Does low point=both arms straight?
 

When my club (all clubs?) get to low point, is this when both arms are straight? Or do both arms straighten AFTER low point?

After low point..

Low point of the clubHEAD is at the left shoulder. Low point of 'thrust' (force) is at both arms straight per 1-L 13 and 1-L 15.

Damn good post. This may be one of the best posts written and shortest. Beautiful.

Grand Slam
 

Is this a great place or what? :notworthy

I think this is a good post but I however have been itching to write a responce to this....

The low point of the clubhead however relative to the ground is not technically speaking directly under the left shoulder (although a useful simplification) because the left shoulder is also moving in a circle that moves its location progressively upwards (plotting this circle is geometrically complex and perhaps make a good lab thread). So it is actually a lil bit further back of directly under the left shoulder. Another point of note is that after impact and low point -----into followthrough the clubhead goes upwards (even with horizontal hinging) more than most appreciate due to the fact that now the left arm and the left shoulder are now going upwards as opposed to the downstroke where the left arm is swinging downwards and the left shoulder going upwards.....

To go into real detail about this though would be extremely complicated....maybe a good future lab thread....

Would you not be able to closely approximate low point from fix rather than address since impact geometry is being simulated there?

I don't actually understand your question?

Regardless of Impact fix where your engineering your impact alignments and these alignments dictate how you are going to hit the ball....and how these alignments affect your axis tilt which dictates again how that left shoulder is going to move, where your shoulders are pointed....etc... the point is that left shoulder is going upwards and because of this fact, low point will still be prior to directly under the shoulder. If you create impact alignments at fix and actually produce them during a real stroke where you have placed the ball directly under the left shoulder as your impact - you are fractionally hitting the ball past low point....however for numerous reasons, I don't think it is very useful to tell people to actually do this ... but geometrically this must occur for that ball location... even with the fact that the left arm is getting 'closer' to the plane and thus extending the radius somewhat (fractionally) is not enough (nowhere near) to counteract to bring low point directly below the left shoulder.

Could there be two "low points"?

There is a low point in the ground of course at the lowest point of the divot.

But there is also a low point in relation to the shoulder joint with regards to the #4 accumulator. Seems to me that once the left arm is directly opposite the left shoulder joint (the in line condition of #4) the left arm is no longer going down . . . but going up. So that would be the low point with regards to the arm swing but maybe not the ground's low point?

Keep in mind how you position the 'machine' may change where the club/ground contact occurs, but that is a different matter than the relationship of the hands (pressure points) to the rest of the machine.

Assuming the radius doesn't change and/or the center does not move (compensations) - every machine must produce identical alignments for a given result. The line of compression per 1-L.