Science question - check an electric fence?

Question

ok, I have a science question that isn't answered in the section...

Simply stated, the question is:

Why do electricians use the back of their hand as a precaution to check an electric fence after they turn off the power?

Answer 1

So the muscles can not hold to the fence.

Answer 2

Ok, I could be totally wrong, but... The way I understand it is if You grab onto the wire and it's still on, depending on the type of current, it can actually contract the muscles in your hand therefore making You REALLY grab the wire and maybe have trouble opening your hand to let go. Using the back of your hand would definitely prevent that nastty mishap!