# Development of a Caterpillar-Type Walker for the Elderly People
## 3 Results
### Upper and Lower Extremity Muscle Activity
#### 3.2.2 Obstacle Terrain  
Table 5 and Figure 9 show the activity of the upper and lower extremity muscles using GTW and CTW in obstacle terrain. The statistical significance of the comparison of muscle activity for the two walkers was confirmed through Wilcoxon signed-rank test. Comparing the results for CTW and GTW, in the case of 1-cm-high obstacles, a reduction of 11% in FDS, 39% in BB, 2% in FDP, and 20% in TB occurred. In the case of 2-cm-high obstacles, a reduction of 40% in FDS, 61% in BB, 21% in FDP, and 48% in TB was observed. Finally, in the case of 3-cm-high obstacles, a reduction of 46% in FDS, 61% in BB, 16% in FDP, and 48% in TB occurred. These were all significant differences in the activity of the upper extremity muscles for all experimental conditions between GTW and CTW (\(p<0.05\)). The \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & **FDS** & **BB** & **FDP** & **TB** & **TA** & **RF** & **GA** & **BF** \\ \hline \multirow{2}{*}{GTW} & \(16.51\pm 3.5\) & \(11.43\pm 3.4\) & \(34.07\pm 4.3\) & \(28.38\pm 4.5\) & \(23.11\pm 2.5\) & \(23.95\pm 2.7\) & \(26.01\pm 3.5\) & \(27.86\pm 4.1\) \\  & (14.7, 13.1–18.8) & (10.3, 7.3–14.4) & (33.1, 26.8–43.8) & (27.2, 23.1–33.2) & (22.3, 17.9–26.7) & (22.9, 16.5–27.9) & (24.5, 19.7–32.1) & (27.8, 20.8–34.1) \\ \hline \multirow{2}{*}{CTW} & \(12.15\pm 3.4\) & \(8.58\pm 4.1\) & \(29.31\pm 4.1\) & \(20.75\pm 5.1\) & \(18.20\pm 2.3\) & \(19.94\pm 3.1\) & \(17.89\pm 2.7\) & \(21.97\pm 3.8\) \\  & (10.8, 6.9–16.2) * & (7.8, 5.5–10.1) * & (30.5, 21.1–35.9) * & (20.3, 14.8–35.9) * & (17.2, 11.2–23.6) * & (19.8, 14.6–26.2) * & (17.5, 13.5–20.4) * & (21.7, 13.1–26.1) * \\ \hline \hline \end{tabular}  
* Notes: (M \(\pm\) SD (median, IQR));
* Significant difference in the uneven terrain extremity muscle activity between when walking with GTW and walking with CTW (\(p<0.05\)).  
\end{table} 
Table 4: Upper and lower extremity muscle activity in uneven terrain. Figure 8: (**a**) Forward stability test; (**b**) backward stability test; (**c**) sideways stability test. statistical significance of muscle activity according to obstacle height for the two walkers was confirmed through a Kruskal-Wallis test. When using GTW, significant increases in muscle activity occurred as the obstacle height increased to 1-2 cm, 2-3 cm, and 1-3 cm, respectively. The increases of 28%, 41%, 35% in FDS, 36%, 41%, 35% in BB, 20%, 13%, 22% in FDP, and 36%, 45%, 39% in TB were observed. As the obstacle height increased, the activity of all upper extremity muscles increased significantly (\(p<0.05\)). When using CTW, the activity of FDS muscle decreased by 5%, 1%, and 7% as the obstacle height increased to 1-2 cm, 2-3 cm, 1-3 cm, respectively. In contrast, in the case of BB, FDP, and TB, the increases in muscle activity occurred as the obstacle height increased to 1-2 cm, 2-3 cm, and 1-3 cm, respectively. The increase of 1%, 7%, 8% in BB, 1%, 5%, 7% in FDP, and 1%, 5%, 7% in TB was observed. The observed differences were not statistically significant. Comparing the results for CTW and GTW, in the case of 1-cm-high obstacles, a reduction of 15% in TA, 12% in RF, 9% in GA, and 42% in BF occurred. In the case of 2-cm-high obstacles, a reduction of 42% in TA, 15% in RF, 21% in GA, and 24% in BF was observed. Finally, in the case of 3-cm-high obstacles, a reduction of 42% in TA, 15% in RF, 28% in GA, and 24% in BF occurred. These were all significant differences in the activity of the lower extremity muscles for all experimental conditions between GTW and CTW, except in the case of BF and RF at heights of 1 cm (\(p<0.05\)). When using GTW, the increases in muscle activity occurred as the obstacle height increased to 1-2 cm, 2-3 cm, and 1-3 cm, respectively. The increases of 31%, 37%, 36% in TA, 15%, 20%, 23% in GA, 5%, 14%, 5% in RF, and 14%, 20%, 18% in BF, occurred, respectively. As the obstacle height increased, the activity of the lower extremity muscles overall increased significantly (\(p<0.05\)).