## Results
### Stability  
Regarding stability, the effects of curvature and usage pattern were not significant (Table 9). Comparing them descriptively, the sample with a curvature of 8R scored the highest, followed by 6R, 4R, and 10R (Table 3). However, the interaction effect between curvature and usage pattern was significant: \(F(9,360)=2.071,p=0.031\). Therefore, a simple effect analysis was conducted separately according to the samples and usage patterns (Table 10).  
In the case of samples, 10R showed a significant difference in grip comfort between the usage patterns: \(F(3,159)=5.034,p=0.002\). Post hoc analysis showed two homogeneous subsets. The first subset comprised usage patterns of (a), (b), and (d), and the second subset comprised curvatures of (c).  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Source**} & \multirow{2}{*}{**Sum of Squares**} & \multirow{2}{*}{**df**} & \multirow{2}{*}{**Mean**} & \multirow{2}{*}{**Square**} & \multirow{2}{*}{\(F\)} & \multirow{2}{*}{\(p\)} \\  & & & **Type** & & & & \\ \hline \multirow{8}{*}{Sample} & \multirow{8}{*}{4R} & Between & 9.369 & 3 & 3.123 & 1.184 & 0.318 \\  & & Within & 411.475 & 156 & 2.638 & & \\  & & Total & 420.844 & 159 & & & \\  & & Between & 4.469 & 3 & 1.490 & 0.729 & 0.536 \\  & & Within & 318.975 & 156 & 2.045 & & \\  & & Total & 323.444 & 159 & & & \\  & & Between & 6.750 & 3 & 2.250 & 1.093 & 0.354 \\  & & Within & 321.150 & 156 & 2.059 & & \\  & & Total & 327.900 & 159 & & & \\  & & Between & 25.119 & 3 & 8.373 & 4.550 & 0.004 \\  & & Within & 287.075 & 156 & 1.840 & & \\  & & Total & 312.194 & 159 & & & \\ \hline \multirow{8}{*}{Pattern} & \multirow{8}{*}{(a)} & Between & 6.919 & 3 & 2.306 & 1.061 & 0.368 \\  & & Within & 339.175 & 156 & 2.174 & & \\  & & Total & 346.094 & 159 & & & \\  & & Between & 31.969 & 3 & 10.656 & 5.263 & 0.002 \\  & & Within & 315.875 & 156 & 2.025 & & \\  & & Total & 347.844 & 159 & & & \\  & & Between & 46.600 & 3 & 15.533 & 7.456 & 0.000 \\  & (c) & Within & 325.000 & 156 & 2.083 & & \\  & & Total & 371.600 & 159 & & & \\  & & Between & 2.619 & 3 & 0.873 & 0.380 & 0.768 \\  & (d) & Within & 358.625 & 156 & 2.299 & & \\  & & Total & 361.244 & 159 & & & \\ \hline \hline \end{tabular}
\end{table}
Table 8: Results of one-way ANOVA for control comfort by each sample and usage pattern.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Source**} & \multirow{2}{*}{**Sum of Squares**} & \multirow{2}{*}{**df**} & \multirow{2}{*}{**Mean**} & \multirow{2}{*}{\(F\)} & \multirow{2}{*}{\(p\)} & \multirow{2}{*}{\(\eta_{p}^{2}\)} \\  & & **Type III** & & & & & \\ \hline Sample & 5.138 & 3 & 1.713 & 1.296 & 0.279 & 0.032 \\ Error (Sample) & 154.613 & 117 & 1.321 & & & \\ Pattern & 14.063 & 3 & 4.688 & 2.307 & 0.080 & 0.056 \\ Error (Pattern) & 237.688 & 117 & 2.032 & & & \\ Sample \(\times\) Pattern & 16.250 & 9 & 1.806 & 2.071 & 0.031 & 0.050 \\ Error (Sample \(\times\) Pattern) & 306.000 & 351 & 0.872 & & & \\ \hline \hline \end{tabular}
\end{table}
Table 9: Results of four-way mixed ANOVA for stability (Test result of within subject effects).  
In the case of usage patterns, however, all patterns showed no significant differences in grip comfort between samples.