Acute forces required for fatal compression asphyxia: A biomechanical model and historical comparisons
Background: Fatalities from acute compression have been reported with soft-drink vending machine tipping, motor vehicle accidents, and trench cave-ins. A major mechanism of such deaths is flail chest but the amount of force required is unclear. Between the range of a safe static chest compression force of 1000 N (102 kg with earth gravity) and a lethal dynamic force of 10–20 kN (falling 450 kg vending machines), there are limited quantitative human data on the force
required to cause flail chest, which is a major correlate of acute fatal compression asphyxia.
Methods: We modeled flail chest as bilateral fractures of six adjacent ribs. The static and dynamic forces required to cause such a ribcage failure were estimated using a biomechanical model of the thorax. The results were then compared with published historical records of judicial ‘‘pressing,’’ vending machine fatalities, and automobile safety cadaver testing.
Results and conclusion: The modeling results suggest that an adult male requires 2550 250 N of chest-applied distributed static force (260 26 kg with earth gravity) or 4050 320 N of dynamic force to cause flail chest from shortterm chest compression