## 4 Discussion
\begin{table}
\begin{tabular}{c l c c c c} \hline \hline  & \multicolumn{2}{c}{**Survey Question**} & \multicolumn{3}{c}{**Mean (M) \(\pm\) Standard Deviation (SD)**} \\ \cline{3-6}  & & **DTG** & **NDG** & **T** & _p-Value_ \\ \hline A6 & \begin{tabular}{c} After the exercise period, I felt like I \\ could steadily exercise in the future. \\ \end{tabular} & 4.12 \(\pm\) 0.99 & 3.59 \(\pm\) 0.80 & 1.72 & 0.048 \\ \hline A7 & Stretching changed my body. & 3.53 \(\pm\) 0.87 & 3.47 \(\pm\) 0.80 & 0.21 & 0.42 \\ \hline A8 & \begin{tabular}{c} I was able to concentrate until the \\ end of the stretching time. \\ \end{tabular} & 4.06 \(\pm\) 0.75 & 3.24 \(\pm\) 1.03 & 2.66 & 0.006 \\ \hline A9 & \
\begin{tabular}{c} I recommend this exercise program \\ to others. \\ \end{tabular} & 4.29 \(\pm\) 0.59 & 4.00 \(\pm\) 0.61 & 1.43 & 0.08 \\ \hline A0 &
\begin{tabular}{c} Please choose the level of enjoyment \\ you felt during the stretching \\ program as your score. \\ \end{tabular} & 3.94 \(\pm\) 0.83 & 3.53 \(\pm\) 0.94 & 1.35 & 0.09 \\ \hline \hline \end{tabular}  
* A: Numbers on the survey questionnaire. DTG: Digital Therapeutic Group. NDG: Non-Digital Therapeutic Group.  
\end{table} 
Table 5: _Cont._The main finding of this study is that stretching application improves flexibility of the lower extremity and dynamic balance, satisfaction, and compliance in healthy adults. Previous studies have shown that satisfaction with exercise influences adherence [30; 31; 32; 56], and exercise adherence influences exercise effectiveness [25]. Therefore, this suggests that using a lower extremity stretching application with an alarm function can improve user satisfaction and adherence, thereby improving exercise effects such as flexibility of the lower extremity and dynamic balance. These results also raise the possibility that the use of a stretching application may improve physical inactivity and exercise avoidance in healthy adults, which may have important implications for future exercise behavior [4; 5; 6]. Furthermore, using stretching applications can improve users' quality of life in social restrictions such as the COVID-19 pandemic (as well as future lockdown situations) [57], and the stretching application with high retention and adherence levels suggests that it may also be applicable to adults with musculoskeletal pain [57; 58]. This study has several limitations. First, some of the subjects demonstrated a lack of motivation to perform the stretching. This voluntary study involved adults who do not frequently exercise. Therefore, subjects in the DTG who did not want to stretch may have struggled to exercise consistently or found the stretching time and intensity inappropriate. These results are evident in the satisfaction survey items. Additionally, although there was a significant difference in participation between groups, the DTG demonstrated a twice-weekly participation rate. This may be due to the nature of the program, which involves voluntary exercise performance without coercion. The results may improve with more appropriate motivation. Second, the intervention was applied over 4 weeks. Stretching must be performed at least twice a week for 5 to 6 weeks to see significant effects [53]. The study period may not have fully reflected the effect of stretching. The subjects may not have felt changes in their bodies due to the reduced stretching frequency and study period. Third, despite the request to fill out exercise performance records honestly, potential problems such as failure to record sessions, falsified data, poor memory leading to inaccurate data, etc., may occur. Fourth, this study was small in scale; therefore, the results of this study may vary if conducted on a large scale. Fifth, the validity and reliability of the satisfaction questionnaire has not been verified. Future studies can apply DTx to the older population, clinical population, and athletes, and should investigate more variables such as strength, endurance, kinesthesis, proprioception, and functional status.