april 9, 2004 – 9:00 am nb interstate 5 kings county, california crash reconstruction occupant...
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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
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Accident Location3 miles north of the Kings/Kern County line
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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.
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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)
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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)
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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
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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
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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.
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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”