Photo Study of the Rafael Nadal Backhand

Generally, the longer and faster the swing, the more the racquet will end up behind the back on the follow-through instead of out in front. Do let your elbows bend after you strike the ball. Many players find the two-hander more uncomfortable than it needs to be because they keep the arms too straight after contact.

The Semi-Western position of Nadal's right hand is clearly visible here.