HB - I think that going from a bent knee position in the downswing to a straight left leg position at impact is nothing more than the O factor principle - as described by Robert Baker in his swing video lesson. It simply depends on how much of a positive O factor one wants to acquire at impact. Some golfers like Tiger Woods have a very straight left leg at impact (which is partially responsible for his left knee damage) while other golfers keep their left knee slightly flexed at impact.
I agree with Robert Baker that it is a good idea to have a positive O factor at impact, but greater amounts of O factor do not necessarily correlate with increased clubhead speed. One only needs enough O factor to get secondary axis tilt that allows the right shoulder to move downplane, which allows for the correct in-to-square-to-in clubhead swingpath when PA#4 releases the left arm into impact.
Jeff.
Jeff I like his pants and the green screen trick and all but only made it half way through "O FActor". Its hard to watch some of these things for me. I hardly ever read a Golf Digest anymore either. He made so many statements in the first half that I would disagree with that I had to turn it off. "Watch , as I speed my hips........." . Like he didnt swing harder with his arms......... so power is a zone 1 thing then?
"O Factor", the name is so derivative maybe and that is what put me off. "X FActor" , O Factor etc.
Factor this....Knowing of Hula Hula, pivot center, axis tilt etc how can you not disagree with his recommendation to tilt at address and set the head back in the stance as a normal procedure? This is a person recommending that you forsake centered balance, in the name of a what? A preset "O Factor" predicated on a misunderstanding of what it is that he is observing on tour at impact? "O FActor" address : Centered hips, but tilted by taking the head back into a wobbly off center position. You must see the implications to low point, balance, the necessity to slide into impact from there etc .............
This by the way is hardly new. I remember as a kid , copping Golf Digests recommendation to set the weight on the back foot at address to pre start the swing. There was a photo of Tom Wieskopf on the cover with his head set back and his shoulders tilted. His hips centered instead of his head. I hit a lot of hooks off of that stance.
Its 30 odd years on lets set the record straight. The uncompensated average every day swing has a pivot center between the feet.
You probably haven't been following the pivot center thread - in terms of my personal views. I don't believe in the idea of a pivot center or a pivot axis.
I simply believe that one needs a small degree of rightwards spinal tilt at address and an appropriate amount of seconday axis tilt at impact.
For short-mid irons, I like Yoda's approach where one places one head in the center at address and acquires a small degree of rightwards spinal tilt by shifting the pelvis slightly left-laterally. That should produce a small degree of positive O factor at address -which RB demonstrates in his video. Because one is hitting a short iron, one doesn't need much secondary axis tilt at impact. HK stated that one should place one's head in the position it will need to be in at impact. Because there will be little need for much secondary axis tilt when hitting a short iron, a centralised head position works very well and complies with HK's recommendation.
For a driver, I think that the head should be positioned back of the center of the stance - roughly midway between the center of the stance and the right foot - because one anticipates a much greater amount of secondary axis tilt at impact. One still shifts the pelvis left-laterally a small amount at address, and that produces a small amount of positive O factor. During the downswing, the degree of secondary axis tilt is going to increase because of a more significant amount of left-lateral pelvic shift onto a braced/straightening left leg. That left-lateral pelvic shift onto a straight left leg produces a definite positive O factor in a driver swing (more than is seen with a short iron where there is virtually no left-lateral pelvis shift in the downswing).
In that sense, I agree with RB re:head position. However, he makes a fetish of the degree of positive O factor and claims that a greater degree of positive O factor at impact will increase clubhead speed. I disagree. I think that the amount of secondary axis tilt required (amount of left-lateral pelvic shift required) depends on the golfer. Jamie Sadlowski and Tiger Woods and Mike Austin have a large amount of secondary axis tilt at impact. However, many other excellent golfers have a lesser amount, and still hit the ball a long way.
Out of interest - here is a series of images of Mike Austin.
Note that his head is well behind the center of his stance at the end-backswing position. Note the significant amount of secondary axis tilt he has at impact and note the significant amount of upwards tilt of the left pelvis at impact (large positive O factor).
Here is Jamie Sadlowski
Note his head position - behind the center of his stance. Note his significant amount of secondary axis tilt and his positive O factor.
Note that his head is well behind the center of his stance at the end-backswing position. Note the significant amount of secondary axis tilt he has at impact and note the significant amount of upwards tilt of the left pelvis at impact (large positive O factor).
Isn't it positively amazing how a talented athlete can compensate for a Ball Position too far aft to accomodate his geometric purpose (Upswing for launch angle / low spin)?
Note the Left Shoulder / Ball Position at Impact.
For those interested in the principle involved, reference 1-L #13 and #15, and study the related areas.
For all others . . .
Good luck.
You are mired forever in the nether world of Position Golf.
It is my impression that MA's ball position is behind the low point and that he is swinging down to the low point. His hands are ahead of the ball position at impact.
It is my impression that MA's ball position is behind the low point and that he is swinging down to the low point. His hands are ahead of the ball position at impact.
C'mon, Jeff. . .
Mr. Austin clearly is 'hitting up' in this sequence. That means -- by definition -- that the Club is ASCENDING from its lowest point in its orbit (opposite the Left Shoulder).
Since that dynamic is so obvious, I must assume that you mean the normal low point -- the left shoulder, as aligned inline by God and unadjusted by an abnormal backwards tilt -- in front of a normal Ball location. Otherwise, your observation makes no sense at all. Clearly, Mr. Austin's Left Shoulder is behind the Impact Ball Positon, thereby mandating his Upward Swing.
Given this abnormal, backwards-adjusted Low Point, Mr. Austin indeed is swinging Down Plane through Low Point -- but up through the Ball -- as required. And, as you correctly have observed, with the requisite "hands are ahead" Impact Alignments (2-J-1). Nevertheless, his 'adjusted' Geometry has produced an Upstroke Clubhead Path (1-L #15).
There's a problem here? Why do I feel like I'm talking to a learning R2D2?
I think that 1-L #15 only applies after the low point. The low point is usually opposite the left shoulder, but when a golfer has as much secondary axis tilt as MA, then the low point may be ahead of his left shoulder. If his clubhead is still descending to its low point at impact, then 1-L #15 may not apply to MA's clubhead in that last photo. The clubhead may be just reaching its low point.
I think that 1-L #15 only applies after the low point. The low point is usually opposite the left shoulder, but when a golfer has as much secondary axis tilt as MA, then the low point may be ahead of his left shoulder. If his clubhead is still descending to its low point at impact, then 1-L #15 may not apply to MA's clubhead in that last photo. The clubhead may be just reaching its low point.
That statement is really an ad hominem style comment, that doesn't make your argument about TGM issues more-or-less legitimate.
Stick to arguing for your viewpoint regarding TGM/biomechanical issues. You are entitled to your viewpoint, but you are not entitled to arbitrarily assume that your opinions are more "right" than mine.
You wrote-: "You seem to keep implying that secondary axis tilt assumes the head to move back of center."
There are two ways to acquire secondary axis tilt. Your way (and mine) is to keep the head central and shift the pelvis left-laterally, which then shifts the lower lumbar spine left-laterally thereby creating secondary axis tilt. However, there is only a finite amount of space between the center of the stance and the left foot, and the body with its desired degree of secondary axis tilt has to fit within that space. Tiger Woods and Mike Austin and Jamie Sadlowski apparently need a greater amount of secondary axis tilt, and there is no room between the center of their stance and the left foot to accomodate that desired degree of secondary axis tilt. They therefore choose to have the stationary head further back - behind the center of their stance.
I believe that adopting a large degree of secondary axis tilt may be advantageous for driving the ball a long distance, but I think that it is not optimum for accuracy/control. That's why most tour professionals keep much more centered, and adopt far less secondary axis tilt, when hitting their iron approach shots.
I am incapable of adopting large degrees of secondary axis tilt because I lack the spinal/torso flexibility, so I do not have the ability to make these personal choices.
Here is a nice video clip - presumably by VJ Trolio
He shows four variations of pelvic pivot action movements. He obviously favors the last one.
I think that many tour PGA golfers prefer the first one - the conventional pivot action where one loads over the right leg and where the head is positioned slightly behind the center of the stance. Hogan used that conventional pivot action for most of his career. Are you arguing that it's a totally unacceptable choice - from a personal, or TGM, perspective?
Hybrid Mode
