Harnessing Thor's Hammer: Experimentally induced lightning trauma to human bone by high impulse current

Lightning fatality identification relies primarily on soft tissue traumatic pattern recognition, prohibiting cause of death identification in cases of full skeletonisation. This study explores the effects of high impulse currents on human bone, simulating lightning-level intensities and characterising electrically induced micro-trauma through conventional thin-section histology and micro-focus X-ray computed tomography (μXCT). An experimental system for high impulse current application was applied to bone extracted from donated cadaveric lower limbs (n = 22). μXCT was undertaken prior to and after current application. Histological sections were subsequently undertaken. μXCT poorly resolved micro-trauma compared to conventional histology which allowed for identification and classification of lightning-specific patterns of micro-trauma. Statistical analyses demonstrated correlation between current intensity, extent and damage typology suggesting a multifaceted mechanism of trauma propagation - a combination of electrically, thermally and pressure induced alterations. This study gives an overview of high impulse current trauma to human bone, providing expanded definitions of associated micro-trauma.