Medicine - transportation related death and injury

Question 1

Forensic issues with transportation related death and injury

Answer 1

o Cause of Death
o Not usually a problem
o Delayed deaths
o Confounding factors
o Who was driving?
o Injuries may help
o Scientific evidence – Blood splatters
o What speed?
o Higher speed usually means more severe injuries
o Injuries rarely useful – cannot determine speed with injuries as it depends on the victim, their age etc as to how the respond to impact
o More useful to look at the car to determine speed rather than the person hit
o How did it happen?
o Injuries invaluable for when pedestrians are struck
o Wearing Seatbelt?
o Can usually tell from injuries
o Mass Disasters
o Main issue identification – teeth, DNA
o Reconstruction of what happened
o (compensation)

Question 2

Road traffic injury patterns - pedestrians (fatalities and injury)

Answer 2

o Fatalities
 <15 years old – 14%
 > 60 years old – 50%
 5-14 – 23% serious injury
 >70 – more likely to be serious injury

o Injury
 Primary – car hits pedestrian
* Legs
o Initial impact tends to be on knee of pedestrian from bumper of car – small cars tend to have lower down bumpers and SUV higher up bumpers – position of injury on leg would indicate this
o More damage done to the car, more severe the pedestrians would have
o Smashed windscreen usually indicates a pedestrian hit with head – usually indicates the pedestrian was upright when hit
* ‘Scooping up’ > 25 mph
o Head
o Usually from head going into windscreen
* ‘Running over’
o More likely a small person would pushed over and then crushed
o More likely a tall vehicle such as lorry or bus would push someone over and then crush them
o Crush injuries
o ‘Flaying of skin’ – skin detached from underlying tissue – wheel has attempted to get traction on skin

 Secondary – Pedestrian hits ground
* Head, chest, pelvis
* ‘Brush abrasions’ – graze
* Pedestrian is projected by car across the road – skate across tarmac and develop large grazes

Question 3

Road traffic injury patterns - car occupants

Answer 3

o Frontal impact
 80% of crashes involve frontal impact
 People inside suffer deceleration
 Driver – face and head go into windscreen and chest into steering wheel
 Passenger – knees go into parcel shelf and face into windscreen

o Rear impact
 People inside are accelerated
 Injuries to neck as head goes forward and then backwards quickly

o Side Impact

o Roll-over

o Ejection from car
 Usually happens from not wearing a seatbelt

o Seat belts
 Stops impact with windscreen, etc
 Spreads deceleration force
* They extends over a large area of body to spread out force to body
 Extends time of deceleration
* Designed to stretch – higher impact, means more stretched
 Prevents ejection
 Injuries from seatbelts
* Whiplash
o Neck injury - Seatbelts restrain the body but not the head so the neck is vulnerable to move
* Damage to pregnancy
* Abdominal injury
o Tells you where they were sitting in car and if they were wearing a seatbelt
* Danger to pedestrians
o Used to believe that if the driver feels safer in the car by wearing seatbelt, they are more likely to drive recklessly causing more harm to pedestrians
* Fire
o Diesel cars do not set alight, only petrol cars but must be a naked flame