Post by imperfectgolfer on Apr 1, 2024 13:14:05 GMT -5
Dr Mann,
I think I finally understand what you are saying.
If from P4-P5.5 there were no other biomechanical actions other than:
a. Rotation of pelvis/chest.
b. Lateral targetward motion of pelvis/torso.
c. Some coupled vertical adduction of trail arm and horizonal abduction of lead arm.
Then DJ's hands would be closer to the target at P5.5 versus P4.
For the hands to not be closer at P5.5 versus their position at P4, would require extra biomechanical actions such as:
d. Protraction of trail scapula.
e. Increased thoracic flexion while the chest is closed to the target during top view images 1, 2 and 3.
Have I got this correct?
DG
To points numbers (d) and (e) I would add another point (f) which would be the pitch elbow motion of the trail arm as seen in DJ's P4 => P5.5 time period where his trail humerus is externally rotated to a small degree at P5.5.
However, if one uses a punch elbow motion, like Rory McIlroy, where the trail elbow is positioned outside the right hip area at P5.5 and where the trail forearm is not angled away from the target due to external rotation of the humerus, then the thorax must be more closed at P5.5 so that the hands can be equally positioned outside the trail thigh at P5.5.
Image 3 is at P5.5. Note that his hands are well outside his trail thigh (similar to DJ). However, his trail forearm is angled away from the target at P5.5 due to the fact that his thorax is more closed (compared to DJ) considering the fact that his trail humerus is neutral - while DJ has to use external rotation of the trail humerus to get his trail forearm angled away from the target at P5.5 because his trail elbow is positioned in front of his trail hip area and it is therefore positioned closer to the target.
Capture image of Dustin Johnson at P5.5.
Note that DJ's thorax is less closed at P5.5 and that he has to use external rotation of his trail humerus to angle his trail forearm away from the target.
Both DJ and RM are flexing their thoracic spine and protracting their trail shoulder between P4 => P5.5.
Jeff.