Anti-static wrist strap around your wrist or around your ankle?
It makes no difference where you connect the anti-static strap to your body.

The reason is that your body is much lower resistance between any two points than the strap is.

Also, most of the resistance between any two points on your skin is getting thru the skin at each point.  You're just a bag of saltwater (electrically, anyway).  The bag has a resistance of a few k&Omega; to a few 100 k&Omega; from the outside to the inside, but once inside, the saltwater effectively shorts everything together relative to the bag's resistance.

So the body adds negligible total resistance to the strap, and resistance between any two points on the body is largely independent of where on the body those two points are.  It's really about how dry the skin is at the connection points, not where the connections are.