Forensic Aspects of Trauma

Question 1

Classification of Injury

Answer 1

• Appearance or method of causation: Abrasion, contusion, laceration, incised wounds, gunshot wounds, burns
• Manner of causation: Suicidal, accidental, homicidal
• Nature of injury: Blunt force, sharp force, explosive

Question 2

Blunt force injury cause

Answer 2

-Caused by impact with blunt object- ground, fist, foot, weapon

Question 3

Types of blunt force trauma

Answer 3

• Contusions (bruises)
  - Burst blood vessels in skin
• Abrasions (graze, scratch)
  - Scraping of skin surface
• Lacerations (cut, tear)
  - Tear/split of skin due to crushing

Question 4

How is a laceration identified?

Answer 4

• tissue bridges
• bruising
• abrasion
• irregular edges

Question 6

Factors affecting prominence of bruises

Answer 6

• Skin pigmentation
• Depth and location - occur more readily over loose skin - eyebrow, scrotum
• Fat - ↑ subcut fat leads to bruising more easily
• Age
  - Children - skin loose and delicate
  - Elderly - blood vessels of skin poorly supported
• Resilient areas- 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 – thrombocytopenia

Question 7

Sharp force injuries

Answer 7

• Injury caused by any weapon with sharp cutting edge

- superficial (incised) wounds or penetrating (stab) wounds

Question 8

Sharp force injury types

Answer 8

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

Question 9

Defensive type injuries

Answer 9

• Blunt and sharp force
• Passive - victim raises arms and legs for protection
  - Sliced shelved incised wounds often with skin flaps over backs of hands and forearms
• Active – victim tries to grab weapon or attackers hand
  - Sliced shelved incised wounds on palmer aspect of hands and web spaces between fingers

Question 10

Self inflicted injuries

Answer 10

• Commonly sharp force
• Site of election - usually wrists/forearms, chest and abdomen
• Parallel, multiple and tentative incisions

Question 11

Head injuries - volume of blood

Answer 11

• 35ml - Symptomatic
• 40-50ml - Clinical deterioration, life threatening
• 80-100ml - Commonly fatal due to ↑ ICP and herniation
• +150ml - Fatal

Question 12

Traumatic Subarachnoid Haemorrhage

Answer 12

• 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
• 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 13

Diffuse axonal injury

Answer 13

-clinical term – immediate and prolonged coma with no apparent mass lesion or metabolic abnormality

Question 14

Traumatic axonal injury

Answer 14

-Pathological term- damaged axons due to trauma

Question 15

Post-mortem injuries

Answer 15

-lack of vital reaction, parchmentation