Forensic Aspects of Trauma 1 Flashcards
What is an injury?
Injury = damage to any part of the body due to the application of the mechanical force
What are important considerations (in terms of laws of physics) for the intensity of a force on the body?
Human body always subject to forces – gravity, intensity of force obeys laws of physics:
- Force directly proportional to mass of weapon and directly square with velocity of impact
- Kinetic energy = ½ mass x velocity2
- Another important factors is are over which force acts
- Smaller area produces greater impact to any given unit of tissue
What can excessive mechanical force cause?
- Compression
- Squashing
- Traction
- Stetching
- Torsion
- Twisting
- Tangential
- Shearing
What does the damage of a force depend on?
- Type of injury and nature of target tissue
How is a traumatic injury classified?
- 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
What are different kinds of “nature of injury”?
- Blunt force, sharp force, explosive
What are different kinds of “methods of causation” of an injury?
- Abrasion, contusion, laceration, incised wounds, gunshot wounds, burns
What are blunt forced injuries caused by?
Caused by impact with blunt object, such as fist, ground, foot or weapon
What are examples of blunt force injuries?
- Contusions (bruise)
- Burst blood vessels in skin
- Abrasion (graze, scratch)
- Scraping of epidermis
- Laceration (cut, tear)
- Tear/split of skin due to crushing
- Associated with more bruising than incised wound
What is the medical term for a bruise?
Contusion
What is a contusion?
- Contusions (bruise)
- Burst blood vessels in skin
What is the medical term for a graze or scratch?
Abrasion
What is an abrasion?
- Abrasion (graze, scratch)
- Scraping of epidermis
What is the medical term for a cut or tear?
Laceration
What is a laceration?
- Laceration (cut, tear)
- Tear/split of skin due to crushing
- Associated with more bruising than incised wound
Is a laceration or incised wound more associated with bruising?
Laceration
What are some patterns of bruising?
- Tramline bruises
- Typical of impact with long cylindrical object
- Finger tip bruising
What are some factors that affect the prominance of bruising?
- Skin pigmentation
- Lighter the skin, the more obvious bruising will be
- Depth and location
- Occur more readily over loose skin such as eyebrow, scrotum
- Fat
- Increased subcutaneous fat bruises more easily
- Age
- Children have loose, delicate skin
- Elderly blood vessels of skin are poorly supported
- Resilient areas
- Buttocks, abdomen bruise less easily than areas with underlying bone which acts as an anvil between bone and inflicting object
- Coagulative disorders
- Thrombocytopenia, Von Willebrand’s disease, haemophilia, liver disease, bone marrow disease
Does lighter or darker skin bruise more?
Lighter the skin, the more obvious bruising will be
Does bruising occur more readily over loose or tight tissues?
Occur more readily over loose skin such as eyebrow, scrotum
What are some areas resilient to bruising?
- Buttocks, abdomen bruise less easily than areas with underlying bone which acts as an anvil between bone and inflicting object
What are some examples of coagulative disorders that increase prominance of bruising?
- Thrombocytopenia, Von Willebrand’s disease, haemophilia, liver disease, bone marrow disease
What are some examples of patterned abrasino?
- Serrated blade
- Bite
- Strangulation
Where do lacerations normally occur?
Normally occurs where skin overlies bone
What is a sharp force injury?
Any injury caused by any weapon with sharp cutting edge
Described as superficial or penetrating
What are the 2 main kinds of sharp force injuries?
- Incised wounds
- Superficial sharp force injury caused by slashing motion
- Longer on skin surface than they are deep
- Stab wounds
- Penetrating injury resulting from thrusting motion
- Wound depth greater than length on the surface
What are incised wounds?
- Superficial sharp force injury caused by slashing motion
- Longer on skin surface than they are deep
What are stab wounds?
- Penetrating injury resulting from thrusting motion
- Wound depth greater than length on the surface
What are some examples of patterned stab wounds?
- Knife with guard
- Screwdriver
- Movement of the blade relative to body
