I want to ask that what are the names of conditions and disease in which rigor mortis does not occurs?

And also is rigor mortis good for meat quality?

Contraction and rigor mortis (http://www.aps.uoguelph.ca/~swatland/ch5_1.htm)
Meat and meat products in human nutrition ... - Meat production and quality, Role of meat and meat products in human nutrition (http://www.fao.org/docrep/T0562E/T0562E02.htm)

Try these links for meat quality and rigor mortis