Case Studies

In Forensic Biomechanics we know the outcome (injury pattern) and work to provide an understanding of the initial event.

Atomic Human Movement Experts can provide expert opinion and analysis across all types of human movement for example; assaults, self defence, accidental injury, use of bladed weapons (knives, meat cleaver or machete), use of improvised weapons and sports tribunal matters.

Below are examples of how forensic biomechanics has been used in previous cases.

The Mechanical Advantage of a Boxer

  • In a combative situation, brawl or “coward punch”, a trained boxer or martial artist has an advantage over an untrained individual. Boxers are trained to evade and receive strikes.
  • One punch from a trained boxer can reach a peak force ranging from 1666 to 6860 Newtons (it requires 3230 Newtons to break a brick), Waikio & Viano (2005).
  • Boxers can “link more of the arm mass into the punch”, Waikio & Viano (2005), this is visible in the illustration below. Motion occurs in the torso and upper arm, before there is any forward motion of the striking fist.

 

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Grip of a Heavy Bladed Weapon

  • Weapons such as a meat cleaver, machete or an axe provide an obvious mechanical advantage of additional reach length. This needs to be considered when determining a victim’s defensive motion or any claim of self-defence.
  • Understanding the hand grip of a heavy bladed weapon or object can assist with determining the body position of the accused at the time of striking. The power grip (illustrated below) is the optimal grip for holding a cylindrical object such as a heavy bladed weapon or a tool. The power grip distributes the force of the grip around the handle, reducing likelihood of slippage. In spite of forces shown to act around the whole of the handle, it is important to understand that each finger does not contribute the same amount of force.
  • The geometry (shape) of a weapon or impacting object will determine the injury pattern received by a victim.
  • Ergonomics research can be transferrable to these “tools”.

 

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