Post by imperfectgolfer on Jun 16, 2019 18:32:30 GMT -5
Dr Mann
I am slightly confused now about what causes the 'release' of PA#4 in a TGM swinger.
You have stated the below:
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The most common method of actively releasing PA#4 is the pivot-driven swing and it is the method used by the majority of PGA tour players.
Basically, there are three general types of pivot-driven swinging actions
i) an upper body swinging action where the lower body remains static and the swinger rotates only his upper body
ii) a total body swinging action where the golfer rotates his lower and upper torso at the same rotational speed - exemplified by Jim Hardy's one-plane swing (Hardy OPS)
iii) a lower body swinging action where the lower torso (pelvis) turns first followed sequentially by a secondary rotation of the upper torso (shoulders) - exemplified by Ben Hogan's and Tiger Woods swing style.
During the first part of the pivot-driven downswing, when the upper torso rotates counterclockwise, the left upper arm temporarily remains in contact with the left pectoral area of the chest wall - which means that there is an increased sense of loading pressure at PP#4 and there is consequently no release of PA#4 in the early downswing. At a certain time-point in the downswing, the upper torso decelerates (speed of upper torso rotation decreases) and the inert left arm is catapulted passively away from the upper torso into a freewheeling left arm swinging motion. That represents the release of PA#4. Homer Kelley states in his TGM book [1], that one should "consider Pivot Thrust as Body Power blasting a Swinger's essentially inert left arm into orbit toward Impact". When a golfer initiates a pivot-driven release of PA#4, the pivot action usually starts with a pelvic shift-rotation movement, which is then immediately followed by an upper torso rotational movement. Many TGM swingers start the upper torso's rotary motion with an assertive thrust motion of the right shoulder in a downplane direction. That right shoulder thrust action causes the entire upper torso to rotate as a single unit, and the left arm is then passively pulled forward by the rotating upper torso.
* I now think that it is over-simplistic to think of the left arm as being a freewheeling inert lever in the later downswing that is simply catapulted away from the chest wall by an active pivot motion, because a golfer is also simultaneously using an active contraction of his left shoulder girdle muscles during the downswing to maintain the downward-forward speed of motion of the left arm, and the straightening right arm may also be applying push-pressure at PP#1 to synergistically assist in maintaining the forward momentum of the left arm. I have described the right arm's potential role in synergistically assisting in the release of PA#4
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For JS's downswing you mentioned the following:
"The major reason for that significant left hand depression is that he is depressing his left humerus at the level of his left shoulder socket joint far more than he is abducting his left humerus at the level of the left shoulder socket joint."
So for JS (and maybe other golfers) who have greater downward components of PA#4 release, doesn't this mean that its the left (and right ) shoulder girdle muscles that are mainly responsible for releasing PA4# (not an active pivot)? If yes, then can they still be categorised as TGM swingers?
DG
You asked-: "So for JS (and maybe other golfers) who have greater downward components of PA#4 release, doesn't this mean that its the left (and right ) shoulder girdle muscles that are mainly responsible for releasing PA4# (not an active pivot)? If yes, then can they still be categorised as TGM swingers?"
Although the left/right shoulder girdle muscles help to produce the downward component of a PA#4 release action, most of the downward motion of the left arm is due to the pivot action which causes the left shoulder socket to move targetwards, thereby pulling on the upper left humerus. Because the left arm is very elevated at P4 in Jamie's golf swing action (when it may be at the 11 - 11:30 o'clock position), there is a large downwards (groundwards) pull exerted on the left humerus when the pivot motion causes the left shoulder socket to move targetwards. Active muscular activity of the left/right shoulder girdle muscles play a supplementary/synergistic role in moving the left arm groundwards.
Jeff.