legal medicine

Legal Medicine:
OTHER FORMS OF PHYSICAL
INJURIES/DEATH
(Explosion, Automotive and
Sports Injuries)
Lysa Lynn Uy-Libanan, MD DPSP
8/3/2012
Legal Medicine CPU
LLLIBANANMD
1

EXPLOSIONS/ BLAST INJURIES:
Definition:
EXPLOSION – sudden release of potential energy
- localized increase in pressure
When investigating:
1. What?
2. Cause?
3. How?
4. Mechanism?
8/3/2012 Legal Medicine CPU LLLIBANANMD 2

• Classification:
– Hydraulic / Mechanical – pressure inside a sealed
container exceeds its structural strength
– Electrical – meeting of two or several electrical
arcs/different electrical potentials producing high degree
of heat that causes expansion of the surrounding air ( e.g.
lightning)
– Nuclear – fusion or fission of atomic nuclei
– Chemical – chemical reaction may produce heat that
dissipates into the surrounding

• Types of Chemical Explosion:
a. Diffused Reactant – must be initiated by
spark/flame/heat
volatile gas + air = heat + pressure
e.g – internal combustion of heat
b. Condensed Reactant
- chemical reaction from a solid /liquid substance that
produce large quantities of gas and heat
- with point of origin – most severe damage when closest
to the source
- oxygen is not a requirement to trigger the explosion

Classification of Condensed Reactant Explosives:
1. Low Order (Deflagrating Explosive)
- rely on burning and confinement  slow build up of
heat and pressure (e.g. Gunpowder explosion)
2. High Order
- detonation – requires a chemical process that rapidly
decomposed nitrogenous compounds producing
heat and gas as by-products
- shock-wave effect explosion
- e.g. Dynamite; Symtex explosives
- Maybe: Stable vs Unstable

Death due to explosives
- destructive effects varies with the kind/amount of explosives,
location of the victim and time of explosion:
1. victim in contact with the explosive
- complete disruption or fragmentation, distortion and
bursting effect of body caused by compression-
decompression effect of the explosion
2. victim within the perimeter of explosive
- severity will depend on the nearness to the source of
explosion
- punctate bruises, abrasions and lacerations to
dismember or disembowel body parts

Death due to explosives
3. Far from explosion – “peppering” injuries
4. Other effects:
- blast wave effect – can knock down a person
unconscious; disrupts or lacerates
internal organs and senses
- Burn injury from flames and heated gas
- Asphyxia due to lack of oxygen
- Inhalation of poisonous gasses
- Direct injuries by flying / falling debris
- “Shrapnel wound”

Identification at the site of explosion and collecting of evidences:
1. Presence of crater
2. Search area for traces of detonation mechanism
3. Sampling of debris

Atomic Bomb Explosion:
- fission of atomic nuclei (e.g. 100 lbs uranium) liberates
energy equivalent to several tons of TNT
- “Mushroom” clouds – ball of luminous gasses and clouds
containing fission products
- “ million pounds/sq inch of heated gas, heat comparable to
the sun, light 30x brighter than noontime sun”
- shock wave move sidewards in all direction

• Rays emitted during nuclear explosions:
– Alpha – positive charge helium; high linear energy transfer with poor
penetrating power; can be stopped by sheet of paper
– Beta – either positive of negative charged electrons; higher
penetrating power than alpha rays but less ionizing power
– Gamma – short rays with high energy and greater penetrating power;
cause much tissue damage
– Neutron – Uncharged; highly penetrating power
• Effects of atomic explosion – tissue damage is inversely
proportional to the distance from the explosion

Factors responsible for the effects of radiation:
1. Age
2. Dosage
3. Kind of Radiation
4. Fractional Dose
5. Sensitivity

Other Sources of radiation:
1. Natural Source
a. Cosmic
b. Terrestrial – radiothorium series of granite rocks
2. Man-made
a. Diagnostic Xrays
b. Clinical nuclear pharmaceutical agents
c. Therapeutic radiation apparatus
d. Nuclear power plants

AUTOMOTIVE CRASH/ACCIDENTS:
FACTORS RESPONSIBLE TO AN AUTOMOTIVE CRASH:
1. Human (Driver)
1. Mental attitude
2. Perceptive defect
3. Delayed or Sluggish reaction time
4. Disease
5. Chemical
2. Environmental
3. Mechanical (Machine/vehicle)
4. Social
5. Pedestrian

Injuries and Death on the Driver and the Passenger:
- two collisions:
1. First Collision
- impact of moving vehicle with another vehicle or a fixed
object; moving vehicle decelerates and stops after
impact
- degree of damage depends on the speed of the moving vehicle
and the vehicles involved.
2. Second Collision
- unrestrained occupants of the moving vehicle
- moves in the same direction and the same velocity towards the
point of impact
- Displacement, ejection or distribution resulting in direct impact
injuries

FRONT IMPACT CRASH:
1. Driver – may strike the steering wheel, hub of steering
column, wind shield, rear view mirror side window, dash
board; usually head, face, neck and chest injury
2. Front Seat passenger – same with the driver
3. Rear seat occupants
- may strike the back of the front seat, pillar between two
front seats, rear side doors, maybe propelled over the
front seat striking the driver or the front seat passenger,
the dashboard and/or the windshield
8/3/2012
Legal Medicine CPU
LLLIBANANMD
15

SIDE IMPACT CRASH
- Common at street intersections
- causes severe injuries because the vehicle has less structural
components to absorb the force of impact and the sides
are less rigid to prevent the intrusion into the passenger
compartment
- usually lateral impacts cause injuries to the chest (rib
fractures, contusion and laceration of the lungs, visceral
organ damage like liver, spleen and kidneys)
8/3/2012
Legal Medicine CPU
LLLIBANANMD
16

REAR IMPACT CRASH
- May occur after change of lane in an express way or crash at the
rear of a parked vehicle
- With rear impact – head moves backward / hyperentend followed
by forward movement until the chin strikes the front portion of the
chest/ hyperflexion
- “Whiplash” injury --- “acceleration-deceleration” – may result to
muscle spasm or injury to the ligaments of the neck
- May cause damage to gas tank at the rear of the vehicle – causing
explosion
ROLL OVER CRASH (Turn-Turtle Impact)
- Unrestrained occupant may be pinned, crushed or ejected
8/3/2012
Legal Medicine CPU
LLLIBANANMD
17

SUICIDAL CRASH
- Usually “single” affair – single vehicle, single occupant
- Head on collision with roadside object
- No evidence of any effort to apply the brake or to avoid
striking the object (foot of the driver still on the
accelerator pedal)
- History of previous suicide attempts
8/3/2012
Legal Medicine CPU
LLLIBANANMD
18

HOMICIDE BY MOTOR VEHICLE
- death usually on account of negligence and rarely intentional
- Reckless driving, lack of necessary skills, aggressive behavior,
under the influence of drugs
- “HIT AND RUN”
- Sometimes a simulation of a crash may occur to conceal a
crime
8/3/2012
Legal Medicine CPU
LLLIBANANMD
19

PEDESTRIAN-VEHICLE COLLISION
1. Primary impact – first violent contact bet the pedestrian
and the vehicle; usually bumper hits the leg of the victim;
severity of the injury depends on the position of the
victim when the impact occurred, the speed of the
vehicle and the amount of bodily support
2. Secondary Impact – impact of the pedestrian to the ground
or other object after the first impact; injury sustained
depends on the force of ground impact, the nature of the
road and parts of the body involved.
8/3/2012
Legal Medicine CPU
LLLIBANANMD
20

PEDESTRIAN-VEHICLE COLLISION
3. Run Over Injuries
- may occur during first impact or thereafter
- crash fractures, skid or tire marks, rupture of internal
organs and internal hemorrhage
- instantaneous death
4. Hit and Run injuries
- fast moving, hit or side swipe, or collide
8/3/2012
Legal Medicine CPU
LLLIBANANMD
21

MOTORCYCLE CRASH
High percentage of accidents because:
1. motorcycle can attain high speed
2. small profile
3. sometime difficult to control when at high speed and in
curved road
8/3/2012
Legal Medicine CPU
LLLIBANANMD
22

MOTORCYCLE CRASH
Severe injuries because:
1. less crushable materials to absorb the impact
2. no restraint system
8/3/2012
Legal Medicine CPU
LLLIBANANMD
23

ATHLETIC SPORTS
BOXING
- Potential injuries:
- most common site - facial injuries
- “spectacle hematoma” – serous effusion on the loose
tissue around the eyeball and in the eyelids;
puffiness and closure of eyes
- “cauliflower ear” - scarring and fibrosis brought abour
by hemorrhagic trauma and necrosis of the
auricular cartilage of the ear pinna
- retinal detachment
- fracture of nasal septum, mandible and maxilla
- Renal damage
- Intracranial injuries – most serious sequalae
8/3/2012
Legal Medicine CPU
LLLIBANANMD
24

ATHLETIC SPORTS
BOXING
Intracranial injuries
– Cerebral concussion - transient LOC
- Subdural Hemorrhage most common injury which may
be localized or extensive; due to tear in dural
emissary vein
- Pontine hemorrhage – aka “Boxer’s hemorrhage”
- due to severe head blow causing acute flexion
and extension of the head resulting in
brainstem to be pinched over the
tentorium with hemorrhage
8/3/2012
Legal Medicine CPU
LLLIBANANMD
25

ATHLETIC SPORTS
BOXING
Effects on the brain of a boxing blow depends on the location,
direction, intensity, velocity and number of blows:
1. Rotation (Angular) Acceleration
- direct blow causing rotation of the head sideways will
cause the inert brain to lag behind the accelerated skull
- effects:
1. Subdural hematoma
2. Intracerebral hemorrhage
3. Diffuse Axonal Injury
2. Linear (Translational) Acceleration
- straight on the face causing focal ischemic lesions in the
cerebellum
8/3/2012
Legal Medicine CPU
LLLIBANANMD
26

ATHLETIC SPORTS
BOXING
3. Injury to the carotid vessels
- blows in the neck area
- dissecting aneurysm or thrombus occlusion
- carotid reflex  hypotension and bradycardia
4. Impact deceleration
- fall on the back causes deceleration injury
- contre coup contusions of the orbital surface of the
frontal lobes and the tips of temporal lobes
“Punch Drunkenness” – traumatic or pugillistic encephalopathy
- slurred speech, slow clumsiness, unsteady gait, tremor,
progressive dementia
8/3/2012
Legal Medicine CPU
LLLIBANANMD
27

END!!!
8/3/2012
Legal Medicine CPU
LLLIBANANMD
28

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