The move is legal. However, if the individual using the move is doing it with intention to harm their opponent, then the move become illegal. At this point it is most likely a judgement call. However, a lot of the times that i see this move the kid who is being put in it is in so much pain so quickly I have to stop the match and award the extra back point for the stoppage while near fall is being obtained. It's a long week after being stuck in a banana split..