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THE INFLUENCE OF ADJUSTABLE PUTTER HEAD WEIGHTING ON THE STROKE

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The purpose of this study was to investigate the effects of putter head weighting towards the heel and the toe on the kinematic aspects of the putting stroke. Seven (n=7) male golfers (age 42.6 ±2.3 y) with high proficiency (handicap 9.5 ±1.4) were recruited for this study. The experiment was carried out in an indoor studio with artificial grass (Stimp 10). Two toe weight and two heel weight settings were tested and compared with the standard weighting. Results suggest that putter head weighing influences the characteristics of the putting stroke, and systematic differences were found between toe and heel weighting. It is concluded that fitting the weight and the balance of a putter head is critical for supporting each individual's stroke and putting performance. KEY WORDS: Golf, putting stroke, golf club design, adjustability. INTRODUCTION: Putting is considered one of the most important factors for scoring of professional Tour players (Alexander & Kern, 2005), and is accounts for 43% ±2% of the strokes per round (Pelz & Frank, 2000). Unlike the long game, where distance and dispersion are discussed, the short game, like putting, is more focused on accuracy and consistency (Hume, Keogh & Reid, 2005). The putting stroke is divided into the Backswing phase (BACKSWING) and the Downswing phase (DS) (Delay, Nougier, Grealy, & Coello, 1997). BACKSWING is defined from address position (BA) to top of backswing (BT); DS is defined from BT to the finish position in the follow-through (FT); impact time (IMP) is defined as the time from BT to impact. Even though rhythm and timing also varies among elite players, rhythm (BACKSWINGRHYTHM, ratio of BACKSWING/IMP time) and impact timing (TIMING, ratio of IMP/DS time) are important factors for consistency and feel in a putting stroke (Marquardt, 2007). Past research mainly focused on the putting performance between competency levels, and results have showed significant differences between handicap levels, with the better golfers having shorter BACKSWING, longer amplitude for FT, and longer stroke duration (Delay et al. and some studies suggested a slower velocity at impact for better players (Delay et al., 1997). Since the rules for golf equipment on "adjustability" have been changed by the USGA and R&A in 2008/01/01, golf club designs have been coming out with innovative adjustable features that help to increase the performance of the golfers through "optimization". According studies have focused on the "long game" golf clubackswing (Neal, Abernethy, Moran, & Parker, 1990; Lindsay, Horton, & Paley, 2002; Shan, Betzler, & Dunn, 2008), other studies have examined influences of putter on shaft length (Pelz, 1990), putter shaft weight (Karlsen & Nilsson, 2007) or putter face groove design (Brouliette & Valade, 2008). The purpose of this study was to examine the influence the putter head weighting of the heel and the toe on the characteristics of the putting stroke. METHODS: Seven advanced golfers were recruited to voluntarily participate in the study (age 42.6 ±2.3y, handicap 9.5 ±1.4). Frequency of playing was minimum of 2 rounds of golf per month. The design of the subjects own putter needed to match to the test putters design (blade-type with peripheral weighting). The basic specification for the test putters were chosen to a blade-typed putter with peripheral weighting, loft of 4°, lie of 71°, swing weight of D2, length of 34 inches and 350 grams for head weight. Five putters of the same designs were used for this study. Weights were installed according to the test protocol in toe and heel sockets, with a combination of 30 grams of discretional weight in total. The standard putters (Std) had a balanced weighting
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30th Annual Conference of Biomechanics in Sports – Melbourne 2012
Yen Lei Wu. The influence of adjustable putter head weighting on the stroke. (211)
THE INFLUENCE OF ADJUSTABLE PUTTER HEAD WEIGHTING ON THE
STROKE
Yen-Lei Wu1, Chen-Fu Huang1, Christian Marquart2 ,Li-Chun Yu1, Su-wei Lee3
National Taiwan Normal University1,
Science and Motion GmbH 2 , Lee-Ming Institute of Technology3
The purpose of this study was to investigate the effects of putter head weighting towards
the heel and the toe on the kinematic aspects of the putting stroke. Seven (n=7) male
golfers (age 42.6 ±2.3 y) with high proficiency (handicap 9.5 ±1.4) were recruited for
this study. The experiment was carried out in an indoor studio with artificial grass (Stimp
10). Two toe weight and two heel weight settings were tested and compared with the
standard weighting. Results suggest that putter head weighing influences the
characteristics of the putting stroke, and systematic differences were found between toe
and heel weighting. It is concluded that fitting the weight and the balance of a putter head
is critical for supporting each individual's stroke and putting performance.
KEY WORDS: Golf, putting stroke, golf club design, adjustability.
INTRODUCTION: Putting is considered one of the most important factors for scoring of
professional Tour players (Alexander & Kern, 2005), and is accounts for 43% ±2% of the
strokes per round (Pelz & Frank, 2000). Unlike the long game, where distance and
dispersion are discussed, the short game, like putting, is more focused on accuracy and
consistency (Hume, Keogh & Reid, 2005).
The putting stroke is divided into the Backswing phase (BACKSWING) and the Downswing
phase (DS) (Delay, Nougier, Grealy, & Coello, 1997). BACKSWING is defined from address
position (BA) to top of backswing (BT); DS is defined from BT to the finish position in the
follow-through (FT); impact time (IMP) is defined as the time from BT to impact. Even though
rhythm and timing also varies among elite players, rhythm (BACKSWINGRHYTHM, ratio of
BACKSWING/IMP time) and impact timing (TIMING, ratio of IMP/DS time) are important
factors for consistency and feel in a putting stroke (Marquardt, 2007).
Past research mainly focused on the putting performance between competency levels, and
results have showed significant differences between handicap levels, with the better golfers
having shorter BACKSWING, longer amplitude for FT, and longer stroke duration (Delay et
al., 1997; Paradisis & Rees, 2002; Lee, Ishikura, Kegel, Gonzalez, & Passmore, 2008); and
some studies suggested a slower velocity at impact for better players (Delay et al., 1997).
Since the rules for golf equipment on "adjustability" have been changed by the USGA and
R&A in 2008/01/01, golf club designs have been coming out with innovative adjustable
features that help to increase the performance of the golfers through "optimization".
According studies have focused on the "long game" golf clubackswing (Neal, Abernethy,
Moran, & Parker, 1990; Lindsay, Horton, & Paley, 2002; Shan, Betzler, & Dunn, 2008), other
studies have examined influences of putter on shaft length (Pelz, 1990), putter shaft weight
(Karlsen & Nilsson, 2007) or putter face groove design (Brouliette & Valade, 2008). The
purpose of this study was to examine the influence the putter head weighting of the heel and
the toe on the characteristics of the putting stroke.
METHODS: Seven advanced golfers were recruited to voluntarily participate in the study
(age 42.6 ±2.3y, handicap 9.5 ±1.4). Frequency of playing was minimum of 2 rounds of golf
per month. The design of the subjects own putter needed to match to the test putters design
(blade-type with peripheral weighting).
The basic specification for the test putters were chosen to a blade-typed putter with
peripheral weighting, loft of 4°, lie of 71°, swing weight of D2, length of 34 inches and 350
grams for head weight. Five putters of the same designs were used for this study. Weights
were installed according to the test protocol in toe and heel sockets, with a combination of 30
grams of discretional weight in total. The standard putters (Std) had a balanced weighting
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30th Annual Conference of Biomechanics in Sports – Melbourne 2012
with 15g each at the heel and the toe, the two heel-weighted putters had 10g (H1) and 20g
(H2) heavier weighted towards the heel, and the toe-weighted putters were 10g (T1) and 20g
(T2) heavier weighted towards the toe.
The putting strokes were measured using a three-dimensional kinematic ultrasound system
(SAM PuttLab system, Science & Motion Sports GmbH) where a triplet with three sensors
has to be attached to the shaft. The sampling rate of the positional data was 70 Hz per
marker. The analysis was done with SAM Puttlab 2010 software which includes specific data
analysis and filtering techniques for processing human movement data (Marquardt & Mai,
1994). The experiment took place in an indoor studio on an artificial turf surface with a Stimp
reading of 10. Golfers warmed-up before practicing with their own putter prior to experiment.
The weights were covered with tape and the putters were randomly given to the subjects to
minimize the effects on the learning progress (Fairweather, 2002). The golfers were
encouraged to go through their normal pre-shot routine prior to each putt, and ten putts were
collected per setting. After recording the strokes, parameters like BACKSWING's
displacement and timing, DS's displacement, timing before impact and after impact, velocity
at impact, maximum acceleration, stroke rhythm and timing of impact, were calculated and
used to analyze the different dimensions of the putting stroke.
Data were processed with SPSS 19.0 software. ANOVA and post-hoc tests were used to test
differences at α=0.5 level.
RESULTS: Table 1 shows the results for the different weight settings for Backswing's
(BACKSWING) and Downswing's (DS) displacement and timing (Table 1). Kinematic
parameters in the DS, velocity at impact (IMP) and maximum acceleration (AMAX) are
shown in Table 2. Lastly, the stroke's rhythm (BACKSWINGRHYTHM) and timing are shown
in Table 3.
Table 1: Summary for backswing and downswing stroke parameters with various adjustable
weighting (mean±SD).
Definition Parameters
Std H1 H2 T1 T2
Standard More- Heel Most- Heel More- Toe Most- Toe
Backswing:
Displacement (m) 0.22±0.01 0.22±0.01 0.21±0.01 0.21±0.01 0.19±0.01**
Time( sec) 0.63±0.03 0.64±0.02 0.63±0.04 0.66±0.03 0.67±0.04**
Downswing
Displacement (m) 0.59±0.01 0.53±0.01 0.57±0.03 0.61±0.02 0.60±0.02
Time( sec) 0.77±0.03 0.78±0.02 0.77±0.02 0.81±0.04** 0.82±0.01**
Top of Backswing
to Impact Time( sec) 0.36±0.01 0.37±0.02 0.36±0.01 0.35±0.01 0.37±0.01
Impact to Follow-
through
Displacement (m) 0.37±0.01 0.31±0.02 0.36±0.02 0.40±0.01 0.41±0.01
Time( sec) 0.40±0.03 0.40±0.15 0.41±0.03 0.46±0.04** 0.44±0.04**
# Significant level relative to Std (standard setting): *α=0.05, **α=0.01
# Std (Standard weight setting, both 15g); H1 (more-heel, 20g in heel, 10g in toe), H2 (most-heel, heel 25g, toe 5g); T1 (more-
toe, 10g in heel, 20g in toe), T2 (most-toe, 5g in heel, 25g in toe).
Table 2: Downswing's kinematics parameters with various adjustable weightings (mean±SD).
Definition Parameters
Std H1 H2 T1 T2
Standard More- Heel Most- Heel More- Toe Most- Toe
Downswing
Kinematics
IMP Velocity (m/s) 1.43±0.65 1.40±0.04 1.27±0.04** 1.45±0.03 1.47±0.02
AMAX (m2/sec) 5.28±0.65 5.66±0.21* 5.65±0.29* 5.07±0.51** 4.91±0.59**
# Significant level relative to Std (standard setting): *α=0.05, **α=0.01
# IMP velocity (Velocity at Impact); AMAX (Maximum Acceleration)
# Std (Standard weight setting, both 15g); H1 (more-heel, 20g in heel, 10g in toe), H2(most-heel, heel 25g, toe 5g); T1(more-
toe, 10g in heel, 20g in toe), T2(most-toe, 5g in heel, 25g in toe).
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30th Annual Conference of Biomechanics in Sports – Melbourne 2012
Table 3: Summary for Stroke's Rhythm with various adjustable weightings (mean±SD).
Definition Parameters
Std H1 H2 T1 T2
Standard More- Heel Most- Heel More- Toe Most- Toe
Rhythm
Backswing Rhythm 1.74±0.04 1.71±0.06 ** 1.74±0.05 1.87±0.06 ** 1.82±0.05 **
Timing 0.47±0.02 0.48±0.02 0.47±0.02 0.43±0.01 ** 0.45±0.02 **
# Significant level relative to Std (standard setting): *α=0.05, **α=0.01
# BACKSWINGRHYTHM (relation of BACKSWING / IMP time);TIMING (relation of Impact time / DS time)
# Std (Standard weight setting, both 15g); H1 (more-heel, 20g in heel, 10g in toe), H2(most-heel, heel 25g, toe 5g); T1(more-
toe, 10g in heel, 20g in toe), T2(most-toe, 5g in heel, 25g in toe).
DISCUSSION: During backswing phase, the toe-weighted were shorter and had longer
duration, while the heel-weighted condition showed no differences. Significant differences
were found with T2, both the backswing displacement was shorter (p<.001) and backswing
duration was longer (p<.001) which was not found for the long game (Shan et al., 2008). The
shorter displacement but longer duration could suggest a more smooth putting stroke. The
velocity at impact still maintains higher speed than other weightings which suggest better
efficiency and trait of higher proficiency (Delay et al., 1997).
From top of backswing to impact phase, there were no significant differences were found and
impact timings were all close the typical range also found in Tour players of 317ms ±35 ms
(Marquardt, 2007). At impact position, the toe-weighted conditions showed comparably more
efficiency, similarity trend with other racquet sport (Cross, 2001), even with a shorter
backswing; H2 showed significantly slower velocity at impact (p<.001) even with a larger
maximum acceleration. This could even suggest that the golfers were voluntarily increasing
the speed, which could also lead to inconsistency (Karlsen et al., 2007). From impact to end
of follow-through, no significant effects were found for displacement while toe-weighting
showed significantly longer duration (p<.001). The toe-weighting might cause larger
momentum on the downswing which has been seen in better players with a longer follow-
through (Craig et al., 2000). Looking at the downswing phase as a whole, the displacement
tends to be shorter for heel-weighting while displacement for toe-weighting tends to be
slightly longer. Duration for T1 and T2 were significantly longer (p<.001), and were closer to
Tour player’s duration of 810ms±31ms (Marquardt, 2007). While toe-weighting results in
longer downswing duration, heel-weighting seems to creates a larger moment of inertia
similar to a heavier shaft (Karlsen et al., 2007).
Looking at the acceleration during the downswing phase, the heel-weighted condition a
significantly larger magnitude of acceleration (AMAX) was found (p<.05), however the toe-
weighted condition showed the opposite (p<.001). Looking at backswing rhythm, toe
weighting resulted in significant longer rhythm (p<.001), whereas heel weighting resulted in a
slightly shorter rhythm, but all were shorter than the Tour players rhythm of 2.2±0.11
(Marquardt, 2007). Looking at timing of the downswing phase, toe-weighting showed
significant shorter timing (p<.001), and are closer to the Tour players timing of 0.39±0.04
(Marquardt, 2007). Overall, the toe-weighting shows characteristics of the putting stroke
comparable to skilled players, like shorter backswing, longer follow-through and longer
rhythm; heel-balanced on the other hand seems to result in a larger moment of inertia that
affects the putting stroke.
CONCLUSION: The results of this study suggest that adjusting the putter head balance with
additional weighting offers an effective method to influence the characteristics of the putting
stroke even for skilled golfers. Significant effects were mostly found for moving more weight
to the toe of the putter. Toe-balanced putters seem to promote a more efficient stroke in at
least some golfers, which also tend to result in longer duration. In contrast, heel-balance
might even impair the stroke, but this will depend on the stroke types, i.e. rotational versus
straight path. Subjects' own putters were similar to the standard putter used in the test, but
the findings might also depend on the individual putting style.
The findings suggest that a more precise fitting of the head balance and weighting of a putter
according to his/her putting stroke and skill level could help to improve the performance on
the green. Putter designs should reflect preferred mechanical properties, but more focus
should be set on identifying the best biomechanical fit for a player. Thus the study confirms
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30th Annual Conference of Biomechanics in Sports – Melbourne 2012
the importance of putter fitting in general and underpins the value of biomechanical testing
for sport equipment optimization.
Further studies should evaluate the relation between individual stroke types and relevant
fitting parameters, which also might be adjusted to different lengths of putts.
REFERENCES:
Alexander, D. L., & Kern, W. (2005). Drive for show and putt for dough? Journal of Sports Economics,
6, 46-60.
Brouliette, M., & Valade, G. (2008). The effect of putter face grooves on the incipient rolling motion of
a golf ball. In, D. Crews & R. Lutz (Eds.), Science and Golf V : Proceedings of the World Scientific
Congress of Golf, 363-368. Mesa, AZ, Energy in Motion.
Craig, C. M., Delay, D., Grealy, M. A., & Lee, D. N. (2000). Guiding the swing in golf putting, Nature,
May(405), 295-296.
Cross, R. (2001). Customising a tennis racket by adding weights, Sports Engineering, 4, 1-14.
Delay, D., Nougier, V., Orliaguet, J.P. & Coello, Y. (1997). Movement control in golf putting. Human
Movement Science, 16(5), 597-619.
Fairweather. M. M. (2002). A critical examination of motor control and issues in putting. In: Thain E,
editor. Science and golf VI. Proceedings of the 2002 World Scientific Congress of Golf: St Andrews
London: E & FN Spon, 100-112.
Hume, P. A., Keogh, J., & Reid, D. (2005). The Role of Biomechanics in Maximising Distance and
Accuracy of Golf Shots, Sports Med, 35 (5): 429-449.
Karlsen, J., & Nilsson, J. (2007). Club shaft weight in putting accuracy and perception of swing
parameters in golf putting. Perceptual and Motor Skills, 105, 29-38.
Lee, T. D., Ishikura, T., Kegel, S., Gonzalez, D., & Passmore, S. (2008). Head-Putter Coordination
Patterns in Expert and Less Skilled Golfers, Journal of Motor Behavior , 40(4), 267-272.
Lindsay, D. M., Horton, J. F., & Paley, R.D. (2002). Trunk motion of male professional golfers using
two different golf clubackswing. Journal of applied biomech,18(4), 366-73.
Marquardt, C. (2007). The SAM PuttLab. Concept and PGA Tour data. In S. Jenkins (Ed), Annual
Review of Golf Coaching 2007. (pp. 101-114). Essex: Multi Science Publishing.
Marquardt, C. and Mai, N. (1994). A computational procedure for movement analysis in handwriting.
Journal of Neuroscience Methods, 52(1), 39-45.
McGlynn, F. G., Jones, R., & Kerwin, D. G. (1990). A laser based putting alignment test. In Science
and Golf I: proceedings of the First World Scientific congress of Golf, 70-75. E. & F. N. Spon.
Neal, R., Abernethy, B., Moran, M., & Parker, A. (1990). The influence of club length and shot
distances on the temporal characteristics of the swings of expert and novice golfers. Cochran A. Ed.
Science and Golf: proceedings of the First World Scientific Congress of Golf. London: E & FN Spon.
Paradisis, G., & Rees, J. (2002). Kinematic Analysis of Golf Putting for Expert and Novice Golfers,
retrieved 05/01/2012 from
http://www.coachesinfo.com/index.php?option=com_content&id=151&Itemid=218.
Pelz, D. (1990). The long putter. The Pelz Report, 1, 3.
Pelz, D., & Frank, J. A.(2000). Dave Pelz's Putting Bible: The Complete Guide to Mastering the green.
NY: Doubleday Publishers.
Shan, G. B., Betzler, N., & Dunn, B. (2008). The Influences of Motor Control Adaptation and Human-
Equipment Interaction on Issues Related to Golf-Club Design and Optimization, The Ergonomics
Open Journal, 2008, 1, 27-33.
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