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The Effect of Passengers on All-Terrain Vehicle Crash Mechanisms and Injuries

Charles Jennissen, MDGerene Denning, PhD

Kari Harding, PhDDepartment of Emergency Medicine,

University of Iowa Carver College of Medicine

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Background

The incidence of ATV-related injuries and deaths has escalated over the past 15 years

Roughly 1/3 are children <16 years of age

Well-over ½ are under 24 years of age

0

15,000

30,000

45,000

60,000

75,000

90,000

105,000Adult

Pediatric (< 16 years old)

Year

Data from the National Electronic Injury Surveillance System (NEISS)

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Background

In fact, more children die from ATV-related events than from bicycle crashes.

Helmkamp JC, Aitken ME, Lawrence BA. ATV and bicycle deaths and associated costs in the United States, 2000-2005. Public Health Rep. 2009;124(3):409-418.

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833 ATV-related deaths in the U.S. in 2006.

Since 1982, children < 16 yrs have comprised just over a quarter of ATV crash fatalities.

US Consumer Product Safety Commission: 2010 Annual Report of ATV Deaths and Injuries.

Background

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Purpose

While common types of ATV-related injuries have been described, the circumstances under which they occur are poorly defined in the literature.

The objective of the study was to better understand the mechanisms and contributing factors of ATV-related injuries, especially related to the presence of passengers.

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Methods

A retrospective chart analysis of all patients entered into the University of Iowa Hospitals and Clinics Trauma Registry with ATV-related injuries from 2002-2009.

Potential subjects coded as having had an off-road vehicle incident were identified.

Vehicles other than traditional 3 or 4-wheeled ATVs (motorbikes, scooters, utility vehicles, etc.) were excluded.

A systematic review of each medical chart was performed.

Details of injury events, potential contributing factors, and resulting injuries were determined and evaluated.

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Results

345 ATV-related cases were identified.

• 79 % of patients were males.

• 32 % were children <18 years of age.

Patients with ATV Injuries by Gender

Female21%

Male79%

Patients with ATV Injuries by Age

Adults68%

Children (<18)32%

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0.0%0.0%

0.9%

2.4%7.7%

33.2%35.3%

39.4%50.3%

90.3%92.2%

94.8%97.1%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Percent of Medical Records that Featured Documentation

WeatherElectronic Device Use

ATV ModelATV Size

Path(straight/turning)Surface Type

SpeedSlope of Terrain

Road/trail/offroad4 vs. 3 Wheels

Time of DayHelmet Use

Seating Position

Cont

ributi

ng F

acto

rs

Medical Record Documentation of Contributing Factors

Documentation

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Passengers

• 20 % of victims were passengers or had passengers with them on the ATV.

Patients with ATV Injuries by Seating

Driver Alone77%

Driver with Passenger

or Passenger20%Unknown

3%

Other0%

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Passengers

• Females were more likely to be passengers (p<.0001).

0%20%40%60%80%

100%

% of

Each

Gen

der

Male Female

Seating Position by Gender

Driver

Passenger

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Helmet Use

• 21 % of all patients were reportedly wearing helmets.

Helmet Use by ATV Crash Victims

No Helmet74%

Helmet21%

Unknown5%

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Helmet Use

• Drivers were more likely to wear helmets than passengers (22.5% vs.6.1%) (p<0.01).

38%

29%

22%

8% 8%6%

0%

8%

0%

5%

10%

15%

20%

25%

30%

35%

40%

% o

f Pts

Doc

umen

ted

as W

eari

ng H

elm

ets

Male, <16 y.o.Driver

Female, <16y.o. Driver

Male, ≥16 y.o.Driver

Female, ≥16y.o. Driver

Male, <16 y.o.Passenger

Female, <16y.o. Passenger

Male, ≥16 y.o.Passenger

Female, ≥16y.o. Passenger

Age, Gender, & Seating Position

Helmet Use by Age, Gender, & Seating Position

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Crash Mechanism

• Crash Mechanism

– Rollovers (42%) were the most common mechanism of injury.

– Collision with an object (20%) and ejection/fall from the machine (13%) were also common.

– Collision with another ATV occurred in 7%.

• The victim was struck by the ATV in 21% and pinned in 9% of the cases.

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Rollovers while Turning

• Turning or spinning the ATV was more likely to result in a rollover compared to all other/unknown direction of travel. (p=0.085)

http://www.atvconnection.com/Features/Feature_Articles/ATV-Riding-Techniques.cfm

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Rollovers on Sloped Terrain

• ATV rollovers on sloped terrain were more likely to have passengers

– Than rollovers on Other and Unknown terrain (p=0.18)

– Than Non-rollovers (p=0.13)

Rollovers Total% Drivers

only

%Drivers +Passengers

Passengers %Other

Sloped terrain 69 69.6% 27.5% 2.9%

Other and unknown terrain 121 77.7% 18.2% 4.1%

Non-rollovers 155 78.71% 18.71% 2.58%

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Backward Rollovers

• Backward rollovers were almost twice as likely to have passengers as all other rollovers (p=0.09, OR = 2.0, [0.9-4.2])

– Also, more likely to have passengers than non-rollovers (p=0.06)

• Forward rollovers appeared less likely to have passengers than all other rollovers (p=0.27)

Type of Rollover Total

% Drivers only

%Drivers +Passengers

Passengers %Other

Unspecified 85 74.1% 21.18% 4.71%

Sideways 40 80.0% 17.5% 2.5%

Backwards 44 65.9% 31.82% 2.27%

Forwards 21 85.7% 9.52% 4.76%

All non-rollovers 155 74.0% 23.00% 3.00%

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Falls/Ejection to the Rear

ATVs with passengers were over seven times more likely to result in a Fall/Ejection to the rear than other types of ejections (p<0.01, OR 7.8 [2.6-23.3]).

– Falls/Ejection to the rear were more likely to have passengers than non-ejections (p<0.01).

Type of Ejection Total% Driver

Alone

% Driver + Passengers Passengers % Other

Self Ejection 9 100% 0% 0%

Thrown over Handlebars 46 89.1% 8.7% 2.2

Fall/ejected to Side 34 73.5% 26.5% 0%

Fall/Ejected from Rear 17 35.3% 58.8% 5.9%

Unspecified Ejection 68 75.0% 20.6% 4.4%

Not Reported as Ejected 171 77.2% 19.3% 3.5%

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Ejections over Handlebars/Self Ejection

Ejections over the handlebars (forward) and self ejections were less likely if there were passengers than other types of ejections. (p=0.02, OR = 0.2 [0.1-0.6])

– Thrown over handlebars (forward) were less likely to have passengers than non-ejections. (p = 0.12)

Type of Ejection Total% Driver

Alone

% Driver + Passengers Passengers % Other

Self Ejection 9 100% 0% 0%

Thrown over Handlebars 46 89.1% 8.7% 2.2

Fall/ejected to Side 34 73.5% 26.5% 0%

Fall/Ejected from Rear 17 35.3% 58.8% 5.9%

Unspecified Ejection 68 75.0% 20.6% 4.4%

Not Reported as Ejected 171 77.2% 19.3% 3.5%

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Head Injury after Ejection

• Those ejected to the rear had the lowest GCS scores.

• Falls to the rear had lower GCS scores than Falls to the side

(p = 0.19).

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12.5

13

13.5

14

14.5

15

Ave

rage

Gla

sgow

Com

a Sc

ale

EjectionUnspecified

Thrown overhandlebars

Thrown/ejected to

side

Fall/ slip toside

Thrown/ejected from

rear

Fall fromrear

Self ejection

Ejection Subtype

Glasgow Coma Scale by Ejection Subtype

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Head Injury after Ejection

• Of those ejected, patients falling or ejected to the rear had the worst head injury scores.

• Falls to the rear had higher head injury scores than Falls to the side (p = 0.13).

0.9

1.1

1.3

1.5

1.7

1.9

Ave

rage

MA

X H

EAD

EjectionUnspecified

Thrown overhandlebars

Thrown/ejected to

side

Fall/ slip toside

Thrown/ejected from

rear

Fall from rear Self ejection

Ejection Subtype

MAX HEAD by Ejection Subtype

0.11

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Extremity Injury after Ejection

• Patients who had self ejected or were thrown/fell to the side experienced the worst extremity injuries (p=<.05).

– Those who had self ejected had significantly worse extremity injury scores than all other types of ejection except Fall/slip to the side (p=<.05).

0.2

0.7

1.2

1.7

2.2

Ave

rage

MA

X EX

TREM

EjectionUnspecified

Thrownover

handlebars

Thrown/ejected to

side

Fall/ slip toside

Thrown/ejected

from rear

Fall fromrear

Selfejection

Ejection Subtype

MAX Extremity Score by Ejection Subtype

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Conclusions

• Passengers on ATVs may be at greater risk for rollovers and fall/ejection to the rear.

• Rearward falls/ejections appear to increase the risk of severe head injuries.

• A strict and enforced “no passenger” rule would help decrease the likelihood of some ATV crashes and injury severity.

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Future DirectionsImprove crash and injury surveillance in the emergency department:

• A multicenter ATV research network.

• Collect data prospectively.

• Standardized collection tool.

Educational and training approaches to increase user knowledge about the danger of riding with passengers.

Engineering approaches to limit seat length and minimize likelihood of passengers.

No passenger legislation for both private and public lands in every state.

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Questions?