title: Does texting while walking really affect gait in young adults?
abstract: BACKGROUND
  Texting on a smartphone while walking has become a customary task among young adults. In recent literature many safety concerns on distracted walking have been raised. It is often hypothesized that the allocation of attentional resources toward a secondary task can influence dynamic stability. In the double task of walking and texting it was found that gait speed is reduced, but there is scarce evidence of a modified motor control strategy compromising stability. The aim of this study is twofold: 1) to comprehensively examine the gait modifications occurring when texting while walking, including the study of the lower limb muscle activation patterns, 2) to specifically assess the co-contraction of ankle antagonist muscles. We hypothesized that texting while walking increases co-contractions of ankle antagonist muscles when the body weight is transferred from one lower limb to the other, to improve the distal motor control and joint stabilization.
  
  
  METHODS
  From the gait data collected during an instrumented walk lasting 3 min, we calculated the spatio-temporal parameters, the ankle and knee kinematics, the muscle activation patterns of tibialis anterior, gastrocnemius lateralis, peroneus longus, rectus femoris, and lateral hamstrings, and the co-contraction (occurrence and duration) of the ankle antagonist muscles (tibialis anterior and gastrocnemius lateralis), bilaterally.
  
  
  RESULTS
  Young adults showed, overall, small gait modifications that could be mainly ascribable to gait speed reduction and a modified body posture due to phone handling. We found no significant alterations of ankle and knee kinematics and a slightly delayed activation onset of the left gastrocnemius lateralis. However, we found an increased co-contraction of tibialis anterior and gastrocnemius lateralis, especially during mid-stance. Conversely, we found a reduced co-contraction during terminal stance.
  
  
  CONCLUSIONS
  Our results suggest that, in young adults, there is an adjustment of the motor control strategy aimed at increasing ankle joint stability in a specific and "critical" phase of the gait cycle, when the body weight is transferred from one leg to the other.
authors.affiliation: Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Torino, Italy. valentina.agostini@polito.it.
authors.forename: Valentina
authors.initials: V
authors.lastname: Agostini
authors.affiliation: Università degli Studi di Torino, Via Zuretti 29, 10126, Torino, Italy. francesco.lofermo@gmail.com.
authors.forename: Francesco
authors.initials: F
authors.lastname: Lo Fermo
authors.affiliation: SC Medicina Fisica e Riabilitazione U, AO Città della Salute e della Scienza, Corso Bramante 82, 10126, Torino, Italy. giuseppe.massazza@gmail.com.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Massazza
authors.affiliation: Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Torino, Italy. marco.knaflitz@polito.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Knaflitz
mesh_terms: D000328:Adult; D000842:Ankle / Q000502:physiology; D000843:Ankle Joint / Q000502:physiology; D001696:Biomechanical Phenomena; D004576:Electromyography; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D007866:Leg / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D060145:Text Messaging; D016138:Walking / Q000502:physiology*; D055815:Young Adult