Post by imperfectgolfer on Jan 9, 2023 11:45:33 GMT -5
Here is another golf instructional video by Craig Hanson/Rob Neal
One of the most infuriating features of the CH/RN videos is how they hype themselves as using "evidence-based" material based on RN's study of 500+ pro golfers. However, what they actually demonstrate in their videos is not new and undiscovered material, but well known facts that have been apparent for a long period of time.
So, in this video they show that pro golfers have a steeper shoulder turn angle near impact compared to the backswing's P4 position.
Here is an example from their video - featuring Collin Morikawa.
One of the most infuriating features of the CH/RN videos is how they hype themselves as using "evidence-based" material based on RN's study of 500+ pro golfers. However, what they actually demonstrate in their videos is not new and undiscovered material, but well known facts that have been apparent for a long period of time.
So, in this video they show that pro golfers have a steeper shoulder turn angle near impact compared to the backswing's P4 position.
Here is an example from their video - featuring Collin Morikawa.
Note that Collin Morikawa has a shoulder tilt angle of 41 degrees at P4 and 55 degrees at P7.
Why do pro golfers have an increased shoulder tilt angle of ~14 degrees through impact and how do they accomplish that goal from a biomechanical perspective.
CH/RN do not really discuss this issue in a detailed biomechanical explanatory manner and the CH drill featured between the 10:13 - 11:34 minute time point of the video is hopelessly inadequate in terms of training a golfer how to optimally steepen the shoulder turn angle during the later downswing, based on an over-simplistic "feel" of how the shoulders are moving during the drill. Putting a clubshaft across the front of the shoulders and then turning back-and-forward (as CH demonstrates in the video) does "nothing" in terms of explaining how one should biomechanically get an additional 14 degrees of shoulder turn steepening during the downswing (compared to the backswing).
I will now explain how I think that it works from a biomechanical perspective - using Collin Morikawa and Dustin Johnson as examples.
Here are capture images of Collin Morikawa's and Dustin Johnson's downswing action.
Collin Morikawa
Dustin Johnson
Image 1 is at P4, image 2 is at P4.5, image 3 is at P5.5, image 4 is at P5.5 and image 5 is at impact.
I have drawn a green line across their shoulder turn angle and a red line along the longitudinal axis of their spine in image 1. Note that they are at a ~90 degree angle relative to each other. I think that it's very easy to achieve that goal if one maintains a constant spinal bend angle during the entire backswing action. CH states that one needs to get the trail hip joint further back by lifting the lead heel, but that only affects the degree of pelvic rotation. What really affects the shoulder turn angle at P4 is not the degree of pelvic rotation happening during the backswing, but the biomechanical method of turning the upper torso more than the pelvis between P1 => P4. Most pro golfers turn the pelvis ~45 degrees clockwise between P1 => P4 and they turn the upper torso an additional 45 - 60 degrees. The key biomechanical move needed to get the "correct" shoulder turn angle by P4 is to maintain the spinal bend inclination angle constant during the backswing action and avoid "standing-up' during the backswing action. If the spine bend inclination angle is kept constant, then it is biomechanically comfortable/natural for the shoulders to turn at a ~90 angle relative to the thoracic spine due to the natural biomechanical rotary motion happening at the level of the 12 thoracic vertebra.
What is much more difficult is getting an additional 14 degrees of shoulder steepening between P4 => P7. CH states that it is a combination of tilts-and-turns, but it is a much more complex issue than simply telling a student golfer to combine some tilt with some turn during the downswing action (as CH demonstrates in his drill near a wall while holding a golf club across the front of his shoulders).
I think that there a few key biomechanical moves that have to happen in the correct sequence.
The first key biomechanical move is to start the downswing with a pelvis shift-rotation move that squares the pelvis by P4.5 - P5 and where the pelvis continues to rotate to an open alignment by P5.5. During that P4 => P5.5 time period, the pelvis must be leading the upper torso from a rotational perspective and the upper torso should not be tilting groundwards more than the amount achieved by acquiring secondary axis tilt (secondary to the targetwards lateral shift of the pelvis). The second key biomechanical move is to continue to rotate the pelvis to an open alignment by impact where the pelvis continuously remains ahead of the upper torso (from a counterclockwise rotational perspective) all the way between P5.5 => P7 and to simultaneously allow the right side of the mid-upper torso to "crunch-in" to a greater degree by adding a finite amount of right lateral bend - as seen in images 3,4 and 5 in those CM/DJ capture images above. It is much easier to acquire right lateral bend between P5.5 => P7 if the pelvis is more open than the shoulders during that entire late downswing time period.
So, when performing that CH drill (when standing near a wall and holding a golf club across the front of one's shoulders), one needs to practice the correct sequencing of the rotational and tilt moves - as described above.
If performed correctly, one should be able to achieve the impact alignments seen in the following capture images of CM and DJ.
Collin Morikawa
Dustin Johnson
The rightwards-tilted green line shows that they have secondary axis tilt (due to left-lateral shift of the pelvis) combined with a finite amount of right lateral bend (acquired after P5.5). That combination allows their trail shoulder to get much closer to the ground and also much closer to the ball by P7 - thereby allowing them to have a bent trail elbow and extended trail wrist at impact.
Note that both CM and DJ are performing a DH-hand release action between P7 (image 1) and P7.4 (image 2) and having a steeper shoulder turn angle combined with the non-stop downplane motion of the trail shoulder under the chin between P7 => P7.4 makes that possible by avoiding a "running-out-of-trail arm" scenario.
Jeff.