Forensic Aspects of Trauma 1 & 2

Question 1

What is the definition of an injury?

Answer 1

Physical harm or damage to someone’s body caused by an accident or an attack

Question 2

Name the factors which impact the severity of an injury

Answer 2

• Intensity of the force

- Area over which the force acts

Question 3

Name the things that excessive mechanical force can cause

Answer 3

• Compression
• Traction
• Torsion
• Tangential (shearing)

Question 4

How can injuries be classified?

Answer 4

• Appearance or method of causation (abrasions, GSW etc.)
• Manner of causation (suicidal, accidental, homicidal etc.)
• Nature of injury (blunt or sharp force, explosion etc.)

Question 5

Describe the mechanism of blunt force injuries and give three examples

Answer 5

• Caused by impact with blunt object (ground, fist, weapon etc.)
• Contusions (bruises)
• Abrasions (graze, scratch)
• Lacerations (cut, tear)

Question 6

Which factors affect the prominence of bruises?

Answer 6

• Skin pigmentation
• Depth and location
• Fat (Increased SC fat - bruise more easily)
• Age (children and elderly)
• Resilient areas: buttocks and abdoment
• Coagulative disorders

Question 7

Describe the mechanism of sharp force injuries and give two examples

Answer 7

• Injury caused by any weapon with a sharp edge
• Incised wounds (slashing motion)
• Stab wounds

Question 8

Describe the two types of defensive type injuries

Answer 8

• Passive: victim raises arms and legs for protection

- Active: victim tries to grab weapon or attackers hand

Question 9

Describe the common features of self inflicted injuries

Answer 9

• Commonly sharp force
• Usually wrists/forearms, chest and abdomen
• Parallel, multiple and tentative incisions

Question 10

Which factors influence the consequences of an injury?

Answer 10

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

Question 11

Describe how different amounts of bleeding in the skull and in the brain have different outcomes

Answer 11

• 35ml: symptomatic
• 40-50ml: clinical deterioration - life threatening
• 80-100ml: commonly fatal due to raised ICP and herniation
• 150ml + : fatal

Question 12

Describe the features of a traumatic subarachnoid haemorrhage

Answer 12

• Due to a rapid rotational movement of the head, usually as a result of a single punch to the jaw or upper part of neck or side of the head
• Sudden unexpected twisting movement
• Causes traumatic rupture of vessels at the base of the brain
• Possibly represents same twisting damage to brainstem
• Immediately unconscious and in cardiac arrest

Question 13

What is a diffuse brain injury?

Answer 13

• Diffuse axonal injury (clinical): immediate and prolonged coma with no apparent mass lesion or metabolic abnormality
• Traumatic axonal injury (pathological): damaged axons due to trauma - can be focal or diffuse

Question 14

Give two examples of post mortem injuries and explain how they can be distinguished

Answer 14

• Animal predation
• Insect predation
• Clues: lack of vital reaction and parchmentation