Ringer,
I agree with your dictionary definition.
What is the i) "series of events" and ii) "the first part of a period of time" - and when is
early with respect to i) and ii)?
Jeff.
Ok, glad we agree on at least that definition. ;D
Lets use two reference points to talk about the action of the upper left arm during the swing. The ribcage of the left side of your body, and the left elbow.
I think we can both agree that you can rotate your upper arm so that the elbow is either pointing at your ribcage (supinate) or pointing out away from the ribcage (pronate). You can rotate the upper arm nearly 180 degree's depending on the flexibility of the upper arm.
Now, lets talk for a moment about about the forearm.
Again we're not discussing which muscles rotate it we're just talking about it's motion and relative position.
Lets use the left elbow and the back of your wrist as the two reference points for the amount the forearm rotates.
You can rotate just your forearm so that the back of your wrist faces the same direction that your elbow points (supinate), or rotate your forearm so that the inside of your wrist faces the same direction your elbow points (pronate). You can do this to a near 180 degree rotation.
If you combine the two rotations you get a near 360 degree's of rotation of your entire arm. If you pronate both your upper arm and lower arm then you can face the back of your wrist bone down to the ground. If you supinate both your upper arm and lower arm then you can again face the back of your wrist bone down to the ground. thus 360 degrees of rotation.
Ok, so now that we know the arm can rotate lets look at how this effects the LAFW.
If we position the club so that the the shaft is in line with our left arm, when we turn our upper and lower arm the clubface will rotate with them. So essentially this is clubface control.
Now with just the left hand on the club, if we cock the left wrist this puts together the LAFW and the shaft is 90 degrees to our left arm. If you now rotate your upper arm so that your elbow points at your ribcage, and you rotate your forearm so that the back of your left wrist faces the same direction of your elbow the clubshaft should be pointing in the direction of your target. Not perfectly so, but at least the club head would be left of you.
Now if you rotate you upper arm so that your elbow points in the direction of your target and you rotate your forearm so that the back of your wrist faces upward this would put the club in a trailing position to your right.
You have essentially rotated your upper arm 90 degrees and your forearm 90 degrees relative to where they were previously. If the club points toward the target your elbow points toward your ribcage and the back of your wrist faces your left thigh. If the butt end of the club points at the target then your elbow is pointed at the target and the back of your left wrist is facing the sky.
So the direction that the LAFW faces is entirely dependent on where both the upper and lower arm are rotated.
You cannot rotate the LAFW without rotating at least one or both of these parts of your arm.
Could you do it soley with your forearm? Sure. You could also do it with just your upper arm. Most people do it with a combination of both.
There is a third component to this rotation and that is the shoulder turn. Generally though, as the shoulders open in the forward swing we actually increase the rotation of our upper arm slightly because of the weight of the club trying to lag behind.
As far as WHEN the rotation starts to happen, it can start to happen as early as the start of the downswing or as late as post impact. I could theoretically continue to point my elbow at the target and rotate just my forearm to square up the clubface. In fact this is one of the ways I teach my students to hit a draw/hook. Not always the best way, but it works.