## 3 Results  
Figure 2 illustrates the on-off muscle timing in the two paddling positions, and Table 1 analyzes the time difference in the activation sequence. A significant EMG difference was observed between the positions in starting activation times in the biceps, wrist flexor, external oblique abdominis, erector spinae, gluteus maximus, and rectus femoris and those in the termination times in the biceps, wrist flexor, rectus femoris, and gastrocnemius.  
Figure 2: Muscle activation sequence in different stages of paddling in different postures. (K): kneeling position; (S): standing position.  
Tables 2 and 3 present the average and maximum EMG activation values of each muscle group in the two positions, respectively. The difference in average EMG activation value for each muscle group was nonsignificant in different postures. However, the biceps tended to have a larger maximum EMG activation value in the kneeling position than in the standing position. The maximum EMG activation values for the triceps, external oblique abdominis, and gastrocnemius were larger in the standing position than in the kneeling position.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & \multicolumn{2}{c}{**Kneeling**} & \multicolumn{2}{c}{**Standing**} & \multicolumn{2}{c}{**\(p\)-Value**} \\ \hline  & & Pectoralis & 2.72 \(\pm\) 3.06 & 2.85 \(\pm\) 3.08 & 0.57 \\  & Lower trapezius & 8.16 \(\pm\) 5.90 & 9.78 \(\pm\) 8.06 & 0.31 \\ Shoulder and upper limb & Latissimus & 7.33 \(\pm\) 4.97 & 7.52 \(\pm\) 6.12 & 0.84 \\  & trapezius & 21.28 \(\pm\) 17.00 & 20.17 \(\pm\) 19.26 & 0.73 \\  & & Triceps brachii & 6.82 \(\pm\) 4.91 & 7.58 \(\pm\) 5.28 & 0.61 \\  & & Wrist flexor & 16.62 \(\pm\) 16.48 & 14.90 \(\pm\) 16.18 & 0.42 \\  & & Wrist extensor & 17.14 \(\pm\) 9.54 & 15.03 \(\pm\) 6.13 & 0.32 \\  & & Rectus abdominis & 3.43 \(\pm\) 3.02 & 2.94 \(\pm\) 1.66 & 0.44 \\  & & External oblique & 2.87 \(\pm\) 1.57 & 2.59 \(\pm\) 1.41 & 0.44 \\  & & Erector spine & 9.42 \(\pm\) 14.45 & 9.30 \(\pm\) 14.43 & 0.85 \\  & & Multifilus & 5.57 \(\pm\) 4.33 & 4.64 \(\pm\) 3.07 & 0.23 \\  & & Gluteus maximus & 1.77 \(\pm\) 0.72 & 1.63 \(\pm\) 0.70 & 0.11 \\  & & Rectus & 3.38 \(\pm\) 1.67 & 5.28 \(\pm\) 3.66 & 0.10 \\ Lower limb muscles & Biceps & 3.05 \(\pm\) 1.99 & 4.23 \(\pm\) 1.75 & 0.10 \\  & & Tibialis anterior & 10.16 \(\pm\) 4.46 & 10.12 \(\pm\) 5.65 & 0.97 \\  & & Gastrocnemius & 2.32 \(\pm\) 2.00 & 3.60 \(\pm\) 2.38 & 0.06 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Average activation of each muscle in different postures (\(\mu\)V).  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & **Kneeling** & **Standing** & \(p\)**-Value** \\ \hline  & & Pectoralis major & 2.72 \(\pm\) 3.06 & 2.85 \(\pm\) 3.08 & 0.57 \\  & Lower trapezius & 8.16 \(\pm\) 5.90 & 9.78 \(\pm\) 8.06 & 0.31 \\ Shoulder and upper limb & Latissimus & 7.33 \(\pm\) 4.97 & 7.52 \(\pm\) 6.12 & 0.84 \\  & & Biceps brachii & 21.28 \(\pm\) 17.00 & 20.17 \(\pm\) 19.26 & 0.73 \\ muscles & Triceps brachii & 6.82 \(\pm\) 4.91 & 7.58 \(\pm\) 5.28 & 0.61 \\  & & Wrist flexor & 16.62 \(\pm\) 16.48 & 14.90 \(\pm\) 16.18 & 0.42 \\  & & Wrist extensor & 17.14 \(\pm\) 9.54 & 15.03 \(\pm\) 6.13 & 0.32 \\  & & Rectus abdominis & 3.43 \(\pm\) 3.02 & 2.94 \(\pm\) 1.66 & 0.44 \\ Trunk muscle group & External oblique & 2.87 \(\pm\) 1.57 & 2.59 \(\pm\) 1.41 & 0.44 \\  & & Erector spine & 9.42 \(\pm\) 14.45 & 9.30 \(\pm\) 14.43 & 0.85 \\  & & Multifilus & 5.57 \(\pm\) 4.33 & 4.64 \(\pm\) 3.07 & 0.23 \\  & & Gluteus maximus & 1.77 \(\pm\) 0.72 & 1.63 \(\pm\) 0.70 & 0.11 \\  & & Rectus femoral & 3.38 \(\pm\) 1.67 & 5.28 \(\pm\) 3.66 & 0.10 \\ Lower limb muscles & Biceps femoris & 3.05 \(\pm\) 1.99 & 4.23 \(\pm\) 1.75 & 0.10 \\  & & Tibialis anterior & 10.16 \(\pm\) 4.46 & 10.12 \(\pm\) 5.65 & 0.97 \\  & & Gastrocnemius & 2.32 \(\pm\) 2.00 & 3.60 \(\pm\) 2.38 & 0.06 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Comparison of the starting and ending activation time for each muscle group in different padding positions (unit: % paddle cycle).