When a group of muscles of a dead body were in state of strong contraction immediately prior to death and remain so even after death, the condition is termed as -
Gas stiffening
Rigor mois
Cadaveric spasm
Cold stiffening
Cadaveric spasm is contraction of group of voluntary muscles during life which become stiff and rigid after death without moving into primary relaxation. Dr. Narayana Reddys Synopsis of Forensic Medicine & Toxicology 27 th edition pg. 81.
Death and postmortem changes