We have reached the top of the pyramid of primary fundamentals – clubface. Club face and club path is impacted by wrist movement throughout the swing. There are three ways wrists can move, and two directions in each of those three ways. The motions of flexion and extension have great impact on club face control.
Flexion is to move the palm of the hand towards the inside of the forearm and extension is to move the back of the hand towards the outside of the forearm. Flexion of the lead wrist effectively closes the clubface and extension of the lead wrist effectively opens the clubface. In an efficient golf swing, the lead wrist goes from extension in the backswing to flexion in the transition and then returns to extension through impact. When done in the right amount at the right time, the club face is being controlled. To execute this level of control of the wrists throughout the swing, dynamic posture must be maintained.
One of the most common forms of losing posture in the golf swing is early extension of the pelvis in the forward swing. When the pelvis early extends, the handle of the club is pushed away and the inertia of the club head falling behind the player causes flexion of the lead wrist that can lead to a closed clubface. From this position, a player is forced to hold on through impact in an attempt to not hook the ball. This means that the lead wrist does not return to extension until well after impact. The only way that the lead wrist returns to extension just after impact is if dynamic posture is maintained.
A great way to work on wrist control is to take slow swings and feel how the wrists change throughout the golf swing. While doing this, observe how posture affects that wrist action.