Defensive Foul in the Post, post defender uses straight arm

This is an example of a defensive foul for illegal contact by a post defender. When guarding an offensive player with the ball and his back to the basket inside the Lower Defensive Box, a post defender may place one hand, with a bent elbow, and/or one forearm onto the back of the offensive player with the ball. On this play, the post defender illegally extends his arm to a straightened position with no bend at the elbow and a defensive foul is called for this illegal contact.