patterns of blunt force injury

 

abdominal trauma
source: Radiology Assistant (Ledbetter S, Smithius R)

 

The forensic pathologist must attempt to determine not only what sort of injury one is observing, but interpret what the pattern of injury says regarding the mechanism of injury/ the circumstances of the infliction of those blunt force injuries.

The floowing pages are concerned with the main patterns of blunt force injuries to be recognised:

  • assault;
  • falls; and
  • blunt force injuries from road traffic collisions.

assault

 

A victim of assault may present with any combination of injuries, to any part of the body. However, certain patterns of injury may be more consistent with assault than, for example, a simple fall.

In order to exclude assault, one must consider the overall pattern and distribution of injuries, and look specifically for defensive injuries, or marks of restraint, as well as injuries which would be inconsistent with the proposed mechanism of damage. 

A patterned injury consistent with a shoe print, may represent the result of a kick, and a curved laceration on the top of the head overlying a depressed curved edged skull fracture may represent the effects of a blow with a hammer, for example.

Injuries are carefully evaluated and documented, and an attempt is made at interpreting their pattern. Body maps can be utilised to demonstrate the distribution of injuries, without the need to show a jury graphic photographs. (See Robinson (2000) for an overview of the examination of victims of assault).

 

Illustration of the pattern of facial injuries more in keeping with an assault than a fall (bilateral blunt trauma not limited to bony prominences)

 

violence in comic book art

 

'the ghostly justice of Lancashire' - the murder of Anna Walker, Blackburne Hundred, Lancashire (1636)

Source: Will Eisner's 'True haunted houses and ghosts Casebook' Ace Books, New York 1976 (via Teachable moments)

kicking, stamping and stomping

 

Injuries caused by kicking and stamping may result in an abraded surface (which may highlight the pattern of the impacting shoe sole), but if the impact is hard enough to cause a laceration, these patterned features may not be evident. These blows are often centered on the head and side of the face/ neck.

Henn and Lignitz (2004) review the pathological findings in homicidal kicking and 'trampling'. They noted that the head was a 'target of choice', and found characteristic abrasions, lacerations and intradermal bruises mirroring the pattern of the sole of the shoe as well as the contour of the heel (although they do not state the frequency with which these patterned injuries are discenable).

64% had fractures of the calvaria, skull base or facial bones. Injuries to the neck included fractures of the throat skeleton in 29%; rib fractures in 1/3 rd cases and ruptures of the liver in 25%.

42% of the victims died of blood loss (internal or external), whilst 12.6% died of blood aspiration.

Experimental studies analysing the forces generated by punching and kicking a 'punch-ball' have shown that men could punch with a force of 500 - 850 N and kick to between 750 - 1200 N, whilst women could reach 350 - 550 N and kick to 500 - 750 N. It can be seen that the lowest registered 'power' by kicking and the highest 'power' by punching overlap, and this is independent of gender.

Experimental measurements of the acceleration of a dummy's head kicked on the ground found that the maximum

acceleration achieved was 103 Gy, comparable to the acceleration of the head in a 50 km/h frontal car crash.

 

Derm Atlas image - scrotal haematoma following a kick 

3D Imaging of shoe print and injury on skin - Thali et al 2005

 

murder by blunt force trauma in the news

 

source: Wikipedia

 

On 2nd April 2012, a 15-year-old boy was convicted of murdering his mother having struck her head and face approximately 7 times, using a claw hammer. He then attempted to dispose of her body by setting it on fire.

He left a lump hammer close to the body, but the forensic pathologist who examined the body was of the view that this had not caused the injuries, rather a claw hammer had been used.

 

blunt force trauma pattern references

 

 

facial fractures - LeForte classification

 


LeForte Type 2 fracture - 3D CT reconstruction (from Radiopedia.org case 7942 Dr Laughlin Dawes)

fractures

 

 

 

 

 

 

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