A correct back swing is performed by a combination of rotating the upper body and also twisting the upper torso in order to make a full shoulder
rotation --- whilst the hips remain held firmly in the frontal facing position.
Therefore in order to fully twist the upper torso you have to hold the hips in the frontal facing position for
as long as it is physically possible, keeping the muscles in the right leg in a firm condition and also keeping the heel of the left foot
firmly on the ground throughout.
During a full back swing movement, the hips must be firmly stopped from rotating away from the frontal facing position and it is only at the very end of the back swing movement that the hips will be forced to rotate for a few degrees, but do not allow the hips to sway away from the target area, however when it occurs,
the left knee should
only move slightly forward from the original address position
and the right knee should only move slightly backwards from the
original address position.
When looking at the video, notice how the hips are held in the frontal facing position
until the absolute end of the back swing movement and the heels of the both feet remain firmly on the ground whilst
the shoulders are rotated to the end of the back swing movement.
This ability to twist the upper torso in this manner increases
the torsion of the muscles between the upper part of the body
and the lower part of the body as you perform the back swing movement,
thus giving you extra power to be released as you perform the
down swing movement.
It is important that you understand
this technique.
The important point to make is that during the back swing
movement, the aim is to achieve a fully twisted condition of the
upper body unit without the hips moving away from the frontal facing position - however if they do rotate, it should only rotate for a few move degrees , but resist it as long as possible.
Therefore it absolutely necessary for you to understand that
whilst the heels of both feet remain firmly on the ground and
the hips are firmly held in the frontal facing position, the only
way to make a fuller rotational movement of the shoulders is twist
the upper torso to its maximum.
To have a better understanding of this technique, practice
this movement whilst sitting on the edge of a chair.
Raise both arms up to shoulder height and hold the shoulders
and the arms as a solid unit.
Therefore whilst sitting on the edge of the chair, slowly
rotate the shoulders around your body without allowing the hips
to move.
At the first attempt you will only rotate the shoulder for
a short distance, but slowly and surely you will gradually increase
the amount of rotation of the shoulders that you are able to make
without any movement of the hips.
When you fully understand how the upper torso can be twisted,
try to repeat the movement of twisting the upper torso whilst
standing but with your back side leaning against a wall.