According to Nysten's Law, how does rigor mortis progress?

Nysten's Law describes the progression of rigor mortis, which is the postmortem stiffening of the muscles. According to this law, rigor mortis starts in the smaller muscles of the body, typically in the face and neck, and subsequently progresses to the larger muscle groups in the limbs. This means that the stiffness moves from the proximal (closer to the center of the body) regions to the distal (further from the center) regions.

This pattern occurs because the smaller muscles become stiff first due to the depletion of ATP, which is necessary for muscle relaxation, while the larger muscle groups take longer to reach the same state of rigidity. Understanding this progression is crucial in forensic medicine, as it can help establish the time of death by correlating the state of rigor mortis with the elapsed time since death.

The other options do not accurately describe this process; particularly, the notion of rigor mortis moving from proximal to distal is the opposite of what Nysten's Law states.