Zasko's phenomenon is seen during

Tendon reaction or Zasko's phenomenon: It occurs after somatic death when molecular death has not occurred. All muscles are in a relaxed state after death. This is a stage of primary relaxation. It is a muscular response to mechanical stimuli that occurs after 1- 2 hrs after death during the primary flaccidity period When the lower third of the quadriceps femoris muscle is struck above the patella with a reflex hammer, it causes an upward movement of the patella because of contraction of the whole muscle. Muscle changes after death :