A golf swing is a simple set of sequential movements of the pelvis, torso, arms and hands.  These movements are stabilized by the legs and feet.  The position of the body, starting at address, creates limitations so that other parts of the body can move inside a range of motion.  In other words, the range of motion of the body is being limited by the subsequent body’s position.  Here is how the movement sequence and body limitations work – from the ground up in the backswing and transition.

At address the trail foot is slightly rotated open in a position to stabilize the trail leg.  The Lead foot is rotated more, opening the upper lead leg.  The trail foot’s slight rotation and lead foot rotation, allows the pelvis to turn to a specific degree in the backswing – but limits the amount as the trail leg stabilizes the rotation.

During the backswing, the lead shoulder, arms and torso begin to rotate together.  In the mid point of the arm motion, the pelvis is slowing down due to the resistance created by the positioning of the legs and feet.

The resistance feels like a bracing on the inside of the trail leg as the body rotates.

When the inside of the trail leg braces it stops the trail side of the pelvis so that the lead side can continue to rotate.  This is why the lead knee will bend inward slightly.

In the backswing sequence, the rotation of stabilizes against the inside of the trail foot and leg.  The allows the torso to continue rotating and then the arms to also move to the top of the swing.  The stabilization of the trail leg allows for a push of the pelvis toward the target during the transition of the swing.

Before the hands reach the top of the backswing position, the pelvis is already being pushed from the inside of the trail leg.Without this stabilized trail leg, you would be unable to move your body into the lead leg in the downswing.

The limits created by the position of the feet have limited the rotation of the pelvis and torso making the case for the importance the attention to the minor details of body positions.