Jim McLean's 6 degree-of-freedom 3D report and other pevis/hips commentary
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Dear Lindsey,
First Happy Holidays yo you and ALL that participate on this wonderfully informative site.
I believe that consistent golf swing performance is ONLY possible with a clear understanding of the UNIQUE rotational characteristics of each golfers hips.
In all my previous posts, I have in some way tried to point out the importance of maintaining dynamic balance and stability margins during the explosive downswing. Without ANY doubt, of all the rotating elements involved in the golf swing the pelvis hips and knees are the ones that have the chance of balancing the enormous centripetal forces/potential imbalances of the upper body elements.
As a result, I introduced 'Bumpy Back, keep it back'(BBKIB) on this site as a somewhat tongue in cheek instruction as an attempt to encourage and help golfers develop more dynamic stability in the downswing.
So in direct answer to your question, relocating the starting location of the trail hip, and 'keeping it back' during the early phase of the downswing, has in my experiences always produced better swing results as measured by using Trackman, FlightScope for launch results,, and both the AMM and MATT's systems, for kinematic and timing considerations.
Lindsey Newman
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JEREMY5577
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So...how does the 40/40 work if you're trying to keep the trail hip back? If the pelvis is supposed to be 40 degrees open at impact wouldn't holding them back be counterproductive?
rafared
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You Sir Just read my mind. How can you lead with the lower body and keep the trail hip back at the same time?
Lindsey Newman
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The last 2 posts show my point
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GaryRead
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Imagine the swing as a top view down and hips as a door with one side 'hinged' .
the trail side is the hinged side on the initiation of the downswing, while the lead side swings open. this trail side will at some point in the downswing break free of its 'hinge'
rafared
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I think I get the image you are suggesting. The question then becomes, for me at least, when does the hinge break? I'm thinking just after impact but could of course be wrong.
JEREMY5577
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I understand BBKIB I've worked on it for 10 months now.
Lindsey, is there a swing out there that uses very little conscious involvement of the lower body and you're trying to say people get too wrapped up in lower body pivot like it's the answer to everything?
rafared
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I had a kvest session very recently and the biggest problem that showed up was a lack on pelvis rotation on the downswing. The sequence was good and most of the other figures were decent enough but my pelvis motion is a problem. It was a max of 17degs open at impact coupled with having its peak speed very close to impact also. What I took away from the session was to work on getting my hips to an impact condition much faster than I do at present.
Ah then you know the sound of one hand clapping. Our relationship to paradox is a barometer of our enlightenment.
Lindsey Newman
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Yes
Dear Jeremy5577,
Happy Holidays, and thanks for using BBKIB for the past 12 months. I assure you, the 'by-products' of this dedicated hip starting position in addition to better dynamic balance involve better external and eventually internal hip rotations, better stretch shorten cycles for the lower and mid body torque producing elements, and best of all from a 'feel standpoint' (where is Steve T ??), much better kinematic/dynamic sequencing.
Now, the MOST important part Jeremy, IMO, there IS NO 40/40 RULE. Every body, every club and to a lesser extent, depending on the golfers degree of swing consistency, these numbers are unique to the natural ranges of motion and bodies internal 'optimization' systems. For instance when eating an ice cream cone, and moving it to your mouth with your eyes closed from different starting locations with your eyes closed, I bet you don't use the analogy of 40/40 rules for the joints involved.
On a more serious and scientifically based note, much medical research on how the body acts involuntarily, results in amazing energy conserving optimizations, always with the constraints and mandatory movements for safety and survival. Regarding the golf swing, seeking the gravity vector for sensing vertical, and using the proprioceptive capabilities of the ankles to internally establish the potential of falling are dominant reflex producing bases if the downswing is not in dynamic balance.
Hope this helps you 'dismiss' any 'rules of thumb' and generalized angular movements and positions in favor of your own body making those decisions after BBKIB.
Sincerely,
art
GaryRead
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This seems to fit in with my post with the idea of imagining the trail hip as a door on a hinge. Anything but a centre rotation I.e the spine as the centre would produce hip movements with independent speeds.
The question then would be do these various motion capturing apparatus identify the centre of rotation of the hips? In theory you could have an example where 2 swings measure the same degrees of rotation but the centres of rotation are different. I think knowing where the centre is is important to quantify. You would need to be able to measure the speed of each hips rotation independently along with degrees of rotation to expose the centre of rotation, can AMM and the like do this and if so shouldn't we be seing the pelvis data broken down into hip speed for trail versus lead. Degrees of rotation doesn't need to be broken down into trail an lead because the degrees of rotation will stay constant relative to the centre.
I have been reading the thread re. The mtrx app. I think its only downside considering its nature is that it is measuring one point of the hip. I have purchased this and find it interesting to see how my TRAIL hip speed contributes to the downswing. I am looking forward to testing out my LEAD hip with the expectation it will be different!
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Dariusz J.
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That's a great answer to a good post (Lia's).
The key is to understand one tricky situation. Pelvis (as a bone) is totally inflexible and moves as a whole. However, RoM of hip joints (these connecting pelvis with femurs) is not negligible. It is because one (spine) is united with two (legs). Therefore:
a. talking about pelvis (girdle) movement as a whole makes sense when watching from the top up, e.g. while comparing angles of shoulder girdle to the hip one;
b. taking about hips movement as a whole makes no sense while watching from the legs perspective; e.g. external rotation of one joint performed simultaneously with internal rotation of the other brings a totally different biomechanical scenario than in case of both joint internally or externally rotated;
c. since humans are bipeds the weight shift problem is always present; we can and sometimes should watch at pelvic movement (especially this from the femurs up) through the prism of it; who knows, perhaps the notion of eccentric elypses when the axis of rotation moves with the weight shift can be the most accurate easy to understand description of the pelvic movement in the golf swing motion.
d. that's why, in view of the above, that even the best studies on golf swing motion without engaging anatomy can be, delicately said, imprecise -- what I have been preaching like a broken record for several years here and there.
Cheers
I see all the time with young baseball hitters "using their hips" to swing. But, it is rear hip dominant and seems to disrupt the kinetic chain in some way because it does not produce the power that you would expect from watching them swing. It is evident they are doing this by watching their rear foot pivot on the ball of the foot with no translation through to the bat. I have coached a few into using their lead hip to power their pelvic turn and it has produced much better power.
I struggled with art's bbkib when he introduced it, but through a few conversations in pm and working on it, I finally understood it as another way of ensuring the lead hip powers the pelvic turn with the rear hip only assisting and maybe even feeling like it just follows along.
lia41985
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spktho...huh? You're missing how the rotational velocity difference between the lead and trail hips plays a very important role in this all. Art talks about this a lot. It makes talking about the pelvis distracting. If you want to better understand stretch shortening cycles in the lower body you'd be wise to observe.
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Actually Lia, I do understand that point. Just trying articulate it in easier to understand terms. Please forgive me for using language so far beneath your superior intellect. Time for you to start up your own golf swing theory website?
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