Forensic Aspects of Trauma

Question 1

what is an injury?

Answer 1

physical harm or damage to someone’s body caused by an accident or an attack. it can also be defined as damage to any part of the body due to the application of mechanical force

Question 2

name two important factors relating to force of injury

Answer 2

intensity - kinetic engergy = 1/2mass x velocity^2

area over which it acts

Question 3

what can excessive mechanical force cause?

Answer 3

compression
traction
torsion
tangential (shearing)

Question 4

name 3 ways inwhich injuries can be classified

Answer 4

appearance or method of causation
manner of causation
nature of injury

Question 5

what are blunt force injuries?

Answer 5

caused by impact with a blunt object

Question 6

what can blunt force injuries result in?

Answer 6

• Contusions – burst blood vessels in skin
• Abrasions – scraping of skin surface
• Laceration – tear/split of skin due to crushing

Question 7

list the factors affecting prominence of blunt force injuries

Answer 7

• Skin pigmentation
• Depth and location – occur more readily over loose skin e.g. eyebrow, scrotum
• Fat – more fat = bruise more easy
• Age
o Children – skin loose and delicate
Figure 2 Blunt Force Injuries
Figure 1 Patterned Bruises
o Elderly – blood vessels of skin poorly supported
• Resilient areas
o Buttocks, abdomen – bruise less easily with given impact than areas with underlying bone which acts as an anvil with skin between bone and inflicting object
• Coagulative disorders
o Thrombocytopenia, Von Willebrand’s disease, haemophilia, liver disease (alcoholic), bone marrow disease

Question 8

what are sharp force injures?

Answer 8

causes by any weapen with sharp cutting edge - superfical or penetrating

Question 9

describe the types of sharp injuries

Answer 9

• Incised wounds
o Superficial sharp force injury caused by slashing motion
o Longer on the skin surface than it is deep
• Stab wounds
o Penetrating injury resulting from thrusting motion
o Wound depth greater than length on the surface

Question 10

what can defensive type injuries be a result of?

Answer 10

blunt and sharp force

Question 11

describe passive defensive injuries

Answer 11

victim raises arms and legs for protection

sliced, shelved often with skin flaps over backs of hands and forearma

Question 12

describe active defensive injuries

Answer 12

o Victim tries to grab weapon or attackers hand
o Sliced shelved incised wounds on palmar aspect of hands and web spaces between
fingers (especially between thumb and index finger)

Question 13

what type of injuries are self-inflicted commonly

Answer 13

sharp

Question 14

where are self-inflicted injuries usually found?

Answer 14

wrists/forearma
chest
abdomen

Question 15

describe self-inflicted injuries

Answer 15

parallel
multiple
tentative

Question 16

what do the consequences of injuriy depend on?

Answer 16

• Type of mechanical insult
• Nature of target tissue
• Forces involved
• Number of impacts

Question 17

describe the features and causes of traumatic subarachnoid haemorrhage

Answer 17

• Specific pathological entity
• Due to rapid rotational movement of head, usually as the result of a single punch to jaw/upper part of neck or side of head
• Sudden unexpected twisting movement
• Causes traumatic rupture of vessels at base of brain – most frequently distal portion of intracranial vertebral arteries at point where they cross the dura
• ? possibly represents same twisting damage to brainstem
• Immediately unconscious and in cardiac arrest

Question 18

describe the features of diffuse brain injury

Answer 18

• Diffuse axonal injury
o Clinical term
o Immediate and prolonged coma with no apparent mass lesion or metabolic
abnormality
• Traumatic axonal injury
o Pathological term
o Damaged axons due to trauma
o Focal or diffuse – graded 1-3 depending on severity