MUSCULAR CHANGES

RIGOR MORTIS

• Body becomes hard & fixed. (no shortening)
• The shape or position depends upon the position at the time of death.
• If the body is supine then the large joints of the limbs become slightly flexed.
• Rigor does not cause any significant change in the attitude adopted at death.
• Rigor involves both voluntary and involuntary muscles.
  

• Latin for "stiffness of death".
• Starts within the first 4 hours(90%)
• The face first then hands and feet.
• Maximal rigor develops in 12 to 48 hours
• Rigor disappears in 36-48h in cool temp or early 9-12h in hot climates.
• Intensity of rigor depends on muscle mass.
• Later leads to flaccidity due to lysis.

• Fall in ATP – links actin and myosin – rigor.
• Exhaustion before death – Rapid rigor.
• Rapid cooling of the body after death can inhibit rigor mortis, but rigor appears rapidly when the body is thawed.

Category: Forensic Medicine Notes