Post by imperfectgolfer on Oct 25, 2020 11:42:51 GMT -5
Watch this AMG video on issues relating to pelvic rotation.
I normally produce threads to point out why I disagree with certain opinions expressed by online golf instructors, but I think that this video is very insightful and I can highly recommend it as an useful "learning experience".
I normally produce threads to point out why I disagree with certain opinions expressed by online golf instructors, but I think that this video is very insightful and I can highly recommend it as an useful "learning experience".
The AMG instructors are discussing the pelvic rotary motion of a an amateur golfer (who they call "John").
"John" has a tendency to shift his pelvis too much towards the ball-target line during his downswing, and the AMG instructors believe that it is due to the fact that his hip joints are too far behind his ankle joint at address.
These GEARS-images show John's address posture compared to 4 pro golfers.
Note that they have drawn a vertical arrowed line down from the right hip joint and it hits the ground behind John's ankle joint - but either directly over the ankle joint or just ahead of the ankle joint in the 4 pro golfers. The cause is due to the fact that John has too little knee joint flexion, and too much hip joint flexion, at address that moves the center of his pelvis behind his ankle joints.
What effect does this pelvic address-alignment have on his pelvic motion during the backswing and downswing?
Look at the Before image showing his P4 position. The vertical white line was drawn along the back of his right buttocks at address and one can see that his right buttocks moves away from that line during his backswing action. In other words, the AMG instructors claim that his pelvis is moving towards "early extension" between P1 => P4 because the entire pelvis is moving closer to the ball-target line. I don't quite agree with their claim because I personally think of the phenomenon of "early extension" as being simultaneously associated with the conversion of anterior pelvic tilt towards posterior pelvic tilt while the entire pelvis simultaneously moves closer towards the ball-target line. In this scenario, I cannot see any motion of the pelvis in the direction of anterior pelvic tilt => posterior pelvic tilt, and I think that what is really happening is that his pelvis is moving towards the ball-target line between P1 => P4 as he rotates his pelvis clockwise.
Here is another GEARS-image showing this pelvic motion.
The solid blue dot represents the location of the center of his pelvis at address and at impact, and the curved blue line shows the directional motion of the center of his pelvis between P1 => P7. This image is at ~P3 and one can see that the center of his pelvis has moved 2" towards the ball-target line during his early backswing without any lateral shift motion. I suspect that it happens so that he can better keep in balance during his backswing's pelvic rotary motion.
Here is the directional pelvic motion of the center of the pelvis in 3 pro golfers.
Note the location of their pelvis at address.
Here is where their center of their pelvis is located at P3.5. It has moved very little away from its address location.
Here is their center of their pelvis location at P4.
Note that the center of their pelvis has shifted targetwards without moving towards the ball-target line. The AMG instructors refer to that as the "re-centering shift phenomenon" where the pelvis shifts targetwards during the late backswing. I personally think that it merely reflects a natural biomechanical phenomenon that happens if you start to rotate the pelvis counterclockwise between P3.5 => P4, rather than waiting until P4 to start the downswing's counterclockwise pelvic rotary motion.
Here are GEARS-images of the 3 pro golfers at the P5.5 position.
Note how much more the pelvis has shifted targetwards between P4 => P5.5. The AMG instructors refer to this phase as the 2nd rotary phase, but I think that is more accurate to refer to it as the shift-rotation phase because the pelvis is rotating counterclockwise while it is simultaneously continuing to shift towards the target. In other words, I think that it is artificial to label the pelvic motion as undergoing separate "shift => rotate => shift => rotate" patterns between P1 => P7 because the pelvis is continuously rotating during any shift motion of the center of the pelvis laterally. However, I do agree with their depiction of the optimum directional motion of the center of the pelvis - it should not move towards the ball-target line during either the backswing, or the early downswing between P4 => P5; and it should move targetwards during the downswing phase of the full golf swing action. I think that the amount of targetwards motion of the center of the pelvis will be greater in golfers who use a rightwards pelvic loading pattern during their backswing action - like Mickey Wright.
Here are capture images of Mickey Wright's pelvic motion.
I have drawn vertical red lines upwards from the inside of her feet at address (image 1).
Note how much her pelvis has shifted rightwards by P4 (image 2). So, it would be natural for her to shift her pelvis by an increased amount in a targetwards direction during her hip-squaring phase that happens between P4 => P5.
Here are capture images of MW's downswing action.
Image 1 is at P4 and image 3 is at P5 (end of her hip-squaring phase). Note that she does have a lot of targetwards shift of her pelvis between P4 => P5, but it happens while the pelvis is rotating counterclockwise.
In conclusion, although I do not like their use of the term "early extension" to describe any translational motion of the center of the pelvis towards the ball-target line if it is not simultaneously associated with a conversion from anterior pelvic tilt => posterior pelvic tilt - I do think that they have provided an useful golf instructional video that shows the optimum directional motion of the center of the pelvis between P4 => P7.
Jeff.