Pastern

   
I came across the word pastern the other day and found it defined as that part of the foot of a hoofed mammal from the fetlock to the hoof. That's OK if you know what the fetlock is!

The fetlock, it seems, is the joint between the cannon bone and the pastern. So where is the cannon bone?

Alternatively the fetlock is the common name for the metacarpophalangeal and metatarsophalangeal joints (MCPJ and MTPJ) of horses, large animals, and sometimes dogs.

I'm sorry I started this one....