Motion sickness in rally co-drivers. C Motion sickness in rally co-drivers. C. Meistelman University Hospital Nancy Université de LorraineNancy, France

Motion sickness Sensory conflict / mismatch Mismatch Pallor Cold sweating Headache Epigastric awareness Sialorrhea Nausea, vomiting Bradycardia Hypotension Vertigo Dizziness Coordination troubles Visual afference Motion sickness Central nervous system Mismatch Vestibular afference Somesthetic afference

Motion sickness has not been investigated in rallies Driver – Co-driver Recces – special stages Surface asphalt - gravel and sand - ice and snow Different cars engine - body - suspension - net door reconnaissance: standard car, legal speed special stages: racing car, closed roads

Motion sickness and co-drivers During the special stages, the co-driver reads his pace notes to alert the driver The co-drivers, who are reading the pace notes are particularly subjected to a wide range of accelerations provoking Motion Sickness

Subjects and methods Participants Methods 85 co-drivers, 21 female Questionnaire adapted from the motion sickness susceptibility questionnaire (MSSQ) Reason - Brand, Golding Specific items relevant for rally were added

Subjects et methods - Questionnaire (1) Sexe / Age / Nb years licence Have you ever been motion sick ? never as front-seat passenger as rear-seat passenger when reading in a car as co-driver when reading pace notes (speciales) as co-driver when reading the road (reconnaissance) when driving a car in a boat roundabouts, entertainments only during chilhood

Subjects and methods - Questionnaire (2) MS favoring factors on-board temperature on-board smells type of road surface oversteer understeer type of meal stress trial duration winding road related to the acceleration plane anterior-posterior (acceleration / braking) right - left (turn) upright (bump, pothole…)

Aviat Space Environ Med, 84: 473-477; 2013 Motion sickness in co-drivers Co-drivers (n = 85) n (%) Cochran’s Q, p-value Special stage 2 (2.3) Q = 29.80, p < 0.001 Reconnaissance 13 (15.3)a Reading a book in a car 22 (25.9)b Rear-seat passenger 22 (25.9)c a Special stage vs. Reconnaissance: McNemar’s χ² test, χ² = 7.69, p = 0.005 b Special stage vs. Reading a book in a car: McNemar’s χ² test, χ² = 18.05, p < 0.001 c Special stage vs. Rear-seat passenger: McNemar’s χ² test, χ² = 16.40, p < 0.001 Aviat Space Environ Med, 84: 473-477; 2013

Results Aviat Space Environ Med, 84: 473-477; 2013 Motion sickness in female and male co-drivers Female (n = 21) n (%) Male (n = 64) χ² or Fisher’s exact tests, p-value Special stage 0 (0) 2 (3.1) Fisher’s exact test, p = 0.99 Reconnaissance 3 (14.3) 10 (15.6) Fisher’s exact test, p = 0.90 Reading a book in a car 5 (23.8) 17 (26.6) χ² = 0.06, p = 0.80 Rear-seat passenger 9 (42.9) 13 (20.3) χ² = 4.18, p = 0.041 Aviat Space Environ Med, 84: 473-477; 2013

Co-drivers motion sickness favoring factors Motion sickness causal factors Frequencies (in %) Stress 63.0 On-board smells 46.5 On-board temperature 43.0 Unexpected accelerations (not indicated in the pace notes) 24.0 Twists and turns (winding road) 18.0 Duration of the special stages 15.5 Vertical accelerations 14.0 Medio-lateral accelerations 12.0 Type of food 10.5 Oversteer 9.5 Understeer Anteroposterior accelerations 3.5

Discussion In special stage motor racing, low rate of motion sickness despite stress smells temperature higher accelerations MS

Results (4) 13 % – Anti-MS medications 3.5 % – troubled by optokinetic stimulation induced by trees

How can we explain the lower prevalence of MS in co-drivers during the race itself?

Vision and gaze stabilisation Reconnaissance Special stages Peripheral vision +++ (environment (landscape)) + (head tilt, crash helmet, door net) Central vision / Gaze road book road writing the pace notes pace notes

Gaze / head / trunck stabilization Reconnaissance Special stages Road book: not precise information Pace notes: precise information Hand (writing) and head alternatively stabilised Head flexed head mobility (crash helmet) Body fixed (bucket seat) Head motions: VOR gain frequent modulation Coriolis accelerations Stiff suspensions car sloshing > 0.5 Hz Stress

Cognitive anticipation of upcoming movements 50 mètres Droite à fond, gauche 80 pour Droite 60 et épingle gauche Droite pour gauche 60 pour épingle droite Droite 70. Gauche droite gauche 90 borne kilométrique Gauche pour droite 80 pour gauche 70 large Droite à fond pour Gauche 70 pour droite 60 long Gauche 70 large se referme en 60 Droite 80 et 90 approximate speed, bend configuration

Italy Sweden Destra media plu Sinistra Media e destra meno et tornante sinistra Sinistra media e tornante destra Destra Media piu 60 sinistra media plu destra media piu sinistra media ... Italy Sweden

Passenger discomfort Air sickness incidence is usually well below 1% but rises to about 8% in severe turbulence The impossibility to anticipate the accelerations caused by the turbulences are promoters of motion sickness

Restriction of head and body movements by the safety devices Crash helmet Belts Hans device, seat

Co drivers During SS: Head motions and especially lateral head motions are limited codrivers information is focused on central retina rather than peripheral Pace notes are cognitively interpreted and allow anticpation of the forthcoming accelerations recorded by the inner ear. Car movement frequencies are higher than 0.5 Hz and therefore out of range of MS

Co drivers During Recces: head motion +++, codrivers move all the time their head to look from the road to the road book and back to write notes It induces modifications of vestibulo ocular reflex (VOR) and generates Coriolis accelerations (triaxial simulation and acceleration) Use of peripheral retina The writing of notes cannot ptovide on time cognitive information which can allow anticipation of the acceleration

Discussion During special stages anticipatory cognitive processing Co-drivers anticipatory body strategy Habituation, sports involving the use of prorioceptive inputs Sports vision therapist and vision therapy?

Motion sickness and CART: Texas Motor Speedway 2001 Disorientation, dizziness and postural imbalance in race car drivers: a problem in G-tolerance, spatial orientation and both: F Guedry, A Raj and T Cowin The Institute for Human and Machine cognition University of West Florida, Pensacola

Conclusion and highlights Motion sickness MS is more reported in reconnaissance than in special stages Pace notes may lead an anticipation of the vestibular accelerations In reconnaissance, head movements may include Coriolis accelerations The type of visual information influences MS susceptibility.

Current study Jacobs (2002) Backman et al (2005) Beaune et al (2010) n 260 7 (Cart divers) Open-wheel: 9 Rally: 9 Open-wheel: 8 Age (years) 23.5 + 9.6 30.0 + 4.7 Open-wheel: 22 + 3 Rally: 24 + 4 18.7 + 3.4 Weight (kg) 64.6 + 13.7 74.5 + 9.5 Open-wheel: 68 + 7 Rally: 79 + 14 64.1 + 8.2 Height (cm) 170 + 12 Open-wheel: 177 + 4 Rally: 182 + 8 178 + 8 BMI (kg/m2) 22.1 + 1.8 Open-wheel: 21.7 + 1.9 Rally: 24.0 + 3.2 20.1 + 1.8