Maintaining balance on a moving bus: The importance of three-peak steps whilst climbing stairs

In a previous work of the authors, the impact of bus acceleration in level walking was presented. However, climbing stairs is physically more challenging than level walking and results in a high number of falls, hence substantial medical costs. Understanding the impact of a dynamic environment, such as that of a bus, on people’s gait whilst walking on stairs, would enable the reduction, or even the elimination of balance-loss falls. The gait of 29 healthy and regular bus users (20–80 y.o.) was monitored whilst ascending and descending a static and “moving” staircase. The tasks took place in a real double-decker bus which was initially stationary. When the bus was moving, ascending was tested during medium acceleration (+1.5 m/s²), while descending during medium deceleration (−1.5 m/s²), reproducing the most common movements aboard buses. Examining healthy people enables the identification of differences in gait that are accounted for the alteration in the bus environment and gives the opportunity to further consider the challenges mobility impaired passengers are experiencing. After applying the method established in level walking, chi-square tests were performed on participants’ step type (resulting from the ground reaction force profile), taking into account participants’ age and gender and the bus acceleration. The outcomes revealed that age and gender affect people’s gait in a dynamic environment. Moreover, there is a significant correlation between the increase of acceleration and the type of steps passengers use to sustain their balance, as the number of three-peak steps was increasing with the increase of bus acceleration. Hence, the bus environment forces people to use a walking style other than their natural one and older people in particular, unconsciously increase the contact area between their foot and the floor (three-peak steps) to increase balance. Surprisingly, males appear less able than females to control balance. People’s stair walking in a moving vehicle was investigated for the first time and has opened-up new horizons for gait analysis in dynamic environments