Post by imperfectgolfer on Jun 26, 2024 11:46:31 GMT -5
This is an old video, which BD has re-posted.
It is basically nonsensical and it is based on a poorly expressed RB video on the issue of "resonance" with respect to a golf club's motion. BD even claims that the "force" needed to move the golf club in the downswing must be 2x the force needed to move the club in the backswing. Where is the scientific evidence to support such a ridiculously unscientific claim? BD even claims that the body/arm motion of a pro golfer executing a golf swing is identical to the body/arm motion that a person would use to hit an empty box with a stick (as seen at the end of the video)!!!
I think a person who uses a stick to hit an empty box may possibly exhibit the same body/arm motions as a pro golfer, but not necessarily because he may decide to have a kinematic sequence where the upper torso moves before the pelvis and with disproportionate force or he may apply force with the trail arm via the biomechanical mechanism of a hitting action (release of PA#1). I personally believe that most pro golfers usually use a pivot-induced TGM swinging action (lead arm swinging action) with a consistent kinematic sequence where the pelvis leads the upper torso and where the release of PA#4 (release of the lead arm) is optimised to create maximum lead hand speed at ~P5.5, and where the hand arc path shape combined with the changing hand couple force being applied by the trail hand determines the timing and speed of release of PA#2.
Both Sasho MacKenzie and Dr. Kwon have used inverse dynamics modelling to calculate the forces/torques being applied to the club handle between P4 => P7 and they have come to the same conclusion. Linear work is performed by the pivot-induced release of PA#4 and angular work is performed to release the club (release PA#2). They have calculated the timing and magnitude of these forces/torques and they are perfectly consistent with the forces/torques that would happen if a golfer performed a pivot-induced TGM swinging action - as described in topic number 5 of my downswing chapter at perfectgolfswingreview.net/downswing.htm#topic5
BD is mentally incapable of understanding the forces/torques that are being applied to the club handle during a pro golfer's downswing action and he therefore has a propensity to foster simplistically nonsensical explanations from golf instructors like Marcus Bell and Martin Ayers.
Jeff.