Refers to the STD acquired by male exotic dancers from a Windsor, Ontario strip club. When they dance, they don't need to touch you for you to get crabs. Hence the saying, "Crabs can pole vault."
Kristyna: Hey lets go to Lanny's in Windsor on Saturday night!
Alleigh: No way! I heard that their dancers have crabs pole vaulting!
Kristyna: Wow, Looks like that ruins our Saturday night.