I have no idea what opinions you are trying to communicate.
I particularly don't know what the abbreviations FT, FP and FC mean.
The FT would be the instantaneous force vector along the hand path while
FC would be a 'centripetal force ' vector which would have to be a pull force via the left arm.
FP would have to be some push vector outwards of the FT right hand path direction.
Rather than use the 'Hand Couple' and 'Net Force' by inverse dynamics, why not conceptualise a 'Linear Force ' and its associated MOF by each hand on the grip?
I am therefore trying to understand which hand force/direction would maximise its own MOF around P5.5 for different wrist cocks . Then one can assess which combination might create an optimal 'Net MOF' to increase the angular acceleration of the club.
PS. The optimal combination would also need to produce a 'Hand Couple' too to fit the 'inverse Dynamics'.
Post by dubiousgolfer on Jun 22, 2020 12:50:39 GMT -5
No matter Dr Mann as its all just hypothetical anyhow and I'll just state below what I'd theorise the outcome to be.
If a golfer wanted to maximise the MOF via the forces in each hand (and therefore the 'Net MOF') he'd need to:
1. Increase his wrist cock angle by P5.5 2. Optimise his FT maybe with a pull action via the left arm/hand 3. Optimise his FC with a pull force across the club via the left arm/hand. 4. Optimise his FT with his right arm/hand . 5. Minimise FP with is right arm/hand.
The combination of the above will also produce FT 'components' and FP 'components' across the club to produce a 'positive torque' via the hands (which would fit in with the theory of positive torque caused by a 'Hand Couple' using inverse dynamics).
Note: The net FT force along the hand path will have a direct relationship with FC .
"I've been trying to figure out how hand forces could be applied during release to maximise MOF angular acceleration of club and how wrist cock could affect the optimisation of those MOFs."
The question is, given an optimal swing sequence and reasonable force applied prior to release, is there anything to gain by applying force during release and, if so, how much? I suspect that the answer is perhaps a little but it's not worth the effort.
As you may recall from his articles describing an alternative swing, Dr. Allen contended that the tour pro applied greater and greater force during transition (for purposes of clubhead speed) in order to curtail rotation (non-axial) of the club (thereby releasing the club over a greater distance) in order to better control shot dispersion. This led him to envision a swing that would not maximize applied force at transition (so that there would not be excessively rapid acceleration of the left arm). To compensate for less applied force at transition, he envisioned both a "pause" of the hands at the release point and the force of intentional right wrist palmar flexion via a split-hand grip (which can apply greater torque).
I think that his alternative swing idea has merit especially in terms of answering the question you posed. However, Dr. Allen also stated that this "more efficient" swing likely wouldn't result in clubhead speed as great as that exhibited by tour pros who apply great force at the start of the downswing.
Post by dubiousgolfer on Jun 23, 2020 9:50:55 GMT -5
As far as I'm aware Ben Allen Jnr has devised 2 types of 'back friendly' swings to avoid the lateral flexion (side crunching) element of the 'modern swing'
1. The Bad Slap Swing-The technique centers upon use of a hands and arms lever scheme that maximizes angular velocity as the core mechanistic concept. ""The BAD slap swing technique centers upon the mechanics of a hands driven system for which the major power action source is back swing flexion of the dominant elbow followed by down swing extension."
2. The Bad Snap Swing- reengineering effort that isolated centripetal acceleration as the dominant swing feature. "Knowing that the left arm must be stable and centered through impact helps to understand how important it is to avoid swinging the arms."
Dave Tutelman has already advised Ben Allen Jnr that the physics he is using in his 'Bad Snap Swing' is flawed so unsure whether he will redefine some of his ideas. If he was using hand speed/path to explain his swing using linear forces and 'secondary MOF /Hand ' torques then I could better appreciate his concepts.
However, his idea of actively restricting the swing radius to the length of the club by pausing the left hand in space through impact to 'generate a burst of clubhead speed' is 'putting the cart before the horse'. Torque increases clubhead angular velocity , while centripetal acceleration sustains the angular velocity that is being produced. That's why I mentioned in my previous post that "The net FT force along the hand path will have a direct relationship with FC".
Personally, I think his 'Bad Slap Swing' is just a right arm adduction move with active arm straightening using triceps contraction. He also mentions that both swing techniques need to incorporate a 'Roll-through-impact' hand release action (not exactly sure how he defines that) but I think it's a 'Flip Roll' similar to Harry Vardon.
After rereading my post, I didn't mean to say that that Dr. Allen's idea has merit in terms of a model to use - it just has merit in terms of application to your original question. I saw no advantage in incorporating his model. With regard to flaws, I do not believe that shaft bend at transition has anything to do with powering the downswing. I also do not believe that the distance over which release occurs meaningfully differs among tour pros such that one can readily classify them according to "roll" characteristics. He defines roll as how long it takes for the clubhead to pass the hands from a face on view, which is, according to him, the distance over which release occurs. I'm not aware of flaws in the application of physics that DT pointed out to him. I didn't see much more than the formula for centripetal acceleration. I referred to Dr. Allen's alternative swing models because they promote "doing something" during release to try to speed the clubhead, which was your original question. I believe that one can "do something," to meaningfully affect speed provided that the downswing speed before release is slow enough but, as you hinted, such would be a preposterous idea to incorporate.
"wg , blue arrow, shows where the club head would go if only the force of forward travel, momentum, were driving it down the line"
"The pull of a golfers hands on the club, 'cf' , aids the club head path from where it wants to go, wg, to where the combination of club head momentum and the pull of the golfers hands, 'fg', aids it to go."
I think Dave Tutelman has interpreted Ben Allens 'wg' vector to be 'momentum' not 'Force' therefore one cannot add the 'Centripetal Force' vector 'cf' with 'wg' because they represent different physical quantities, therefore Ben Allens physics to explain his concept is flawed.
If Ben Allen had defined 'wg' to be 'Tangential Force component' created via the hands on the club along the instantaneous hand path , then his 'vector' diagram would have made more sense.
I get the feeling that Ben Allen intuitively knows that hand speed/path can increase clubhead angular velocity , but he didn't have the maths/physics to explain it properly. But by getting the maths/physics wrong , he has made an error in the biomechanics required to create that 'burst of clubhead speed'. First the golfer will need to create that 'wg' force (which will increase the clubhead speed) while also having to increase his centripetal force to keep the clubhead travelling on a circular path at that greater speed (it goes hand in hand). If the golfer can then somehow create other forces to change his hand path and instantaneously create a MOF across the COM of the club , the clubhead speed can be made to increase. That change in hand path and the subsequent change in clubhead speed will require a greater centripetal force to sustain that new clubhead speed. The biomechanics involved to create the latter scenario is way more complicated than just trying to limit the swing radius by actively pausing the left hand motion through impact.
Yes, you are correct , Ben Allen is proposing active torque via the the hands to increase clubhead speed during release for his 'Bad Slap' swing.
I don't think any errors in Dr. Allen's diagrams are significant with respect to his central thesis, which is that the distance over which release occurs affects centripetal acceleration, and which defines the degree of "roll through mechanics." In other words, the diagrams don't specify the mechanical procedure that is used.
Dr. Allen's assumption that golfers' release radii, such as those of Nicklaus and Mickelson, are substantially shorter than those of golfers who use "neomodern" techniques is exaggerated. In one article, he stated that Holmes' radius is 40% greater than Nicklaus' radius and, consequently, Nicklaus' swing was 40% more efficient that Holmes' swing. His evidence were still, overhead photos of the two golfers that he marked up to show the comparative radii. Such is impossible to determine from photos, not to mention that the ball flight lines of both golfers were not the same in their photos and the sizes of the photos themselves were not comparable.
Dr. Allen's concept of adding wrist torque (as evidenced by use of a split-hand grip) with a hands pause is central to reducing the release radius. However, he did not show the mathematical tradeoff between the reduction in release radius and the reduction in hand speed to accomplish the reduction in release radius. This coupled with an obvious error in his judgment of release radius subjects his ideas to criticism.
In one article, he estimated maximum distance achievable with a 7-iron (200 yds.) using his alternative swing biomechanics. I found this to be quite remarkable and wondered how he came up with such an estimate. From correspondence with him, I know that he spent many hours "field testing" his theories but I doubt that at his age and physical ability he personally achieved that feat.
In any event, his ideas can show one how to alter net force in terms of hand speed and applied wrist torque. Such alteration is, however, quite questionable.