Figure 1

Plasticine models versus real injuries. Surface geometry of injured skin surface (bottom image row) was modelled using plasticine blocks that were then digitized (top image row). Abrasions during sliding or impacting on rough surface such as roads or walls typically result in an irregularly shaped injury surface (A2) that can contain groves as well as rounded indented or protruding features, often with apparently poor delineation. These are simulated by applying similar rough flat surface structures to plasticine (A1). Such injuries typically occur in road traffic accidents, building or reconstruction sites or falls. Gunshot entry wounds (B2) are geometrically simulated with circular penetrating defects to a plasticine block (B1). Patterned lacerations (C2) typically combine delineated edgy boundaries and indented or protruding skin flaps where straight edges might still be identifiable. Using a longitudinal sharp-edged object, similar wound features result on plasticine (C1). Such injuries are found after using sharply edged objects such as for example metal covers found in buildings or ventilation funnels, on trains or other vehicles. Strangulation marks (D2) contain a longitudinal groove whose ’valley’ surface may or may not exhibit a finely striated substructure. This can reflect indentation of the skin by a rope-like structure such as textured strangulation marks simulated in our plasticine model (D1). Bar length is 1 cm in all images.