Short communication Cell phones change the way we walk Eric M. Lamberg, Lisa M. Muratori * Department of Physical Therapy, School of Health Technology and Management, Stony Brook University, Stony Brook, NY 11794, USA 1. Introduction While the dangers of cell phone use when driving dominate public discussion, concerns have recently been raised about the effects talking and texting may have on walking. Cell phone use among pedestrians leads to increased cognitive distraction, reduced situation awareness (SA) and increases in unsafe behavior leading to injury and death [1–5]. Results from the few studies conducted on cell phone use while walking show that cell phone users recall fewer objects when conversing [1], walk slower [4] and are more unsafe when crossing a street [1]. Although well-practiced, gait is not automatic; instead, cognitive areas of executive function and attention are active [6,7]. Using dual-task methodology and evaluating performance changes, we can assess the extent of the cognitive demand. Successful performance of walking while using a cell phone requires cognitive and motor abilities and an appropriate division of attention to each. Engaging in a dual-task, such as talking or texting while walking, may interfere with working memory and result in walking errors. To our knowledge, this is the first time a direct examination of gait during talking and texting has been undertaken. We propose that cell phone use will negatively influence walking, and that the more novel task of texting while walking will lead to greater disruptions in gait. We discuss our findings in relation to pedestrian safety and models of control underlying memory and attention. 2. Methods 2.1. Subjects Thirty-three healthy participants (13 male, mean age = 26 (SD 4)) were randomly assigned (11 per group) to either walk, walk while talking on a cell phone (TALK), or walk while texting on a cell phone (TEXT). All participants reported owning a cell phone and familiarity with texting. Approval from the Institutional Review Board at Stony Brook University was obtained. 2.2. Protocol To assess how gait is affected by cell phone use, participants initially completed a baseline assessment. During baseline participants visually located a target 8-m ahead. Then, vision was occluded using a hood that obscured both the floor and target but would allow the cell phone to be seen and manipulated. With vision occluded participants were instructed to walk at a comfortable pace until they thought they reached the previously seen target. Duration and final location of the heel were noted and hooded participants were guided back to the start in a Gait & Posture 35 (2012) 688–690 A R T I C L E I N F O Article history: Received 14 July 2011 Received in revised form 9 November 2011 Accepted 1 December 2011 Key words: Gait Dual-task Texting Working memory Attention A B S T R A C T Cell phone use among pedestrians leads to increased cognitive distraction, reduced situation awareness and increases in unsafe behavior. Performing a dual-task, such as talking or texting with a cell phone while walking, may interfere with working memory and result in walking errors. At baseline, thirty- three participants visually located a target 8 m ahead; then vision was occluded and they were instructed to walk to the remembered target. One week later participants were assigned to either walk, walk while talking on a cell phone, or walk while texting on a cell phone toward the target with vision occluded. Duration and final location of the heel were noted. Linear distance traveled, lateral angular deviation from the start line, and gait velocity were derived. Changes from baseline to testing were analyzed with paired t-tests. Participants engaged in cell phone use presented with significant reductions in gait velocity (texting: 33% reduction, p = 0.01; talking: 16% reduction, p = 0.02). Moreover, participants who were texting while walking demonstrated a 61% increase in lateral deviation (p = 0.04) and 13% increase in linear distance traveled (p = 0.03). These results suggest that the dual-task of walking while using a cell phone impacts executive function and working memory and influences gait to such a degree that it may compromise safety. Importantly, comparison of the two cell phone conditions demonstrates texting creates a significantly greater interference effect on walking than talking on a cell phone. ß 2011 Elsevier B.V. All rights reserved. * Corresponding author at: Department of Physical Therapy Stony Brook University School of Health Technology and Management Stony Brook, NY 11794, USA. Tel.: +1 631 444 6583. E-mail address: lisa.muratori@stonybrook.edu (L.M. Muratori). Contents lists available at SciVerse ScienceDirect Gait & Posture jo u rn al h om ep age: ww w.els evier.c o m/lo c ate/g aitp os t 0966-6362/$ – see front matter ß 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.gaitpost.2011.12.005