## 5 Discussion  
The previous studies on the walking of the elderly are focused on individuals with a particular disease. It is known that the variability in the number of steps and stride time is huge in elderly with diseases [22; 23] and that such individuals display the characteristics of slow walking [24; 25] as the stride increases. Additionally, it has been suggested that as the age increases [26], walking disabilities worsen. On the other hand, there are not many gait studies conducted on the elderly without diseases that affect walking or who walk on their own without using any assisting device, although such individuals constitute the highest proportion. In particular, there are not many comparative studies on the walking characteristics of normal walking and maximum walking. This study may be considered valuable in this regard. Additionally, to extract the comparative results of walking characteristics attributed to aging, kinetic and kinematic measurements of ordinary individuals during normal walking and maximum walking were analyzed, and we make suggestions below. The differences between the normal walking and maximum walking of ordinary individuals and the elderly in terms of the walking variables are as shown in Table 11. The increased rate of walking speed in the elderly is about 5% less than that in ordinary individuals, and the variables related to balance (Center of Mass (C.O.M. ), pelvic frontal move, Center of Pressure (C.O.P.)) were measured to be about 12% greater. This result implies that in the same situation, walking speed increases minimally, but imbalance, which could directly lead to a fall accident, greatly occurs. This suggests that the characteristic of maximum walk of the elderly is increased movement. While the shoulder movement of ordinary individuals was minimally reduced, the right shoulder movement of the elderly, which is the main side for use, increased by 41.3%. Moreover, muscular strength of the ankle joint was shown to have increased by >10%. In case of the elderly, they try to forcefully increase the walking speed using a bigger movement, which leads to an excessive use of the body. Therefore, the center of the body is increasingly shaken and alterations such as those in the external environment and physical contact with others occur. Freezing of gait phenomenon follows and leads to a failure of maintaining the balance, thereby resulting in a fall accident. This problem is more pronounced in a maximum walk than in a normal walk. Thus, in a situation which requires maximum walking, external factors that caused sudden changes should be eliminated and a consistent maintenance of the environment until the completion of the maximum walking in the gait facility is required to prevent a fall accident. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Knee (Nm)**} & \multicolumn{3}{c}{**Ankle Joint-Torque (Nm)**} \\ \cline{2-9}  & **Extension** & & **Flexion** & & **Right** & **Left** \\ \hline  & **Ave.** & **S.D.** & **Ave.** & **S.D.** & **Ave.** & **S.D.** & **Ave.** & **S.D.** \\ \hline Normal walk & 62.53 & 47.82 & 35.09 & 23.51 & 102.82 & 79.29 & 91.79 & 51.38 \\ Maximum walk & 92.75 & 89.50 & 57.03 & 68.45 & 91.12 & 101.04 & 94.58 & 73.34 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Comparison of muscle factor during the normal walking and maximum walking of ordinary individuals. To allow an easy recognition of the difference between walking characteristics of the elderly and ordinary individuals during normal walking and maximum walking, the variability rate was suggested in the bar chart as shown in Figures 9-12. As shown in Figure 9, gait factors exhibited similar patterns in both ordinary individuals and the elderly, while as shown in Figure 11, the biggest difference in balance factors was confirmed. It is a fact that everyone knows that balance factors must be strengthened to prevent and reduce fall accidents.