Read all about the bio-mechanics of knife stab attacks using high-tech equipment in this comprehensive document.

Equipment, materials and methods for the measurement of the bio-mechanical parameters governing knife stab attacks have been developed and data has been presented that are relevant to the improvement of standards for the testing of stab–resistant materials.

A six–camera Vicon motion analysis system was used to measure velocity, and derive energy and momentum during the approach phase of the attack and a specially developed force–measuring knife was used to measure three–dimensional forces and torque during the impact phase. The body segments associated with the knife were modeled as a series of rigid segments: trunk, upper arm, forearm and hand.

The velocities of these segments, together with knowledge of the mass distribution from bio-mechanical tables, allowed the calculation of the individual segment energy and momentum values. The instrumented knife measured four components of load: axial force (along the length of the blade), cutting force (parallel to the breadth of the blade), lateral force (across the blade) and torque (twisting action) using foil strain gauges.

Three styles of stab were used: a short thrust forward, a horizontal style sweep around the body and an overhand stab. These styles were chosen based on reported incidents, providing more realistic data than had previously existed.

Twenty volunteers were asked to stab a target with near maximal effort in this experiment.