title: Cervical motion assessment using virtual reality.
abstract: METHODS
  Repeated measures of cervical motion in asymptomatic subjects.
  
  
  OBJECTIVE
  To introduce a virtual reality (VR)-based assessment of cervical range of motion (ROM); to establish inter and intratester reliability of the VR-based assessment in comparison with conventional assessment in asymptomatic individuals; and to evaluate the effect of a single VR session on cervical ROM.
  
  
  BACKGROUND
  Cervical ROM and clinical issues related to neck pain is frequently studied. A wide variety of methods is available for evaluation of cervical motion. To date, most methods rely on voluntary responses to an assessor's instructions. However, in day-to-day life, head movement is generally an involuntary response to multiple stimuli. Therefore, there is a need for a more functional assessment method, using sensory stimuli to elicit spontaneous neck motion. VR attributes may provide a methodology for achieving this goal.
  
  
  METHODS
  A novel method was developed for cervical motion assessment utilizing an electromagnetic tracking system and a VR game scenario displayed via a head mounted device. Thirty asymptomatic participants were assessed by both conventional and VR-based methods. Inter and intratester repeatability analyses were performed. The effect of a single VR session on ROM was evaluated.
  
  
  RESULTS
  Both assessments showed non-biased results between tests and between testers (P > 0.1). Full-cycle repeatability coefficients ranged between 15.0 degrees and 29.2 degrees with smaller values for rotation and for the VR assessment. A single VR session significantly increased ROM, with largest effect found in the rotation direction.
  
  
  CONCLUSIONS
  Inter and intratester reliability was supported for both the VR-based and the conventional methods. Results suggest better repeatability for the VR method, with rotation being more precise than flexion/extension. A single VR session was found to be effective in increasing cervical motion, possibly due to its motivating effect.
authors.affiliation: Physical Therapy Department, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel. hbahat@research.haifa.ac.il
authors.forename: Hilla
authors.initials: H
authors.lastname: Sarig-Bahat
authors.forename: Patrice L
authors.initials: PL
authors.lastname: Weiss
authors.forename: Yocheved
authors.initials: Y
authors.lastname: Laufer
mesh_terms: D000328:Adult; D000886:Anthropometry / Q000295:instrumentation / Q000379:methods*; D002574:Cervical Vertebrae / Q000033:anatomy & histology / Q000502:physiology*; D004185:Disability Evaluation; D055590:Electromagnetic Phenomena; D005260:Female; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D015588:Observer Variation; D011843:Radiculopathy / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D012399:Rotation; D012680:Sensitivity and Specificity; D014584:User-Computer Interface; D018910:Video Games / Q000639:trends; D055815:Young Adult