 6-year-old children on a course and on a balance beam regardless of the presence of the obstacles. Both walking abilities develop markedly in 4-year-old children, and children between 5.5 and 6 years walk at a similar speed. The two forms of walking, regardless of the presence of an obstacle, showed little difference based on sex in children aged 4–6 years. A 10-cm-high obstacle affects walking in 4-year-old children, but not in children older than 5 years.


Introduction
Nerve function and coordination develop remarkably in children between infancy and kindergarten age. Balance ability is an important component of coordination and is largely categorized into static balance and dynamic balance. During their development, it is possible for young children to achieve various locomotive movements, and dynamic balance contributes strongly to this achievement. Hence, it is important to adequately evaluate the balance ability. Walking on a balance beam and on a line have often been used to evaluate the dynamic balance of preschool children (Demura, Nagasawa, & Kasuga,1994 ;Aoki, Demura, Kasuga, Shin, & Kawabata, 2011 ;Bürgi, Meyer, Granacher, Schindler, Marques-Vidal, Kriemler, & Puder, 2011;Kasuga, Demura, Aoki, Shin, Sugiura, & Uchida, 2012a;Kasuga, Demura, Aoki, Sato, Shin, & Kawabata, 2012b). However, it is possible that a developmental evaluation of dynamic balance by age may differ according to the type and the degree of difficulty of the tests. For example, according to Kasuga et al. (2012a), the walking time on a course with obstacles showed a nonsignificant difference between 5and 6-year-old children, but Aoki et al. (2011) reported that the walking time on the balance beam was significantly longer in 5-year-old children than in 6-to 6.5-year-old children. In brief, the walking time for children older than 5 years may differ for walking on a course and on a balance beam.
Many previous studies have also reported on the sex difference in the dynamic balance of preschool children (Demura, 1993;Demura et al., 1994;Demura, 1995;Aoki et al., 2011). Aoki et al. (2011) observed that no sex difference was found in the walking time on a balance beam in 5 and 6 year olds. Also, Kasuga et al. (2012a) reported that no sex difference was found in 4-6 year olds in the walking time on the course. Demura et al. (1994) examined the sex difference in 3-6 year olds in the walking time on a balance beam and line, and in the times for a series of one-legged hopping and hopping from stone to stone, and reported that a significant sex difference was found only in the time for the series one-legged hopping. According to Harcherik, CArbonari, & Cohen, (1982) considering forward, backward, toe, and heel walking times on a balance beam in 4-to 14-year-old children, a significant sex difference was found only in backward walking times. From the above, a sex difference in achievement time may be found in difficult tasks, but not in easy tasks. In addition, Kasuga et al. (2012a) reported that 4-year-old children are slower than 5-and 6-year-old children in walking on a course; however, Demura et al. (1994) reported that there was no difference between 4-and 5-year-old boys in walking on a balance beam, and that 4-year-old girls were slower than 5-year-old girls. In short, it is assumed that the shortness of walking time differs between boys and girls by age.
This study aimed to examine sex and age-level differences in preschool children with respect to walking time on a course and on a balance beam with obstacles.

Subjects
Subjects were 324 healthy preschool children from 4 to 6 years. Table 1 shows the details of the subjects. The experimental purpose and methods were explained to all the children and their parents, and their consent was obtained. This study protocol was approved by the Ethics Committee on Human Experimentation of Faculty of Education, Kanazawa University.

Methods of Tests
Walking on a course test: obstacles (depth, 11.5 cm; width, 23.5 cm) with different heights (5 cm and 10 cm) were set at the halfway point of a course (width, 10 cm; length, 200 cm). The children walked on the course under three conditions: no obstacle, low obstacle, and high obstacle.
Walking on a balance beam test: the same obstacles as in the walking on a course test were set at the halfway point of the balance beam (width, 10 cm; height, 30 cm; length, 200 cm). The children walked on the beam under three conditions: no obstacle, low obstacle, and high obstacle.
In both tests, the time was measured from when the children crossed the starting line (line tape length, 10cm; width, 10cm), reached a turn line, and then returned to the starting line. The children were instructed to walk as fast as possible, to change direction quickly after reaching the turn line, and to return to the original position. We measured the time again if they fell or their foot touched the obstacle while walking. The children carried out three trials for each test. In addition, if a child fell, or if his or her foot touched the obstacle three times in succession, we judged it impossible to measure the time.

Statistical Analysis
The intraclass correlation coefficient (ICC) for each test was calculated to examine the reliability. A three-way ANOVA was used to examine the mean differences in sex, age, and obstacle conditions for each walking time. When a significant interaction or main effect was found, a Tukey's Honestly Significant Difference (HSD) test was used for a multiple comparison. The linear or curve regression was calculated to examine the relationship between each walking time and the child's age, and the significance of the above coefficients was tested. The level of significance was determined to be 0.05.

Results
The ICCs of the walking time in each condition were 0.64-0.71 in 4-year-old boys, 0.71-0.81 in 4-year-old girls, 0.64-0.83 in 5-year-old boys, 0.68-0.82 in 5-year-old girls, 0.66-0.78 in 6-year-old boys, and 0.60-0.72 in 6-year-old girls. Table 2 shows the basic statistics of the walking time on the course according to sex, age, and obstacle, and the results of the three-way ANOVA (age × sex × obstacle). Nonsignificant interaction was found in all conditions, and a significant main effect was found in age and obstacle factors. For walking on a course, a multiple comparison test showed the following: the walking times in the no-, low-, and high-obstacle conditions were longer in 4-to 4.5-year-old children than in 5-and 6-year-old children, and longer in 4.5-to 5-year-old children than in 5.5-to 6-year-old children and 6-year-old children. In addition, the walking time in the low-obstacle condition was longer in 5-to 5.5-year-old boys than in 6.5-to 7-year-old boys, and in the high-obstacle condition it was longer in 5-to 5.5-year-old boys and girls than in 6.5-to 7-year-old boys and girls. Moreover, a significant difference among conditions was found only in 4 year olds, and the no-obstacle condition showed a shorter time than the high-obstacle condition.  Male aged 5-5.5 years > aged 6.5-7 years aged 6.5 to 7 years 3.7 0.6 3.9 0.9 4.2 1.   to 5 years 11.9 5.7 o 5.5 years 8.3 2.7 to 6 years 7.9 3.9 o 6.5 years 5.6 1.7 to 7 years 5.8 1.7 o 4.5 years 15.9 7.8 to 5 years 14.2 6.8 o 5.5 years 9.1 4.2 to 6 years 8.5 4.5 o 6.5 years 6.4 2.4 to 7 years 6.5 1.9 Figure 1. Reg statistics of w ANOVA (age × was found in ag following: the than in 5-to 6 6-year-old chil obstacle condi the high-obsta -year-old child eover, a signifi no-obstacle con tics of Balance king Time g to sex, age, a n was found in m walking, the bstacle conditi 5-year-old chi han in 4.5-to an in 6.5-to 7ear-old children d in 5.5-to 6-y nd only in 4-y bstacle conditi Three-Way AN le, F6: age × ob 5-year-old, 6-year-old aged 4.5-5 years aged 5.5-6 years, 6-year-old 5-year-old, 6-year-old aged 4.5-5 years aged 5.5-6 years, 6-year-old 6.5-7 years 5-year-old, 6-year-old aged 4.5-5 years aged 5.5-6 years, 6-year-old > aged 4.5-5 years h obstacle post-hoc Vol. 5, and obstacle, a n all conditions results of a m ions was longe ildren than in 5-year-old girl -year-old boys n than in 6-ye year-old childre year-old childre on. NOVA bstacle, F7:sex 5-year-old > 6-year-old aged 5-5.5 years > 6-ye aged 5.5-6 years > 6-ye (curvilinear regression). It is recognized that walking on a balance beam or stepping over a high obstacle even when walking on a floor has a significant effect on the walking of 4-year-old children, but has little effect on children over 5 years. On the other hand, for girls, after age 5, even the walking time in tasks with low difficulty (with or without a low obstacle) was minimally short (curvilinear regression). Demura et al. (1994) reported that walking in a line is significantly faster in 6-year-old boys than in 5-year-old boys, but the same is not true for girls. From the above report, it is considered that girls, as compared with boys, have a brief walking time based on their age when they experience walking with low difficulty, such as walking on a line. In short, they can walk at almost the same speed after they are 5 years old. It is recognized that children after age 5.5 can walk on a course within a certain amount of time even if the difficulty is high, which means the course contains a high obstacle, because they have developed sufficient walking and dynamic balance abilities.

Conclusion
In conclusion, walking on a course and on a balance beam, regardless of the presence of obstacles, is slower in 4-year-old children than in 5-and 6-year-old children. Both walking abilities develop markedly with age after 4 years, but children after age 5.5 can walk with almost the same speed. A sex difference in 4-to 6-year-old children is not found in either form of walking described above. Even a 10-cm-high obstacle affects walking in 4-year-old children, but has little effect in children over 5 years.