April 9, 2004 – 9:00 amNB Interstate 5

Kings County, California

Crash ReconstructionOccupant DynamicsInjury Biomechanics

Mauro v. Ford Motor Company

Accident LocationInterstate 5 – Kings County, California

N

N

Accident Location3 miles north of the Kings/Kern County line

Inte

rsta

te 5

Mauro v. Ford Motor CompanyCase Questions

What were Mr. Mauro’s occupant dynamics during the rollover crash of April 9, 2004?

Would Mr. Mauro have sustained severe/fatal head/neck injuries if he had been restrained in the front-right seat position and not ejected?

1. Crash Reconstruction - Performed by Stan Andrews

2. Occupant Dynamics - Occupant Motion - Occupant Loading

3. Injury Biomechanics - Injury Patterns - Injury Mechanisms

Science-Based Approach

1993 Ford E350 15 passenger van

Mauro Vehicle

• Rollover damage exhibited over most body panels.

• Extensive roof crush over front-right passenger seat.

N

Crash Reconstruction

Rollover Crash Analysis performed by Stan Andrews

Vehicle Speed: Location of Tire Tread: 69 ± 7 mph Start of Tire Mark: 66 ± 7 mph Initiation of Rollover: 48 ± 3 mph

Crash Reconstruction

Rollover Phase (Stan Andrews)

N

3

Rollover Angular Speed: Roll 1: 244 ± 15

deg/sec Roll 2: 321 ± 20

deg/sec Roll 3: 372 ± 23

deg/sec Roll 4: 172 ± 11

deg/sec

Rollover: Distance: 192 ft Number of Roll Revolutions: 4 Duration: 5.1 to 5.8 seconds

The occupant move[s] upward

Occupant DynamicsInitial Phase of Rollover

(Parenteau et al., 2001)

r

Occupant DynamicsCentripetal Force

Slingshot

Amusement Park Ride

Children's Play

Rapid Rotation Forces Objects Outward

Occupant Dynamics

Severe Roof Crush at First Inverted Ground Impact

N

Occupant Dynamics

Timing of portal availability and Mauro ejection

Injury DiagramRobert A. Mauro, 5’10”, 185 lbs, BMI:

26.5

large abrasion on L pectoral area

abrasion

abrasion

bilateral anterior

closed rib fxs

multiple abrasions of

the lower chest + upper

abdomenAutopsy report: “significant

negative findings: No

evidence of the use of a vehicle safety restraint

system(s)”

L hemothora

x

Far-Side Rollover“Diving” Injury Mechanism

Dr. Piziali: • “[T]he injury patterns observed in both diving and rollover accidents are similar.” • “[A] kinematics analysis of an offside occupant in a rollover shows that the body

orientation relative to the ground and the velocity vector at impact can be similar to those for a diving impact.” (Piziali et al., 1998)

Diving Injury Rollover Injury

Far-Side Rollover

Injury Biomechanics

Head Impact Speed

Roll Velocity (1st roll): 243 ± 15 deg/sec

Radial Offset (r): 3 to 4 feet

Impact Speed: 12.0 to 18.1 ft/sec

Neck Force: 1,277 to 1,915 pounds

r ≈ 4’

Injury BiomechanicsComparison with Experimental Research

Neck fracture occurred in majority of tests with head impact speeds of 10.5 to 11.5 ft/sec.

Nightingale et al., 1996

Neck fracture occurred in majority of tests with head impact speeds of 15.1 to 18.4 ft/sec.

Nusholtz et al., 1981

Mr. Mauro Head to Roof/Ground Impact Speed: 12 to 18 ft/sec

Severe Injury/Fatality Likely for Mr. Mauro

Injury BiomechanicsInjury/Fatality Risk for Head/Neck

Severe Injury/Fatality Likely for Mr. Mauro

Neck

Forc

e (

Pounds)

Tolerance: 504 ± 124 lbs

(McElhaney et al., 1995; Nightingale et al., 1997)

1,277 to 1,915 lbs

Neck Force: 1,277 to 1,915 pounds

Factor of Risk (Φ) = 2.2 to 3.8

1. Crash Reconstruction - Performed by Stan Andrews

2. Occupant Dynamics - Occupant Motion - Occupant Loading

3. Injury Biomechanics - Injury Patterns - Injury Mechanisms

Science-Based Approach

Opinions

Rollover: 4 Revolutions

Occupant Head Impact and

Neck Loading

Severe Injury/Fatality

Likely Regardless of Seatbelt Use

Nightingale et al., 1996

Ejection Timing - Throw Distance

Piziali assumes longest throw possible

Ejection near 1 revolution and 1 3/8 revolution agree with Mauro’s rest

position

Occupant Dynamics

Vertical inverted impact

Piziali asserts driver’s side of roof contact ground first

Downward roof crush indicates vertical impact.

r

Blood Evidence

Front-Right Passenger Seat Head Restraint

Blood deposited as roof crushed head restraint.

“Head and spine injuries comprise a large proportion of the injuries sustained by rollover occupants (Moore et

al., 2005; Parenteau et al., 2001; Parenteau et al., 2000)”

“In rollovers where the occupant is not ejected, the

source of these injuries is the vehicle roof in most rollovers (James et al., 1997; Parenteauet

al., 2001)”

Injury BiomechanicsHead and neck injuries are common in rollover

crashes

Injury Biomechanics

Most common known source of head injury is the roof

Occupant DynamicsSeat Belts may Spool-Out in Rollover Crashes

“Research of occupant movements during rollover events has shown that a restrained occupant will load and unload the seat belt several times during the rollover sequence.”

“If the occupant loads the seat belt system during the same period of time that the inertial sensor is in a neutral position, the potential for webbing spool-out exists.”

Studies have validated rollover cases in which the restrained occupant has been ejected”