ECPN Student Poster Contestant: Minimizing Distraction: Cell Phone Use While Walking

In the US, cell phone related pedestrian injuries treated in Emergency Rooms increased more than 6-fold from 2005 to 2010. When pedestrians use a cell phone, they reduce their attention to the environment and this alters their walking biomechanics, which may lead to accidents. Nevertheless, 25% of pedestrians in a busy street and 43.2% of pedestrians on a University campus use a cell phone while walking. Thus, it is critical to evaluate the amount of risk associated with using a cell phone by pedestrians in different environments. Our intention was to identify target points for intervention.

Thirty healthy adults (age 18-29) walked on a treadmill in a virtual reality environment. They performed three avoidance tasks (No, Simple and Complex), with and without using a cell phone. When using a cell phone, participants had to tap objects that randomly appeared on the screen and scores were calculated as the number of objects tapped. During the Simple avoidance task, participants were randomly presented red balls. In the Complex avoidance task, participants were presented either red or green ball. They had to avoid (move away from) the red balls and hit (move towards) the green balls. A failure to respond to a ball within 2 seconds was considered a collision. For each ball encounter, we calculated Movement Time (MT) (the time taken to move laterally). Percent Collision was calculated as number of failures divided by total number of objects ´ 100. Two-factor ANOVAs compared Percent Collision, Mean and standard deviation of MT between trials with or without texting and between the three avoidance tasks.

Percent Collision was higher (p < 0.001) during the cell phone use, but did not differ with avoidance task complexity (p = 0.281). Movement Time was longer (p < 0.001) during the cell phone use. Additionally, MT was longer (p = 0.002) for the Complex obstacle avoidance tasks when compared to the Simple obstacle avoidance tasks. Variability of MT was increased (p < 0.001) when using a cell phone, but was not influenced (p = 0.688) by the complexity of the obstacle avoidance task.

During walking, cell phone use and the complexity of the environment led to a delay in response and an increase in collisions. The increased variance due to the cell phone use is likely due to the switching of attention between cell phone and the environment. We identified a significant effect of using a cell phone on the ability to avoid obstacles in a complex environment. Thus, it is critical to limit the use of a cell phone by pedestrians in busy streets and on university campuses, to prevent accidents due to distraction.