Post by imperfectgolfer on May 18, 2023 10:17:42 GMT -5
It would seem that Sportsbox is having an increasing influence in the world of golf instruction.
Sportsbox apparently has the ability to measure so many features of a golf swing action that it can provide a flood of information for a golf instructor to digest.
Here is one of Sportsbox's latest videos.
This video focuses on the kinematic sequence and the Sportsbox app can provide data on what Phil Cheetham calls "speed gain" elements that can be operant during a full golf swing action.
Sportsbox apparently has the ability to measure so many features of a golf swing action that it can provide a flood of information for a golf instructor to digest.
Here is one of Sportsbox's latest videos.
This video focuses on the kinematic sequence and the Sportsbox app can provide data on what Phil Cheetham calls "speed gain" elements that can be operant during a full golf swing action.
At the 22:49 minute time point of the video. PC states that he can calculate how much speed gain can be obtained, and added, across each joint in the kinematic sequence. He then introduces the controversial "idea" of a smash factor for the body and at the 24:00 minute time point he presents the "idea" of a gain factor for the core, the shoulders and the wrist. Note that he states that the gain is calculated by measuring the angular velocity of the "subsequent segment" divided by the angular velocity of the "previous segment" in terms of their angular velocity measurements.
PC then amazingly states at the 24:59 minute time point that he can calculate the degree of muscle contribution from the legs, core muscles, shoulders, and the wrists to a golfer's clubhead speed generation ability.
Ryan Crawley then shows how he uses these gain measurements when instructing a golfer.
I think that their logic is highly flawed. It makes an unscientific assumption that the energy used to move the club in space is directly related to the accumulative effect of a specific kinematic sequence where energy is transferred from one segment to the next segment in a fixed sequence. However, we know that this is not true?
Here is PC's kinematic sequence measurements of multiple PGA tour golfers.
Ernie Els manifests the PC-described kinematic sequence where the pelvic angular velocity peaks before the upper torso's angular velocity and where the upper torso's angular velocity peaks before the lead arm's angular velocity.
However, the "real life" reality is that pro golfers vary considerably in the magnitude and timing of their pelvis. upper torso, and lead arm speeds. For example, JB Holmes has relatively slow pelvis/upper torso/lead arm speeds and they peak at the same time - but he generates the fastest clubhead speed at impact among this group. Note that Zach Johnson's pelvic graph peaks after his lead arm's peak. Note that Corey Pavin's upper torso graph only peaks post-impact.
Here is Jon Rahm's kinematic sequence.
Red graph = Pelvis angular velocity
Green graph = Upper torso angular velocity
Blue graph = Lead arm angular velocity
Note the slope of his blue graph and note how it steepens very fast in the early downswing independently of the pelvis/upper torso graphs. The "idea" that his lead arm speed is totally dependent on the accumulative gain effect in a specific set sequence of his pelvis/upper torso's motion makes no sense. The "real life" reality is there is no "standard" kinematic sequence model (eg. PC's kinematic sequence model) that is optimal for all golfers.
I think that the "idea" that a golf instructor can use Sportsbox to identify specific weaknesses in a student golfer's kinematic sequence - as Ryan Crawley attempted to demonstrate in the video - is unscientific and irrational.
Jeff.