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Post by dubiousgolfer on Oct 26, 2021 9:38:17 GMT -5
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Post by imperfectgolfer on Oct 26, 2021 9:53:50 GMT -5
I don't know why he labels that motor control theory as new.
From my perspective, I favor a pivot-induced TGM (lead arm) swinging action where the pivot motion induces the release of PA#4 via the motion of the lead shoulder socket.
That is the same as saying that "the leading role is endowed to a joint that has mechanical advantage in the limb. Because of relatively high inertia and the increased musculature of the proximal limb (or trunk) segment, the mechanical influence of the proximal joint motion on distal joints is much higher than the influence of the distal motion on proximal joints. For this reason, the leading join is often the proximal joint that acts similar to a whip handle; a single wave of which can cause complex motion of the cord. ---- In contrast to the leading joint, the subordinate joints must control the interactive torques that are created by the motion of the leading joint."
Jeff.
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Post by dubiousgolfer on Oct 26, 2021 10:22:20 GMT -5
Yes, it seems that way.
Dr Phil Cheetham says:
"The LJH also has significant implications in the training of a skill, implying that the correct action of the leading joint should be learned first and the subordinate joint second"
So I'm assuming he is saying that the body pivot needs to be optimised first , then the movement of the shoulders next.
DG
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Post by imperfectgolfer on Oct 26, 2021 17:42:29 GMT -5
Yes, it seems that way. Dr Phil Cheetham says: "The LJH also has significant implications in the training of a skill, implying that the correct action of the leading joint should be learned first and the subordinate joint second" So I'm assuming he is saying that the body pivot needs to be optimised first , then the movement of the shoulders next. DG If the pivot motion is optimised, then the two shoulder sockets motion should resultantly also be optimised. An optimum motion of the two shoulder sockets then makes it much easier to move the two upper limb's subordinate joints in the optimum manner. Jeff.
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Post by imperfectgolfer on Oct 27, 2021 9:45:42 GMT -5
The more I think about Cheetham's abstract theorising about brain/nervous system functioning, the more worthless I think it is from a golf swing perspective.
I don't think that one needs to theorise if one uses simple common sense combined with practical experimenattion.
Imagine that you want to throw a frisbee as far as possible, and as accurately as possible, using one upper limb. There is a choice - a lead arm throw performed back-handed or a trail arm throw performed forward-handed.
Let's presume that you want to use the lead arm, which incorporates a back-handed throw action.
What are the potential sources of throw power?
Here are the potential power sources - i) rotation of the torso counterclockwise that moves the lead shoulder socket in a targetwards direction, ii) activation of the lead shoulder girdle muscles that will allow one to throw the lead upper arm into abduction if the throw motion starts with an adducted lead upper arm, iii) active triceps-induced straightening of the lead elbow if the throw motion starts with a fully bent lead elbow and iv) active wrist muscle-induced motion of the lead wrist in a lead wrist extension/ulnar deviation direction if the throw motion starts with the lead wrist radially deviated and palmar flexed.
Simple common sense, combined with some simple personal experimentation, should allow one to readily realise that the throw motion will be optimised if the kinematic sequence happens in a proximal => distal manner. Secondly, one should then realise that if the thrower is very flexible and athletic, that he could generate a tremendous amount of lead hand speed via the pivot motion combined with the use of the lead shoulder girdle muscles that in simultaneous active combination will generate a lot of targetwards speed of the lead arm, and therefore lead hand. Then, simple personal experimentation + common sense reasoning should show that one can generate roughly the same lead hand speed if the lead arm is kept straight (and not bent at a right angle at P4) and if the wrist release phenomenon happens passively (and not due to any muscular activation of the lead wrist's extensor and ulnar-deviator muscles). In other words, the optimum technique would be a TGM swinging action involving the active pivot-induced release of PA#4. Then, if one uses a golf club instead of a frisbee, simple common sense + personal experimentation will demonstrate that one can generate greater clubhead speed through the impact zone if the lead wrist is bent to a ~90 degree angle at P4 and if the release of the club (representing the release of PA#2) happens passively in a similar manner to a driven double pendulum model. In other words, common sense, combined with little bit of practice, should show that a pivot-induced release of PA#4 followed by a passive release of PA#2 is the optimum way of performing a lead arm swinging action.
One does not have to perform any mental/abstract theorising about "how the brain and nervous system control human movement" to come to this obvious conclusion.
Jeff.
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