When shooting a ball, it is legal for any part of the foot to land on the foul line, even if it is the heel. As the shooter moves forward in his throwing motion, is the play fair or foul if the players heel lifts off the foul line?
This is an age old question and is always a fun one. The actual answer involves what the rules call the “forward foot.” When making a throw there are two positions of the feet. One is planted and the other is in the air and is called the forward foot. As long as the planted foot is on the line when the throw is initiated and the forward foot is still in the air or does not touch the surface, the throw is valid. The rules do not address the toe, sole or heel of the foot.
In summary, if the planted foot is on the ground and any part of the foot is intersected by the plane of the foul line the throw is good. It does not matter that the heel lifted during the completion of the throw.