Types of Trauma

• Types of trauma

  
• Blunt force trauma

  -Refers to any injury caused by a force that has a wide area of impact and relatively low velocity

  -Result of:

  • Compression, bending, shearing forces
  • Dynamic force

  -Exhibits both discontinuities and fracture lines

  -Depending on force simple fractures or comminuted fracturing can b present

  -Caused by being impacted by object or impacting a hard surface
• Sharp force trauma

  -Refers to any injury caused by a force that has a narrow area of impact with a low velocity

  -Results from:

  • Compression or shearing forces
  • Dynamic forces

  -Puncture and chop marks are common when perpendicular force is applied

  -Incisions are common when force is applied at an angle

  - Complete discontinuities common with chopping instruments

  -Infarctions common with cutting instruments

  -Usually discontinuities or displacements rather than fracture lines
• Ballistic/ projective trauma

  -Distinct wounding characteristics

  -Results in complete discontinuities with both displacement and fracture lines

  Results of:

  • Compressive force which can also include bending
  • Dynamic loading at high velocity
  • Focus is mixed initially small then becomes wide as projectile passe through bone
  • Projectile and ballistic weapons involved
• Burning trauma

  • Requires an understading of thermal effects on bone and soft tissue
  • Pugilistic pose
  • Muscle shrinkage
  • Associated fracturing
  • Colour changing
  • Unaltered- calcineal
  • Associated fractures types e.g thumbnail fracture
  • Not dynamic in nature
  • Discontinuities and fracture lines present
• Weapon types

  • A weapon is anything that is capable of inflicting damage through the transfer of kinetic energy
  • Weapons may have their own characteristics leaving potential individuating tool marks on soft and hard tissue
  • Alternatively the pattern of injuries maybe attributed to class
• Blunt force (BFT) wounding types

  • Includes any tool which may deliver 'blunt' force. i.e. human fist, head butt. Portable tool- baseball bat, house brick, hammer. Contact surface- floor, wall, stairs
  • The severity, extent and appearance of blunt force trauma injuries depends on:

  -The amount of force delivered to the body

  -The time over which the force of delivered

  -The region struck

  -The extent of the body surface over which the force is delivered

  -The nature of the weapon

  -Force is dependent on Kinetic energy (KE= 1/2 MV2)
• Sharp force(SFT) wounding types

  • Sharp force provides a narrow, high pressure or compressive edge
  • Actions may include slashing, stabbing, cutting, swings and hacking
  • Can link skeletal lesions to specific instruments within limits (PCAST)
  • Multiple weapon and blade types based upon characteristics
  • Cutting edge (straight, serrated etc.)
  • Blade mass (1/2 MV2) and dimensions (length, breadth)
  • Blade pattern (single edge, double edge etc.)
• Projectile and Gun types

  Low velocity

  • Usually under 1800 feet per second (approx. 550m/s)
  • Primarily handguns, shotguns
  • Shot burned or non-ridged long barrel
  • Maybe single shot, scenic or fully automatic

  High velocity

  • Velocity greater than 1800-2000 feet per second (550-610 m/s)
  • Includes rifles and machine guns/ machine pistols
  • Often designed to be fired from shoulder
  • The magnitude of the damage is obvious
• Explosion

  -Explosions have various effects on the body

  1. Injuries associated with expansion of gases associated with impact of an over-pressure wave impacting on the body
  2. Injuries from fly debris
  3. Injuries from being thrown by the blast wind
  4. Burns etc
  5. Long-term conditions associated with inhalation/ ingestion of vaporized particulates (debated)