Pressure sensor measurements

[imperfectgolfer]

There has been endless debates as to whether a golfer is swinging or swing-hitting, and I have always stated that we need to embed pressure sensors in the shaft to see how much force is being exerted on the grip by the left hand (in a pulling manner) and the right hand (in a pushing manner) to accurately answer this question.

Interestingly, these pressure sensors exist and measurements have been made by researchers.

See this article - dspace.lboro.ac.uk/dspace-jspui/handle/2134/3577

You can freely download a pdf file of that paper from that link and read the entire paper.

Those pressure sensors are of two types and they are amazing.

Unfortunately, the way the experiment was performed and the way the results were presented doesn't answer the debate question re: swinging versus swing-hitting. However, it offers many clues.

The best graph relates to the scratch handicap golfer.



The graph shows the total force exerted on the grip, and it is broken down to left hand forces and right hand forces.

This photo shows where the golfer is during different time points.



I have yellow-colored the area of the right hand force graph that occurs between P5 and P7.

Some crude generalisations that can be inferred from this graph.

The golf swing is mainly a left hand action between P4 and P7.5, and there is very little right hand force being exerted during that time. A small amount of right hand force becomes operant in the mid-late downswing and it reaches its maximum value at impact (yellow-colored area). That fits in with my description of the golf swing - as described in my review papers where the release of PA#4 supplies most of the grip-moving power, and the right hand only contributes some "force" during the later downswing. It certainly shows that BM's theory that there is no force being exerted by the right hand across the shaft at impact is wrong.

Also, note that the left hand force always exceeds the right hand force post-impact between P7 and P7.5, which is the foundation of my biomechanical explanation regarding how a golfer maintains a FLW/intact LAFW from P7 to P7.5+.

Note that the right hand force only increases dramatically between P7.5 and P9 - during the finish swivel action when the club is swivelled onto the inclined plane after P8.

Now that I understand that these pressure sensors already exist, I also realise that we could use them to measure push-pressure exerted by the right hand at PP#1 (which is above the coupling point) and at PP#3 (which is below the coupling point) to answer the important question as to whether the right hand exerts a push-pressure on the shaft below the coupling point between P5 and P6.6 as BM suggests in his rotation-about-the-coupling point theory. In other words, golf researchers actually have the means to prove/disprove the RACP theory - if they set up their experiment correctly.

Jeff.

[virtuoso]

Hey jeff, cool stuff. I just took a quick glance and didn't read the actual research, but is there a way to determine the difference between push force or pull force vs. the hand(s) just tightening their grip?

[gmbtempe]

Credit should go to Art for bringing this research to the boards as I had not seen it yet.

The push pull relationship fits my mental model of the swing, its mostly left hand but the right hand is involved, the theory put forth by Homer Kelly that you do all of one, or all of the other, and mixing the two is disaster is not correct. I think every good player mixes the two, though I do believe that some players use more right hand earlier than others (hitting), and like Jeff said the means to test this is there.

I often wonder how much of that late addition of the right hand force is actually an effort by the player to keep the bodies rotation going and not stall into the swivel protion of the swing.

[imperfectgolfer]

Virtuoso,

No - their technique of obtaining pressure measurements includes multiple sensors in each hand and they produce a TOTAL force graph that doesn't differentitate between finger-grip pressure and arm pressure. Also, they don't understand TGM mechanics so their measurements of left thumb pressure is not necessarily due to the left thumb adducting against the grip, but it could rather be due to right palm pressure against PP#1. THey would need to put a pressure sensor not only under the left thumb, but also over the top of the left thumb to determine how much push-pressure exerted under the left thumb is actually due to push-pressure exerted over the left thumb by the right palm.

Nonetheless, it is interesting to know that these pressure sensors exist - I just need to find a group of golf researchers who would perform the appropriate experiment, which I could easily design. It would be very useful to know whether the right arm/hand is contributing to the release of PA#4, and PA#2 and also PA#3 in a swinger (like you). It would also be very nice to know how much push-pressure is being exerted by the right palm at impact, and whether it can stabilise the clubface in the presence of off-center hits (as John Erickson asserts). These pressure sensors make this type of research possible.

Jeff.

p.s. Note that left hand force remains high immediately after impact, which wouldn't happen if a golfer flipped after impact (like BM recommends in his pinata-release action). I believe that left hand force must remain high after impact in order to keep the left wrist flat, and to maintain the forward momentum of the FLW after impact so that the LAFW can remain intact - in the manner that you performed my preferred delayed full-roll hand release action.