|
Post by dubiousgolfer on Nov 20, 2023 8:00:55 GMT -5
Dr Mann Looking at Jon Sinclair's Lead/trail supination & pronation graphs , it seems that there is very slight lead forearm pronation happening (while trail forearm supinating) immediately after P4, which suggests a possible degree of club shallowing. Do you think the majority of tour pros , if shallowing , attempt to do so during transition (ie. before the clubhead has reached the top of the backswing) so that it actually occurs very early in the downswing , say by P4.2? DG
|
|
|
Post by imperfectgolfer on Nov 20, 2023 10:18:25 GMT -5
Dr Mann Looking at Jon Sinclair's Lead/trail supination & pronation graphs , it seems that there is very slight lead forearm pronation happening (while trail forearm supinating) immediately after P4, which suggests a possible degree of club shallowing. Do you think the majority of tour pros , if shallowing , attempt to do so during transition (ie. before the clubhead has reached the top of the backswing) so that it actually occurs very early in the downswing , say by P4.2? DG I think that many pro golfers adduct their trail upper arm actively between P4 => P5, but the degree is variable so the degree of clubshaft shallowing during that time period will also be variable. If the clubshaft shallows, then that means that the back of the lead hand must be getting more horizontal and that can be either due to lead forearm pronation and/or an increased degree of internal rotation of the lead humerus. We do not have a reliable scientific way of measuring changes in the degree of rotation of the lead humerus, so we do not know to what degree it happens between P4 => P5. Here is one of Jon Sinclair's lead forearm pronation/supination graphs containing examples of different tour golfers. The blue graph shows a tour golfer who pronates his lead forearm a lot during the P4 => P5 time period, and he may have lot of clubshaft shallowing happening during the early downswing (eg. like Sergio Garcia). Here is Colin Montgomerie's clubshaft shallowing action. The red splined path is his hand arc path. Image 1 is at P4 and image 2 is at P4.5. Note how his trail elbow drops well below his lead elbow by P4.5 due to his active trail upper arm adduction maneuver - and that causes clubshaft shallowing. It looks to me that his lead humerus is internally rotating between P4 (image 1) => P5 (image 3) as his lead arm lowers.
Jeff.
|
|
|
Post by dubiousgolfer on Nov 20, 2023 11:23:25 GMT -5
Many thanks Dr Mann
This means that we have a gap in the 3D data information that might also explain shallowing via internal rotation of the lead humerus, even without any lead forearm pronation.
DG
|
|
|
Post by imperfectgolfer on Nov 20, 2023 13:11:57 GMT -5
Many thanks Dr Mann This means that we have a gap in the 3D data information that might also explain shallowing via internal rotation of the lead humerus, even without any lead forearm pronation. DG Correct - about the lack of 3D data regarding internal rotation of the lead upper arm. By looking at DTL capture images showing the hand arc path, it is easy to determine whether clubshaft shallowing is happening between P4 => P5. Certain 3D systems can measure the degree of lead forearm pronation that is happening during the early downswing, but they seemingly cannot measure the degree of internal rotation of the lead humerus that is happening during the same time period. Jeff.
|
|