## 3 Results
### Reliability
Similarly, the two-way random model for absolute agreement (ICC2) and the two-way fixed model for consistency (ICC3) both reported ICC values of 0.974 (95% CI: 0.946-0.988), reinforcing the reliability of the MyJump system. When analyzing average agreement, the one-way random model (ICC1k) and the two-way random model (ICC2k) both produced ICC values of 0.987 (95% CI: 0.972-0.994), while the two-way fixed model (ICC3k) returned a nearly identical value of 0.987 (95% CI: 0.973-0.994), further confirming the high precision of the measurements. These findings indicated excellent intra-rater reliability, suggesting that the MyJump application provides consistent and repeatable squat jump measurements across trials and the low SEM and SEE values further highlight the precision of the MyJump system, demonstrating that systematic error was minimal. Lastly, the Bland-Altman analysis was conducted to assess the level of agreement between the CMJ MyJump test and retest measurements. The mean bias was 0.153 cm (95% CI: \(-\)0.380 to 0.686 cm), indicating a negligible systematic difference between the two measurement sessions (Table 10 and Figure 11). The limit of agreement (LoA) ranged from \(-\)2.142 cm (lower LoA; 95% CI: \(-\)3.068 to \(-\)1.216 cm) to 2.449 cm (upper LoA; 95% CI: 1.523 to 3.375 cm). These results indicated that while some variation exists, the magnitude of discrepancies remains small, supporting the reliability of the MyJump application in consecutive CMJ assessments. Overall, the Bland-Altman analysis indicated strong  
Figure 10: Reliability assessment of SJ measurements using MyJump: initial vs. retest. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Model** & **Measures** & **Type** & **ICC** & **Lower CI** & **Upper CI** \\ \hline one-way random & Agreement & ICC1 & 0.974 & 0.946 & 0.987 \\ two-way random & Agreement & ICC2 & 0.974 & 0.946 & 0.988 \\ two-way fixed & Consistency & ICC3 & 0.974 & 0.947 & 0.988 \\ one-way random & Avg. Agreement & ICC1k & 0.987 & 0.972 & 0.994 \\ two-way random & Avg. Agreement & ICC2k & 0.987 & 0.972 & 0.994 \\ two-way fixed & Avg. Consistency & ICC3k & 0.987 & 0.973 & 0.994 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Intraclass correlation coefficients for reliability analysis of squat jump (S) measurements. agreement between test and retest measures, reinforcing the repeatability and consistency of MyJump for assessing CMJ height. The narrow confidence intervals and minimal bias further suggest that the observed differences are within an acceptable measurement error range for practical applications. The Bland-Altman analysis was also conducted to evaluate the agreement between the squat jump (S) MyJump test and retest measurements. The mean bias was 0.186 cm (95% CI: \(-\)0.118 to 0.490 cm), indicating minimal systematic difference between the two measurement sessions (Table 10 and Figure 12). The limit of agreement (LoA) extended from \(-\)1.122 cm (lower LoA; 95% CI: \(-\)1.650 to \(-\)0.595 cm) to 1.495 cm (upper LoA; 95% CI: 0.967 to 2.023 cm). These results demonstrate that measurement variation remains within an acceptable range, supporting the consistency and reliability of the MyJump application for squat jump assessments. Overall, the Bland-Altman analysis suggested strong agreement \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**CMJ**} & \multicolumn{2}{c}{**SJ**} \\ \hline  & \multicolumn{4}{c}{**95\% Confidence**} & \multicolumn{4}{c}{**95\% Confidence**} \\
**Bland–Altman** & \multicolumn{4}{c}{**Interval**} & \multicolumn{4}{c}{**Interval**} \\ \cline{2-7}  & **Estimate** & **Lower** & **Upper** & **Estimate** & **Lower** & **Upper** \\ \hline Bias (n = 21) & 0.153 & \(-\)0.380 & 0.686 & 0.186 & \(-\)0.118 & 0.490 \\ Lower limit of & \(-\)2.142 & \(-\)3.068 & \(-\)1.216 & \(-\)1.122 & \(-\)1.650 & \(-\)0.595 \\ Upper limit of & \(-\)2.449 & 1.523 & 3.375 & 1.495 & 0.967 & 2.023 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Bland–[PERSON] analysis of CMJ and SJ MyJump test–retest agreement.