## 3 Results  
The Scheirer-Ray-Hare test revealed significant differences for grasp, spot, and their interaction (\(\alpha<0.05\)). However, repetition and interactions with other factors were not significant (\(\alpha>0.8\)). Therefore, in order to look for spots and grasps with significantly different muscle activity, Bonferroni post hoc analyses were conducted, as well as fourteen Kruskal-Wallis analyses, with A50V as the dependent variable: seven (one per spot) with grasp as factor, and other seven (one per grasp) with spot as factor (notice that averaged values across repetitions were used since repetition was not significant). All Kruskal-Wallis analyses per spot were significant (\(\alpha<0.05\)) for the grasp factor, and all Kruskal-Wallis analyses per grasp were significant (\(\alpha<0.05\)) for the spot factor. Tables 2 and 3 summarize the results of all the Bonferroni post hoc analyses. Overall, the spots tended to present similar values to each other (Table 2), regardless of the type of grasp. However, there was one exception, spot 2 during IntPP grasps, which exhibited significantly different values compared to all other spots. Upon closer examination of each spot, two main patterns emerged, depending on the kind of grasp: power or precision. During precision grasps (two/three-finger PpP, Lum grasp, and LatP) the wrist and finger flexors (spots 1, 2, and 3) displayed similar values, as did the wrist extensors, finger extensors, and thumb muscles (spots 4, 5, 6, and 7). In power grasps (Cyl, Obl and IntPP grasps), the wrist ulnar deviators exhibited similar activation levels (spot 1 and 7), while the thumb muscles (spot 4) acted similarly to the finger muscles (flexors and extensors, spot 3 and 5) and the wrist extensors and ulnar deviators (spots 6). In other words, antagonistic muscles, such as flexors and extensors, were activated similarly to provide a stable and secure grasp. Table 3 shows spots with significant differences between grasps. Four cases presented no spots with significant differences: two-finger PpP versus three-finger PpP and Lum grasp, Lum grasp versus LatP, and Obl grasp versus IntPP grasp. On the contrary, Cyl grasp versus Lum grasp and LatP showed significant differences in almost all spots. Spot 5 did not exhibit significant differences between any grasps. Table 4 and Figure 5 show the mA50V and 95% CI of each spot during each grasp performed. The median values ranged from 4.4% (spot 3, lateral pinch) to 32.8% (spot 7, cylindrical grasp). Ranges of 95% CI varied between 0.5% (spot 3, two-finger pad-to-pad pinch) and 5.5% (spot 1, intermediate power-precision grasp). Spot 2 exhibited consistently low mA50V and 95% CI values across all grasps. Cyl grasp required the highest muscle activity among all spots, while LatP demanded the least. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & & **1** & **2** & **3** & **4** & **5** & **6** & **7** \\ \hline \multirow{2}{*}{Two-finger PpP} & mA50V & 9.9 & 5.1 & 5.7 & 15.3 & 15.1 & 20.1 & 15.5 \\  & 95\% CI & 2.1 & 1.1 & 0.5 & 4.0 & 2.1 & 3.5 & 2.1 \\ \hline \multirow{2}{*}{Three-finger PpP} & mA50V & 10.9 & 6.6 & 9.8 & 14.1 & 20.0 & 26.2 & 18.3 \\  & 95\% CI & 2.6 & 1.4 & 1.3 & 3.3 & 4.7 & 4.2 & 1.8 \\ \hline \multirow{2}{*}{Cyl} & mA50V & 30.5 & 14.7 & 25.1 & 25.6 & 21.7 & 24.2 & 32.8 \\  & 95\% CI & 3.0 & 2.5 & 3.6 & 4.7 & 4.3 & 2.9 & 4.3 \\ \hline \multirow{2}{*}{Lum} & mA50V & 9.7 & 8.0 & 9.3 & 13.5 & 16.4 & 13.0 & 20.6 \\  & 95\% CI & 2.0 & 1.8 & 2.1 & 3.0 & 3.1 & 2.8 & 2.6 \\ \hline \multirow{2}{*}{LatP} & mA50V & 7.2 & 5.3 & 4.4 & 12.6 & 14.3 & 10.7 & 20.1 \\  & 95\% CI & 1.3 & 0.9 & 0.8 & 0.7 & 1.8 & 2.4 & 2.0 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: mA50V and 95% CI values of each spot during each grasp performed. Values are presented in %, with respect to the MVC.