Rigor mortis is the temporary stiffening of the muscles that occurs after death. Immediately after death, muscles generally enter a period of relaxation. Several hours later, the muscles begin to stiffen as the body's supply of adenosine triphosphate, or ATP, is depleted. ATP is the energy source that allows muscles to relax.
Rigor usually begins within the first several hours after death, often becoming noticeable first in smaller muscles such as those of the eyelids, jaw, and face before progressing to larger muscle groups. There isn't a universal timeline for when rigor will set in. Temperature, physical activity before death, metabolic condition, illness, and the circumstances surrounding death can all influence when rigor begins and how long it lasts. Warmer temperatures generally accelerate its development and resolution, while colder conditions can delay its onset and prolong its duration.
As decomposition progresses, the muscle proteins themselves begin to break down. The stiffness eventually disappears and the body returns to a more relaxed state, known as secondary flaccidity. Depending on the circumstances, this may happen over roughly a day or more, but the timing is highly variable.
Rigor mortis develops gradually and can come and go in the sense that different areas of the body may become stiff and then later relax as the transition progresses. It may begin within a few hours after death, become more pronounced over the following hours, and eventually resolve over the course of a day or more. Rigor develops, intensifies, and eventually resolves, with different parts of the body entering and leaving rigor at different times.
Despite how often television portrays it, rigor mortis isn’t precise enough to tell you exactly when someone died. Its timing is affected by so many variables that forensic professionals use it alongside other postmortem findings to determine probable time of death.
What does this mean for a home funeral?
Rigor mortis can affect how a family approaches after-death care, particularly if they want to wash, dress, position, or shroud their loved one.
If the body has already entered rigor, some joints may be difficult to move. Families may need to work with the body's natural position rather than trying to force a limb into a particular position. Gentle massage or movement of the affected muscles may sometimes help with positioning, particularly when stiffness is beginning to develop. Using gentle, back and forth movements over the contracted muscle and slowly working with the joints can help the body relax into a more natural position. However, limbs should never be forced or manipulated aggressively. If the body is very stiff, it may be easier to work with the position the body has naturally taken and or wait for the rigor mortis to resolve on its own.
Early preparation and planning can be helpful for families choosing hands on after-death care. It can also be helpful to understand that the body will continue to change. There is no one “correct” appearance or position that a family needs to achieve when it comes to positioning their loved one.
Most importantly, rigor mortis is a temporary physiological process, and is natural.
For families learning to care for their own dead, understanding these normal changes can take away some of the fear and replace it with something much more useful: knowledge.
For more information on postmortem changes you can visit this article by the National Library of Medicine wrote by Rutwik Shedge; Muhammad Zubair. Last Update: June 19, 2026.
Or the Encyclopedia of Forensic and Legal Medicine (Second Edition), 2016. Made available online by ScienceDirect. Please note that this article displays images of real bodies during the rigor mortis phases. Viewer discretion is advised.