title: Effects of Visual Display on Joint Excursions Used to Play Virtual Dodgeball.
abstract: BACKGROUND
  Virtual reality (VR) interventions hold great potential for rehabilitation as commercial systems are becoming more affordable and can be easily applied to both clinical and home settings.
  
  
  OBJECTIVE
  In this study, we sought to determine how differences in the VR display type can influence motor behavior, cognitive load, and participant engagement.
  
  
  METHODS
  Movement patterns of 17 healthy young adults (8 female, 9 male) were examined during games of Virtual Dodgeball presented on a three-dimensional television (3DTV) and a head-mounted display (HMD). The participant's avatar was presented from a third-person perspective on a 3DTV and from a first-person perspective on an HMD.
  
  
  RESULTS
  Examination of motor behavior revealed significantly greater excursions of the knee (P=.003), hip (P<.001), spine (P<.001), shoulder (P=.001), and elbow (P=.026) during HMD versus 3DTV gameplay, resulting in significant differences in forward (P=.003) and downward (P<.001) displacement of the whole-body center of mass. Analyses of cognitive load and engagement revealed that relative to 3DTV, participants indicated that HMD gameplay resulted in greater satisfaction with overall performance and was less frustrating (P<.001). There were no significant differences noted for mental demand.
  
  
  CONCLUSIONS
  Differences in visual display type and participant perspective influence how participants perform in Virtual Dodgeball. Because VR use within rehabilitation settings is often designed to help restore movement following orthopedic or neurologic injury, these findings provide an important caveat regarding the need to consider the potential influence of presentation format and perspective on motor behavior.
authors.affiliation: Ohio University, School of Rehabilitation and Communication Sciences, Athens, OH, United States. thomasj5@ohio.edu.
authors.forename: James S
authors.identifier: http://orcid.org/0000-0001-7668-9578
authors.initials: JS
authors.lastname: Thomas
authors.forename: Christopher R
authors.identifier: http://orcid.org/0000-0002-4723-0247
authors.initials: CR
authors.lastname: France
authors.forename: Megan E
authors.identifier: http://orcid.org/0000-0001-8111-7312
authors.initials: ME
authors.lastname: Applegate
authors.forename: Samuel T
authors.identifier: http://orcid.org/0000-0002-3150-4207
authors.initials: ST
authors.lastname: Leitkam
authors.forename: Peter E
authors.identifier: http://orcid.org/0000-0001-9497-900X
authors.initials: PE
authors.lastname: Pidcoe
authors.forename: Stevan
authors.identifier: http://orcid.org/0000-0003-3578-2586
authors.initials: S
authors.lastname: Walkowski
keywords: avatar presentation; joint kinematics; virtual reality