Determination of critical time points in non-collision incidents of elderly passengers in standing position on urban bus.

Objective: Due to the reduced physical ability of elderly, the occurrence of non-collision incidents is higher for these passengers in standing position. Therefore, the purpose of the present study is to determine the critical time points of non-collision incidents using the level of leg muscle activity in elderly standing passengers on urban bus.Methods: To determine the critical time points in the occurrence of non-collision incidents, the level of muscular activity of the standing passengers was analyzed using a surface electromyography (surface EMG) device during the movement scenario of the bus. The results of assessing the leg muscle activity was analyzed in SPSS software.Results: The contraction pattern of the leg muscles in standing passengers was consistent with Newton's First Law. The results showed that the level of muscular activity decreased in the right leg muscles when changing the phase of bus motion from acceleration to constant velocity. This level of muscular activity in the left leg muscles increased when constant velocity changed to deceleration. These changes were quite significant in the medial gastrocnemius and soleus muscles (P < 0.05).Conclusions: According to these findings, it was found that the acceleration and deceleration phases, especially the starting and changing phases of bus motion, are the most critical time points in the occurrence of non-collision incidents in elderly standing passengers on urban bus.