Questionable golf science! Dec 5, 2019 12:50:36 GMT -5
Post by imperfectgolfer on Dec 5, 2019 12:50:36 GMT -5
Look at this video by BeBetterGolf featuring Bertie Cordle.
Bertie Cordle promotes the "idea" of having lag tension at impact (defined as having the clubshaft lagging behind the lead arm) because he believes that it results in better control of the clubshaft at impact (via the lead hand applying forward pressure at PP#2 and via the rear hand hand applying push-pressure against the aft side of the club handle). Those biomechanical elements would certainly apply to a punch shot type of swing technique, which is basically a handle-dragging technique - but I do not believe that it can apply to the driver swing of a pro golfer who releases PA#2 via the principle of the double pendulum (based on the D'Alembert physics principle) where the peripheral clubshaft is bent forward relative to the proximal clubshaft between P6 and impact.
Bertie Cordle now even believes that there is "scientific proof" that proves that a lag tension swing technique will produce more consistently accurate ball flight.
His "proof" is mainly based on this forward dynamics model study produced by Sasho MacKenzie - www.dstgolf.com/upload/Assessment-of-DST-Impact-Line.pdf
First of all, this theoretical study is not based on a study of pro golfers' "real life" golf swings, but it is based on a theoretical computer-based study that is based on forwards dynamics modelling. If you read SMK's paper, you will see that he apparently adjusts the degree of muscle activation of different muscle groups to create either a lag tension swing or a flipped swing. However, SMK does not describe which specific muscles are being activated and how he established what is the optimum timing/duration of muscle contraction. SMK even claims that his computer model has "values" for the active muscle contraction involving lead wrist flexion/extension and lead wrist ulnar deviation. I have never seen any "scientific evidence" that proves that pro golfers are using active muscular contraction of their lead wrist flexors, lead wrist extensors and/or lead wrist ulnar deviators to a well-defined and specific degree during the downswing. I suspect that SMK's model is an unscientific "black box" that is ill-defined and that has not been shown to accurately correlate with what is happening in the "real life" golf swings of pro golfers.
Regarding the theoretical results of the theoretical study, the results are not surprising that the lag tension swing (where there is forward shaft lean at impact ) will have slightly better results with respect to the average loft angle error and average clubface angle error - even though the difference in average clubhead path error, average attack angle error and average clubhead speed at impact was negligible. I am personally in favor of avoiding flipping through impact because it is difficult to control the degree of flipping on a consistent basis. I personally prefer that golfers have a GFLW or bowed left wrist at impact and that they use a DH-hand release action through impact - but the fundamental question remains is how does one teach this type of non-flipping golf swing technique for a driver golf swing action that is not based on handle-dragging (which is more suitable for a short iron golf swing action). Neither Bertie Cordle, SMK or BD provide any guidance on how this can be practically accomplished in a "real life" golf swing action. I have, at least, described a TGM swinging technique based on the sequential release of PA#4 => PA#2 => PA#3 where I have described all the actions needed to optimize the sequential release of those PA's - but I have never seen BC or SMK explain how a pro golfer should perform a driver golf swing action from a practical perspective. As previously discussed in this forum, SMK's forward dynamics model - as described in his paper at www.sashomackenzie.com/publications/MacKenzie%202009%20A%20three%20dimensional%20forward%20dynamics%20model%20of%20the%20golf%20swing.pdf is highly problematic. Now, SMK seemingly claims that his forward dynamics model has "values" for the degree of muscle contraction causing lead wrist wrist flexion, extension and ulnar deviation.
I would really like to see SMK provide much more detail on his assumptions and calculations so that we can better assess his "black box" computer-model!