Abstract: Objective To observe changes of the length of sarcomere of rat when restiffening. Methods We measured the length of sarcomere of quadriceps in 40 rats in different condition by scanning electron microscope. Results The length of sarcomere of rigor mortis without destory is obviously shorter than that of restiffening. Conclusion The length of sarcomere is negatively correlative to the intensity of rigor mortis. Measuring the length of sarcomere can determine the intensity of rigor mortis and provide evidence for estimation of time since death.

Key words: rigor mortis, restiffening, scanning electron microscope, sarcomere