Danny White said:
OK, I looked this up.
It's supposedly good luck to rub a hunchback's hump.
Ues, it's a century old superstition, and is considered partially responsible for the genesis of sports mascots.
100 years before Rowdy, baseball teams employed bat boys with a pronounced physical disability. It was flt rubbing the misformed limb before coming to bat would give you good luck. The person was typically a hunchback or a dwarf.
I've read Connie Mack, owner of the old Philadelphia Athletics, was particularly superstitious in this regard. He employed a dwarf for many years who rated higher with him then his players. Gave him a lot of credit for an early 20th cent championship. When it became "politically incorrect" to haul around disabled folks and expose them to the ridicule of rival fans, and players, the switch began to cartoon/animal character mascots, especially those who reflected a team's name.
There's a sports writer from Brooklyn who has worked chiefly out of Canada, named Allen Abel who has done a lot of beautiful baseball history, and has mentioned the practice.