Injuries: stab wound depth: practice question

A Forensic Medicine question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Forensic Medicine · Injuries: stab wound depth

Sample item

A man is stabbed once in the abdomen. The knife blade recovered is 9 cm long, but the wound track in the abdomen measures 12 cm. Which is the most likely explanation?

AThe weapon was a double-edged bladeBThe abdominal wall was compressed by the force of the thrustCPost-mortem stretching lengthened the trackDThe recovered knife cannot have caused the wound, because track depth never exceeds blade length

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. The abdominal wall was compressed by the force of the thrust

The depth of a stab wound in the trunk can exceed the blade length, because the force of the blow compresses the soft abdominal or chest wall, allowing the blade and hilt to indent the tissues. Wound depth alone should not be used to exclude a weapon, and a hilt abrasion often marks such a thrust.

Option by option

A. The weapon was a double-edged blade
Whether a blade is single- or double-edged does not alter depth.
B. The abdominal wall was compressed by the force of the thrust (correct)
Correct. Compression of the abdominal wall lets the track exceed the blade length.
C. Post-mortem stretching lengthened the track
Post-mortem changes do not lengthen a wound track.
D. The recovered knife cannot have caused the wound, because track depth never exceeds blade length
Track depth can exceed blade length in the trunk, so depth alone does not exclude the recovered knife.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Forensic Medicine question

What is the answer to this Forensic Medicine question?

The best answer is B, The abdominal wall was compressed by the force of the thrust. The depth of a stab wound in the trunk can exceed the blade length, because the force of the blow compresses the soft abdominal or chest wall, allowing the blade and hilt to indent the tissues.

Why is "The weapon was a double-edged blade" not the answer?

Whether a blade is single- or double-edged does not alter depth.

Why is "Post-mortem stretching lengthened the track" not the answer?

Post-mortem changes do not lengthen a wound track.

Why is "The recovered knife cannot have caused the wound, because track depth…" not the answer?

Track depth can exceed blade length in the trunk, so depth alone does not exclude the recovered knife.

What concept does this question test?

It tests Injuries: stab wound depth in Forensic Medicine. Wound depth alone should not be used to exclude a weapon, and a hilt abrasion often marks such a thrust.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Injuries: stab wound depth?

Learn postmortem changes with their timelines, and toxicology as poison, sign, test and antidote. Then use the flashcards and the other Forensic Medicine questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.