title: Touch-screen tablet user configurations and case-supported tilt affect head and neck flexion angles.
abstract: OBJECTIVE
  The aim of this study was to determine how head and neck postures vary when using two media tablet (slate) computers in four common user configurations.
  
  
  METHODS
  Fifteen experienced media tablet users completed a set of simulated tasks with two media tablets in four typical user configurations. The four configurations were: on the lap and held with the user's hands, on the lap and in a case, on a table and in a case, and on a table and in a case set at a high angle for watching movies. An infra-red LED marker based motion analysis system measured head/neck postures.
  
  
  RESULTS
  Head and neck flexion significantly varied across the four configurations and across the two tablets tested. Head and neck flexion angles during tablet use were greater, in general, than angles previously reported for desktop and notebook computing. Postural differences between tablets were driven by case designs, which provided significantly different tilt angles, while postural differences between configurations were driven by gaze and viewing angles.
  
  
  CONCLUSIONS
  Head and neck posture during tablet computing can be improved by placing the tablet higher to avoid low gaze angles (i.e. on a table rather than on the lap) and through the use of a case that provides optimal viewing angles.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, MA 02115, USA.
authors.forename: Justin G
authors.initials: JG
authors.lastname: Young
authors.forename: Matthieu
authors.initials: M
authors.lastname: Trudeau
authors.forename: Dan
authors.initials: D
authors.lastname: Odell
authors.forename: Kim
authors.initials: K
authors.lastname: Marinelli
authors.forename: Jack T
authors.initials: JT
authors.lastname: Dennerlein
mesh_terms: D000328:Adult; D003201:Computers; D006804:Ergonomics; D005260:Female; D006257:Head; D006801:Humans; D008297:Male; D009333:Neck; D011187:Posture