Its original meaning was something you said before you hit someone or while you hit someone. Much like in Street Fighter two when Ryu performs a fireball or Dhalsim does his Yoga Fire.
The popularity of the word grew and has now become part of a film called Kung Fu Panda though with a slightly skewed meaning.
(While throwing a punch)
Example two: Later usage - as a warning.
"I'm going to skadoosh you in a minute".
2) verb: to relieve oneself through genital stimulation with the hands; to forcefully stomach bump someone
Mickey skadooshed in the tent with Matt through his cha chi last night
I went to give Alex a handshake; however, he forcefully skadooshed me into the wall