FM5.1 | Types & Classification of Mechanical Injuries — Summary & Reflection

KEY TAKEAWAYS

Mechanical injuries are classified by the causative force into blunt force and sharp force categories. Blunt force injuries include abrasion (epidermis only, no gap, no tissue bridges), contusion (intact skin, subcutaneous haemorrhage), and laceration (torn irregular edges, tissue bridges present). Sharp force injuries include incised wound (clean margins, length > depth, no tissue bridges), stab wound (depth > length, penetrating), and chop wound (heavy sharp weapon, combined incised and lacerated features). The tissue bridge is the single most important distinguishing finding between laceration and incised wound. Beyond wound type, forensic interpretation extends to special patterns: defence wounds (ulnar forearm/dorsum of hand, indicating resistance), self-inflicted wounds (accessible site, parallel superficial, hesitation marks), and fabricated injuries (superficial, no vital reaction if post-mortem, no defence wounds). Medico-legal opinions on wound type directly determine weapon class and legal charge under the BNS, making precision in wound characterisation a core forensic competency.

REFLECT

You have just seen a patient with a wound over the scalp. Your junior colleague has documented it as a 'cut' in the casualty notes. On your re-examination, you note irregular margins and reddish tissue strands spanning the wound base. How does reclassifying this wound from 'cut' to 'laceration' change the medico-legal certificate — and what does this mean for the investigation into whether a sharp or blunt weapon was used? Consider the consequences if the original documentation had gone uncorrected.