Sharp Force Injuries Flashcards
Name two typs of SFI?
- Incised wounds (cuts, slashes)
2. Puncture wounds (stabs)
“clean division of the full thickness of the skin or tissue under the pressure of a sharp edged instrument”
Incision
What type of wound is a paper cut?
Incised
What can dicing injuries ndicate?
Location in vehicle
When might you get irregular ragged margins with incised wounds?
Glass
Skin folds
Can you identify weapon in incised injuries?
Almost impossible
Chop wounds: are they longer than are deep?
Yes
Defn: “Penetrating injury caused by separation of the skin and tissues under the pressure of a sharp or blunt pointed instrument”, or
“a small hole made with a sharp point”
Stab wound
Sharp & flat (e.g. knife)
stab
Sharp & thin (e.g. needle)
needle puncture wound
Blunt, long & rigid (e.g. spike, screwdriver)
puncture wound
Extremely common in homicide
Stab wounds
What might examination of a stab wound provide information on?
Weapon: dimensions, type, taper, movement, deptth of insertion, direction of insertion and amount of force used
What causes stab wounds to gape?
Contraction of elastic fibres within the skin
What causes stab wounds to appear smaller than with blade in situ?
Elastic retraction of the skin
What distorts the appearance of wounds?
Langer lines
What shape of wound do single-edged blades make?
Boat shaped
What kind of knife gives fine v-pointed end?
Sharp cutting knife
What kind of knife gives squared off or rounded end?
Blunt back edge
What kind of knife gives split “fish-tailed” end?
Heavy/thick blade
What kind of knife gives RAGGED END?
Serrated/hunting knife
If both edges of stab wound are squared off or rounded what does that mean?
Knife insreted to the ricasso
If both ends of srab wound reach a fine-vshaped point what does it mean?
Sharp cutting edge
Shark-fin skin tags along wound edges
Parallel scratch abrasions
Striated cuts on cartilage
Serrateed blade: No definitive way of distinguishing from serrated glass fragments
What does taper correlate to?
Wound length on the skin
What offers most resistance to estimating force?
Clothes and skinq
Does wound depth indicate force?
No
What is most resistant tissue for knife penetration?
Bone, then skin, then muscle
What is the most important factor in skin penetration?
Sharpness of knife
What are commonly involved in assult SFI?
Clothing
Typically to hands and forearms
defensive injuries
Wounds to legs may indicate?
Victim was lying on ground
What bleeds more- partially tdivided or transected vessles#’/#
Partially divided
What is more vulnerable: heart or large thoracic arteries?
Large thoracic arteries
What kind of trauma do road traffic accidents cause?
BVlunt force
How many people die each year as a result of road traffic crashes?
1.25 million
What is the leading cause of death amongst young people aged 15-29?
RTA
iN rta WHAT do the legs contact?
the front fascia of the car
iN rta WHAT do the chest/upper abdomen contact?
Steering wheels
Injuries from airbags include?
abrasions to the face, neck and chest, minor
friction burns to the upper limbs and eye injuries
What occur occur commonly in occupant fatalities?
Rib fractures over 70%- seen more often in drivers
RTA Cervical spinal injuries incude?
atlanto-occipital disruption leading to instantaneous death
Liver injury, ranging from
superficial surface laceration to
complete disruption, are slightly
more common in?
Drivers
When do pelvic injuries occur more frequently?
In front seat occupants and during side impacts
Who accounts for nearly 40% of all pedestrian RTC
Children under 15 years
Are pedestrians more commonly struck b front or side of car?
Front
Name three primary impact injuries?
Lower leg (bumper)
Upper leg
Pelvis (bonnet)
Name 3 secondary impact injuries?
Head
Shoulders
Chest (windscreen)
Name two tertiary impact injuries?
Head
Body (road surface/rash)
What injuries to cyclists not get that pedestrians do?
Bumper fractures
Who experience a death rate 35 times greater
than the occupants of cars
Motorcyclits and cyclists
What does use of helmet reduce fatal head injuries by?
One third
Injury above ? in smaller individual e.g. toddler?
Above shin level
What measurement might indicate potential vehicle?
Height of injury from heel
