A body is found at a scene with a knife tightly grasped in the hand. The hand and arm are stiff, but the rest of the body is flaccid. The most likely interpretation of this finding is:
- A Rigor mortis affecting the flexor muscles preferentially
- B Cadaveric spasm (instantaneous rigor) ✓
- C Postmortem lividity causing muscle fixation
- D Heat stiffening due to environmental temperature
Explanation
Cadaveric spasm is a rare form of instantaneous rigor that occurs at the moment of death, bypassing the primary flaccidity of ordinary rigor mortis. It is typically localized to the muscles that were in violent contraction at the time of death, such as a weapon grasped in the hand during a state of extreme emotional tension or nervous exhaustion. Ordinary rigor mortis (A) affects all muscle groups symmetrically and does not occur instantaneously at death. Postmortem lividity (C) is blood pooling, not muscle stiffening. Heat stiffening (D) requires extreme environmental heat and affects the whole body.
Reference: Pillay's Textbook of Forensic Medicine and Toxicology, 18th ed.
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Written and medically reviewed by the StethoPrep medical team.