## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline
**Group** & **Test** & **Mean** & **SD** & **\(t\)-Test (\(p\))** & **ICC** & **95\% CI** & **CV** & **SD** & **SEM** & **SEM\%** & **MDC \%** \\ \hline \multirow{2}{*}{G\({}_{9-10}\)} & Test & 74.66 & 13.96 & \multirow{2}{*}{0.968} & \multirow{2}{*}{0.663} & \multirow{2}{*}{(0.280-0.896)} & \multirow{2}{*}{0.083} & \multirow{2}{*}{0.077} & \multirow{2}{*}{8.17} & \multirow{2}{*}{10.82} & \multirow{2}{*}{22.65} & \multirow{2}{*}{30.01} \\  & Retest & 76.27 & 14.58 & & & & & & & & & \\ \hline \multirow{2}{*}{G\({}_{11-12}\)} & Test & 98.56 & 29.66 & \multirow{2}{*}{0.285} & \multirow{2}{*}{0.922} & \multirow{2}{*}{(0.797-0.972)} & \multirow{2}{*}{0.075} & \multirow{2}{*}{0.059} & \multirow{2}{*}{8.23} & \multirow{2}{*}{8.48} & \multirow{2}{*}{22.80} & \multirow{2}{*}{23.49} \\  & Retest & 95.60 & 30.14 & & & & & & & & & \\ \hline \multirow{2}{*}{G\({}_{13-14}\)} & Test & 155.96 & 36.63 & \multirow{2}{*}{0.615} & \multirow{2}{*}{0.918} & \multirow{2}{*}{(0.778-0.972)} & \multirow{2}{*}{0.061} & \multirow{2}{*}{0.037} & \multirow{2}{*}{10.66} & \multirow{2}{*}{6.78} & \multirow{2}{*}{29.53} & \multirow{2}{*}{18.79} \\  & Retest & 158.33 & 39.03 & & & & & & & & & \\ \hline \multirow{2}{*}{All Girls} & Test & 94.79 & 35.94 & \multirow{2}{*}{0.661} & \multirow{2}{*}{0.890} & \multirow{2}{*}{(0.764–0.951)} & \multirow{2}{*}{0.010} & \multirow{2}{*}{0.085} & \multirow{2}{*}{11.95} & \multirow{2}{*}{12.72} & \multirow{2}{*}{33.14} & \multirow{2}{*}{35.26} \\  & Retest & 93.17 & 36.16 & & & & & & & & & \\ \hline \multirow{2}{*}{All Boys} & Test & 122.81 & 40.06 & \multirow{2}{*}{0.764} & \multirow{2}{*}{0.951} & \multirow{2}{*}{(0.889–0.978)} & \multirow{2}{*}{0.075} & \multirow{2}{*}{0.052} & \multirow{2}{*}{9.81} & \multirow{2}{*}{7.96} & \multirow{2}{*}{27.19} & \multirow{2}{*}{22.06} \\  & Retest & 123.75 & 48.60 & & & & & & & & & \\ \hline \multirow{2}{*}{All Sample} & Test & 108.77 & 43.26 & \multirow{2}{*}{0.896} & \multirow{2}{*}{0.935} & \multirow{2}{*}{(0.887–0.963)} & \multirow{2}{*}{0.091} & \multirow{2}{*}{0.076} & \multirow{2}{*}{11.26} & \multirow{2}{*}{10.37} & \multirow{2}{*}{31.22} & \multirow{2}{*}{28.75} \\  & Retest & 108.46 & 45.10 & & & & & & & & & \\ \hline \hline \end{tabular}  
* G\({}_{9-10}\) = aged group 9–10 years. G\({}_{11-12}\) = aged group 11–12 years. G\({}_{13-14}\) = aged group 13–14 years. SD: standard deviation; \(t\)-test (\(p\)) = \(p\) value of paired \(t\)-test; ICC = intraclass correlation coefficient; 95% CI = confidence interval of ICC; CV: coefficient of variation; SEM = standard error of measurement (absolute values); SEM (\(\%\)) = SEM percentage values. MDC = minimal detectable change (absolute values); MDC% = MDC% = MDC percentage values.  
\end{table} 
Table 5: Muscle power (W) values at 60% of 1 RM in SBP test. The process of maturation and growth is associated with changes of increasing muscle mass and in muscle morphology and architecture, such as pennation angle [42], and changes mediated by hormonal variations during the maturation and growth period [43]. This is the reason why the repeatability analyses were analyzed by grouping the sample into three different age groups. The maximum strength of the LE increases over the courses of growth and development, with significant differences (\(p<0.001\)) between all age groups in our sample. However, in the strength of the SBP, the increase only appears in the age near to 14 years old. In general, for the whole population, and particularly the infant population, use of the musculature of the lower extremities is continuous during activities of daily life, including supporting of the coronal weight when walking, transporting a school backpack, jumping, and running. However, the use of the upper extremities is predominantly limited to actions of precision supporting relatively low loads [44; 45].