Necromancy a common practice in Indonesia

[stormlord]

I've heard that peoples hands can be frozen in a death grip. I've also heard that sometimes after people die their limbs will spasm. I don't know how a limb could move after death. How would the nerves survive? Would they die all at once or slowly? If there's no energy in the body to power the limb, how does it move? If it does move, where does the energy come from? Is it possible to feed energy into a dead body to make its limbs move?