## 3 Results  
The movement of absolute and relative distances regarding non-throwing arm joints during the completion phase is outlined in Table 1. The results revealed that the absolute distance of distal joints was longer than proximal joints during the phases of completion, transition, and delivery. The relative distance of distal joints was longer than proximal joints during the transition phase, while that of proximal joints was shorter than that of distal joints during the delivery phase. The displacement of the non-throwing arm in the coronal axis, sagittal axis, and vertical axis is described in Figure 3. The non-throwing arm joints changed the direction of displacement in three axes, and the sequences can be summarized as follows: in the coronal axis, the shoulder of the non-throwing arm moved from the left side to the right side, followed by the elbow and hand; in the sagittal axis, the direction of displacement regarding non-throwing arm joints was from back to the front, and the trend of shoulder displacement was not more obviously than that of the elbow and hand. Moreover, the changes in the elbow and hand were similar compared to the shoulder; in the vertical axis, the shoulder was the first joint to change the direction of displacement, followed by the hand and elbow. The joints of the non-throwing arm's displacement velocity regarding the axis of coronal, sagittal, vertical, as well as resultant velocity, are shown in Figure 4 and Table 2. During the completion phase, the trend of resultant velocity regarding joints of the non-throwing arm performed decreases and increases at the end of the phase, similar to the changing of the sagittal axis velocity of the joints. The coronal axis velocity increases when moving from right to left, then decreases in the second half and changes direction before release. The vertical axis velocity regarding joints of the non-throwing arm was changed from positive to negative, which indicates the changing in direction from upside to downside, and the direction was changed before release. The joints of the non-throwing arm's displacement changed the direction and decreased the velocity before release. \begin{table}
\begin{tabular}{c c c c c c} \hline  & **TPL** & **RTPL** & **DPL** & **RDPL** & **CPL** \\ \hline Shoulder & 0.31 & 32.5 & 0.64 & 67.5 & 0.94 \\ Elbow & 0.58 & 44.4 & 0.72 & 55.6 & 1.30 \\ Wrist & 0.83 & 49.9 & 0.84 & 50.1 & 1.67 \\ \hline \end{tabular}
\end{table} 
Table 1: Absolute distance (m) and relative distance (%) of different stages of displacement of non-throwing arm at completion phase. The angular change during the completion phase is shown in Figure 5. During the completion phase, the angles of the shoulder and elbow have shown the flexion trends, and the elbow angle exhibited brief periods of extension. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Touch Down** & **Smallest Knee Angle** & **Release** & **Peak Velocity** \\ \hline Shoulder & 3.41 & 4.92 & 0.54 & 5.82 \\ Elbow & 8.04 & 7.12 & 0.82 & 8.04 \\ Wrist & 10.79 & 9.79 & 1.31 & 11.92 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The velocity changing of joints regarding non-throwing arm (m/s). Figure 4: The velocity of non-throwing arm joints in coronal axis (X Axis), sagittal axis (Y Axis), and vertical axis (Z Axis), as well as resultant velocity. Figure 3: The displacement of non-throwing arm joints in coronal axis (X Axis), sagittal axis (Y Axis), and vertical axis (Z Axis), as well as resultant displacement.