Forensic Trauma Flashcards
Trauma can be applied by 4 basic mechanisms?
- Compression
- Traction (pulling)
- Torsion (Twisting)
- Tangential (Shearing)
What are the 3 major categories we use to describe an injury?
- Appearance/method of causation
- Manner of causation e,g, self-inflicted, accident or homicide
- Nature of injury e.g. blunt or sharp force
What are the types of blunt force injuries?
- Contusions
- Abrasions (scrapes)
- Lacerations (tear/split in skin due to crushing)
Describe some common Contusions Patterns?
- Shoe Treads
- Tyres
- Belt buckle shapes
- FIngers
- Tramline
What is tramline bruising?
Impact of a rod-like object pushing blood to either side causing a long area of pallor with strips of bruising to either side
What factors effect prominence of bruising?
- Skin pigmentation
- Depth & Location
- Fat (more subcut fat = more bruising)
- Age (kids and elderly)
- Resilient areas (e.g. buttocks wheres no bone to act as an anvil)
- Coagulative Disorders
How can we observe an abrasion to learn more about the injury?
skin tags can indicate the direction of the force
Also the pattern of the abrasion can determine the instrument used
What are the different types of sharp force wounds?
Incised - Slashing motion creates a superficial wound longer than it is deep
Stab - thrusting motion creates a penetrating wound deeper than it is long
What can we tell form the pattern of a stab wound?
Different types of instrument e.g. scissors, screwdrivers and knives all look different.
If a knife is double or single bladed
Somtimes the surrounding bruise can indicate the shape of the hilt (if it went all the way in)
What are the types of defensive injuries?
- Passive where the victim raises arms/legs for protection
- Active where the victim tries to grab the weapon or the attackers hand
How do passive and active defensive injuries look different?
Passive shows slices with skin flaps on the back of the hands and forearms
Active shows sliced, shelved wound on the palm & webspaces (mostly the 1st web space)
What appearances would suggest a wound to be self-inflicted?
- Common type/place i.e. sharp force wound to wrists, chest and abdomen
- Parallel wounds, multiple wounds and tentative incisions
- If clothes have been lifted prior to the stab
What factors affect the consequence of an injury
Type of insult e.g. sharp or blunt
Target tissue e.g. fat/muscle vs important vessels/organs
Force e.g. a high speed RTA vs just falling
No. of impacts
Patient presents dead at the scene after being punched to the side of the jaw, what likely happened?
Punch causes a rapid rotation of the neck which ruptures the vertebral arteries as the cross the dura leading to subarachnoid haemorrhage, along with axonal injury to the brainstem resulting in immediate cardiac arrest
Patient presents with an intracranial bleed after RTA, whats the likely course the injury took?
Sudden change of direction of motion in an RTA often causes the brain to pull the bridging veins apart resulting in a subdural haemorrhage
