Impacts of mobile phone texting on vertical ground reaction forces during stair negotiation

Stairs are one of the most dangerous places for accidental falls in both daily life and occupational settings. Knowledge about ground reaction force (GRF) characteristics during stair negotiation can facilitate a better understanding of the causal mechanisms for stair falls. The objective of this study was to investigate the effects of mobile phone texting on GRF during stair negotiation and reveal their implications associated with the safety during stair negotiation. Twelve young male adults were involved in an experimental study. They were instructed to carry out texting tasks with different levels of cognitive load while performing stair negotiation. Vertical GRF (vGRF) parameters accounting for force amplitude and loading/unloading rates were compared between texting conditions. Texting tasks resulted in slower force loading and unloading rates during stair ascent, while weight acceptance force during stair descent decreased with the application of texting tasks. These findings suggested that mobile phone texting can compromise postural stability and increase the risk of falls during stair negotiation. The findings from the present study highlight the necessity of avoiding mobile phone usage during stair negation to prevent accidental stair falls. They also have practical implications for developing effective fall prevention interventions.