## 3 Results  
The pilot study results showed that tube training and SF-ex exhibited a significant interaction for the AbH (F = 5.63, \(p\) = 0.010, partial \(\eta^{2}\) = 0.32) and FDB (F =15.29, \(p\) < 0.001, partial \(\eta^{2}\) = 0.56), but no significant interaction for the FHB (F = 2.73, \(p\) = 0.086, partial \(\eta^{2}\) = 0.19). In the pre- and post-intervention comparison, for the three muscles (AbH, FHB, and FDB), the results for tube training were \(p\) = 0.001, d = 1.14, 95% confidence interval (CI) [0.42, 1.83]; \(p\) = 0.012, d = 0.82, 95% CI [0.17, 1.44]; and \(p\) < 0.001, d = 1.82, 95% CI [0.91, 2.70]. In the SF-ex, the results were \(p\) = 0.010, d = 0.85, 95% CI [0.19, 1.47]; \(p\) = 0.103, d = 0.49, 95% CI [-0.10, 1.06]; and \(p\) < 0.001, d = 1.52, 95% CI [0.69, 2.31]. In the control group, \(p\) = 0.574, d = 0.16, 95% CI [-0.70, 0.39]; \(p\) = 0.881, d = 0.04, 95% CI [-0.59, 0.50]; and \(p\) = 0.267, d = 0.32, 95% CI [-0.24, 0.88]. Therefore, the immediate effects of tube training and SF-ex were confirmed in the AbH and FDB.  
In accordance with the exclusion criteria, 4 out of 23 participants were excluded from the analysis, and 19 participants were divided into each intervention. The basic information for each intervention group is shown in Table 1. No significant differences were found in the basic information at baseline between any of the groups.  
In the intervention study targeting runners, no interaction was observed in any of the items, but the main effect of time was confirmed, and both groups showed significant improvements in toe grip strength (F = 25.64, \(p\) < 0.001, partial \(\eta^{2}\) = 0.60), toe gap strength (F = 11.26, \(p\) = 0.004, partial \(\eta^{2}\) = 0.40), and RSI (F = 4.81, \(p\) = 0.042, partial \(\eta^{2}\) = 0.22) (Table 2).  
Table 3 shows the results of the changes in the toe function pre- and post-intervention within the group. In the tube training, significant increases were observed in all the items, including the toe grip strength (\(p\) = 0.002, d = 1.37), toe gap strength (\(p\) = 0.002, d = 1.37), and RSI (\(p\) = 0.046, d = 0.73). In the SF-ex group, significant increases were observed in the  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Tube Training Group** & **SF-ex Group** & **\(p\)** \\  & **(n = 10)** & **(n = 9)** & **\(p\)** \\ \hline Age, years & 19.4 \(\pm\) 1.2 & 20.0 \(\pm\) 1.5 & 0.342 \\ Body height, cm & 170.4 \(\pm\) 4.1 & 168.7 \(\pm\) 0.4 & 0.394 \\ Body weight, kg & 54.5 \(\pm\) 3.2 & 53.6 \(\pm\) 2.6 & 0.439 \\ BMI, kg/m\({}^{2}\) & 18.8 \(\pm\) 0.5 & 18.8 \(\pm\) 1.0 & 0.948 \\ Toe grip strength, kgf & 19.4 \(\pm\) 4.3 & 20.1 \(\pm\) 4.9 & 0.715 \\ Toe gap strength, kgf & 3.2 \(\pm\) 0.9 & 3.7 \(\pm\) 1.1 & 0.306 \\ RSI & 2.3 \(\pm\) 0.3 & 2.4 \(\pm\) 0.4 & 0.625 \\ \hline \hline \end{tabular} Data presented as mean \(\pm\) SD. BMI = body mass index; RSI = reactive strength index.  
\end{table}
Table 1: Participant characteristics at baseline.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & \multicolumn{4}{c}{**Between-Group Differences**} \\ \cline{3-8}  & & \multicolumn{2}{c}{**Main Effect by Time**} & \multicolumn{2}{c}{**Interaction**} \\ \cline{3-8}  & & **F-Value** & \(p\)** & **Partial \(\eta^{2}\)** & **F-Value** & \(p\)** & **Partial \(\eta^{2}\)** \\ \hline \multirow{3}{*}{Toe grip strength} & Tube training & 25.64 & \textless{}0.001 ** & 0.60 & 0.270 & 0.610 & 0.02 \\  & SF-ex & 11.26 & 0.004 ** & 0.40 & 0.656 & 0.429 & 0.04 \\ \cline{1-1}  & Tube training & 4.81 & 0.042 * & 0.22 & 0.670 & 0.424 & 0.04 \\ \hline \hline \end{tabular} Data presented as mean \(\pm\) SD. RSI = reactive strength index. * \(p\) < 0.05; ** \(p\) < 0.01.  
\end{table}
Table 2: Changes in toe function pre- and post-intervention between groups.  
toe grip strength (\(p\) = 0.019, d = 0.98), but no significant differences were observed in the toe gap strength (\(p\) = 0.200, d = 0.46) and RSI (\(p\) = 0.396, d = 0.30).