This document discusses injuries that can occur in traffic accidents involving pedestrians and vehicle occupants. It describes primary, secondary, and tertiary injuries pedestrians may sustain depending on the point of impact. Specific injuries from impacts with different vehicle parts are outlined. Injuries to unrestrained drivers and passengers in frontal collisions are also summarized, including common injuries to the head, chest, and abdomen. The document provides an overview of injuries that can result from different accident scenarios like rear impacts, rollovers, and being struck by different vehicle types.

1. TRAFFIC ACCIDENTS
Dr. Santosh Koirala, MD
Forensic Expert

2. INJURIES TO PEDESTRIANS
• PATTERNS OF INJURY:
1. Primary impact injuries( the first part struck)
2. Secondary impact injuries( further injuries caused
by the vehicle)
3. Secondary injuries/tertiary injuries
Injuries caused by victim’s striking objects, such as
the ground

3. Primary injuries
• Part of the body involved depends upon the
position of the person in relation to the vehicle
when struck, i.e. whether crossing the road
from one side to the other or walking with or
against the traffic.
• Injuries also depend upon the relative heights of
various parts of the vehicle, i.e. bumper,
fender, radiator, door handles, e.t.c

4. Bumper injuries
• In the typical case, the victim is struck by the
front of the vehicle, and sustains so called
bumper injuries on legs.
• These injuries may be severe with fractures of
tibia and fibula often compound and extensive
tissue damage.

5. Secondary impact injuries
• If the foot is fixed, a fracture results, and the buttocks and back
will come in contact with the car and then pushed forward.
• He may sustain a fracture – dislocation of the lumbar or thoracic
spine, sometimes associated with the fractures of adjacent ribs.

6. Secondary injuries
• When a person is thrown clear of the vehicle soon after the
impact, he may sustain secondary injuries which vary greatly in
severity.
• They may be abrasions, contusions, fractures of various bones
including the skull.
• The margins of the lacerations show contusions in primary impact
injuries, and abrasions in secondary impact injuries.
• If the person is facing the vehicle, he may sustain intra-abdominal
injuries, and injuries to the chest wall and the thoracic contents.

7. Rear impact.
• If the victim is struck from behind, a characteristic series of
superficial, parallel linear and irregular linear tears of the
abdomen or the inguinal regions are seen due to overstretching of
the skin which appear dry, yellow and bloodless
• Many impacts are on front corner of the car and
• pedestrian may be knocked diagonally out of the
• path of the car.

8. Side impact:
• When a pedestrian walks into the side of a vehicle,
pressure abrasions or tears on the side or front of the
face are produced which are sometimes patterned.
• The chest or loin may be injured sometimes with
fractured ribs and rupture of lungs, diaphragm, spleen
or liver.
• If the person falls and is run over by the back wheels,
crushing injuries of the head, trunk and limbs are seen.

9. Injuries caused due to straight and high-front
vehicle
• If a fast moving bus, truck or van having a straight and
high front end hits an adult, the impact is naturally
much higher, at hip or even shoulder level and may
cause primary damage to pelvis, abdomen, shoulder
girdle arm or head.
• If the body is hit at hip level, the victim will be pushed
down, or he may be carried on the radiator grille for
some distance and fall in front of the vehicle as it
slows down , or comes to a halt, and the victim may
be run over.
• The most extensive fractures are produced by the
head striking a flat surface. Extensive surface
laceration with much subarachnoid and often subdural
bleeding may occur.

10. Rolling injuries
• Rolling injuries are produced when a vehicle with low chasis,
‘rolled’ the victim along the roadways as it passed over him.
• They are usually located on two or more body surfaces and run
circumferentially. They are mostly abrasions, grease soiling and
burns from exhaust system.
• At very high speeds( 130km/hr), impacts result in hemisection of
the victim.

11. Injuries due to run over
• If the person is run over, there may be
1. Tyre marks, often spread a little due to yielding and
flattening of the body from pressure .Tyre marks or
grease from the under carriage of the vehicle may
sometimes be seen on surface of body in contact
with road, while the opposite side of the body shows
brush burns.
2. Grazes
3. Avulsion. The rotatory effect against a fixed limb
may strip off almost all tissues down to the bone.

12. Contd…
4. If the brakes of the vehicle are applied, the wheels will lock
and long lacerations are produced due to the shearing action
of tangential force.
5. Burning of the skin due to the heat produced by sliding of
the body and discharge or hot exhaust.
6. Deep crushing of the head, chest, organs and flattening
deformities of the head, chest, or pelvis

13. • 7. Decapitation or complete amputation of an extremity may
occur
• 8. When a child is run over by a vehicle, fractures may not be
produced, because of the elasticity of partly cartilaginous
skeleton.

14. Occupants of the vehicle

15. Injuries to the driver
• Most of the vehicular accidents are frontal
( colliding head-on or vehicle striking a fixed object)
• The unrestrained driver 1st slides forward so that his
legs strike the fascia parcel shelf area, knees hit the
bottom of the dashboard causing fractures of patella or
distal femur, and his abdomen or lower chest strikes the
lower edge of the steering wheel. Dislocation at the
hip-joint or fracture of the neck of femur may occur.
This is called Secondary accident

16. Head injuries
• The head strikes the upper part of the window glass, frame and
adjacent roof; upper limbs and thorax strike the windows-sill and
adjacent door structures; and hip and abdomen strike the arm-
rest area.
• Multiple, short linear, angular, rectangular and square, punctate
lacerations of the face are produced due to the shattering of the
windscreen glass into multiple small rectangular , square or
cubical fragments with relatively blunt edges( “ sparrow foot”
marks; dicing injuries)

17. • Thoracic injuries:
• aorta is usually disrupted with deceleration. It may be associated
with a severe whiplash effect on the thoracic spine. The aortic
rupture is circular and clean cut, and appears as sharp as if it has
been transected with a knife.
• Sometimes multiple transverse intimal tears are seen adjacent to
the main rupture, the so called- “ladder tears”.

18. • Abdominal injuries:
when the car overturns, the occupants may be pinned and
crushed, showing classical traumatic asphyxia or the chest
and abdomen may be crushed with serious injury to the
heart, lungs, liver, spleen or kidneys.

19. • Tail gaiting;
• Occasionally occurs with cars driving into the back of large trucks.
In such case, the windscreen and front of the passenger
compartment are smashed with severe injuries to the head and
the shoulders and in some cases decapitation of the occupants of
the front seat.

20. Air bags:
• It consists of a large fabric bag, which is normally folded into
steering wheel hub in the case of drivers position and into fascia
in front of front-seat passenger.
• In this sodium azide is converted into nitrogen
gas in milliseconds.
Deflation is also rapid.

21. • They protect chest from impact on steering wheel
and column and prevent whiplash motion of head.
• Fatal Injuries include cervical spine dislocation,
fractures, eye injuries are common, chemical burns
etc.
• Reduce fatalities alone by about 14% in drivers
compared with 45% of lap-shoulder belts used alone.
• If both are used fatalities are reduced by 50%

22. Delayed deaths
Delayed deaths can be caused by;
Continuing bleeding, secondary hemorrhage
Renal failure from hypertension/extensive muscle damage
Fat embolism
Local or systemic infections
Myocardial or cerebral infarction.

23. CYCLIST AND MOTORCYCLIST
• Falling from the vehicle , especially at speed can
cause visceral damage, especially rupture of the
liver, spleen .
• Pillion riders falling off the backs of motor cycles
have a laceration of the back of the head, a
fracture of the posterior fossa, contrecoup
contusions of the frontal lobes and abrasions of
back and elbows.

24. Boxing injuries
• Fracture of skull is rare.
• Intracranial hemorrhage common
• Some victims may show pontine hemorrhage, the so called “boxers
hemorrhage”
• Punch-drunk( traumatic encephalopathy or dementia pugilistica)
condition may arise years after the last injury. Punch drunk
syndrome in its final form is recognized by slurred speech,
defective memory, slow thought process, stiff limbs, parkinsonian
like facial appearance and dementia.

25. MASS DISASTERS
• A mass disaster is considered to have occurred
when the number of casualties occurring in a single
event exceeds twelve.
• Classification:
A. Natural( non biological like earth quake, flood,
landslide and biological like epedimec disease,
mass food/liquor poisoning.
B. Man made( accidental transportation, industrial
explosions, civil riots, warfare bombardments)

26. Objects of pathological investigation;
To retrieve and reconstruct bodies and fragmented bodies
decently.
To establish personal identity.
To obtain material for toxicological analysis esp. alcohol and CO.
To seek evidence of the cause of disaster from autopsy
examination.

27. This Photo by Unknown Author is licensed under CC BY-NC