Can i shuffle a basketball player in the post while he is standing with his back ?

I like to play basketball but I am arguing with my friend about "pushing" and "shuffling".Can i shuffle an offensive player with my forearm in the post when he's standing with his back ? Could it be that in the basketball rules pushing and shuffling is considered as the same?Can i shuffle a basketball player in the post while he is standing with his back ?
No you can not. But you can do that on rebound to get position.Can i shuffle a basketball player in the post while he is standing with his back ?
yes it's not against the rulesCan i shuffle a basketball player in the post while he is standing with his back ?
It depends on if you want the rules by the letter or as it really is in the game. Real world - You can lean on the player with an arm bar but you can't displace him/her (much). Once that player has the ball you need to be careful as refs will tend to call a foul if you arm bar during a shot.