Let the neck be free. You will notice that the phrase starts with “let”. This is important. It means that the pupil should avoid stiffening the neck – not that he should do something to free it. I frequently find pupils going through all sorts of contortions in the belief that they are “freeing the neck”. They are usually, in fact, producing an extra stiffening by so doing.
Patrick MacDonald (“On Giving Directions, Doing and Non-Doing” – STAT Memorial Lecture 1963)