title: A kinematic analysis of a haptic handheld stylus in a virtual environment: a study in healthy subjects.
abstract: BACKGROUND
  Virtual Reality provides new options for conducting motor assessment and training within computer-generated 3 dimensional environments. To date very little has been reported about normal performance in virtual environments. The objective of this study was to evaluate the test-retest reliability of a clinical procedure measuring trajectories with a haptic handheld stylus in a virtual environment and to establish normative data in healthy subjects using this haptic device.
  
  
  METHODS
  Fifty-eight normal subjects; aged from 20 to 69, performed 3 dimensional hand movements in a virtual environment using a haptic device on three occasions within one week. Test-retest stability and standardized normative data were obtained for all subjects.
  
  
  RESULTS
  No difference was found between test and retest. The limits of agreement revealed that changes in an individual's performance could not be detected. There was a training effect between the first test occasion and the third test occasion. Normative data are presented.
  
  
  CONCLUSIONS
  A new test was developed for recording the kinematics of the handheld haptic stylus in a virtual environment. The normative data will be used for purposes of comparison in future assessments, such as before and after training of persons with neurological deficits.
authors.affiliation: Rehabilitation medicine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at Göteborg University, Guldhedsgatan 19, Göteborg, Sweden. jurgen.broeren@mednet.gu.se
authors.forename: Jurgen
authors.initials: J
authors.lastname: Broeren
authors.forename: Katharina S
authors.initials: KS
authors.lastname: Sunnerhagen
authors.forename: Martin
authors.initials: M
authors.lastname: Rydmark
mesh_terms: D000328:Adult; D000368:Aged; D001132:Arm; D001696:Biomechanical Phenomena / Q000295:instrumentation*; D003625:Data Collection; D005260:Female; D006225:Hand; D006801:Humans; D007858:Learning; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D012016:Reference Values; D015203:Reproducibility of Results; D013647:Task Performance and Analysis; D014584:User-Computer Interface