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Post by golfdad on Dec 5, 2011 15:29:28 GMT -5
Hello natep, hip rotation is defined relative to the midline of the body/pelvis. With a golf swing, pelvis moves and the center of reference moves. It is better to consider that to avoid the confusion.
hip ext rotation: think of charlie chaplin's boots (that direction)
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Post by natep on Dec 5, 2011 15:31:30 GMT -5
Yeah thats my point, its the right leg relative to the hip right? ?And whether or not that leg is internally or externally rotated relative to the hip, which is considered zero?
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Post by lia41985 on Dec 5, 2011 15:38:01 GMT -5
The point I was making wasn't that the leg isn't externally rotated in relation to some point. Rather, I was stating that the right leg goes from maximal external rotation and maximal extension to internally rotating (because it's not being held) and flexion simultaneously with the left leg externally rotating. The term "held" is therefore misleading because the right leg immediately loses external rotation along with gaining flexion.
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Post by golfdad on Dec 5, 2011 15:44:32 GMT -5
natep, for the sake of simplicity and clarity, at the expense of preciseness, external rotation of hip is the same as external rotation of the leg because the leg cannot externally rotate anyway therefore whoever writes that is understood as meaning the hip ext rotation.
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Post by jeffy on Dec 5, 2011 16:00:15 GMT -5
Lukman says a step is skipped and the right hip goes from internal rotation to internal rotation. No! I'm not talking about the hips! Kelvin talked about the right leg. I'm talking about the right leg. The right leg goes from being maximally rotated and extended while the left leg is maximally internally rotated and simultaneously the right leg flexes and internally rotates as the left leg is internally rotated. Well that is simply wrong. The femur rotates away from the body in external hip rotation. As the backswing starts, the right femur rotates away from the body (clockwise) intially, until the knee reaches the end of its range of motion. Then, the pelvis rotates clockwise around the stable femur putting the hip into internal rotation. The confusion arises because Kelvin refers to the "externally rotated right leg" at the top of the backswing. I suppose, technically, it isn't really "externally rotated" at the end of the backswing (as golfdad pointed out a few hours ago). The right hip and femur are, in fact, internally rotated at the top of the backswing. But the right knee is still in the same clockwise rotated position reached during the backswing (perhaps with some extension), which Kelvin, with some artistic license, calls "externally rotated". Maybe that was a mistake. In transition, the hips and knees flex and the right leg more or less "holds" its clockwise rotated position as the pelvis reverses its rotation and and the right hip goes into external rotation. Very dynmaic players like Jamie and JB flex the right leg dramatically, raising the right heel early in transition. Lukman seems to equate this with "internal rotation", but it isn't: internal rotation requires the right femur to rotate counter-clockwise in the hip socket, which it clearly isn't doing at this point. Players like Palmer, Snead and Kenny Perry have much quieter leg action, with the right foot staying flat. What none of them do at this stage is to actively drive the right knee counterclockwise toward the target, which would tend to maintain the right femur in its internally rotated position. Simultaneously with the right side movements, the left femur is rotated away from the body (counter-clockwise) into external rotation. Once that maxes out, both hips/femurs are externally rotated and abducted, and the bow-legged squat is achieved. Then, the thighs adduct, bringing them together, and the glutes internally rotate both hips, creating a powerful push/pull coupling force that rotates the hips. Jeff
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Post by lia41985 on Dec 5, 2011 16:13:37 GMT -5
Jeff, There are some typos in the post that you've quoted but I'm satisfied that you now that you say that the flexing of the right knee is what is being confused as "holding" I see you've understood me. No such "holding" is going on. The right leg goes from I called a maximal external rotation (right knee turns clockwise to the ground, as you point out) with the knee extended to less than maximal external (clockwise) rotation and knee flexion. This counter-clockwise rotation with corresponding flexion means there's no "holding" going on. I hope Kelvin gets it too.
All the best, Lukman
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Post by jeffy on Dec 5, 2011 16:27:05 GMT -5
Lukman- Well, there is definitely a "delay" of the right knee moving toward the target during the transition in the swings that have the bow-legged "squat" move. During this "delay" flexion also occurs. The counter-clockwise rotation of the right knee you reference seems to be discussed in Kelvin's article, in the "Dual Hip Flexion" section, below an animation of Snead: "From this view, the right knee movement has a circular movement." Check it out. www.aroundhawaii.com/lifestyle/health_and_fitness/2011-04-whats-a-hip-turn-part-2.htmlJeff
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Post by lia41985 on Dec 5, 2011 16:45:01 GMT -5
Jeff, I don't see a delay. Look at the two video I posted of Sadlowski. I'm sorry but I just don't see it. Furthermore, I don't think many, if any, proficient athletic movements display the sort of discontinuity that you and Kelvin are advocating. I thought stalling was a bad thing! Look, I've gone as far as I can go with this. I have exams to study for and papers to write and really, I did this because I think there's something you, Kelvin, and golfdad could all learn from it. golfdad's talented daughter is learning a contrived move that's not actually occuring in what Kelvin believes are the elite swings. Looking at your swing video, so are you. I'm also sorry to say that there's no way that your radar reads accurately although for comparative purposes it suffices. Best of luck on your continued work to improve your game and the same to golfdad's daughter.
All the best, Lukman
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Post by jeffy on Dec 5, 2011 16:58:40 GMT -5
Lukman-
Well, I see you aren't getting much traction over at Manzella's, either, so it probably makes sense to go back to the books.
As for my SwingSpeed radar, Bolt, Brian and Mike Jacobs all thought it was accurate enough at the last school I attended and my swingspeed now exceeds all of theirs (using the same unit, of course).
Jeff
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Post by rohlio on Dec 5, 2011 18:00:53 GMT -5
natep, for the sake of simplicity and clarity, at the expense of preciseness, external rotation of hip is the same as external rotation of the leg because the leg cannot externally rotate anyway therefore whoever writes that is understood as meaning the hip ext rotation. Correct! This is what happens when people try to use the language of one discipline but are not disciplined in it. Anatomists refer to the "Thigh/hip" as the Femur. The "leg" is only the tibia and fibula. So in this way you cannot externally rotate the leg because the knee is a dual condylar joint (which makes it functionally a hinge joint with only extremely minimal rotation), meaning if you externally rotated the leg you would have to dislocate your knee.
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Post by jeffy on Dec 5, 2011 18:34:59 GMT -5
Lukman-
Ouch! Things are getting a little rough over at Manzella's. Not quite the love fest you were hoping for.
Good point, though, by birly about the "Manzella house rules": no posts about another instructor except to trash him!
Jeff
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Post by jeffy on Dec 5, 2011 19:19:06 GMT -5
This video, which discusses the distinction between motion of indivudual bones and relative joint motion and was forwarded to me by Kelvin, may clear up some of the confusion concerning the "externally rotated right leg" and internal/external hip rotation:
Jeff
PS: Kelvin asked me to post this because he is too busy filling orders for the Impact Snap Device and responding to reader inquiries: his viewership has at least tripled! Thanks, Lukman!
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Post by golfdad on Dec 5, 2011 20:54:59 GMT -5
Thank you Jeffy (Kelvin) for this clip, quite informative. It demonstrates the rather confusing and deceptive nature of hip rotation against pelvic rotation. A 4th possibility is when the right lower limb is planted in the ground and the pelvis starts to turn left, causing a relative ext rot of the right hip, a contentious point and highlight of the day! Jeffy, please continue to share with us information so that we can read up and judge for ourselves whether we can incorporate the info into our own lives. You have a talent for that. Take it easy with your other pursuit!
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Post by natep on Dec 5, 2011 20:57:36 GMT -5
+1 I think I understand now.
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Post by golfdad on Dec 5, 2011 21:06:38 GMT -5
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