An Analysis Of Injury Type And Distribution Of Belted, Non-ejected Occupants Involved In

Rollover Crashes

Stephen A. Ridella1, Ana-Maria Eigen2, Jason Kerrigan3, Jeff Crandall3

1-National Highway Traffic Safety Administration2- Federal Highway Administration,

United States Department of Transportation3-Center for Applied Biomechanics – University of Virginia

2010 SAE Government/Industry MeetingJanuary 29, 2010

This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permission

2

Issue

Fatality Trends in Passenger Vehicles

9,773 10,140 9,959 10,15710,729 10,442 10,590 10,870 10,742

10,240

8,999

12,977 12,680 12,818 12,623 12,670 12,42612,074 11,955 11,609

11,064

9,729

1,085 1,105 1,133 1,164 1,165 1,236 1,101 1,098 1,039 1,019 855

7,387 7,516 7,613 7,430 7,598 7,549 7,4677,010 6,648

6,1315,228

0

3,000

6,000

9,000

12,000

15,000

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Year

Fata

litie

s

Rollover Front

Rear Side

Source: FARS 1998-2008 This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permssion

3

Issue

About 25% of rollover fatalities are to belted, non-ejected occupants.

Little published data on nature of specific injuries to these rollover-involved occupants on a national scale.

This study to determine distributions of specific injury types in rollover crashes of belted, non-ejected occupants from recent years of the NASS-CDS database.

This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permssion

4

Dynamic Rollover Assessment

NHTSA is exploring dynamic rollover test procedure. Need to assess vehicle, crash, and occupant parameters

sensitive to occupant injury frequency and severity. Data will help to understand mechanisms associated

with most severe injuries and help to develop test procedure including dummy assessment and injury criteria.

This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permission

5

AIS 3+ Injury Distribution by Body Region/Rollover Crash Type from CIREN*

0

10

20

30

40

50

60

70

HEADFACE

NECK

THORAX

ABDOMENSPIN

E

UPPER EXTREMITY

LOW

ER EXTREMITY

Body Region Injured

Perc

ent o

f AIS

3+ In

juri

es b

y G

roup

Multi EventPure Roll

* Ridella and Eigen, 2008 IRCOBI

This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permssion

6

Method

Data Source – NASS-CDS 2003-2007 Rollover Crashes (weighted data analysis)

Selection parameters (similar to Ridella and Eigen, 2008)– Occupant: Adult, front-row, outboard, belted, non-ejected– Vehicle: Passenger vehicles, <= 2 roof inversions (eight ¼ turns or less)

Analysis– AIS3+ injury distribution by body region for pure and multi-event rollovers– Determine top 10 injuries (by AIS90 code) for both rollover modes– Determine top 5 body region injury codes for pure rollover crashes– Determine demographic information

This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permission

7

AIS 3+ Injury Distribution by Body Region and by Rollover Crash Type

0%5%

10%15%20%25%30%35%40%

HEADFACE

NECK

THORAX

ABDOMENSPIN

E

UPPER EXTREMITY

LOWER EXTR

EMITY

Body Region Injured

Perc

ent o

f AIS

3+

Inju

ries

by R

oll

Cras

h Ty

pe

Multiple EventPure Rollover

This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permission

8

(HTX = hemothorax, PTX = pneumothorax)

Pure Rollover Multi-Event Rollover

Injury N % Injury N % Cervical Spine fracture facet

1,128

12.0%

Lung contusion unilateral with or without HTX/PTX

2,518

8.2%

Lung contusion bilateral with or without HTX/PTX

954

10.1%

Pelvis fracture open/displaced/comminuted

1,916

6.2%

Orbit fracture open/displaced/comminuted

768

8.1%

Humerus fracture open/displaced/comminuted

1,512

4.9%

Cerebrum subarachnoid hemorrhage

710

7.5%

Tibia fracture shaft open/displaced/comminuted

1,434

4.6%

Radius fracture open/displaced/comminuted

693

7.4%

Radius fracture open/displaced/comminuted

1,279

4.2%

Lung contusion unilateral with or without HTX/PTX

675

7.2%

Lung contusion bilateral with or without HTX/PTX

1,084

3.5%

Cervical Spine fracture lamina

616

6.5%

Femur fracture shaft

956

3.1%

Cervical Spine fracture pedicle

458

4.8%

Cerebrum contusion single small

913

3.0%

Thoracic Spine fracture lamina

418

4.4%

Orbit fracture open/displaced/comminuted

908

3.0%

Cerebrum hematoma/hemorrhage subdural small

289

3.1%

Cervical Spine fracture facet

803

2.6%

(% is of total AIS 3+ Injuries for that crash type)

Top Ten AIS 3+ Injuries by Rollover Crash Type

This is a work of the U.S. Government and is not subject to copyright in the United States; it may

be used or reprinted without permssion

Distribution of Top Ten AIS 3+ Injuries by Injury and Rollover Crash Type

0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

Cervical/

Thoracic

Spine Fx

Brain blee

d/Facial

Fx

Lung Contusion

Extrem

ity Fx

Multi-eventPure

This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permssion

(% is of total AIS 3+ Injuries for that crash type)

10(% is of total AIS 3+ Injuries for that body region)

Top 5 AIS 3+ Injuries for Head, Spine and Thorax for Pure Rollover Crash Type

Head Spine Thorax

Injury N % Injury N % Injury N %

Cerebrum subarachnoid hemorrhage

710 37.1% Cervical Spine fracture facet

1,128 34.2% Lung contusion bilateral with or without HTX/PTX

954 46.9%

Cerebrum hematoma/hemorrhage subdural small

289 15.1% Cervical Spine fracture lamina

616 18.7% Lung contusion unilateral with or without HTX/PTX

675 33.2%

Cerebrum hematoma/hemorrhage intra-cerebral bilateral

202 10.6% Cervical Spine fracture pedicle

458 13.9% Rib cage fracture open/displaced/comminuted with HTX/PTX

173 8.5%

Cerebrum hematoma/hemorrhage epidural or extradural NFS

127 6.6% Thoracic Spine fracture lamina

418 12.7% Lung NFS 105 5.2%

Base (basilar) skull fracture without CSF leak

105 5.5% Thoracic Spine fracture vertebral body major compression

232 7.0% Rib cage fracture >3 ribs on one side and <4 ribs on either side

67 3.3%

This is a work of the U.S. Government and is not subject to copyright in the United States; it may

be used or reprinted without permssion

11

Head Spine Thorax % Two roof inversions

62.3

38.8

58.7

% Max Intrusion > 30cm 54.6 46.2 45.2 Median Age (yrs) 30 43 30

% Obese (BMI > 30) 21.4 41.3 0.0 Near/Far Occupant ratio 3.4 1.2 0.3

Selected Occupant and VehicleStatistics for Top 5 Injuries by Body Region

This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permssion

12

Continuing Work

Determine Specific Injuries for All Body Regions– Focus on head, cervical spine and thorax– More NASS and CIREN analysis in progress

• Injury causation and injury mechanism analysis

Determine Injury Clustering ScenariosMulti-variate regression analysis to find significant

factors involved

This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permssion

13

Summary/Conclusions

National estimates for rollover injury types using recent crashes

Data helps to determine priorities for:– Test procedure development– Crash dummy response requirements and injury criteria– Countermeasure development to mitigate injuries

This is a work of the U.S. Government and is not subject to copyright in the United States; it may be used or reprinted without permssion