title: Motion sickness in rally car co-drivers.
abstract: BACKGROUND
  Car sickness is a frequent and potentially disabling problem, commonly related to a theory of sensory conflict, in particular visuo-vestibular, and between actual and anticipated sensory signals. This study aimed to evaluate predictors of motion sickness (MS) in rally car co-drivers exposed to various accelerations.
  
  
  METHODS
  The subjects were 85 rally co-drivers (21 women) who filled in a questionnaire investigating MS symptoms in 4 situations: 1) special stages (competition itself); 2) special stages reconnaissance; 3) reading a book in the car; and 4) rear-seat passenger. The main factors related to MS were also investigated.
  
  
  RESULTS
  Women reported more MS than men only in the rear-seat passenger situation. MS is reported with increasing frequency in special stages (2.3%), special stages reconnaissance (15.3%), when reading a book in a car (25.9%), and as a rear-seat passenger (25.9%). Stress (63.0%), on-board smells (46.5%), and on-board temperature (43.0%) were the main risk factors for MS.
  
  
  CONCLUSIONS
  In special stages, the lower MS occurrence could be related to the kind of visual input: central vision focuses mainly on accurate pace notes while peripheral vision is restricted by the crash helmet and the head being bent forward. A cognitive process involved in the interpretation of the dynamic environment may lead to anticipation of upcoming accelerations, optimizing integration of vestibular and proprioceptive signals. During reconnaissance, the constant change of gaze between looking at the specifics of the road and the road book for taking notes requires frequent adjustments of the gain of the vestibulo-ocular reflex and the associated head movements could generate Coriolis accelerations.
authors.affiliation: Equilibration et Performance Motrice, Université de Lorraine, UFR STAPS de Nancy, 30, rue du Jardin Botanique, 54 600 Villers-lès-Nancy, France. Philippe.Perrin@univ-lorraine.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: Perrin
authors.forename: Alexis
authors.initials: A
authors.lastname: Lion
authors.forename: Gilles
authors.initials: G
authors.lastname: Bosser
authors.forename: Gérome
authors.initials: G
authors.lastname: Gauchard
authors.forename: Claude
authors.initials: C
authors.lastname: Meistelman
mesh_terms: D000328:Adult; D001334:Automobile Driving; D003312:Coriolis Force; D007758:Ear, Inner / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009041:Motion Sickness / Q000209:etiology* / Q000503:physiopathology; D009812:Odorants; D011434:Proprioception / Q000502:physiology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D012307:Risk Factors; D013315:Stress, Psychological / Q000209:etiology; D011795:Surveys and Questionnaires; D013696:Temperature; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult