Throbbing

I've got a throbbing in my foot. I just noticed it. I'm sitting in front of the computer desk, leaning back in my chair, with my legs crossed atop my desk. And I see a throbbing in my foot. It's right below my ankle in what I usually think of as the 'weak' part of my foot.

I say weak because it's a place on my foot where the skin is kind of strange. It's more wrinkly than the rest of my foot-skin, like a little triangle of thin-skin, and now it's throbbing. It's maybe going one beat per second at the moment, in-out-in-out. It's kind of like the stomach part in Aliens. I can't get it to stop. I move my foot to a different angle -- no luck. I think it's odd that I just noticed it.