Table 2.
Statistics of the original and normalized SampEn(2, 0.05, 350) and the original and normalized ASI values for the children in the young, middle, and elder age groups. Statistical differences between pairs of age groups are evaluated by the Mann-Whitney U hypothesis test (significance level p < 0.01). SampEn: sample entropy. ASI: average stride interval. ∗: U test between the young and middle age groups; ∗∗: U test between the middle and elder age groups; ∗∗∗: U test between the young and elder age groups.
| Entropy parameters | Statistics (mean ± standard deviation) | p value | ||
|---|---|---|---|---|
| Young group | Middle group | Elder group | ||
| (aged 3–5 years) | (aged 6–8 years old) | (aged 10–14 years) | ||
| SampEn (bit) | 0.408 ± 0.109 | 0.194 ± 0.088 | 0.1 ± 0.058 | 0.001∗ |
| 0.001∗∗ | ||||
| 0.001∗∗∗ | ||||
|
| ||||
| Normalized SampEn by leg length (bit/m) | 0.755 ± 0.229 | 0.304 ± 0.139 | 0.129 ± 0.084 | 0.001∗ |
| 0.001∗∗ | ||||
| 0.001∗∗∗ | ||||
|
| ||||
| Normalized SampEn by body mass (bit/kg) | 0.023 ± 0.008 | 0.008 ± 0.003 | 0.003 ± 0.002 | 0.001∗ |
| 0.001∗∗ | ||||
| 0.001∗∗∗ | ||||
|
| ||||
| ASI (s) | 0.904 ± 0.041 | 0.961 ± 0.041 | 1.059 ± 0.063 | 0.004∗ |
| 0.001∗∗ | ||||
| 0.001∗∗∗ | ||||
|
| ||||
| Normalized ASI by leg length (s/m) | 1.661 ± 0.132 | 1.495 ± 0.122 | 1.35 ± 0.106 | 0.001∗ |
| 0.002∗∗ | ||||
| 0.001∗∗∗ | ||||
|
| ||||
| Normalized ASI by body mass (s/kg) | 0.051 ± 0.008 | 0.039 ± 0.005 | 0.026 ± 0.004 | 0.001∗ |
| 0.001∗∗ | ||||
| 0.001∗∗∗ | ||||