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Post by imperfectgolfer on Oct 11, 2019 9:21:51 GMT -5
DG, You wrote-: "That if the angular velocity of the club is so large (when forward bend is happening in the late downswing) , that any active release of PA1# and flexion/extension (left hand) and extension/flexion (right hand) will just not be enough to influence the golf swing? The golf club is actually pulling the hands/arms into impact so isn't it in the interest of the golfer to try and 'keep up' to prevent the clubshaft flipping the wrists too much 'before/at' impact and for several inches post impact (for DH purposes and as a buffer to stop clubface deflection for off-centre strikes)?"
Although there may be a small amount of negative left wrist torque existing in the later downswing when the peripheral clubshaft is bent forward, I suspect that it is very small and I personally don't experience the "feel" that the club is pulling the hands into impact. In fact, I am not even biomechanically aware of experiencing that negative torque at the level of the hands/wrists when performing a TGM swinging action - even though it is theoretically present. In your diagram, you state that there must be pressure felt in the fingers of the left/right hand in a direction that is away from the target - but I am not aware of "feeling" that pressure (even if it theoretically must exist). Are you?
Theoretically, an active release of PA#1 should only happen in a TGM hitting action where the manual release of PA#2 is controlled manually by the release of PA#1 and it should theoretically over-ride any centrifugal release (which operates according to the D'Alembert principle). It would be interesting to see if the peripheral clubshaft has forward shaft bend in the immediate pre-impact phase in TGM hitters. I do not know whether this has ever been studied.
Jeff.
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Post by dubiousgolfer on Oct 11, 2019 10:02:41 GMT -5
Dr Mann "In fact, I am not even biomechanically aware of experiencing that negative torque at the level of the hands/wrists when performing a TGM swinging action - even though it is theoretically present. In your diagram, you state that there must be pressure felt in the fingers of the left/right hand in a direction that is away from the target - but I am not aware of "feeling" that pressure (even if it theoretically must exist). Are you?" No I do not feel those pressure forces during that very fast action into impact. Maybe the reason is that it takes time to feel a touch from the moment it occurred (its not instantaneous -see below statement from a neurophysiologist). "Axonal transmission is extremely fast. The sensation of touch is carried in type A fibres, which have a conduction velocity of about 100m/s. So the transmission from your forehead will take about 5 milliseconds. However, your brain will process it a lot more slowly. We can actually see this happening on the EEG (Electroencephalography ). If you apply a stimulus to someone (say a click in their ear, or a flash of light in their eyes) we can record it reaching their cerebral cortex.EEG signals involve lots of randomness, so in order to see these recordings (we call them Evoked potentials) we need to repeat the stimulus many times, and average out the EEG. The background EEG averages out to zero, leaving the measurable response. The time between the stimulus and the response is known as the latency. For an electrical jolt to your arm, the latency is 20ms. That's the time it takes for that jolt to be transmitted up to your brain, and your brain to register it. The size of the response is known as the amplitude. " I am assuming in the downswing using stats for Peter Jacobsen (in Tutelmans website) , lead forward bend occurs about 20ms before impact , so any feel as per arrows in my diagram would probably coincide very close to impact or maybe post impact. DG
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Post by dubiousgolfer on Feb 29, 2024 21:13:37 GMT -5
Dr Mann
There is a YouTube video just published which mentions your past opinions regarding Jim Hardy's book.
DG
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Post by imperfectgolfer on Feb 29, 2024 22:56:10 GMT -5
Dr Mann There is a YouTube video just published which mentions your past opinions regarding Jim Hardy's book. DG Very amateurish review. Matt Kuchar's trail elbow is in a punch position, and not a push position, at P6. I have no idea why he believes that I harbor his "Jeffrey Mann" quoted opinions. Interestingly, I got a number of facts wrong in my video review because I thought at that time that the trail forearm had to be pronating between P6 => P7 in the RIT release. I now realize that it is possible to keep the trail forearm supinated to roughly the same degree during that P6 => P7 time period - even if the lead forearm is supinating a lot because the golfer uses a weak lead hand grip strength. By the way, Matt Kuchar uses a very strong lead hand grip, so he performs a minimal degree of lead forearm supination between P6 => P7 and it is therefore not surprising that his trail forearm does not rotate counterclockwise much between P6 => P7.
Jeff.
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