Classifying mechanical injuries
- Topic
Mechanical injuries are classified by the object that caused them: blunt, sharp-edged, pointed, heavy-edged (chopping) or a firearm projectile.
What it is
In forensic medicine an injury is named by its mechanism and by the kind of object that caused it, not by its clinical severity. Blunt objects (no edge or point) cause abrasions, bruises, haematomas, lacerations and fractures. Edged objects cause incised wounds; pointed objects, puncture wounds; pointed and edged objects, stab wounds; heavy edged objects, chop wounds. Firearm projectiles form a group of their own. Using the right term in the record matters: a "laceration" and an "incised wound" point to different objects and circumstances, and the difference can be argued in court.
Key facts
- Laceration: irregular, bruised edges, irregular base, tissue bridges between the edges.
- Incised wound: clean straight edges, no tissue bridges, longer than deep.
- Puncture or stab wound: a small skin opening over a deep track; the danger lies in what it passes through.
- Chop wound (machete, axe): cut edges with bruising and, often, injury to the underlying bone.
- Gunshot wound: entry wound, track and, sometimes, an exit wound.
Types of mechanical injury
| Agent | Typical injuries | Telltale feature |
|---|---|---|
| Blunt | Abrasion, bruise, haematoma, laceration, fracture | Irregular edges, surrounding bruising, tissue bridges |
| Sharp edge | Incised wound | Clean edges, longer than deep |
| Point, or point and edge | Puncture wound, stab wound | Deeper than long; sharp or blunt ends depending on the blade |
| Edge and weight (chopping) | Chop wound | Cut edges with bruising; bone injury is common |
| Firearm projectile | Entry wound, track, exit wound | Abrasion ring at the entry; residues depending on range |
Next step: what to do and document
- Treat the emergency first; if there is a forensic question, describe and photograph with a scale before suturing or debriding when the patient's condition allows.
- Number each injury and record its type, shape, size in centimetres and position relative to fixed anatomical landmarks.
- Write down what the patient says in their own words and keep that account separate from your findings.
- Keep clothing, projectiles and foreign bodies with chain of custody: Law 906 of 2004 (art. 255) makes health staff responsible for collecting, preserving and handing them to the authority.
- If the injury suggests a crime, start the institution's reporting pathway and any mandatory notifications that apply.
- Official text checked on 2026-11-05 at funcionpublica.gov.co.
Legal framework in Colombia
- Law 906 of 2004 (Code of Criminal Procedure), art. 254: chain of custody shows that evidence is authentic and records every person who handled it.
- Law 906 of 2004, art. 255: health-service staff who come into contact with physical evidence are responsible for collecting, preserving and handing it to the authority.
- Law 906 of 2004, art. 67: everyone must report crimes that are prosecuted ex officio; art. 68 exempts, among other cases, when professional secrecy applies (see its limits in Medical ethics).
Test yourself
Think of the answer, then tap the question to see it.
Which feature tells a laceration from an incised wound?
A laceration has irregular, bruised edges with tissue bridges in its base; an incised wound has clean edges and no tissue bridges.
What kind of wound does a machete cause?
A chop wound: it combines the edge (cut margins) with the weight of the weapon (bruising and, often, bone injury).
Why is writing "wound" or "cut" not enough in the record of a case with legal interest?
Because the type of wound points to the type of object and the mechanism; a vague description cannot support a reconstruction and can be challenged in court.
Which Colombian law makes health staff responsible for preserving physical evidence?
Law 906 of 2004, art. 255: health staff who come into contact with physical evidence must collect, preserve and hand it to the authority.
Elsewhere in DurgiPedia
- Mandatory reporting: public health, violence and abuse
- Resolución 1995 de 1999: the medical record
- Mechanical and electrical injury: abrasion, contusion, laceration, wounds
Connections
Educational content on forensic and legal medicine; not legal advice and no substitute for the technical guides of Colombia's National Institute of Legal Medicine and Forensic Sciences. Laws change: each page links the official text and says when it was last checked. For a real case, follow the guide in force and ask the competent authority.
Sources: Trauma Forensics in Blunt and Sharp Force Injuries (Journal of the West African College of Surgeons (PMC), 2022); Blunt Force Trauma (StatPearls) (NCBI Bookshelf, StatPearls Publishing, 2023); Ley 906 de 2004, Código de Procedimiento Penal (Función Pública, Gestor Normativo, 2004).
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Representative model, for educational purposes only.