ATV rollover, rider response, and determinants of injury: in-depth analysis of video-documented ATV rollover events.

OBJECTIVE

All-terrain vehicle (ATV) rollover events can lead to serious and fatal injuries. Crush protection devices (CPDs) are intended to reduce injury by reducing the frequency of significant contact between an inverted ATV and rider. Currently, field data on real-world ATV rollovers are primarily limited to injury causing events and lack ATV and rider dynamics necessary to evaluate injury mitigation effectiveness and possible unintended consequences of CPDs. Unlike restrained automobile occupants, ATV rider posture and positioning are highly variable and scant data are available to define the dynamically changing rider position in a roll scenario. Additional data on the complex real-world dynamics and interactions of riders and vehicles are needed to further develop and evaluate the effectiveness of rollover injury prevention strategies.

METHODS

Using YouTube videos of real-world rollover events, vehicle, environment, and rider factors were categorized with a focus on vehicle dynamics and rider responses, including dismount kinematics.

RESULTS

One hundred twenty-nine ATV rollover events were coded, with side rolls representing 47%, rear 44%, and forward rolls 9%. The speed at onset of roll was relatively low, with 86% of the rolls occurring at speeds of 10 mph or less and 53% occurring at less than 3 mph. No injury was identified for 79% of the events; 16% resulted in injury due to ATV contact and 5% resulted in injury unrelated to ATV contact. Active dismount of the ATV was a commonly employed strategy, with 63% of the riders attempting active dismount, resulting in successful separation from the ATV in 72% of the attempts. The overall injury rate for riders attempting active dismount was 15% and the injury rate for riders not attempting active dismount was 32%. This investigation confirmed the importance of active rider movements, including active dismount and subsequent separation in determining the outcome of ATV roll events.

CONCLUSIONS

Rider active dynamics need to be considered when introducing new injury prevention strategies that may obstruct, impede, or otherwise contact riders during an attempted separation. To the authors' knowledge, this is the first systematic use of real-world video-documented ATV rollover events to quantify and analyze ATV rollover dynamics and rider responses. These data and techniques can guide effective design and implementation of injury mitigation strategies.