## 3 Results
### Electrical Activation During the Movement Phases  
Significant differences were found in the electrical activity (RMS) between the phases and in the three exercises (F\({}_{2,26}=52.27\); \(p=0.02\); \(\eta^{2}=0.80\)). In the Bulgarian squat exercise (Figure 5), significant differences were found between phases (F\({}_{10,58}=12.18\); \(p<0.001\); \(\eta^{2}=0.68\)). In all quadriceps muscles, the isometric phase was the one that  
Figure 4: Intra-muscular group activation pattern (mean \(\pm\) standard deviation) in percentage. The intragroup muscular ratio expresses the activation of each muscle with respect to the total surface muscular activity of each muscle. The brackets (*) with an asterisk show that there is a significant difference between these two exercises. The vertical lines around the data represent the standard deviation (SD). \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Muscle**} & \multicolumn{2}{c}{**Bulgarian Squat (N = 19)**} & \multicolumn{2}{c}{**Lunge (N = 19)**} & \multicolumn{2}{c}{**Squat (N = 19)**} \\ \cline{2-9}  & **Mean \(\pm\) SD** & **CI 95\%** & **Mean \(\pm\) SD** & **CI 95\%** & **Mean \(\pm\) SD** & **CI 95\%** \\ \hline RF & \(14.83\pm 4.50\%\) * & 12.66 & 17.00 & \(16.56\pm 5.70\%\) * & 13.81 & 19.31 & \(18.69\pm 6.54\%\) * & 15.54 & 21.84 \\ \hline VM & \(56.35\pm 6.71\%\) * & 53.12 & 59.58 & \(58.85\pm 8.02\%\) * & 54.98 & 62.72 & \(53.41\pm 8.03\%\) * & 49.54 & 57.28 \\ \hline VL & \(29.17\pm 5.19\%\) * & 26.67 & 31.67 & \(25.71\pm 6.10\%\) * & 22.77 & 28.65 & \(28.67\pm 6.90\%\) * & 25.34 & 32.00 \\ \hline BF & \(47.50\pm 10\%\) * & 42.68 & 52.32 & \(44.35\pm 6.93\%\) * & 41.01 & 47.69 & \(49.37\pm 9.50\%\) & 44.79 & 53.95 \\ \hline ST & \(51.43\pm 11.22\%\) * & 46.02 & 56.84 & \(55.65\pm 6.94\%\) * & 52.31 & 58.99 & \(50.63\pm 9.50\%\) & 46.05 & 55.21 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Intra-muscular group activation (mean \(\pm\) standard deviation) in percentage. registered the greatest electrical activity (\(p\) = 0.01). The ascent phase had greater activation than the descent phase (\(p\) = 0.03). It was the vastus medialis muscle that showed the greatest activation of all in this phase. In the hamstrings, the ascent phase was greater than the other two (\(p\) = 0.02) in both biceps femoris and semitendinosus. In the lunge exercise (Figure 6), significant differences were found between the three phases (F\({}_{10,54}\) = 16.85; \(p\) \(<\) 0.001; \(\eta^{2}\) = 0.76) for all muscle groups, except for the semitendinosus, where the descent and ascent phases had similar activation (\(p\) = 0.07). Figure 5: Mean activation (V \(\times\) 10\({}^{-5}\)) of all the muscles in each phase in Bulgarian squat. The first phase corresponds to the descent, the second to the isometric phase and the third to the ascent. The vertical lines around the data represent the SD. Figure 6: Mean activation (V \(\times\) 10\({}^{-5}\)) of all the muscles in each phase in lunge. The first phase corresponds to the descent, the second to the isometric phase and the third to the ascent. The vertical lines around the data represent the SD. In the squat exercise (Figure 7), there were significant differences between the phases (F\({}_{10,46}=8.04\); \(p<0.001\); \(\eta^{2}=0.64\)). In the rectus femoris, the isometric phase had greater activation than the descent and ascent phase (\(p=0.04\)), and there were no significant differences between ascent phase and descent phase (\(p=0.09\)). In the vastus medialis, the isometric phase had greater activation than the descent phase (\(p<0.001\)), there were no significant differences between the isometric phase and the ascent phase (\(p=0.25\)) and the ascent phase had greater activation than the descent phase (\(p=0.04\)). In the vastus lateralis, the isometric phase had greater activation than the descent phase (\(p=0.02\)), the ascent phase had greater activation than the descent phase (\(p=0.03\)) and there was no difference between the isometric and ascent phase (\(p=0.87\)).