## 3 Results
### Statistical Analysis  
The variations in wrist velocity, angular velocity of the trunk torsion, and angular velocity of the arm rotation and the statistical results for one athlete are presented in Table 4.  
In the statistical analysis for Phase F1 and both throws, we observed a moderate effect size, and the \(t\)-test highlighted a statistically significant difference between S1 and S2 (\(p=0.026<0.05\); tobs \(=-2.296\); and df \(=45\)).  
In the statistical analysis for Phase F2 and both throws, we observed a large effect size, and the \(t\)-test highlighted a statistically significant difference between S1 and S2 (\(p=0.0001<0.05\); tobs \(=-4.89\); and df \(=35\)).  
In the statistical analysis of Phase F1 and both throws, we observed a large effect size, and the \(t\)-test highlighted a significant statistical difference between S1 and S2 (\(p=0.0001<0.05\); tobs \(=-3.72\); and df \(=75\)).  
In the statistical analysis for Phase F2 and both throws, we observed a large effect size, and the \(t\)-test highlighted a statistically significant difference between S1 and S2 (\(p=0.0001<0.05\); tobs \(=-19.79\); and df \(=55\)).  
In the statistical analysis for Phase F1 and both throws, we observed a moderate effect size, and the \(t\)-test highlighted a statistically significant difference between S1 and S2 (\(p=0.008<0.05\); tobs \(=-2.72\); and df \(=75\)).  
In the statistical analysis for Phase F2 and both throws, we observed a large effect size, and the \(t\)-test highlighted a statistically significant difference between S1 and S2 (\(p=0.007<0.05\); tobs \(=-2.84\); and df \(=55\)).  
We analyzed the correlation between the kinematic parameters for S1 and S2 and Phases F1 and F2 using [PERSON]'s correlation coefficient, and the results are presented in Table 5.  
The Pearson correlation demonstrated that for S1 in Phase F1, there was a good correlation between the angular velocity of the trunk torsion and the angular velocity of the arm rotation; however, in Phase F2, we found a good correlation between the angular velocity of the trunk torsion and wrist velocity.  
For S2 in Phase F1, there was a good correlation between the angular velocity of the trunk torsion and wrist velocity; however, for Phase F2, there was a good correlation between the angular velocity of the arm rotation and wrist velocity.  
In conclusion, wrist velocity is influenced by the other two kinematic parameters, especially the angular velocity of the arm rotation. This means that the development of explosive forces in the muscles of the trunk and arm could improve the wrist's velocity and also increase the optimization of throwing in handball.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{2}{c}{**Parameter and Phases**} & \multicolumn{4}{c}{**\(t\)-Test Values**} \\ \hline
**Kinematic** & & & **95\% Confidence** & \\
**Parameter** & **Difference** & **Average** & **Interval** & \(p\)* & **Null Hypothesis** (Equal Average) \\ \hline \multirow{2}{*}{
\begin{tabular}{c} Wrist velocity \\ \end{tabular} } & S2F1–S1F1 & \(-472.65\) & \((-887.36;-57.9)\) & 0.026 & reject \\  & S2F2–S1F2 & \(-2294.2\) & \((-3245.37;-1343)\) & 0.0001 & reject \\ Angular velocity of trunk torsion & S2F1–S1F1 & \(-126.68\) & \((-1944;-58.9)\) & 0.0001 & reject \\ Angular velocity of trunk torsion & S2F2–S1F2 & \(233.62\) & \((209.96;257.28)\) & 0.0001 & reject \\ Angular velocity of arm rotation & S2F1–S1F1 & \(-58.66\) & \((-101.49;-15.87)\) & 0.008 & reject \\ Angular velocity of arm rotation & S2F2–S1F2 & \(-67.21\) & \((-115.08;-19.34)\) & 0.007 & reject \\ \hline \hline \multicolumn{2}{c}{* \(p=0.05\).} & & & \\ \end{tabular}
\end{table}
Table 4: Statistical indicators of variation of kinematic parameters in phases F1 and F2.