title: Definition and measurement of rider-intrinsic physical attributes influencing all-terrain vehicle safety.
abstract: OBJECTIVE
  All-terrain vehicle (ATV) usage has grown tremendously over the years, reaching 9.5 million vehicles in use in 2007. Accompanying this growth has been a concomitant increase in rider morbidity (including traumatic brain and spine injuries) and death, especially in children. The purpose of this study was to define and measure, through field testing, those physical attributes intrinsic to riders, such as height, weight, and wingspan, which may have implications for ATV riders' safety.
  
  
  METHODS
  Three field tests (J-hook, brake, and bump) were developed and performed to allow direct measurement of the lateral, longitudinal, and vertical dynamics in 5 riders of varying heights, weights, and wingspans. Two ATVs, a utility and a sport model, were tested for further comparisons. Data were acquired using a comprehensive data acquisition system attached to the ATVs. Assignment of individual rider/ATV test safety ratings and a rider/ATV Total Safety Rating were made from the results of these field tests.
  
  
  RESULTS
  The J-hook test results demonstrated that larger rider wingspans positively influence ATV rider safety and mitigate against lateral instability. From the brake test it was determined that a 10-in (25.4-cm) longitudinal displacement, such as that experienced during a sharp deceleration, for a rider of any height or weight, breached the level of defined safety. As rider weight increased, displacement decreased. The bump test provided evidence that increased rider weight also mitigates against vertical displacement.
  
  
  CONCLUSIONS
  Individuals with light weights and small wingspans, such as those in the pediatric population, are under considerable risk of injury when operating an ATV due to lateral, longitudinal, and vertical operational instability.
authors: Department of Neurosurgery, Illinois Neurological Institute, Peoria, Illinois 61637, USA. tobiasmattei@yahoo.com
authors: Tobias A
authors: TA
authors: Mattei
authors: Brandon J
authors: BJ
authors: Bond
authors: John W
authors: JW
authors: Hafner
authors: Martin J
authors: MJ
authors: Morris
authors: Jennifer
authors: J
authors: Travis
authors: Greg
authors: G
authors: Hannah
authors: Jim
authors: J
authors: Webster
authors: Julian J
authors: JJ
authors: Lin
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control*; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D001265:Athletic Injuries / Q000453:epidemiology* / Q000503:physiopathology / Q000517:prevention & control; D001696:Biomechanical Phenomena / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D001930:Brain Injuries / Q000453:epidemiology / Q000503:physiopathology / Q000517:prevention & control; D002648:Child; D016489:Head Injuries, Closed / Q000453:epidemiology* / Q000503:physiopathology / Q000517:prevention & control; D006801:Humans; D015541:Off-Road Motor Vehicles / Q000331:legislation & jurisprudence / Q000592:standards*; D055815:Young Adult