This post includes a lot more technical detail than I normally talk about. I am going to discuss a topic that will hopefully spark some good quality discussions which can further our understanding of the golf swing, and specifically impact. I am also going to, in this and future articles, suggest the practical implications of this information.
Full credit goes to Chris Como for this information. He is currently doing ground-breaking research on this topic and was kind enough to share information with me, which I hope can help some players and teachers. Also, Sasho Mackenzie has done some modeling on this topic and, as I understand, has worked with Chris on proving this theory.
If a pendulum (or club) is swinging from left to right across the screen, we could speed up the pendulum by pulling the end of the string (or club) in the direction of the green Arrow. Forces want to line up in the direction of the pull, so the bottom end of the pendulum will try and line up with the dotted line by speeding up towards it. This has been coined ‘parametric acceleration’.
What are the advantages of this?
1. A longer and shallower low point
It can offer a larger margin for error. If the first point of contact with the ground is too far behind the ball, it will have less of an effect on the ball flight and control. Conversely, a swing which doesn’t include this pull in the direction of the green arrow will continue to descend. This will mean that the control of the first point of contact with the ground will need to be much more precise.
2. More speed.
The pull in the direction of the green arrow will speed up the clubhead, offering a mechanical advantage (much more speed with for the amount of physical effort applied).
3. More compression.
The player will be able to hit the ball with a more forward leaning shaft position (relative to swing direction), allowing the club to be delofted, hence lowering spinloft and helping the player hit the ball further for the same swing speed.
Without this pull away from the ball, the player could only achieve this decreased loft by having the ball further back in the swing circle. The problem with this is that the player will have an increased angle of attack (steeper) and so spin loft (and hence compression) may not be improved. Also, the player may hit massive divots which need to contact the ground in the right place more precisely, lowering margin for error.
4. Longer line of compression
with these moves, the angle of attack and dynamic loft through the impact interval will remain more constant (than without), offering a longer line of compression. I am not sure we fully understand what this means yet, in practical terms. But it could offer potential benefits to consistency of distance control.
So, is there evidence of professionals doing this?
We can see in the above picture (pre transition) that Tiger’s head has already significantly dropped in height.
- Get the sternum further away from the ball
- Scapular retraction (left shoulder)
- Allowing left shoulder to raise through impact through the body rotation
- Shorten the radius of the swing (bending arms)
The irony of most of this is that, the movements which produce a good hand path have often been frowned upon. Dropping your height and jumping up through impact, for example. The theory has been that, the less moving parts we have, the more consistent we can make the movement.
Whilst this may be true logically, in a biological system which requires ‘margin for error’, more moving parts and more degrees of freedom may offer several benefits over something which looks prettier, more symmetrical and ‘tidy’. It is no surprise that Tiger Woods exhibits a lot of the traits described, and that he has also been one of the best (if not THE best) iron players in the world over the course of his career, as well as a long hitter of the ball. Again, ironically, these good traits he has were almost taught out of him. Luckily for him, his body never really listened to his training, and he continued with what he did naturally.
Take home notes
So, in summary, if you provide an upward pulling force through the hitting area, you can not only create speed through parametric acceleration, but you create a longer low point (for more consistency) and the ability to hit the ball with a lower spinloft (more compression). You will also create a longer line of compression. All of these are good things.
Also, more degrees of freedom and more moving parts can actually be a good thing. Most teachers try to be too restrictive. Whilst this can work, and there are often times I do it myself (if I deem necessary), the idea that less moving parts = more consistency can be taken too far.
What amazes me the most is how our bodies are so intelligent. Tour pro’s have found these macro movements without being told about them, and often in spite of being taught the complete opposite. It also amazes me how the human body can organise so many moving pieces, all moving in different planes of motion, at different speeds, rates of acceleration etc, yet combine them all to produce the impossible; a ball which flies 300 yards down the fairway. Just a couple of degrees out and the ball is offline, yet we manage to do it on (almost) regular occasion. Without going too much into the theory of the uncontrolled manifold hypothesis, it is safe to say that we, as humans, are pretty damn amazing at organising all of these complex movements into one harmonious symphony. We should try and tap into our self-organising skills more often.
I must mention Jon Hardesty for our discussions on this topic. It is also right of me to mention Chris Como and Sasho Mckenzie for their information on hand path, and also Brian Manzella for consistently bringing hand path to my attention. And also to Jeffygolf for the use of the parametric acceleration video.