INFLUENTIAL GOLF SWING POSITIONS
Michael Jacobs
Michael Jacobs PGA Golf Professional Rock Hill Golf Club Jacobs 3D Golf mj@jacobs3d.com Copyright Jacobs 3D Golf 2022 All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the publisher, except in the case of brief quotations embodied in critical reviews and certain other noncommercial uses permitted by copyright law.
Con t en ts Introduction 4 8 9 11 13 17 18 20 22 24 26 28 29 30 Position 1. Position 2. Position 3. Position 4. Position 5. Position 6. Position 7. Position 8. Position 9. Start-up – the initial movementof the golf club Takeaway– 45 degrees Club Horizontal - 90-degreeclub Club Vertical– 180-degreeclub Top- highest point of the hands
seconds beforeimpact
second beforeimpact
.05 seconds beforeimpact. Impact
impact
afterimpact
Conclusion
-.2
-.1
-
Position 10. After
Position 11. 180 degrees
Position 12. Finish
As an avid book collector, I have accumulated much of golf’s early writings that trace back to Scotland, where the “Society of St. Andrews Golfers” wasformedin1754.Whenyoudothemath,13.5 generations have passed down rules, equipment, courses, and instruction. Passion lies with these genres, but there isn’t a single drivingrangeorpracticeareaontheplanet thatisn’tsubjectedtoa dailydoseof amateur and professional instruction. Fromfatherto son, grandpa to grandson, friend and foe alike, we have all heard eachother’sswingtheoriesorlatestdiscoveries.
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Introduction
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As you scroll through the annals of experts, you will find a common thread:adescriptionoftheinfluentialpositionsofa swing.
Addressposition, takeaway,top of thebackswing, thestart ofthe downswing,impact,follow-through,andfinisharethe usualsuspects. Thereisagoodreasonthatwecommonlyuse theseevents:becausethey makeintuitivesense,andyouwill see some of them with a fresh definition in the Jacobs 3D convention.
Overthepast10 years,wordslikealpha,beta,andgamma have become good friends. Authors choose a convention to frame their discussion and remove ambiguities. In all our published works, we have been very consistent with our alphabet.
As we continue our biomechanical studies of the golf swing, these influential positions described below will be a fundamentalpartofour analysis.
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Two Important Jacobs 3D Terms
1. The Hub
The Hub is the defined as the center point between the two hands on the grip (Image from Jacobs 2016)
The hub’s movement path is an important swing characteristic.
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2.Force
The golfer pushes and pulls the club to move it around in a curve.
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(Images from Jacobs 2019 & 2021 overlayed)
POSITION 1. Start - up – the initial movement of the golf club
Golfers have a variety of triggering mechanisms when they begin their swing. This makes a common starting point difficult to define. By selecting the moment the club moves, we can define a standard. This explanation does not diminish the importance of everything that leads up to the start- up. Pre-start movements within the body and their energy transfers are an important part of a golfer’s preparation.
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POSITION
Envision a protractor placed around a golfer with ZERO DEGREES being the start of the swing.
Influential Golf Swing Positions
2. Takeaway – 45 degrees
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POSITION 3. Club Horizontal90 - degree club
Here the club has moved to 90 degrees on the simplified protractor. Body rotations, the movement of the arms relative to the torso, and the location of the club relative to the golfer all play a big role in how the golfer will finish their backswing. 11
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POSITION 4. Club Vertical –180 - degree club
In many of Dr. Nesbit’s papers, he refers to this moment in the swing as the “club vertical. ” From 90 to 180 degrees, the center of mass of the club aligns vertically with the hands, so there is a switch taking place in the alpha force direction. The head of the golf club and the center of mass are now moving to the interior part of the hub path.
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Club Center of Mass Images from Science of the Golf Swing (Jacobs 2019)
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Switch of Alpha Force Direction
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Center of Mass Moving Inside the Hub Path
Images from Elements of the Golf Swing (Jacobs 2021)
Center of Mass Moving Outside the Hub Path
POSITION 5. Top - highest point of the hands
The top of the golf swing is an often revered position. Whether the analysis looks at body positions, club locations, displacements, or even clubface angles, there is a reason that this portion of the swing would merit investigation and popularity.
Experts often define the top as when the club has finished its backswing motion and reversal into the downswing is beginning. This is not the “TOP” of the swing. It is extremely rare to find a golf swing that reaches its top point at the same time as the club’s reversal into the downswing. I find this very idea to be a pitfall that has removed the dynamic nature of many golf swings. The highest point that the hands reach is almost always during the backswing motion of the club.
The highest point that the hands reach is defined as the ‘Top of the Swing.’
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POSITION 6. -.2 seconds before impact
The duration of a typical downswing is 0.25 seconds. In just a quarter of a second, the club reverses from the backswing and arrives at ball impact. With the “top” taking place during the club’s backswing, the downswing of the hands generally begins before the club’s reversal. To encompass variations and styles, -.2 seconds before impact was chosen.
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This image has positions 5 and 6 overlayed on top of one another. Here you can see the difference in this golfer’s Top vs -.2 position. By choosing -.2, we can be assured that the downswing is underway.
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POSITION 7. -.1 second before impact
Several common swing characteristics take place around the time of -.1 before impact. The club moves out away from the golfer; the hands slow down, club rotational resistance ramps up and joint interaction forces increase to transfer energy to the distal segments. This is where we start to see glaring differences between amateur and accomplished players.
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This image has positions 6 and 7 overlayed on top of one another.
POSITION 8. -.05 seconds before impact.
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The club is in its delivery position -.05 seconds before impact. This position is around the time of last horizontal (90 degrees before impact).
The swing direction, path, and angle that the club is moving at make for an interesting point of analysis. The golfer’s rotational and lateral stability intertwine with the ability to move the club into impact in a repeatable pattern.
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POSITION 9. Impact
The collision of the ball and club is a complex interaction. With the aid of launch monitors and high-speed cameras, we have been able to better fit a golfer’s clubs and maximize the flight of the ball. The golfer is experiencing high interaction forces as the body acts like a human whip in highperformance players.
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POSITION 10. .05 after impact
Around the time of the club horizontal on the follow-through side, .05 seconds after impact is extremely informative in showing how the golfer has balanced out their linear and angular momenta.
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POSITION 11. 180 degrees after impact
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POSITION 12. Finish
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Con c l u s i on
The golf swing is one of the most complex movements in all sports. A standard set of analytical tools can assist us in better describing biomechanics. Over the past 10 years, we have collected a detailed database of golfers and have identified influential times and positions in the swing. Comparisons within this convention provide us with the analytical tools necessary to describe and improve golfers’ performance. Future publications will contrast golfers in these influential positions.
Michael Jacobs is golf instructor and researcher based on Long Isalnd, New York. In addition to his work coaching players at every level from elite professional major champions to everyday amateurs, Michael conceived and designed with Dr. Steven Nesbit the Jacobs 3D sports movement analysis system, which measures and evaluates the forces and torques in athletes’ bodies and the implements they use. A member of Golf Digest’s 50 Best Teachers and Golf Magazine’s Top 100 Instructors as well as a recipient of multiple PGA of America section teaching and coaching honors, Michael is based at Rock Hill Golf and Country Club on Long Island.
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Influential Golf Swing Positions Con tact 32 mj@jacobs3d.com www.jacobs3d.com
