Perturbation in public transport as a basic concept for perturbation-based balance training for fall prevention

The aim of the study was to collect real-world sensor data on acceleration and deceleration while riding a bus or tram. With respect to the risk of suffering fall-related injuries while using public transportation, our interest was to understand the amplitude of real-world perturbations to translate them to innovative reactive balance training programs.

Acceleration and deceleration data were collected during 12 days in buses and trams in a German city. A sensor, which was fixed to a vertical bar in the vehicle, measured the acceleration signals. Additionally, extreme values of deceleration during full braking were collected in a driving school bus.

For the incident type acceleration from standing extreme values of acceleration and jerking were higher in buses compared to trams with a maximum acceleration of 3.37 m/s² and 1.80 m/s², respectively, and extreme jerking of 13.30 m/s³ and −5.56 m/s³, respectively. Similarly, for the incident type deceleration approaching a stop extreme values of deceleration and jerking were higher in buses compared to trams with maximum deceleration of −3.12 m/s² and −2.31 m/s², respectively, and extreme jerking of −19.19 m/s³ and −10.83 m/s³, respectively. Extreme values for maximum deceleration and extreme jerking as simulated at the driving school were not reached during real-world measurements. The duration of incidents in acceleration from standing and deceleration approaching a stop was shorter for buses than for trams.

Acceleration and jerking values were higher in buses compared to trams. Based on this study, laboratory simulation paradigms can be developed to study balance responses in older persons and to design fall prevention interventions which are ecologically valid.